Unfortunate noise from top-end

dominicbeesley · Apr 8, 2013

Hello all,

Just been on a long run to Glasgow and back this weekend and the top end of the engine has developed an unfortunate tapping noise. It sounds a little like the indicators are on when idling and is not really noticeable when driving.

There's no power-loss or any other symptoms, just a worrying noise.

I got a bit of tubing out to use as a stethoscope and ran with the rocker cover off. Its coming from the third valve (inlet of #2 piston). I checked the tappet clearance and it was out by a little but not loads. Nipping it up to spec has not cured or changed the noise.....so where to look next and what are the likely causes?

Followers? Unleaded valve inserts loose? Cracked / damaged cam roller? chipped valve????

Any advice on a good logical way to track it down would be appreciated...

PS: Before anyone says its due to my advance timing experiment I've knocked that back to a sensible 6 degrees BTDC a week or so before that... and no pinking. I only ran about 20 miles with it over advanced then chickened out.

johnny curt 1 · Apr 8, 2013

i had the same thing with me diesel 2.25 and it turned out to be the tappet cam roller follower had done this due to age

dominicbeesley · Apr 8, 2013

Will be annoyed if it's that only done a few thousand since I swapped em!

johnny curt 1 · Apr 8, 2013

dominicbeesley said:
Will be annoyed if it's that only done a few thousand since I swapped em!

if they were britpart i wouldnt be surprised

and thinkin about it mine did that after i had mine timed up to the bollox aswell so might not have been age but they were original and appear to be the weakest link in the cam to valve train in my opinion

dominicbeesley · Apr 9, 2013

They are ACR heavy duty followers and rollers...

johnny curt 1 · Apr 9, 2013

dominicbeesley said:
They are ACR heavy duty followers and rollers...

same ones as in a 200tdi

should be reet with them

dominicbeesley · Apr 9, 2013

Just ordered another head gasket and related bits so it might be a head-off job tomorrow evening....doesn't look like I'm gonna get much done on the other project as I've got my bus to get back on the road in the next month too. Got it moving for the first time in 18 months yesterday after freeing the brakes and clutch off...

ebbadger · Apr 9, 2013

double check u havent got a slight blow from exhaust manifold before going and stripping, does sometimes sound very similar

cheers steve

dominicbeesley · Apr 10, 2013

Thanks Steve, I had a good poke round with the stethoscope and its definitely coming from the valve/rocker. I'll try taking the rockers off tonight and checking those, the push rods and looking down into the followers. I guess I should be able to check the roller through the cam inspection plate jobby hole too?

dominicbeesley · Apr 10, 2013

Right, I've got carried away and taken it to bits...

I've chedked the following:

1) Cam/roller
Opened the inspection plate on the side and felt/looked at the #3 valve roller/cam and it all feels and looks good. No marks or burrs

2) Rockers
Taken rockers off and they all look good as new (they should be they were all replaced about 6 month ago). Faces nice and smooth and nice and smooth action on the pivot

3) Follower/push rod
Visually looks ok, felt push rod movement with end of finger whilst cranking engine and its nice and smooth

4) Head off
All looks ok apart from a bit of carbon
No signs of any leaks on manifold gaskets or head

3) valves out
valve seats look ok but valves look a bit mucky/tatty could it be that?
The inlet valves especially looks pretty crappy to say its not done more than 11,000 miles...

I'll be regrinding the valves gently before refitting...

Other than that I'm stumped!

D

ferretboy · Apr 10, 2013

You could have a failing injector !! They tick like mad !! Crack each one see if it stops the sound !!

dominicbeesley · Apr 10, 2013

I hope not...it's a petrol!

dominicbeesley · Apr 13, 2013

Played a bit more with this today - I still can't see what was causing the tapping other than some very slight pitting on one inlet valve. Followers, rollers etc are all fine.

Exhaust valves look very tired to say they are quite low mileage. I'm not sure what this is down to? Exhhaust valve pictured before and after quiet a bit of (20 minutes) lapping with coarse paste.

Valve seats all look ok and valve guides feel fine.

1- Old webber carb was running quite lean due to jetting and a leak round the throttle spindle (new one is richer)
2- I deliberately ran over-advanced for a short time (about 40 miles)
3- Cheapo chinese dissy was running too retarded at mid-high rpm (due to wrong spec weights)

I'm guessing 2 shouldn't have done this - but not ruling it out
1 could but unlikely, 3 definite possibility?

Not sure whether the valves are worth lapping in or whether to replace? Also looks like I've got oil in #4 piston, probably rings going as gasket was ok and valve guides, seals were ok and no sign of oil in the top-end....

D

jamesmartin · Apr 13, 2013

is there much side ways movement in valve ? valves are poor but ive seen much worse running ,if you lap them dry a couple of times you should see a bright line form which if unbroken and all the way round shows were and that valve seals , id get yours refaced ex at least as they are the ones that suffer ,might be trhe time to get 4 new exhaust valves and fit the 4 exhaust seats needed to make head unleaded ,cant see anything to cause tapping ,head gasket and manifold gasket if fitted not blowing ?

dominicbeesley · Apr 13, 2013

Thanks James, the seats, guides, valves, seals are new unleaded ones (ACR 2.1 head) and those valves have only done approx 10,000 miles which is why I'm surprised...
I can see no tracking under the gasket and it didn't sound like that more like a slow tick/tock noise from that one valve...

jamesmartin · Apr 13, 2013

dominicbeesley said:
Thanks James, the seats, guides, valves, seals are new unleaded ones (ACR 2.1 head) and those valves have only done approx 10,000 miles which is why I'm surprised...
I can see no tracking under the gasket and it didn't sound like that more like a slow tick/tock noise from that one valve...

yes ,i can see that now ive enlarged the pic ,usually a leaking valve has a manifold echo ish noise to it ,plus yours just has pitting without the blow by signs,followers ok ?ive known the brass follower catch in a worn guide ,rocker bushes ,lift pump ?

dominicbeesley · Apr 13, 2013

Followers etc are all new HD ones and feel fine sliding up and down with fingers. Wish I'd listened for the noise cranking with plugs out before taking it to pieces to rule out any sort of gasket leak...It's definitely coming from the valve/tappet/rocker for #3 valve I checked round with a stethoscope....

jamesmartin · Apr 13, 2013

but so would a noisy lift pump,or even little end as i had once

dominicbeesley · Apr 13, 2013

Sorry, meant to say I tried with the lift pump off. I had one fitted but don't use it so tried with a blanking plate over the hole...could be a little end I suppose but its not doing it now when I crank the engine with the head off.

dominicbeesley · Apr 13, 2013

Is there a way to check the little-ends without taking the piston out or should I just bite the bullet and do a full engine rebuild...is a bugger because other than the noise it was running really well!

Unfortunate noise from top-end

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Attachments

Well-Known Member

Well-Known Member

Well-Known Member

Attachments

Active Member

Well-Known Member

Well-Known Member

Attachments

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Similar threads