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Hey all,

My V6 has developed a knocking rattle at idle and low engine speeds, definitely from the top end. It's coming from the rear bank at the timing belt end and is proportionate to engine speed. I'm thinking camshaft bearing or maybe hydraulic tappet failuire but the engine has only done 75,000 with regular, good quality oil changes.

Any ideas? I'd rather get some suggestions of things to look for before I dismantle it!

Scott

Given the mileage, has it had a recent cambelt change? Could be one of the camshaft sprocket adjustment bolts is loose or something similar...

Don't forget to order a new inlet manifold gasket from the dealers (dirt cheap, buy a spare ) if you take the inlet manifold off...

Oooh, worrying It's not a very common engine here, although I seem to recall some mention of just such a problem over on the Coupe Club (wrong oil?) so perhaps it might be worth a search on there. Any questions you post over their won't drown too...

I was thinking about the oil. This long cold spell is not too good for the oil which can shear-down through petrol contamination and condensation build up.

An oil change would be the cheapest way of starting your investigations in my mind

Welly wrote:I was thinking about the oil. This long cold spell is not too good for the oil which can shear-down through petrol contamination and condensation build up.

An oil change would be the cheapest way of starting your investigations in my mind

Yeah, think that's a good shout buddy.

It's as if one set of tappets isn't getting oil because the noise goes away when you rev (increasing the oil pressure). They must be the tappets that are farthest from the oil pump. I'll flush it and change it tomorrow.......fingers crossed it solves it!!

Scott

Well, found out what the rattle was.....

Changed the oil for 15w40 and the filter too, noise *seemed* to quieten down. Would only arrive briefly and went away when revved as previous.

Then the bearing of the idler pulley inbetween the camshaft sprockets underneath the engine mount finally let go, giving the true source of the noise away. Now the car is off the road. I have no idea whether any of the 24 valves have been hit or not....Just have to fit a belt and pulley and see....



After stripping down the mounts and taking the covers off, it looks to be a real heavy duty job. It's recommended to use a tensioning gauge....yours for £526!

It's such a lovely car, only done 75000, but I don't know if I can justify the time/expense to fix it. It's just ran out of MOT and Tax too




Anyways, I'll keep progress posted. Maybe even start a project thread! Could be an excuse to go all out, ported, flowed, reground cams, decat.....the works!

Scott

Holy crap! Hope it's not too serious, keep us posted!

The belt's still there but do you think it slipped a few teeth?

sorry to see that . Maybe you could carefully replace the bearing and turn the engine over by hand and see if all the timing marks line up. Hopefully they will, but if not you can at least work out the cost of repair. Fingers crossed and goodluck

Welly wrote:The belt's still there but do you think it slipped a few teeth?

It's hard to say Welly. The bearing collapsed as I was idling it and I shut it off straight away. It never sounded like it ran out of time but maybe that's just me being hopeful!

markyp130 wrote:sorry to see that . Maybe you could carefully replace the bearing and turn the engine over by hand and see if all the timing marks line up. Hopefully they will, but if not you can at least work out the cost of repair. Fingers crossed and goodluck

I thought about that, but even if I does turn over and time OK, I'm still going to have to replace the belt as it was damaged slightly when the bearing let go. Might as well as do the lot in one go!

I've tracked down a the procedure list for doing the job and yikes is it big! Although I think the only things I really need are a few drill bits and some M8 bolts to lock down the tensioner. As for setting the tensioner, guesswork seems the only way to go....I have no frame of reference as the old one is loose....and I ain't buying a £500 tensioning gauge!!

I'll keep you guys posted and ask for help if need be

Scott

I think I'd be tempted to stick the roller in and make a vague attempt at the tension (half a turn on the longest stretch seems to be about the norm) just to know if it's alive or dead. There'd be nothing so disheartening to spend all that time changing the belt etc only to find the engine's a box of swarf.

steve_earwig wrote:I think I'd be tempted to stick the roller in and make a vague attempt at the tension (half a turn on the longest stretch seems to be about the norm) just to know if it's alive or dead. There'd be nothing so disheartening to spend all that time changing the belt etc only to find the engine's a box of swarf.

That's a good shout, Steve. I think the tensioner stays as is once set, so if I stuck a pulley on it'd be the correct tension (I assume). But I don't know how far to go, the belt took a little score from the pulley breaking, but it'd probably be OK to run it for a min to see if it's goosed or not. I don't know, it's guesswork and assumptions I suppose.

I'll price the bearing and see how big the hold in the wallet will be...

Scott

Rammstein406 wrote:

steve_earwig wrote:I think I'd be tempted to stick the roller in and make a vague attempt at the tension (half a turn on the longest stretch seems to be about the norm) just to know if it's alive or dead. There'd be nothing so disheartening to spend all that time changing the belt etc only to find the engine's a box of swarf.

That's a good shout, Steve. I think the tensioner stays as is once set, so if I stuck a pulley on it'd be the correct tension (I assume). But I don't know how far to go, the belt took a little score from the pulley breaking, but it'd probably be OK to run it for a min to see if it's goosed or not. I don't know, it's guesswork and assumptions I suppose.

I'll price the bearing and see how big the hold in the wallet will be...

Scott

hi scott i can get trade price gates timbelt kits so i could get one for you if need's be, ive just bought mine and it was only £48 insteed of £89 (list price)
let me know if ya need one

Definitely a good idea to check first before splashing money on a new belt or kit, because they're not cheap for this engine! Last time I looked it was something daft like £700 for genuine belts, tensioners, rollers etc, and there weren't any aftermarket ones available

Now, eurocarparts appear to do a timing belt kit for £260 which is a lot more palatable, but still daft if you find out the engine's dead after forking out...


One thing to watch is the aux belt tensioner (the roller bracket not the spring). It can seize up requiring the purchase of a new one at nearly £200, and it's a royal pain in the backside to fit. Do yourself a favour and give yours some copper slip. Grab some tippex and draw a line on your crankshaft pulley too. The rubber bit inside can break down leading to slipping and squealing as well as PAS and alternator problems. A line drawn over it and checked regularly will let you know if it's giving way.

mjb wrote:Definitely a good idea to check first before splashing money on a new belt or kit, because they're not cheap for this engine! Last time I looked it was something daft like £700 for genuine belts, tensioners, rollers etc, and there weren't any aftermarket ones available

Now, eurocarparts appear to do a timing belt kit for £260 which is a lot more palatable, but still daft if you find out the engine's dead after forking out...


One thing to watch is the aux belt tensioner (the roller bracket not the spring). It can seize up requiring the purchase of a new one at nearly £200, and it's a royal pain in the backside to fit. Do yourself a favour and give yours some copper slip. Grab some tippex and draw a line on your crankshaft pulley too. The rubber bit inside can break down leading to slipping and squealing as well as PAS and alternator problems. A line drawn over it and checked regularly will let you know if it's giving way.

ive just priced it out of curiosity and its £205 but with out the reg they cant tell me if its that one so may be cheaper