M52B28 tap tap tap tap tap tap tap when hot!

[Jacko_]

Shameless copy and paste i'm afraid but i was wondering if you guys could help.
Hi guys, i've got a bit of a head scratcher of a problem and would like your advice on what you think it could be.

I've installed an M52 engine into my E21, the engine came out of an E36 with around 100k on the clock. Now when the engine was in the e36 i used it for drifting at a local track and in these conditions the engine would 'tick' when really hot, normal cold start and driving it was ok (as i remember it anyway as it was some time ago)

So i dropped this engine into my E21, fitted some 257 duration cat cams and at the time swapped out a couple of the followers as they were worn. I've also fitted S52 exhaust manifolds and dbilas individual throttle bodies. The engine, after i've been driving it and it's nice and warm will 'tick' it doesn't do it from cold (well, it makes a slight ticking noise for a second then goes away and it sounds very much like the vanos and seems pretty normal to me. So the noise when it's hot, this 'ticking' noise doesn't go way it's constant and really annoying, sounds like a tappety noise that you'd get on a car with fixed tappets when not set correctly. If you rev the engine i can't tell if the noise goes away or is just drowned out by the engine, intake, exhaust etc.

I'm wondering what it could be? Could it be something to do with the followers not filling with oil, or the oil becoming too thin? Could it be down the grade of oil (i think i'm running 10/40 fully synth (i run the halfords stuff in the silver bottles)) could it be the oil pump is losing pressure when the oil is thin and causing it oil starvation at the top of the engine? Could it be the vanos? Could it be something to do with the timing (I’ve not long had the cams installed by a BMW indy so you’d hope they’d know what they were doing..? (do the chains stretch, can a faulty vanos or timing cause this or would it be constant? Or last but not least, could it be a hairline fracture in the exhaust manifold that when hot, is making a noise? I've had a stethoscope all over the top of the engine and i can't pin-point it at all and it's doing my head in. My car is quite clean and it gets some looks but i feel a right chump when they pull alongside and it sounds like a diesel. :-/

I need to do an oil pressure test, i may look to see how much they are to buy, i want to run a gauge inside the car at some point but in the meantime i'd like to know if it's the pump that's failing. do you know what the oil pressure should be when cold, when hot and when the engine is under load?

Secondly to this i want to change the oil for something better like mobil1, millers etc. Would you recommend chainging the grade and is so what too? I'm wondering if a 10/60 would work well here?

Thirdly, i'd like (but haven't got the tools) to do a bore scope, i'm wondering if the chain could stretch and knock the timing out and cause valve to piston contact? If anyone knows if this is possible please say...i'm scared if it's this...!

Fourthly i wouldn't mind either deleting the vanos if possible or advisable or rebuilding it. I've had a quick look for vanos delete for M52's on google but can't see anything so i'm guessing it's no possible.

Once i've got to the bottom of this i really need to get the car mapped but holding off doing this till i can figure out what's causing this. The engine seems to run fine, although mapping would help smooth things out, i think the engine may be running lean so not sure if this is doing damage or not? On an NA engine this isn't as bad is it but how bad could this be, what could happen?

Hope you can help, sorry for the essay but i'm really scratching my head with it and would like your opinions before i start spending money.

[DanThe]

I havnt read in detail but it just sounds like normal over heating of the oil, fit an oil cooler and it will most likely solve the problem

[Jacko_]

I'm uploading a vid of the noise; i'm deaf in one ear so pinpointing it isn't easy for it. TBH i think the timing is out, either that or it really does need mapping it's very lumpy...

[Jacko_]

I did a vid...

[craigieeb]

Sticky tappet?

[Jacko_]

I'm not sure Craig...it only does it once the engine is warm...

[BATTS91]

What grade oil do you use?

[DanThe]

Could be a crack in the exhaust manifold somewhere, difficult to tell but it doesnt sound tappy enough to be a lifter IMO

[Jacko_]

I'm using 10-40 halfords fully synth (comes in the silver bottles if anyone uses it)

I was going to try 10-60 mobil one do you think that'd be a better grade?

[BATTS91]

10-40w should be fine wheter its fully or semi in your case as its when warm and not from cold start up :/hmm personally thats that rules out .

Check as dan says your exhaust , i had a pinhole and it sounded like bottom end at first hearing , id definatly give manifolds and downpipes thorough inspection tho

[Jacko_]

See I thought from day one the manifold but normally you can pinpoint where it coming from but I'm struggling to do so this time around. You can normally feel where it's leaking from as well but these manifolds get so hot so quickly and it's pretty cramped to get your hand in and have a feel around without burning yourself.

Then I started to think about the 101 other things it could be and the fact that it did used to do it when I used the engine / e36 for drifting so got me thinking it could be something else.

What else should I do to check the top end of the engine over?

[Jacko_]

Call me sir Isaac stupid.

Well, i rolled my selves up and turned some spanners last night. So turns out the exhaust shop when they modified the manifolds and made the system up didn't tighten the stud nuts up very well. Not had a chance to get it up to temp but here’s hoping that's all it was. I'll report back hopefully a happy man once again.

Wish i had tried better last time i looked at it, but it's such a ball bag to get to and get a spanner on them i gave it a half arsed attempt then gave up because i couldn't be bothered.

[BATTS91]

Tops!

[Jacko_]

Lets not get ahead of ourselves just yet, I'll be testing it later today after the dentists orally fingered me! Gulp!

[Jacko_]

Still tapping when hot

Oil pressure test next...i'll report back with my findings.

[E30BeemerLad]

I used 5w30 fully synth in mine

[randomspeedfreak]

i have the same problem with a standard engine (other fuelling issues aswell). the boys on here help me decide it might be the tappets? i have no evidence as yet to suggest anything conclusive though

ill be following this thread carefully

[Jacko_]

I parked the car up for winter and forgot all about it, time to drag the car out the garage and re-investigate this problem. :-/