What the hell is this noise

[325_driver 422]

My thoughts

Worst case senario Big end bearings

ive had big end bearing problems before and their much more of a knocking "dock dock dock" noise,

this nearly sounds like a dead lifter, or maybe like theres no oil pressure ?

Do oil pumps fail often ?

Video

any insight would be awsome !! before i start ripping the damn motor out

edit: "like a dead lifter" correction, it reminds me of when i adjusted the tappets accidentially to the wrong measurements, and it made a similar noise

Edited May 29, 2010 by 325_driver

[Jamez 2147483647]

tappets with 0mm clearance? have you taken the valve cover off to check everything?

Edited May 29, 2010 by Jamez

[antil33t 90]

It sounds liftery to me... maybe a broken rocker?

[mark247 39]

Take the cover off, have a look, check the clearances and go from there

[325_driver 422]

That exactly what i was thinking, it is SHOCKINGly loud, so loud i thought WOW maybe big ends !

but its coming from under the top end.

Is it common, or has any one heard of the tappet clearance / adjusters coming loose ?

Will be looking into it today

[325_driver 422]

Rocker cover is off, what exactly am i looking for, i cant check tappets correctly untill i find the feeler guages, but im assuming a broken rocker should stick out like a sore thumb ?

are the rockers supposed to move freely ?

is there another thread i can refer to?

[325_driver 422]

video number 2, closer look inside rocker cover

[BM WORLD 1283]

check tappet clarences , should only move a small amount , check for wear grooves on the cam lobes etc

[325_driver 422]

Video number 3, rocker arm movement,

does this look excessive ?

checking tappet clearances when brother brings homes feeler gauges, this thread might come in handy one day for some one else with a similar problem

[325_driver 422]

Chance that a cam lobe has shat its self and it now wacking against a rocker arm ?

how often does that happen

[325_driver 422]

feeler gauges arrived, and some interesting findings.

most clearances are approx 0.152mm (0.006)" or less, since .152 is the smallest size i have, how on earth does this happen ?

no one has touched the tappets, did an eccentric possibly crap its self ?

Would this be enough to cause horrible tapping

[325_driver 422]

Ok, maybe im not covering my basics here, but carefully did the clearances, and now it wont fire, just before i start assuming the worst, im going to ask :

is it possible that i some how could have muffed up the tappet clearances, causing the car not to start. It splutters, it almost sounds like the timing is way out on the dizzy, but that was all fine before i touched it.

I wont know for sure until i get a compression tester

[antil33t 90]

Did you do the clearences with each piston at TDC? or with the lobes pointing downwards?

I used the pelican parts guide to do mine with great sucess.

I'm not sure if you can break an eccentric, but I'm sure you'd notice an odd one out when adjusting them.

[*Glenn* 854]

From the short No2 video clip there doesnt seem to be any oil coming out of the squirter rail. If theres no lubrication you might have a damaged camshaft and damaged rocker arms. Does the engine have oil pressure and have you checked the oil level ?.. might be a bit too late for that now but I suggest you check first. A broken valve spring can also cause the problem you have as well, and as Michael said... did you check valve clearances on the back of the cam ? The feeler guage must also go between the accentric adjuster and the valve, not at the camshaft end of the rocker.

[325_driver 422]

From the short No2 video clip there doesnt seem to be any oil coming out of the squirter rail. If theres no lubrication you might have a damaged camshaft and damaged rocker arms. Does the engine have oil pressure and have you checked the oil level ?.. might be a bit too late for that now but I suggest you check first. A broken valve spring can also cause the problem you have as well, and as Michael said... did you check valve clearances on the back of the cam ? The feeler guage must also go between the accentric adjuster and the valve, not at the camshaft end of the rocker.

Thanks glenn, um i am pretty certain there is oil pressure, might be just hard to see on camera, but there is plenty of oil circulating.

I did the clearances at TDC or close enough, very hard to do when i cant take a spark plug out to measure position of cylinder, so it is possible that there was room for error, so gathering from michael's comment, i should be checking the clearances with the cam lobes facing down into the head ? which i may not have done, (i just used my knowledge of where a cam lobe should be in relation to just before tdc) which after this circus event might be incorrect. Then again its hard to measure any thing with out ruling out other problems such as timing, and idle mixture related things, as there was a long list of annoying problems before i took it apart.

Any thanks to all for the insight on this, it doesnt go un appreciated, hoping to get to the bottom of this, for future reference

[325_driver 422]

Compression test result's as follows

C1: 160psi

C2: 170psi

C3: 166psi

C4: 138psi - hinting maybe some worn valve's it will get near 160psi 3 more cranks later

C5: 130psi - hinting maybe some worn valve's it will get near 160psi 3 more cranks later

C6: 150psi

Could incorrect tappet clearances on C4, C5 cause that low PSI ?

Does any one know what the minimum compression in a m20 cylinder is for recommended detonation, i thought it was only 80 - 110psi cold or some thing.

With these results would you expect a car not to start? Im going to recheck the clearances again, the spark plugs seem a little wet. Do you think that the spark plugs could be playing a major factor in it not starting

Thanks

[*Glenn* 854]

I'm starting to know wonder whether your cambelt has jumped a couple of teeth... low compression and noisy valve train could indicate valves have touched pistons...next step would be to do a cylinder leak test

First I would do valve clearances again properly... then do the cylinder leak test ( not a compression test) you may not have the gear to do this though

Edited May 31, 2010 by *Glenn*

[325_driver 422]

Yeah i went on the assumption first that i mucked up the clearances, looks like the other set of feeler gauges, all be it they had the same numbers on them, didnt look like the same distance. So i used a friends feeler gauges, re did the clearances, fired straight away, purrs nicely.

But kudos you glenn, because i think you nailed some thing on the head, about the oil pressure through the rail, i could only notice it during the dark when the light was on one rail, and oil was squirting fine, but the other 4 it was barely dripping.

Could this mean use thinner oil? or replace the rail ?

so i manually squirted oil on the place where the rocker hits the cam and the noise dissapeared substantially, the clearances were way out before, so it was a good thing the clearances were done in the first place.

So could i have your recommendation's glenn, would the cam and rocker arm be worn ? or is it the rocker arm that would need to be replaced ?

Thank you for your excellent insight.

[antil33t 90]

Check the rail hasn't come loose, bolts on the front and back of the head.

I was reading in a guide somewhere to check the rail was tight when you do the adjustments.

[325_driver 422]

Check the rail hasn't come loose, bolts on the front and back of the head.

I was reading in a guide somewhere to check the rail was tight when you do the adjustments.

Rail is tight, my brother was driving it far too long, and i heard the noise gradually evolve to its current state, so im pretty certain that the cam is damaged. Just the next question is do i replace the cam, or do i replace the cam and all the rockers also ?

Waiting on some advice from glenn on that.

Jonathan

[*Glenn* 854]

If the cam "is" damaged you would have to remove the head to replace it. You might also find that the rockers, rocker shafts and accentrics are worn as well. Doing this is expensive and I would also suggest doing the cambelt along with anything else that is getting a bit tired. Do you know any technicians down your way that maybe could have a look and give you a professional opinion on the camshaft first before ripping it all apart ??

You could try cleaning out the oiler tube and unblock the squirter holes... do the clearances again and just run with it in the meantime... without seeing it, its hard to say, you might have caught it in time.. time will tell.

[325_driver 422]

So this problem continue's,

Rocker's were replaced, cam was replaced with some thing newer, cam was polished at engine reconners,

this is the updated sound

[Jacko 2157]

It sounds like a steam engine!

Yikes!

[325_driver 422]

It sounds like a steam engine!

Yikes!

yah i know, maybe i should just roll with it !

it nearly sounds like its running dry, do those e30 oil pumps f out often? some thing glen might know.

the cam that is in there is from a 323i M 1983, with a higher lifting cam, any chance the clearances should be different ? does any one know the measurement if so

[325_driver 422]

apparently a damaged rocker arm shaft can cause this sound, what to look for in diagnosing this ? we just put another FN one in, and carefully too !

Edited August 15, 2010 by 325_driver