S52 Engine Screeching Noise Issue

[Lights]

I start up my S52B32 engine and hear a very loud screeching noise. I have been chasing this issue now for a couple of weeks and I just swapped this engine and finally finished my build. Initially the screeching noise would only occur when the engine started to heat up and sounds like it was coming from the bottom end. I took off the belt and the noise persists. Now I go to turn it on today and the screeching is 5x worse and nonstop. I turned it off immediately after recording this video. Anyone have any experience with what this could be? I'm thinking bent valves or maybe a seized bearing on the bottom end.

This engine came with an aftermarket AMC head so it makes sense if it overheated and ruined parts inside. I pulled off the valve cover and can see some rainbow colors on the cams and even some scoring. There is a ticking coming from the top end, could be the lifters but my main concern is the screeching. It's Very disappointing to have bought full price for a engine that will need more money in repairs than I paid for it. If anyone could help me out or has any ideas to what it could be I would greatly appreciate it.

Cam Pictures:

https://gyazo.com/fc4bc31f9e5a927b3c3f62e825ff34d7

https://gyazo.com/bb27c22780646f471c1dbe8783857bb8

[ADEN]

Looks like metals are rubbing against each other a bad water pump impeller or a chain guide rail.

[mjweimer]

Need to install an oil pressure gauge and see what that's doing. Cams don't look bad to me but hard to tell in the pictures. Do you know if the check valve was installed in the new head? If there is lifter noise on start-up every time and the oil pressure is low, that may indicate a missing valve.

Agree that it sounds like something self-machining clearance. What flywheel is on the engine?

[Lights]

Looks like metals are rubbing against each other a bad water pump impeller or a chain guide rail.

The water pump is brand new, when I first go the engine I put a new oil pump nut onto it with a wire with thread lock because I heard they can back off. Maybe I need to check that out.

[Lights]

Need to install an oil pressure gauge and see what that's doing. Cams don't look bad to me but hard to tell in the pictures. Do you know if the check valve was installed in the new head? If there is lifter noise on start-up every time and the oil pressure is low, that may indicate a missing valve.

Agree that it sounds like something self-machining clearance. What flywheel is on the engine?

I am not sure about the check valves, I know AMC heads usually come with the valves all assembled but idk what they previous owner did. Lifter noise is on startup every time. The screeching noise used to only come on when it started to warm up but now is very bad and does it on startup. I need to test oil pressure for sure so I don't replace parts and have the same thing happen. So my car would start and have compression if one valve was missing? I can't find a straight answer about it. I plan on taking the cams out and inspecting the valves to see if any look bent.

I am using a Valeo flywheel and clutch that I installed with the engine but have not drove the car or anything yet.

[mjweimer]

You may have a couple of different problems. If your lifters are loud after start-up they either have not been bled properly or the check valve in the head could be missing allowing the oil to drain when the engine is shut down. The check valve is not related to the intake or exhaust valves and is inserted into the oil supply circuit for the cylinder head and is located on the bottom of the head.

This: https://www.ecstuning.com/b-genuine-...e/11121735180/


This has also be known to cause a low oil pressure issue if missing. There is a good thread here to learn more:

https://www.bimmerforums.com/forum/showthread.php?2058783-Low-oil-pressure-oil-pump-ok-bearings-ok

Your screeching issue may be unrelated to the lifters, I asked about the flywheel just in case it was interfering with the back of the engine. Sometimes the back of the G260 flywheel will interfere with the oil pan on the M/S 5x swaps and one or the other needs to be clearanced.

[Lights]

I removed the Cams today and it looks to me like some of the bearings are scratched and not good. Can anyone confirm that these are bad cams and bearings? I have no previous experience so I don't know for sure but on many of the cam caps and trays I can run my finger and it jagged and feels rough.

cams: https://gyazo.com/804fb9b37231b77c7e41721db5610b7a

https://gyazo.com/1a5530b5e8e47696dface96363aa806f

https://gyazo.com/0b6975a8d8b632b1357c1fadd70eedb6

https://gyazo.com/c8d3948cd851db093102b72f3d647a42

https://gyazo.com/e6c9816fd68bc7472395e88b7d96bc22

cam caps: https://gyazo.com/f5f4c2d8607c2d3f0f64ac52477d54f1

https://gyazo.com/70b2937c41541b13980b03d7242ccb3c

Does this look like it would cause the screeching in the video? I am hoping this is my problem.

[ADEN]

Even out of specs cam bearings won't produce the sound you have.
Valve train noises mostly happen at cold starts or has low oil pressure and lose oil pressure when warm.

Can you confirm the noise is changing or not present after you push the clutch pedal at idle?
My input shaft started making noises at idle after putting my engine due to my stupid mech. hitting engine backward hard many times trying to mate the engine with transmission.

[Northern]

I don't think that looks any different from typical 24v cam/cap wear. Every engine I've had apart looks pretty similar to that.

[Northern]

How long has the engine run also? like this is only the first or second start, and it takes a while for the lifters to fill at idle.
Anyone who has autox'd with a 24v will know how it takes minutes for the lifter tick to stop after a run.

[Lights]

Need to install an oil pressure gauge and see what that's doing. Cams don't look bad to me but hard to tell in the pictures. Do you know if the check valve was installed in the new head? If there is lifter noise on start-up every time and the oil pressure is low, that may indicate a missing valve.

Agree that it sounds like something self-machining clearance. What flywheel is on the engine?

Thank you for your post! I tested the check valve from the forum post using the method to gauge how far the zip tie goes into the stud and I believe it is missing.. I will confirm when I get the head off but that would explain the ticking if the lifters are loosing oil. Now I hope that screeching noise was the bearings becoming dry from that valve not being there and not the bottom end. If the valve is not there then who ever reassembled the engine could of missed other crucial parts when putting it back together.

[Lights]

You may have a couple of different problems. If your lifters are loud after start-up they either have not been bled properly or the check valve in the head could be missing allowing the oil to drain when the engine is shut down. The check valve is not related to the intake or exhaust valves and is inserted into the oil supply circuit for the cylinder head and is located on the bottom of the head.

This: https://www.ecstuning.com/b-genuine-...e/11121735180/


This has also be known to cause a low oil pressure issue if missing. There is a good thread here to learn more:

https://www.bimmerforums.com/forum/showthread.php?2058783-Low-oil-pressure-oil-pump-ok-bearings-ok

Your screeching issue may be unrelated to the lifters, I asked about the flywheel just in case it was interfering with the back of the engine. Sometimes the back of the G260 flywheel will interfere with the oil pan on the M/S 5x swaps and one or the other needs to be clearanced.

I took the head off and sure enough the check valve is missing! Once I get everything back together I will see if the screeching stops but if not I will take the transmission out and check the pilot bearing. Its a valeo clutch that I put into it. Thank you so much for the knowledge you saved me a ton of money.

https://gyazo.com/493208f2ef30b4f50b4df356117cb2b6

[mjweimer]

Good deal. At least you know the lifter tick issue should be resolved. Don't forget it takes a bit for the lifters to bleed out all of the air so you will likely hear some ticking once you start and may need to follow the bleeding procedure.

This is a great article for future reference:

https://www.enginebuildermag.com/2009/05/toubleshooting-bmw-hydraulic-bucket-tappet-problems/

Look forward to the next update, you are making good progress.

[Lights]

I took apart the lifters to clean the ball bearing inside and found 4 bearings that seem to not retract when I squeeze them without the spring inside. Can anyone confirm that these are bad and need replaced? This happened after I let them soak in detergent for a couple of hours and only happens on 4 of the 24. When I pick at the ball bearing it is firm and does not really move around when I push it down. I think I am going to replace all of the intake lifters because that is the only side where I found this issue. Can I replace the lifters without replacing the tray?

[Northern]

I'd try to blast through whatever crud is there with some carb cleaner or something similarly strong. Soak a bit then blast it through with some compressed air.
Rinse and repeat and hopefully it will come back.

Alternatively you can remove the clip that holds the ball and spring. I'm not sure how tight it's going to be/if you risk damaging the retaining piece - this pic is from one that wasn't seated right from the factory that I managed to work loose with a pick. The ball and spring are tiny so be careful not to lose them