M50tu knocks when reved only after warm up

[spyderg0d]

Pulled out the widebody for spring today.
Started up first shot as expected.
But as i remember before parked for winter i had a loud tap almost knock issue.
Doesnt make a tap while the car first starts.
Doesnt make any noise while car is warming up.
Doesnt make any noise while at temp and at idle.
Only makes sound when revved at temp.
It doesn't quite sound like a rod bearing as its not so robust and its not a constant at every revolution. But it sounds louder than a tappet.
Has anyone ever had extremely loud tappets that only tap when engine warm and revved?
Or is it suspect of something else? It seems the interweb has chosen to delete moat of its abundant knowledge on the now classic bmws and with it most videos with engine noises being explained.

[Eric93se]

Try to isolate the sound, top/bottom, use a mechanics stheoscope or long screw driver.

[spyderg0d]

Nope. Its loud. Not as loud as a crank bearing, louder than a tappet. Respectfully, you can hear a tappet in the transmission with a stethoscope

[Eric93se]

Since the car sat for a while its probably a dead lifter and not a rod bearing because the bearing issue would have been known from last season. I think you should pull the VC to see if there is anything obvious.

[spyderg0d]

It was there before being parked for winter. Engine has little over 800 miles since build.
Il just have to pull the oil pan and check everything out. Might of went alittle too tight on a bearing clearance. Smh..

[ross1]

Warm only makes sense for worn lifters but since you seem convinced it is not I'd be checking oil pressure. Too tight bearing clearance won't cause this, too loose will as will a worn pump.
Don't forget to check the mains too

[FiberFast]

Don't be a poodle you know what you need to do. Staring down the barrel of this same gun right now as I just had rusty water boil out of my no.1 spark plug hole. I can pretend it was just water that got in there...

[spyderg0d]

If it was rusty, probably was just splash that got under the plastic. Ive had it happen several times on different cars.

But yes, will check oil pressure too.

[FiberFast]

If it was rusty, probably was just splash that got under the plastic. Ive had it happen several times on different cars.

But yes, will check oil pressure too.

Thanks for the hope, but I still have a taping lifter. I would imagine this is a head gasket problem in your case no? I mean if its knocking.

[gdavid]

Is this your stroked motor?, if so perhaps the windage tray needs to be trimmed or reshaped a little more.

[spyderg0d]

I found a way to cheaply check oil pressure witha $20 guage setup through the vanos banjo bolt. Oil pressure was great at 58lb idle and 15lbs at ot.
Im convinced its a rod bearing thats spun and intermittently catches. Either way, the oil pan is coming off and I'm finding out for sure.

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Your right! Very well could be the windage tray! Im now remembering i had a friend put a rod bearing in it over last summer shortly begore finding it still knocking. Its very possible he didnt intall the sump pipe properly or the tray..

[zellamay]

Make sure the spark plugs are tight. According to this site, I was not the first to think I had major problems, only to discover a loose spark plug. I was convinced it was a head gasket. I've heard bad rod bearings. It sounded "Not as loud as a crank bearing, louder than a tappet."

[spyderg0d]

Dropped subframe, pulled pan.. The exact bearing my friend replaced was bad on cylinder 1. Either it was dirty, he didnt torgue it evenly or dry, or it didnt crush right from misalignment. There was a long flake of metal on one side of both bearing halves. The bearing was worn almost through the copper layer with severe pitting and flakes. It did indeed feel dry since it was ran cold for maybe 45 seconds 20 minutes before. Pissed me off pretty bad actually. He broke the oil pan gasket, which leaked lightly making me think a scratch on the pan was a crack and left out the oil pan to trans bolts, along with the oil pan to power steering pump bolt. So i have to search for those somewhere. Just cant trust anyone these days i guess.

[spyderg0d]

I studied the bad bearing. Found crease marks where the bearing spun about a cm. It was pretty obvious he put the baring cap on backwards. Which pisses me off more,. I remember specifically making sure he knew it was bearing tang to bearing tang on the exhaust side. And thats all it takes to make hours and hours of labor and mess and money worth nothing. Lol.

[Eric93se]

We feel your pain

Now piss in his coke and get that E36 back on the road .

[spyderg0d]

Today it will be, after a oil filter and i screen the oil that came out of it. $80 of oil to drive the car around the blovk then sit all winter.

[spyderg0d]

Oil in, new filter. I pulled the coil plugs and fpr and cranked it about 15 seconds first to make sure oil got to the bearing before starting. I forgot how smooth and yet powerful these 3l pur at a good 550rpm idle. Theres something about a slow car modified to go fast, aye?
I almost fogot how fuckin sweet this e36 is. Haha. I think this concludes the thread. Thanks guys!

[spyderg0d]

And it started tapping... F×!k!!!

[spyderg0d]

Its lifter tick. Not normal m50 lifter tap, its the loud m54 lifter knock. Its certainl. Not present at any piont when the car is cold. Maybe from useing sae 10-40 instead of synthetic.

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I guess the only way il now is to maybe switch oils, and drive it. If it starts knocking like it was before, il just have to pull the whole motor instead of messing around with the pan. Then il probably get a new rod, and make it absolutely posative ots not a low end problem.

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Or just buy some new lifters first, as that is probably the easier quicker test. Cant get lifter tick with new lifters.

[Eric93se]

The car sat for a while, some lifters leaked down. 10,40 dyno oil is thick, would have to idle for a while to quite down.

[spyderg0d]

I wish my life was the usual ol' problems, but thats not how whatever creator made me. Haha.
I changed the oil from 10-40 to 5-30 and it helped a bit. It took longer before the tick came, it is down to a very light tap that you have to listen for to spot over the normal engine sounds. And i think this time it may actually be a lifter. As it only comes when its revved and for a few seconds after it settles at idle, then disapears for the most part.

[spyderg0d]

Ordered a custom tune chip from someone random guy in baravia. Lol. Listed off the mods and the requested ews delete on 89 octane. It should be here in a couple weeks. Hopefully it will clear the lack of upper rpm ass and let the 3.91 diff grip like it should.