Strange top end rattle?
Discussion
I’ve been aware of this on the car for some time now… I think it started a couple of years ago around the time the cam was done… although it’s got progressively more noticeable as times gone on..
initially only doing it at say 90 deg when the fans come on.. but now it’s doing it at 80 deg normal running temp?…
Rob at V8D re-did the cam early last year but it didn’t alter the sound much… So it’s done it with 2 new cams, new hydraulic adjusters and new chains…
Basically, when the engine is cold you don’t get it.. but as it warms up to 80 plus deg or so, you start to hear it…
It does it just before returning to tickover say at 1200/1400 RPM?.. so at tickover it’s not there.. rev the engine it’s fine.. but let the rev’s drop back to tickover and it goes thru a band at 1200 RPM where it rattles?.. sounds like a bag of marbles for want of a better way to describe it?.. back to tickover and it’s gone?... and if you hold it at 1200 it don't do it?.. so only as the RPM is dropping?
I have close to 50K on the engine and Rob said he could find no wear on things when it was in bit’s… think it’s top end??
Any one else had this??.. any thoughts?..
Could be rockers…
or pre-load needs re-setting…
what do small ends sound like and when do they make a noise??
initially only doing it at say 90 deg when the fans come on.. but now it’s doing it at 80 deg normal running temp?…
Rob at V8D re-did the cam early last year but it didn’t alter the sound much… So it’s done it with 2 new cams, new hydraulic adjusters and new chains…
Basically, when the engine is cold you don’t get it.. but as it warms up to 80 plus deg or so, you start to hear it…
It does it just before returning to tickover say at 1200/1400 RPM?.. so at tickover it’s not there.. rev the engine it’s fine.. but let the rev’s drop back to tickover and it goes thru a band at 1200 RPM where it rattles?.. sounds like a bag of marbles for want of a better way to describe it?.. back to tickover and it’s gone?... and if you hold it at 1200 it don't do it?.. so only as the RPM is dropping?
I have close to 50K on the engine and Rob said he could find no wear on things when it was in bit’s… think it’s top end??
Any one else had this??.. any thoughts?..
Could be rockers…
or pre-load needs re-setting…
what do small ends sound like and when do they make a noise??
I have something very similar...chain type rattle as the revs fall below 2000 rpm on overrun, not there under load or sustained revs. Asked the question here http://www.pistonheads.com/gassing/topic.asp?t=901...
As usual the finger was pointed to manifolds but I'm familiar with that sound and in fact have since had a manifold gasket done as a bolt came loose and started to blow, which was a different sound altogether... new gasket and the chain rattle is still there as the revs fall.
The good folk at Hexham HC said all 500's do that sir due to high cam lift and claimed that they'd knew of a chap, who had a new cam and chain set in an attempt to cure it without success. (unless that was you?)
I'm still considering a possible cam change at some point and hoping the noise would be cured as a side benefit ...my car is coming up to 45K on the original cam and still feels strong to me, but I would like to get it on a set of rollers to see how healthy it actually is.
In the mean time I'll watch this thread with interest
As usual the finger was pointed to manifolds but I'm familiar with that sound and in fact have since had a manifold gasket done as a bolt came loose and started to blow, which was a different sound altogether... new gasket and the chain rattle is still there as the revs fall.
The good folk at Hexham HC said all 500's do that sir due to high cam lift and claimed that they'd knew of a chap, who had a new cam and chain set in an attempt to cure it without success. (unless that was you?)
I'm still considering a possible cam change at some point and hoping the noise would be cured as a side benefit ...my car is coming up to 45K on the original cam and still feels strong to me, but I would like to get it on a set of rollers to see how healthy it actually is.
In the mean time I'll watch this thread with interest
Edited by gammav on Sunday 10th July 23:37
If it really does sound like a chain, if it's on the overrun, and if it's a serp, there is a possibility the cam chain is just touching the inside of the timing cover. When using duplex gears/chains (which I think the 500 does), everything gets a bit close to the internal webs of the casting where it receives the dizzy. So much so that a flat generally has to be ground onto the casting to allow clearance.
Can't remamber without one in front of me whether it's the cam sprocket itself that's closest or whether it's a run of the chain but, if the latter, then there will be scope for more deflection on overrun and thus more scope for contact (the deflection will increases over time with wear too)
Can't remamber without one in front of me whether it's the cam sprocket itself that's closest or whether it's a run of the chain but, if the latter, then there will be scope for more deflection on overrun and thus more scope for contact (the deflection will increases over time with wear too)
May be not a chain rattle, but reading your previous post, I think we are talking the same thing... It is hard to describe... as I say, more like a bag of marbles being shaken for a second or so... But it's in time with the engine so nothing vibrating or loose as Dave suggests?... I'm running 15/50 Silcolene Pro S so that should be okay...
But in the last 5K miles.. it's had 2 new cams, 2 new chains and sprocketts.. and 2 new sets of adjusters... and it's been there both times.. so can't be related to these parts....
Cam retaining plate?.. don't know if I have one fitted or not... Would need Rob on that one...
I did wonder about the weights in the dizzy and if they could transmit this type of noise??
But in the last 5K miles.. it's had 2 new cams, 2 new chains and sprocketts.. and 2 new sets of adjusters... and it's been there both times.. so can't be related to these parts....
Cam retaining plate?.. don't know if I have one fitted or not... Would need Rob on that one...
I did wonder about the weights in the dizzy and if they could transmit this type of noise??
Edited by TVR Beaver on Monday 11th July 08:12
Hi Guys
Sorry to come over from the dark side Chimaera 450, I have the same sound at the same revs and under the same conditions. I've done the listening stick thing around the engine and everything else sounds fine and smooth but when reving and letting it fall to idle I get a distinct rattle. Maybe they all do the sir??
Sorry to come over from the dark side Chimaera 450, I have the same sound at the same revs and under the same conditions. I've done the listening stick thing around the engine and everything else sounds fine and smooth but when reving and letting it fall to idle I get a distinct rattle. Maybe they all do the sir??
TVR Beaver said:
and 2 new sets of adjusters...
What adjusters are you talking about John? I can only think you mean shims for the pedestals?I don't think the cam retaining plate is an issue at all since you are still running with the dizzy drive retaining the cam (it isn't going anywhere!).
Since you have changed cam / rocker / follower combination the valve train geometry may have changed just enough for the pushrods to catch on the holes cast in the heads - easy enough just inspect the pushrods for signs of scoring. Even a little lash caused by a lazy follower might be enough to just allow a rod to rattle against the casting and enough pushrods have score marks anyway.
I don't buy into the any clearance issues with intermediate timing cover & duplex chains, it's obviously something that has changed in your engine and that hasn't AFIK.
When I say adjusters.. I mean the hydraulic lifters.. push rods and holes in heads.. may be?.. but it does appear to come from both banks.. and I think towards to front of the engine?
But what ever it is has become more noticable over the past few thousand miles or so... only when hot.. and only on reducing rev's??
Was out with Chris52 yesterday for a blast.. his engine is at 75K and not a trace of this sound at all?
What does it sound like if the pre-load is not right or loose?.. or may be the lifters loose a bit of pressure as it comes back to tickover?.. but that said, why would it not do it at tickover?... all very strange....
..
Have you got a std cam and hydraulic adjusters?.. makes you think about Dave's comments above if after market ones allow the push rod's to wonder a bit more off centre than std ones?...
But what ever it is has become more noticable over the past few thousand miles or so... only when hot.. and only on reducing rev's??
Was out with Chris52 yesterday for a blast.. his engine is at 75K and not a trace of this sound at all?
What does it sound like if the pre-load is not right or loose?.. or may be the lifters loose a bit of pressure as it comes back to tickover?.. but that said, why would it not do it at tickover?... all very strange....
..
ellesmereFNC said:
Hi Guys
Sorry to come over from the dark side Chimaera 450, I have the same sound at the same revs and under the same conditions. I've done the listening stick thing around the engine and everything else sounds fine and smooth but when reving and letting it fall to idle I get a distinct rattle. Maybe they all do the sir??
James.. joint the party.. no problem.. may be worth posting on the Chim forum see whats suggested there also but would have thought most look at the Griff site anyway... I know I'm always on the Chim side (mostley trying to wind them up )Sorry to come over from the dark side Chimaera 450, I have the same sound at the same revs and under the same conditions. I've done the listening stick thing around the engine and everything else sounds fine and smooth but when reving and letting it fall to idle I get a distinct rattle. Maybe they all do the sir??
Have you got a std cam and hydraulic adjusters?.. makes you think about Dave's comments above if after market ones allow the push rod's to wonder a bit more off centre than std ones?...
Front of engine?? Cat rattling? - I've had it before on one car (not a TVR), although not sure I'd have described it as being as loud as a bag of marbles.
http://www.rangerovers.net/repairdetails/catalytic...
Wandering back to 'the dark side now'.
http://www.rangerovers.net/repairdetails/catalytic...
Wandering back to 'the dark side now'.
I had it on my last Griff' 500 and a freind had the same, [rattle on overrun when hot] drove us mad trying to find out what it was. Took it to several places up and down the country and was given allsorts of differing diagnosis.
Anyhow, couldn't get the preload within correct tolerance on all valves, some were in and some out
Then with the help of pedestal shims some got within but then threw others out as the shims raise
the whole rocker assembly. Then noticed that when a steel rule was held over valve tops there was quite a difference in the heights so made it impossible to get preload correct over all valves.
So could be have heads off and valves looked at.
or maybe cheaper fix could be adjustable pushrods.
Anyhow, couldn't get the preload within correct tolerance on all valves, some were in and some out
Then with the help of pedestal shims some got within but then threw others out as the shims raise
the whole rocker assembly. Then noticed that when a steel rule was held over valve tops there was quite a difference in the heights so made it impossible to get preload correct over all valves.
So could be have heads off and valves looked at.
or maybe cheaper fix could be adjustable pushrods.
Seems to be a common problem. My Griff 500 used to do it too - exactly the same symptoms as described by the OP. I couldnt pin it down to any one specific item but having had the motor apart recently I suspect that it was the chain on over-run as has been previously described in this thread. The duplex chains aren't tight on the cam and crank wheels when new and have no adjuster so are only taut as the crank pulls the cam. God alone knows what happens in there on the over-run. Put 50,000 miles of wear on it as well and its probable that this is a contributary factor if not the sole cause. I couldnt find any wear marks on the inside of the timing cover though so dont think its chain contact with the cover.
Havent had mine running for any length of time since nailing it all back together to tell if its been sorted during the rebuild. Wouldnt want to put money on it though.
Ive rebuilt mine with new cam, followers and adjustable pushrods so can report back once Ive got it MOT'd and a few miles on it if anyone would be interested?
I think Hexham HC are spot on - they all do that sir.
Havent had mine running for any length of time since nailing it all back together to tell if its been sorted during the rebuild. Wouldnt want to put money on it though.
Ive rebuilt mine with new cam, followers and adjustable pushrods so can report back once Ive got it MOT'd and a few miles on it if anyone would be interested?
I think Hexham HC are spot on - they all do that sir.
Edited by Marty V8 on Wednesday 13th July 00:18
Marty V8 said:
Seems to be a common problem. My Griff 500 used to do it too - exactly the same symptoms as described by the OP. I couldnt pin it down to any one specific item but having had the motor apart recently I suspect that it was the chain on over-run as has been previously described in this thread. The duplex chains aren't tight on the cam and crank wheels when new and have no adjuster so are only taut as the crank pulls the cam. God alone knows what happens in there on the over-run. Put 50,000 miles of wear on it as well and its probable that this is a contributary factor if not the sole cause. I couldnt find any wear marks on the inside of the timing cover though so dont think its chain contact with the cover.
Havent had mine running for any length of time since nailing it all back together to tell if its been sorted during the rebuild. Wouldnt want to put money on it though.
Ive rebuilt mine with new cam, followers and adjustable pushrods so can report back once Ive got it MOT'd and a few miles on it if anyone would be interested?
I think Hexham HC are spot on - they all do that sir.
Hi Marty... Strange thing is, my chain had done 45K with no issue... since then I've had 2 new chains (now just under 50K) and its done it with both of them.... Did you look and measure your small ends at all?... where they okay??Havent had mine running for any length of time since nailing it all back together to tell if its been sorted during the rebuild. Wouldnt want to put money on it though.
Ive rebuilt mine with new cam, followers and adjustable pushrods so can report back once Ive got it MOT'd and a few miles on it if anyone would be interested?
I think Hexham HC are spot on - they all do that sir.
Edited by Marty V8 on Wednesday 13th July 00:18
Chilliman said:
I have it on good authority that the 500's have a problem with wear between the piston and gudgeon pin, with both piston and pin experiencing wear. This is manifested as the 'clatter' you hear as the revs drop back to tick over. Mine was driving me mad.
So what did you do... new pistons and rods?... Chilliman said:
John, check your mail 
.. Ok.. understood....So, If it was new pistons... do you need new rods also.. or is the problem at the pin to the piston interface? From what people are saying it appears the rods will be okay... so £250 for a set from Power??.. But does not sound like a typical Small end noise to me at all.. ?
Edited by TVR Beaver on Thursday 14th July 11:35
It's seemingly the fit between the piston and the 'pin, so it's entirely possible the small ends are perfectly ok. Con rods I don't believe are affected at all. So, new pistons, new gudgeon pins, and new small end bearings (as a matter of course). I don't know if it's caused by the stroke angle being different on the 500 causing premature wear on these components, or if it's the components themselves (are they same pistons/pins as on other capacity Tivs ?) Would just point out that this is the diagnosis on my engine and may not be the cause of every 500 clatter..... Of course, whilst you've got things apart you might as well ..
Latest on the clatter noise… Talking with a few V8 builders including Power etc…. Sounds like the clatter is due to the lifters loosing pressure as the RPM drops… (got to say the sound does sound very much like that)
This can be due to modern, well flowing and very slippery oils… Clearances on the mains (especially side clearance) allowing it to down pressure slightly on the hydraulic adjuster feed… Reduction in pump pressure (due to wear or again modern oils)… or hydraulic adjuster holes going slightly oval….
Basically nothing to worry about with any of the above…. Sounds good to me
What do we think? I've had a few PM's on this also.. people not wanting to post saying their car has the same issue in case it's a big problem and they are trying to sell... but by the sound of it.. quite a few 500 / 450's have the same sound...
This can be due to modern, well flowing and very slippery oils… Clearances on the mains (especially side clearance) allowing it to down pressure slightly on the hydraulic adjuster feed… Reduction in pump pressure (due to wear or again modern oils)… or hydraulic adjuster holes going slightly oval….
Basically nothing to worry about with any of the above…. Sounds good to me
What do we think? I've had a few PM's on this also.. people not wanting to post saying their car has the same issue in case it's a big problem and they are trying to sell... but by the sound of it.. quite a few 500 / 450's have the same sound...
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