Chimaera 4.0hc tappet problem? Advice please
Discussion
Ive been hearing a tapping/ rattle from the engine which I thought initially was noise due to low oil pressure, i.e. failing oil pump. Turns out the oil pressure gauge on the dash was reading low and my pressure is good. So, what's the rattle? I've been trawling through you tube and the videos on tappet/ hydraulic lifter issues seems to fit my symptoms.
I've taken some video so what do other think? Tappets/ lifters or worse?
https://m.youtube.com/shorts/7Y1WlrmoCgU
I've taken some video so what do other think? Tappets/ lifters or worse?
https://m.youtube.com/shorts/7Y1WlrmoCgU
2 sMoKiN bArReLs said:
When I had a rattling (loud ticking) noise it turned out to be a broken exhaust manifold gasket.
I had that twice on two different cars. Just a thought.
Did it sound like the video? I'll check the gaskets but it sounds more mechanical than exhaust. Could be wrong though so I'll check. ThanksI had that twice on two different cars. Just a thought.
I had a failing hydraulic valve lifter about 5 yrs ago on a previous Chimaera 400, it could be that. You have to take off the plenum, rockers, inlet head and valley gasket to expose them. I could push the plunger in with my finger.
I just changed the one, being a skinflint, but with only 60k miles on it, the others were actually fine, no 'dishing.' If it is that, they're not pricey:
https://racetechdirect.co.uk/car-parts/engine/engi...
Probably even cheaper elsewhere.
I just changed the one, being a skinflint, but with only 60k miles on it, the others were actually fine, no 'dishing.' If it is that, they're not pricey:
https://racetechdirect.co.uk/car-parts/engine/engi...
Probably even cheaper elsewhere.
I’ve been chasing a similar sounding ticking noise for a while.
Initially I was convinced that it was an exhaust manifold, so refitted the manifolds and later upgraded to ACT SS manifolds, but the ticking was still there, so I’m now convinced it isn’t the manifolds.
I then looked at the rocker gear and lifters. Checked them all cleaned them up and then set the preload twice, the second time with adjustable push rods as I couldn’t set it correctly with shims. This did reduce the ticking, but it was still there and recently seems to be getting worse again. I’ve also changed the serp belt, tensioner pulley and PAS pump pulley, which made no difference. May be I’m overly conscious of the noise and should just live with it, but it does drive me nuts, especially when sitting in traffic at idle, when its the most noticeable.
Anyway, I just watched a rebuild series on you tube, where the guy had a bad ticking / tapping sound on start-up after a full rebuild. The diagnosis starts at episode 14. https://www.youtube.com/watch?v=c5U3xSsi508&li...
After a number of attempts to fix the problem it turned out to be poor quality aftermarket lifters which were loosing compression. So I’m starting to wonder if that could be a more common issue.
Now planning to strip it down again to have another look and recheck all the lifters. I’ve also got a couple of other upgrades planned so will be taking off the heads and sump for a more thorough engine health check.
Initially I was convinced that it was an exhaust manifold, so refitted the manifolds and later upgraded to ACT SS manifolds, but the ticking was still there, so I’m now convinced it isn’t the manifolds.
I then looked at the rocker gear and lifters. Checked them all cleaned them up and then set the preload twice, the second time with adjustable push rods as I couldn’t set it correctly with shims. This did reduce the ticking, but it was still there and recently seems to be getting worse again. I’ve also changed the serp belt, tensioner pulley and PAS pump pulley, which made no difference. May be I’m overly conscious of the noise and should just live with it, but it does drive me nuts, especially when sitting in traffic at idle, when its the most noticeable.
Anyway, I just watched a rebuild series on you tube, where the guy had a bad ticking / tapping sound on start-up after a full rebuild. The diagnosis starts at episode 14. https://www.youtube.com/watch?v=c5U3xSsi508&li...
After a number of attempts to fix the problem it turned out to be poor quality aftermarket lifters which were loosing compression. So I’m starting to wonder if that could be a more common issue.
Now planning to strip it down again to have another look and recheck all the lifters. I’ve also got a couple of other upgrades planned so will be taking off the heads and sump for a more thorough engine health check.
I’d use a long screwdriver with one end pressed to my ear and the other end pressed on the engine in various places until you isolate where the sounds coming from.
Personally I’d put some injector cleaner/ lube in the fuel as injectors can tap quite loudly and see what difference that makes. You’d be surprised!
I used to think I could hear tappet type noises and often tried to isolate it yet some days the sound seemed to move around.
It was noisy injectors solved by periodically adding Injector cleaner.
It’s worth doing just to discount this often forgotten area.
After that I’d add a litre of 20/50 oil and see what that does.
Hi lift cams will introduce more cam noise as a matter of fact on old engines and we use a thinner oil which overall is better for the engine but can result in a looser sounding engine at lower revs.
A dab of classic thicker mineral oil added to a 10/40 semi synthetic oil can help that tappet sound.
I never use 20/50 alone as it robs the engine of hp ( takes longer to spin up ) it’s too thick imho but if you are a cruiser and never over stress the engine adding 20/50 does make the top end quieter in my experience.
It’s probably a lifter but these two cheap fixes are worth doing before pulling it apart.
Personally I’d put some injector cleaner/ lube in the fuel as injectors can tap quite loudly and see what difference that makes. You’d be surprised!
I used to think I could hear tappet type noises and often tried to isolate it yet some days the sound seemed to move around.
It was noisy injectors solved by periodically adding Injector cleaner.
It’s worth doing just to discount this often forgotten area.
After that I’d add a litre of 20/50 oil and see what that does.
Hi lift cams will introduce more cam noise as a matter of fact on old engines and we use a thinner oil which overall is better for the engine but can result in a looser sounding engine at lower revs.
A dab of classic thicker mineral oil added to a 10/40 semi synthetic oil can help that tappet sound.
I never use 20/50 alone as it robs the engine of hp ( takes longer to spin up ) it’s too thick imho but if you are a cruiser and never over stress the engine adding 20/50 does make the top end quieter in my experience.
It’s probably a lifter but these two cheap fixes are worth doing before pulling it apart.
Edited by Classic Chim on Wednesday 14th June 10:39
Edited by Classic Chim on Wednesday 14th June 11:04
Great advice, thanks. I will get some cleaner and run that through before doing any stripping down. I'm also going to give the stethascope approach a go too as I've seen that done before and find it fascinating.
Ref. bad lifters: I had a really good/ honest chat with a well known supplier today and the reality is that globally, hydraulic lifters for this engine are poorly made regardless of where you buy them from. The original, and best, are no longer available anywhere. The Chinese/ Korean ones are the ones you get even if they're branded something else, and they're simply a mixed bag. None come with the correct machined groove on the bottom that allow the lifter to rotate properly. Some will simply be bad. Its random.
My plan is to check through the pretty comprehensive history I have on the car to see if they've changed the cam at some point as they probably swapped out the lifters with new ones that could very well be lesser units than the originals. I'm going to buy a slack handful of lifters and, assuming the cleaner solution doesn't work, open up the top end and look at replacing any ones that aren't to tolerance. I'm not going to just arbitrarily replace them all as some might be originals in which case I'd be swapping out good ones for randomly bad ones. I'll also be examining the cam while I'm at it.
Ref. bad lifters: I had a really good/ honest chat with a well known supplier today and the reality is that globally, hydraulic lifters for this engine are poorly made regardless of where you buy them from. The original, and best, are no longer available anywhere. The Chinese/ Korean ones are the ones you get even if they're branded something else, and they're simply a mixed bag. None come with the correct machined groove on the bottom that allow the lifter to rotate properly. Some will simply be bad. Its random.
My plan is to check through the pretty comprehensive history I have on the car to see if they've changed the cam at some point as they probably swapped out the lifters with new ones that could very well be lesser units than the originals. I'm going to buy a slack handful of lifters and, assuming the cleaner solution doesn't work, open up the top end and look at replacing any ones that aren't to tolerance. I'm not going to just arbitrarily replace them all as some might be originals in which case I'd be swapping out good ones for randomly bad ones. I'll also be examining the cam while I'm at it.
Have a good look at the rocker tips too, they have been known to come off but I'd guess the noise would be worse.
I dont think the valvetrain tolerances were that great when these engines were built, lifter pre load etc can be all over the place.
Some report using a 10/40 semi synthetic oil can quiten things down as mentioned above.
Maybe it's just a case of some wear on the cam which are known to be made of chocolate and in most cases worn out by 60k miles.
Did you speak to an engine builder or just a parts supplier?
I would say having a chat with someone like V8D or Powers may benefit you as these guys must have a lot of experience in the aftermarket parts.
Worth a call if you can't find anything yourself but be prepared to maybe spend some money!
I dont think the valvetrain tolerances were that great when these engines were built, lifter pre load etc can be all over the place.
Some report using a 10/40 semi synthetic oil can quiten things down as mentioned above.
Maybe it's just a case of some wear on the cam which are known to be made of chocolate and in most cases worn out by 60k miles.
Did you speak to an engine builder or just a parts supplier?
I would say having a chat with someone like V8D or Powers may benefit you as these guys must have a lot of experience in the aftermarket parts.
Worth a call if you can't find anything yourself but be prepared to maybe spend some money!
I've used 10W/40 semi synthetic in all my TVRs except for the Cerbera 4.5. Never had a Rover V8 let go (that's 3 x Chimaeras and a Griff since 2001). Several specialists, including a former TVR agent, reckon it's all the Rover V8 needs. Quite old spec engineering basically.
If you've modified it for even more power (turbo / supercharger) or added solid lifters and different rockers, or a regular track day user, maybe.
If you've modified it for even more power (turbo / supercharger) or added solid lifters and different rockers, or a regular track day user, maybe.
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