10W40 Weight Causing A Lot Of Tapping.

[ross1]

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Wonderful. Does that mean you have a simpler (less thought-out) explanation for why some lifters are quiet when cold, and then noisy when the engine is warm (without being turned off or losing oil pressure while it warmed up)? I'm eager to hear it.

Yeah, there is no steam in the lifters.
Either the oil isn't heavy enough to resist the compression force on worn lifters or isn't circulating quickly enough. Since the problem is when hot I'd favor not heavy enough which is seems verified since when using an oil with a higher bottom number it doesn't exhibit the problem.
These things are a bit finicky about oil, especially when elderly. Adjusting the bottom # up a notch usually is the answer.
FWIW I prefer 15/40 diesel oil and have good results. My wife's M52 will always tell me when it needs a change as it will tick ever so briefly on start up when the oil has gotten tired.

[R Shaffner]

Either the oil isn't heavy enough to resist the compression force on worn lifters or isn't circulating quickly enough. Since the problem is when hot I'd favor not heavy enough which is seems verified since when using an oil with a higher bottom number it doesn't exhibit the problem.
These things are a bit finicky about oil, especially when elderly. Adjusting the bottom # up a notch usually is the answer.
FWIW I prefer 15/40 diesel oil and have good results. My wife's M52 will always tell me when it needs a change as it will tick ever so briefly on start up when the oil has gotten tired.

Drewusmaximus: Please excuse this diversion on your thread. And please forgive and forget my comments about moisture. It shows up in the crankcase every time we start a cold engine, but let's not bother with that and the lifter discussion.

Ross1: I respect and agree with many of your helpful posts here, but I can't agree with most of this last one. Perhaps what I read isn't exactly what you meant.

For example, you said the thinner oil might not be heavy enough to handle the compression load... Surely you don't mean that. Generally, oil isn't compressible. Jack oil is usually 10W, and 0W-30 oil works in many lifters just fine. So both thin and heavy oils will handle the compression forces.

And you said that oil with a higher bottom number works better than others when the engine is hot. I gather that must be your experience, which again I respect, but that's hard to explain. The first number shows the viscosity at freezing, the second shows it a boiling. The oil engineers are telling us that 0W-40 and 15W-40 have the same viscosity at 100C (the same as 40 weight oil), which is the temp of these engines when hot.

My experience is different. The spec oil for my '97 540i was what you like: 15W-40 Rotella. That's all the car ever got until I changed the chain guides at about 200,000 miles. After sitting with the oil drained for most of a week, most of the lifters made noise when I started it back up. All but one got quiet within a minute. But one lifter just kept ticking. I revved the engine as BMW recommends, drove it hard and easy. Even added some cleanser at the next oil change. No luck. So I tried a round of 10W-30 synthetic oil -- a little thinner, different detergents, and synthetic. The lifter got quiet before the next oil change, when I went back to 15W-40 Rotella.

In short, I agree that thicker oil can help make many internal parts of the engine quieter. But when it comes to forcing oil back into an old lifter, my personal experience (and logic) is that thinner oil will flow into that tight/partially clogged space easier.

That's all from me on this topic.

[drewusmaximus]

Drewusmaximus: Please excuse this diversion on your thread. And please forgive and forget my comments about moisture. It shows up in the crankcase every time we start a cold engine, but let's not bother with that and the lifter discussion.

Ross1: I respect and agree with many of your helpful posts here, but I can't agree with most of this last one. Perhaps what I read isn't exactly what you meant.

For example, you said the thinner oil might not be heavy enough to handle the compression load... Surely you don't mean that. Generally, oil isn't compressible. Jack oil is usually 10W, and 0W-30 oil works in many lifters just fine. So both thin and heavy oils will handle the compression forces.

And you said that oil with a higher bottom number works better than others when the engine is hot. I gather that must be your experience, which again I respect, but that's hard to explain. The first number shows the viscosity at freezing, the second shows it a boiling. The oil engineers are telling us that 0W-40 and 15W-40 have the same viscosity at 100C (the same as 40 weight oil), which is the temp of these engines when hot.

My experience is different. The spec oil for my '97 540i was what you like: 15W-40 Rotella. That's all the car ever got until I changed the chain guides at about 200,000 miles. After sitting with the oil drained for most of a week, most of the lifters made noise when I started it back up. All but one got quiet within a minute. But one lifter just kept ticking. I revved the engine as BMW recommends, drove it hard and easy. Even added some cleanser at the next oil change. No luck. So I tried a round of 10W-30 synthetic oil -- a little thinner, different detergents, and synthetic. The lifter got quiet before the next oil change, when I went back to 15W-40 Rotella.

In short, I agree that thicker oil can help make many internal parts of the engine quieter. But when it comes to forcing oil back into an old lifter, my personal experience (and logic) is that thinner oil will flow into that tight/partially clogged space easier.

That's all from me on this topic.

I appreciate your insight. I was using 15W40 previously. I had lifter tick with that weight but, not like now. I'm going to inspect the oil filter tomorrow and replace it, just for sake of sanity. I have to say, the lifters are unusually ticking after this oil change. If I have to pull off the VC to inspect, I will but, It's a uncomfortable feeling driving 60 miles a day at reasonably high RPMs to rid the ticks.
Hopefully I will have a breakthrough tomorrow.

[bluptgm3]

Oil pressure…you may be chasing a problem that pressure related.


Sent from my iPhone using Tapatalk

[R Shaffner]

It's a uncomfortable feeling driving 60 miles a day at reasonably high RPMs to rid the ticks.
Hopefully I will have a breakthrough tomorrow.

The BMW technical bulletin that addresses these lifters says to rev the engine at 3,000 rpm for 5 minutes and return it to idle. Then it says to repeat a few more times if the problem persists, perhaps up to 10 (I can't remember). I didn't like sitting in the car and revving it, so I'd just have periods of leaving it in a lower gear so it was near 3,000 rpm for a few minutes.

The scary thing in your case is that if the engine isn't getting enough oil (low pressure) you don't want to be driving it much, and certainly not at higher rpm.

My personal experience is limited, but odd things can happen. On this forum I recently read about a 540 whose oil pressure relief spring had compressed, lowering the pressure. But his oil light was coming on at idle. And another driver's oil pump failed and sent small pieces of metal everywhere.

Can you post a video with the sounds you're hearing? No disrespect, but for your sake I'm hoping something else might be making noises.

[Thomas525]

How would you explain lifters that are consistently quiet when cold, and noisy when hot? That's pretty common in my experience.

Oil is thick when cold, thin when hot. You can do the rest of the math on that I'm sure.

I changed the oil last week, using 10W40 conventional. Prior to the change I used 15W40. At cold start up, it runs great but, as soon as it reaches temp, the tapping starts to occur a lot.

I have to say, the lifters are unusually ticking after this oil change. If I have to pull off the VC to inspect, I will but,

So there's your problem. Maybe you're wondering why its ticking when hot when both oils are supposed to be 40 weight when hot. Simple. They &**)()_ the grades slightly in the bottles that you're using.

So you solve your problem in the following simple ways. Go get sae 50 oil. Straight 50. Pour in 4-5 litres. Run the engine 10 minutes at idle to mix it up nice and good. You'll get a blend that's thicker when hot - should fix your problem. Drain out half of it and set it aside for your next oil change. Leave the rest of it in there, ensure there is enough oil. Finish.

All engine oil is a blend.

Or add 3 litres sae 50 oil. Not multigrade oil. That will fix your problem immediately. At the usual oil change interval, don't change the oil, just change the filter. Then wait another 50% of the usual oil change interval and then change the oil and filter together. Switch to 20w50 oil. At your mileage you should be doing that. Ask Shaffer, he will tell you that BMW recommends that for higher mileage M50s.

IF these solutions don't solve your problem, then its time for you to change the lifters.

[drewusmaximus]

The BMW technical bulletin that addresses these lifters says to rev the engine at 3,000 rpm for 5 minutes and return it to idle. Then it says to repeat a few more times if the problem persists, perhaps up to 10 (I can't remember). I didn't like sitting in the car and revving it, so I'd just have periods of leaving it in a lower gear so it was near 3,000 rpm for a few minutes.

The scary thing in your case is that if the engine isn't getting enough oil (low pressure) you don't want to be driving it much, and certainly not at higher rpm.

My personal experience is limited, but odd things can happen. On this forum I recently read about a 540 whose oil pressure relief spring had compressed, lowering the pressure. But his oil light was coming on at idle. And another driver's oil pump failed and sent small pieces of metal everywhere.

Can you post a video with the sounds you're hearing? No disrespect, but for your sake I'm hoping something else might be making noises.

I posted the video earlier with the sounds of the ticking/tapping. Let me know what you think. I recorded the video when I pulled into my driveway after work.

https://youtube.com/watch?v=bfsbUebK...ature=youtu.be

[demetk]

That doesn't sound like valve lifters. It's more like rod bearing knock.

[R Shaffner]

I posted the video earlier with the sounds of the ticking/tapping. Let me know what you think. I recorded the video when I pulled into my driveway after work.

https://youtube.com/watch?v=bfsbUebK...ature=youtu.be

(As you're seeing, one cannot mention oil on this site without getting many different opinions, including mine.)

I missed the video before. Sorry. I (and perhaps others) have been responding more to the title of the thread instead, and focusing on lifters and oil weight.

Dude, I'm hearing more than just lifter tick. I could easily be wrong and hope I am, but something is also making a louder, deeper knocking sound. Especially at the beginning of your video. (If you titled this thread "Help me ID this knocking sound" and posted the video, this whole discussion would have been different. In fact, I think you should still do that, to get more opinions about that, and not just lifter tick and oil weight.)

Here are some things I've seen make a noise like that. (It's hard to tell in person, and harder to tell from a short video.)

A worn/failing rod/wrist bearing -- That's pretty serious, of course. The sound might vary based on rpm and oil weight, a little. I'm not an expert, but I understand that an easy way to test for this is to unplug the coil pack for cylinders one at a time to see if that knock goes away. If it goes away or gets a lot softer when one coil pack is disconnected, then you might have a bad rod bearing for that cylinder. (The rod would still have play, but it won't make as loud a knock without combustion.) Of course, you can also test for a loose bearing by pulling the oil pan and seeing if there is play in any of them. (Thicker oil can help reduce the sound of loose rod bearings, and perhaps buy one a little more time. More on thicker oil below. Anything that makes the oil pressure higher can help reduce the knocking sound, including higher rpm. But of course it won't fix a bad bearing.)

A leak from a head gasket or exhaust manifold gasket at the head -- I've seen cases where a small exhaust leak from one cylinder sounds just like a more serious mechanical knock. That sound won't go away with rpm, but it would vary with the throttle and load. And if you unplug the coil for that cylinder it will also go away (without combustion, like in the example above.) When I've had a leak like that, I could hear it clearly when I got my ear (or a tube to my ear) close to the leak. And I could put a finger near it and feel the hot exhaust pulses that made the sound.

Pre-ignition -- I doubt the knock is from that just at idle, but I suppose it's possible, and in the video it went away after the rpm was higher and you released the throttle. I have heard of cases where carbon build-up in a cylinder gets glowing hot and ignites the fuel early. How do your spark plugs look? Has your car been running rich?

Low Oil Pressure -- Recently a 540 owner here posted a video with a similar knock. Most people said it was a bad rod bearing, but he checked it and found no play. Eventually he pulled the oil pump and found a bad spring in the pressure release valve. In his case the oil light would come on after a drive, when the engine was hot. So he knew the knocking was probably from low oil pressure.

And finally back to oil... When all is working well, the oil pump creates the pressure, of course, and the pressure lease valve keeps it from getting too high. Usually the pressure is maintained throughout the system passages until is flows out and back down to the sump. Thicker oil would normally create higher pressure, except the pressure release valve opens at the same pressure regardless. So when oil leaves the pump and valve it starts off with the same pressure. But since thicker and colder oil doesn't flow as well, it doesn't leak out of the rest of the system as fast.

AND...if there is a leak in the oil system, like from badly worn bearings, then faster flow from the pump (higher rpm) will help. And colder/thicker oil will leak out slower (past worn bearings) and help keep the pressure higher elsewhere in the system.

That's why the old school trick for making a noisy engine quieter has been to put thicker oil in it. (STP Oil Treatment, which sold well decades ago, was just a very heavy oil -- like syrup -- that one could add t increase the effective weight.) And finally, if that's your problem, heavier oil could help make everything quieter, including the lifters. (Not because thicker oil would flow into the lifters easier, but because thicker oil helps maintain higher pressure throughout the rest of the system, which can put higher pressure at the lifters.

So... I suggest checking for the things I listed above, to see if you can ID the source of the knock (other than the lifters). If that doesn't help. Then I'd post the video and knock as a new thread for more opinions and insight. And if you think it's a bearing, I'd go ahead and try heaver oil, or adding an oil thickener like STP to your crankcase. But I mean significantly heavier oil. Not 50W as one poster said. But I'd definitely try 20W-50.

Good luck! And I'm hoping I'm wrong and it's not serious.

(And of course, if thicker oil helps make it quieter, it won't cure the bad bearing, but it can help protect the rest of the engine until you get the bearing fixed.)

[drewusmaximus]

(As you're seeing, one cannot mention oil on this site without getting many different opinions, including mine.)

I missed the video before. Sorry. I (and perhaps others) have been responding more to the title of the thread instead, and focusing on lifters and oil weight.

Dude, I'm hearing more than just lifter tick. I could easily be wrong and hope I am, but something is also making a louder, deeper knocking sound. Especially at the beginning of your video. (If you titled this thread "Help me ID this knocking sound" and posted the video, this whole discussion would have been different. In fact, I think you should still do that, to get more opinions about that, and not just lifter tick and oil weight.)

Here are some things I've seen make a noise like that. (It's hard to tell in person, and harder to tell from a short video.)

A worn/failing rod/wrist bearing -- That's pretty serious, of course. The sound might vary based on rpm and oil weight, a little. I'm not an expert, but I understand that an easy way to test for this is to unplug the coil pack for cylinders one at a time to see if that knock goes away. If it goes away or gets a lot softer when one coil pack is disconnected, then you might have a bad rod bearing for that cylinder. (The rod would still have play, but it won't make as loud a knock without combustion.) Of course, you can also test for a loose bearing by pulling the oil pan and seeing if there is play in any of them. (Thicker oil can help reduce the sound of loose rod bearings, and perhaps buy one a little more time. More on thicker oil below. Anything that makes the oil pressure higher can help reduce the knocking sound, including higher rpm. But of course it won't fix a bad bearing.)

A leak from a head gasket or exhaust manifold gasket at the head -- I've seen cases where a small exhaust leak from one cylinder sounds just like a more serious mechanical knock. That sound won't go away with rpm, but it would vary with the throttle and load. And if you unplug the coil for that cylinder it will also go away (without combustion, like in the example above.) When I've had a leak like that, I could hear it clearly when I got my ear (or a tube to my ear) close to the leak. And I could put a finger near it and feel the hot exhaust pulses that made the sound.

Pre-ignition -- I doubt the knock is from that just at idle, but I suppose it's possible, and in the video it went away after the rpm was higher and you released the throttle. I have heard of cases where carbon build-up in a cylinder gets glowing hot and ignites the fuel early. How do your spark plugs look? Has your car been running rich?

Low Oil Pressure -- Recently a 540 owner here posted a video with a similar knock. Most people said it was a bad rod bearing, but he checked it and found no play. Eventually he pulled the oil pump and found a bad spring in the pressure release valve. In his case the oil light would come on after a drive, when the engine was hot. So he knew the knocking was probably from low oil pressure.

And finally back to oil... When all is working well, the oil pump creates the pressure, of course, and the pressure lease valve keeps it from getting too high. Usually the pressure is maintained throughout the system passages until is flows out and back down to the sump. Thicker oil would normally create higher pressure, except the pressure release valve opens at the same pressure regardless. So when oil leaves the pump and valve it starts off with the same pressure. But since thicker and colder oil doesn't flow as well, it doesn't leak out of the rest of the system as fast.

AND...if there is a leak in the oil system, like from badly worn bearings, then faster flow from the pump (higher rpm) will help. And colder/thicker oil will leak out slower (past worn bearings) and help keep the pressure higher elsewhere in the system.

That's why the old school trick for making a noisy engine quieter has been to put thicker oil in it. (STP Oil Treatment, which sold well decades ago, was just a very heavy oil -- like syrup -- that one could add t increase the effective weight.) And finally, if that's your problem, heavier oil could help make everything quieter, including the lifters. (Not because thicker oil would flow into the lifters easier, but because thicker oil helps maintain higher pressure throughout the rest of the system, which can put higher pressure at the lifters.

So... I suggest checking for the things I listed above, to see if you can ID the source of the knock (other than the lifters). If that doesn't help. Then I'd post the video and knock as a new thread for more opinions and insight. And if you think it's a bearing, I'd go ahead and try heaver oil, or adding an oil thickener like STP to your crankcase. But I mean significantly heavier oil. Not 50W as one poster said. But I'd definitely try 20W-50.

Good luck! And I'm hoping I'm wrong and it's not serious.

(And of course, if thicker oil helps make it quieter, it won't cure the bad bearing, but it can help protect the rest of the engine until you get the bearing fixed.)

Thank for the wealth of info. I don't think it's a rod knock because the engine starts up quiet until it heats up. In retrospect, testing for rod knock using the method as you mentioned was inaccurate, because regardless if someone pulls the coil pack or even the spark plug, the crank will still turn and produce the knock. One way of testing rod knock would be to pull a spark plug, get a long screw driver, insert in plug hole, rotate engine until that cylinder reaches the top, turn a hair more and if you can push the screwdriver down (even a hair) without the crank moving, a bearing is worn.
Here is the link to the cold startup. There's no rod knock, no ticking/tapping. Maybe I should put a heavier oil. If so, what do you all recommend?
Thanks in advance..

https://youtu.be/AzpiUuvAS98

[R Shaffner]

I agree that sounds better. Oil is cold, somewhat thicker. And it sounds like it has a faster cold idle (faster pump movement means higher pressure), and you've said the sounds were less with more rpm. So both of those are probably helping.

Yes, you can test for play from a loose rod bearing that way, with a screwdriver, rod, or dowel in the plug hole. Why not? Remember the play might be very slight.

About pulling the coil during a warm idle... I've seen it both in person and in a video, where disconnecting the spark made the rod knock quieter. Yes there was still play with each up and down cycle, but combustion in that cylinder made the knock significantly louder. (No reason not to test that too. Easy.)

I'd let it warm up and check for an exhaust leaks by the head gasket and manifold gasket too. Again, you might as well.

A worn rod bearing would explain all the symptoms. And sure, if you don't find an exhaust leak or another source of the warm idle knocking, I'd try thicker oil, or just add a thickening oil treatment to what's in there now. (I'd probably try that before draining the oil. Again, why not?)

Good luck!

[drewusmaximus]

I agree that sounds better. Oil is cold, somewhat thicker. And it sounds like it has a faster cold idle (faster pump movement means higher pressure), and you've said the sounds were less with more rpm. So both of those are probably helping.

Yes, you can test for play from a loose rod bearing that way, with a screwdriver, rod, or dowel in the plug hole. Why not? Remember the play might be very slight.

About pulling the coil during a warm idle... I've seen it both in person and in a video, where disconnecting the spark made the rod knock quieter. Yes there was still play with each up and down cycle, but combustion in that cylinder made the knock significantly louder. (No reason not to test that too. Easy.)

I'd let it warm up and check for an exhaust leaks by the head gasket and manifold gasket too. Again, you might as well.

A worn rod bearing would explain all the symptoms. And sure, if you don't find an exhaust leak or another source of the warm idle knocking, I'd try thicker oil, or just add a thickening oil treatment to what's in there now. (I'd probably try that before draining the oil. Again, why not?)

Good luck!

My apologies. You're right, the sound does change when pulling out the spark plug. I'm going to switch the filter and add an a thickener. Any recommendations on a thickener?

Thanks!

[Thomas525]

https://youtu.be/AzpiUuvAS98

That is a terrible sounding engine when cold. Something is seriously wrong, and the rod knock or whatever it is, is still there but more in the background.

Remove all your belts and then start up the car from cold. Reduce the idle to the lowest it can go - 550rpm - by adjusting the throttle cable. If you are very lucky, the noise will stop entirely - meaning it is not the engine screwing up the show.

Frankly, you should take the car into a shop. Sounds are difficult to diagnose over the internet, and you are clearly not experience at this at all - what you hear on both cold and hot videos, is very far from lifter tick, have no idea how you came to that conclusion. And if it went from normal to that after an oil change...

Wait a sec. Your cold video - is that what you consider to be normal? Before the oil change, if it was like that when hot, then an obvious existing problem merely became more obvious with lighter oil.

[R Shaffner]

My apologies. You're right, the sound does change when pulling out the spark plug. I'm going to switch the filter and add an a thickener. Any recommendations on a thickener?

Thanks!

OK. So the warm knock has been narrowed down to one cylinder, right? That's progress. If it were my car, I'd check to make sure it's not an exhaust leak by the head from that cylinder, just to be sure. (I once had a leak that sounded just like a knock.)

If you don't find a leak, then yes I'd try thicker oil. Years ago Road & Track tested STP Oil Treatment and said it was like adding 10 points to the crankcase oil. (They also said it made little sense to use it. That instead one could just use thicker oil from the start.) Some people will say it's OK. Others will call it crap. I used it once in a car that was about to die, and sure enough it made the knocking stop for a while.

If I had the time I'd probably put 20W-50 in it, any brand. If I needed to use it as a driver right away, I'd probably try a can of STP to see how it worked, and look to change to 20W-50 relatively soon.

(I know there are many other high-tech oil additives and treatments out there. I don't know much about them, but I don't think they work by simply increasing viscosity.)

(And you'll get many different opinions, I'm sure.)

[fo3]

Sounds like you've got bad piston slap as well.

When are you doing your ls conversion

Mines only minor (only when the engine is hot, only on accel roll on and off)

[drewusmaximus]

Sounds like you've got bad piston slap as well.

When are you doing your ls conversion

Mines only minor (only when the engine is hot, only on accel roll on and off)

I would like to go LS! LOL At the very least, find another M50 and freshen it up.

I added STP additive, changed the filter, started up the car, revved to 2k for a minute and no more ticking/tapping. I let it run at idle for 15 minutes and no ticking. I haven't driven the car yet but, I will in a bit and see if there is a change.

[drewusmaximus]

OK. So the warm knock has been narrowed down to one cylinder, right? That's progress. If it were my car, I'd check to make sure it's not an exhaust leak by the head from that cylinder, just to be sure. (I once had a leak that sounded just like a knock.)

If you don't find a leak, then yes I'd try thicker oil. Years ago Road & Track tested STP Oil Treatment and said it was like adding 10 points to the crankcase oil. (They also said it made little sense to use it. That instead one could just use thicker oil from the start.) Some people will say it's OK. Others will call it crap. I used it once in a car that was about to die, and sure enough it made the knocking stop for a while.

If I had the time I'd probably put 20W-50 in it, any brand. If I needed to use it as a driver right away, I'd probably try a can of STP to see how it worked, and look to change to 20W-50 relatively soon.

(I know there are many other high-tech oil additives and treatments out there. I don't know much about them, but I don't think they work by simply increasing viscosity.)

(And you'll get many different opinions, I'm sure.)

I didn't pull the plugs to test. I just replaced the oil filter, added STP additive and started it up. I have to run to the store. I'll take the long way so the engine can warm up and observe.

[drewusmaximus]

That is a terrible sounding engine when cold. Something is seriously wrong, and the rod knock or whatever it is, is still there but more in the background.

Remove all your belts and then start up the car from cold. Reduce the idle to the lowest it can go - 550rpm - by adjusting the throttle cable. If you are very lucky, the noise will stop entirely - meaning it is not the engine screwing up the show.

Frankly, you should take the car into a shop. Sounds are difficult to diagnose over the internet, and you are clearly not experience at this at all - what you hear on both cold and hot videos, is very far from lifter tick, have no idea how you came to that conclusion. And if it went from normal to that after an oil change...

Wait a sec. Your cold video - is that what you consider to be normal? Before the oil change, if it was like that when hot, then an obvious existing problem merely became more obvious with lighter oil.

Unfortunately, there is no shop near me that works on BMWs. Nearest one is about an hour and a half away. I'm not sure how a normal M50 sounds at cold startup but, from the videos I'd seen on YouTube with M50s starting up, they sound the same as mine at cold start. On the cold start video, you hear the belt and fan. Is there a video I can listen to with an M50 at cold startup that sounds normal? I think that will help me better understand the sound dynamics.

[R Shaffner]

Well, that will sound better and protect the rest of the system. Again, I'm sorry for the diversions and for not seeing the video when you first posted it.

I like your idea of checking the bearing play thought the plug hole. I'd do that too when convenient, just so you're sure of what you got. (Whether there is play in that cylinder that you can feel, how much, and whether there is also play in other cylinders.)

What I don't know is how much it will hurt it by driving it more this way, and how soon you should take care of any badly worn bearings. (For example, is the play now confined just to worn rod bearings, and could you get by with just replacing those? And might driving it longer cause you to have to do work beyond the bearings later, on the crank or the rods? And if one had to do the latter, whether buying a used engine might be the cheaper/easier path.)

I don't know those answers for that car. But I bet others here can help. (You can search for threads on those questions or start some.) Good luck!

[drewusmaximus]

Well, that will sound better and protect the rest of the system. Again, I'm sorry for the diversions and for not seeing the video when you first posted it.

I like your idea of checking the bearing play thought the plug hole. I'd do that too when convenient, just so you're sure of what you got. (Whether there is play in that cylinder that you can feel, how much, and whether there is also play in other cylinders.)

What I don't know is how much it will hurt it by driving it more this way, and how soon you should take care of any badly worn bearings. (For example, is the play now confined just to worn rod bearings, and could you get by with just replacing those? And might driving it longer cause you to have to do work beyond the bearings later, on the crank or the rods? And if one had to do the latter, whether buying a used engine might be the cheaper/easier path.)

I don't know those answers for that car. But I bet others here can help. (You can search for threads on those questions or start some.) Good luck!

No worries about not seeing the video. I don't think it's a bearing. I was just stating a method that I was aware of that works in checking for worn bearings. I took your advice and bought the STP additive. Interestingly, the engine is not tapping/ticking at all. I drove it about 5 miles and no ticking. I stopped at a light, no ticking/tapping. Normally while I am at a light the ticking will start and go away at second gear. This time it didn't. I let it idle for another 3 minutes after driving and no ticking/tapping. Very odd the STP make such a change. Either way, I'm going to replace the lifters during my vacation, when I have plenty of time to work on it. Also, I'm going to pull the oil pan off to replace the gasket and check all underneath. I have to say, when I changed the oil I used the STP oil filter, since that was the only one available at AutoZone. I ordered the Mann filter from Amazon and it came in today. Not sure if that also helped but, it fit very well, in oppose to the STP filter. The STP filter seem a bit bigger, which raised the oil housing cap like an 1/8 of inch higher, which caused more tension when tightening the cap. I'm going to order several Mann filters so I can have them available for the next few oil changes.

[drewusmaximus]

That doesn't sound like valve lifters. It's more like rod bearing knock.

My wife's friend purchased a newer used car. One day she pulled into the neighbor's driveway and i heard her engine knock. I asked her, what is going on with the engine. She said, she didn't know. I looked at her car and it had a rod knock. The knock was constant at startup and through all revs. My neighbor and I tested the knock on her car and he confirmed it was a knock. The knock sound is definitely distinct but, my engine doesn't sound like that at all. After adding the STP additive and change the filter to a Mann filter, there was more power when accelerating. I'll check for rod knock when the rain stops.

[R Shaffner]

??? So you didn't have the right oil filter, one that fit properly? (I thought you'd said you used a Mann filter.)

I suppose that could have caused all these problems, if it restricted proper flow. (I'm not sure of the e34, but my e39 has 3 oil lines to the filter; one in from the pump (pressurized), one back out to the engine (also pressurized to go to the vital parts), one back to the sump (not pressurized, as a by-pass in case the filter gets too clogged). It's possible that the poorly fitting filter restricted flow the right way, and/or let oil flow back to the sump without sending enough the right way.)

In short, I don't think the STP hurt and it might have helped. But changing the filter and putting in the right one might have solved the oil flow problem. And there must have been some reason why removing the spark helped stop the knocking. Don't you think?

[drewusmaximus]

??? So you didn't have the right oil filter, one that fit properly? (I thought you'd said you used a Mann filter.)

I suppose that could have caused all these problems, if it restricted proper flow. (I'm not sure of the e34, but my e39 has 3 oil lines to the filter; one in from the pump (pressurized), one back out to the engine (also pressurized to go to the vital parts), one back to the sump (not pressurized, as a by-pass in case the filter gets too clogged). It's possible that the poorly fitting filter restricted flow the right way, and/or let oil flow back to the sump without sending enough the right way.)

In short, I don't think the STP hurt and it might have helped. But changing the filter and putting in the right one might have solved the oil flow problem. And there must have been some reason why removing the spark helped stop the knocking. Don't you think?

I never removed the spark plugs. I never tested for rod knock. In our earlier discussions, you mentioned testing for a rod knock by removing the spark plug. I was just conversing the methods. I only use Mann filters but, this past oil change I grabbed the STP because I didn't get a chance to order the Mann and I hoped the local auto store carried a Mann filter, but they didn't this time. In closing, I can say your recommendation of adding the additive made a huge difference. It could've been the oil filter but, The change was basically immediate. And after shutting off the car, starting it back up, driving around, and letting it idle for a couple of minutes on the driveway after driving, the engine remained quiet. Thank you for the insight and support...

[R Shaffner]

Glad if I helped. Figuring out these old cars and keeping them running is often a journey and I keep learning more too.

[bigsixe34]

The way you guys are talking about an m50 could reasonably lead one to believe that it is the internal designation for a Ferrari flat 12

I’m glad you seem to be on your way to figuring it out though. For what it’s worth, various degrees of ticking is more or less expected of a 283k mile motor with hydraulic lifters. But there is certainly a difference between that developing with age and coming on instantly.

You said you put in 6.1 quarts. Seems a little low. Doesn’t an m50 take 7 at refill?
Edit:looked this up and it is indeed 6.1qts
It’s not unheard of to add a little over spec in these motors to help quiet them down.

At 283k you should probably keep a passive hunt for a spare motor going in your free time. Refresh it at a cool pace and replace down the line if yours let’s go. Or if you simply want a worry-free powerplant in there.