Intermittent Chattering

[drewusmaximus]

Hi all, 1995 525i M50 5SPD 280k

At times, during first startup, it will start smooth. Other times at first startup, I hear a loud fast then slow TAP TAp Tap tap, then goes away after three seconds and runs smooth. While at normal temp, it chatters while idling, then goes away, then chatters, then goes away. At times, the chatter/tapping occurs during all RPMs, then other times it's smooth during all RPMs. What baffles me is the inconsistency. I was using 15w40, then switched to 10w40 the past two oil changes but, this has been occurring even with the 15w40 oil.
Any idea what might be going on? No oil light. Oil level is fine. I recently replaced the OFHG so, no more slow oil leak and I use 93 octane. I'm, worried I am hurting the engine and I drive 60 miles a day, 5 days a week.

Thanks in advance...

[fo3]

Probably lifters. I knwo you said you were going to replace them anyway.
Me too
I usually use 20w50. It was generally noisy for 2-3min but then it went quiet. But recently changed to 15w40 and it's quiet at first but after a minute it taps until well and truly warm, so doesn't shut up for 10min or more!
$45-50/5l 20w50 with extra zinc and other premium additives was way way better than $30/5l 15w-40 at quietening down this old engine. I've been annoyed every time I drive it now after that oil change I did 3 weeks ago.

I need lifters, I need guides and a chain I know...
I'm just waiting until I either get a m54b28 crank and pistons for a stroker, or a b28/b30 combo for lower compression and turbo (or use nissan/toyota)

Anyway, as long as you're not getting metal in your oil, it's most likely lifters aren't holding, thicker oil helps a bit with blown lifters.

[drewusmaximus]

Probably lifters. I knwo you said you were going to replace them anyway.
Me too
I usually use 20w50. It was generally noisy for 2-3min but then it went quiet. But recently changed to 15w40 and it's quiet at first but after a minute it taps until well and truly warm, so doesn't shut up for 10min or more!
$45-50/5l 20w50 with extra zinc and other premium additives was way way better than $30/5l 15w-40 at quietening down this old engine. I've been annoyed every time I drive it now after that oil change I did 3 weeks ago.

I need lifters, I need guides and a chain I know...
I'm just waiting until I either get a m54b28 crank and pistons for a stroker, or a b28/b30 combo for lower compression and turbo (or use nissan/toyota)

Anyway, as long as you're not getting metal in your oil, it's most likely lifters aren't holding, thicker oil helps a bit with blown lifters.

I have the lifters and cam locking tool waiting for my Go. I'm a bit intimidated since this will be my first time doing this and it's my daily. There are a couple of videos on lifter replacement on YouTube that seems very detailed, which I will follow but, not exactly sure how long the job will take. I would also like to replace the vanos while I'm in there but, I haven't purchased it from Dr. Vanos yet. I would like to swap out the lifters before Winter because I drive 60 miles a day but, I don't have a garage. All is done on the driveway while engine remains in the car. No metal in the oil so far. Iw ill at least switch to 20w50 for the time being.
I'm looking for advice on how to tackle the lifters swap. How long will it take? Will I be able to complete the job over a weekend?

[fo3]

I've learnt a lot by watching these guys (from Finland I think), strip down, rebuild, stroke out and turbo BMW motors. Looks like they've done it a few times.
https://youtu.be/uapRQ-tAw48?t=12m19s

[drewusmaximus]

I changed my oil yesterday and used 10w40. The car starts up nice and quiet but, as soon as the engine warms up to normal temp, the damn tapping starts.. UGH... It's so weird how the tapping starts and stops, then it sounds like the tapping is at different areas. I can definitely hear it from the top of the engine. I'm going to disconnect the injectors to see if they're the culprit. I think I am going to replace the lifters but, I am worried I won't finish the job on time. I'm worried that the engine will die soon because I drive 60 miles a day.
Anyone have an idea how long this job will take? I have all the tools required.
Below are the only links I can find related to this type of job.

https://www.youtube.com/watch?v=wRnqy-7dT28

https://www.youtube.com/watch?v=wRnqy-7dT28&t=3s

https://www.youtube.com/watch?v=23jXHhkpV_I

[moroza]

VANOS rattle usually happens at cold startup. So does lifter tick. I imagine either could happen randomly, but this seems less common.

20W50 is quite heavy for NYS winters.

[drewusmaximus]

VANOS rattle usually happens at cold startup. So does lifter tick. I imagine either could happen randomly, but this seems less common.

20W50 is quite heavy for NYS winters.

I'm using 10w40. It's very frustrating to diagnose because the symptoms don't match to the common symptoms. I'll record the sounds at first startup, second startup (after the car has warmed up), and during idle at engine temp.
prior to the oil change, sometimes when I first start the car (cold) I would hear a loud tap for 2 to 3 seconds and it would disappear. As the engine reaches temp, I can hear the tap slowly increasing in sound and increase to several taps.
When I pulled up to the house Friday after work, my stepson was outside playing with his little brother and sister. He said, what is wrong with your car? It sounds horrible. After driving 15-20 miles, if I pull up to a stop light, I can hear the tapping. I can hear it as I accelerate. It sounds as if 10-15 lifters are tapping at the same time during acceleration. I still have power under load. I'm just afraid the engine is going to go any day now. After changing the oil yesterday, the engine was quiet until I drove about 20 miles. I pulled in Dunkin Donuts this morning, about 20 miles form my house, and I can hear the damn tapping. I was so disappointed. Sigh....

[fo3]

Does it sound like my vid?
My engine makes a racket and I know the injectors are loud and so are the lifters and the chain sometimes - all this is normal for old engines, but when warmed up (and only when up to full temp) it makes a very unhealthy noise. When I hear that sound I know that it's something very serious but no idea what.
https://www.bimmerforums.com/forum/s...9#post30114119
https://youtu.be/1pzmnCwInPs

I'm guessing super bad timing chain and guides, but I don't think you can change the tensioner guide without pulling the head

[drewusmaximus]

Does it sound like my vid?
My engine makes a racket and I know the injectors are loud and so are the lifters and the chain sometimes - all this is normal for old engines, but when warmed up (and only when up to full temp) it makes a very unhealthy noise. When I hear that sound I know that it's something very serious but no idea what.
https://www.bimmerforums.com/forum/s...9#post30114119
https://youtu.be/1pzmnCwInPs

I'm guessing super bad timing chain and guides, but I don't think you can change the tensioner guide without pulling the head

Yes. Mine sounds just like yours when at full temp. I get the consistent rattle when accelerating, like yours. When I am at a stop light, it sounds like a diesel engine. It's so loud, it is embarrassing. All of the manifold bolts are in tact so, I know it's not the manifold.
I haven't tested the injectors yet but, if it were the injectors, wouldn't they make noise at startup? My engine is quiet during startup until the engine is at normal temp. I guess what keeps me sane is that the engine is nice and quiet at cold startup. Even when the engine is at normal temp, when I shut the car off and turn it back on, the engine is quiet but, only for a minute or two, in oppose to a cold startup.
I want to replace the lifters this weekend since it's a three day weekend for me but, I can't get confirmation on how long the job is. If I can get a confirmation on how long it takes to replace the lifters, I can determine if this weekend is a good weekend.

[fo3]

If it sounds like mine then it's super special piston slap that only happens went hot(insert absurdly huge interrobang here because that makes no f'n sense at all). Or some weird stuff happening at the bottom end that's like rod knock (but not rod knock, huge interrobang here because that makes no f'n sense at all)

When my engine is cold the loudest thing is the injectors. That is to say it's pretty damn quiet. After it warms up I get a bit of chain and lifter noise, then this noise as it gets hotter.

I'm hoping it's the chain, because it sounds 'chainy' plus I have seen the chains on these motors i)eat through the guides, ii)eat through the pins behind the guides iii)try to eat through the timing cover behind those pins.
It's my best guess and if I'm wrong, then nothing lost because super special non explainable piston slap only when hot or a weird type of rod knock that's not quite what you expect is uneconomically* repairable anyway - give up and rebuild a junkyard motor on the side instead.

*e: what I mean by economically is not due to cost but also time. Like you I need my car on the road most days - for me every 3 days, so not enough time to strip down properly and send a block out for reboring or a head for machining, so it would be a rushed slapped together job not worth the money if I tore mine apart first to check every problem and then send out parts for machining and order in parts. If a junkyard m50 was bought to be rebuilt on the side then it wouldn't be rushed and I could take my time getting a m54b30 crank and pistons etc and make it worth the time and money.

[drewusmaximus]

If it sounds like mine then it's super special piston slap that only happens went hot(insert absurdly huge interrobang here because that makes no f'n sense at all). Or some weird stuff happening at the bottom end that's like rod knock (but not rod knock, huge interrobang here because that makes no f'n sense at all)

When my engine is cold the loudest thing is the injectors. That is to say it's pretty damn quiet. After it warms up I get a bit of chain and lifter noise, then this noise as it gets hotter.

I'm hoping it's the chain, because it sounds 'chainy' plus I have seen the chains on these motors i)eat through the guides, ii)eat through the pins behind the guides iii)try to eat through the timing cover behind those pins.
It's my best guess and if I'm wrong, then nothing lost because super special non explainable piston slap only when hot or a weird type of rod knock that's not quite what you expect is uneconomically* repairable anyway - give up and rebuild a junkyard motor on the side instead.

*e: what I mean by economically is not due to cost but also time. Like you I need my car on the road most days - for me every 3 days, so not enough time to strip down properly and send a block out for reboring or a head for machining, so it would be a rushed slapped together job not worth the money if I tore mine apart first to check every problem and then send out parts for machining and order in parts. If a junkyard m50 was bought to be rebuilt on the side then it wouldn't be rushed and I could take my time getting a m54b30 crank and pistons etc and make it worth the time and money.

I can't see piston slap occurring only when the engine is warmed up. I'm hoping someone on this forum can tell me how long it will take to replace the lifters (for a first timer). From what I've noticed on the videos I saw, the hardest part looks like the Vanos removal and re-installation.