Ticking/tapping below 2000 on over-run

[taylormj4]

As the title, the noise is light ticking or tapping on over-run below 2000rpm, coming from the engine bay.

Shouldn't be exhaust manifold gaskets as just had a chassis refurb so they have recently been off and replaced. Also just been serviced.

Otherwise, am I looking at the cam area / followers / push rods ?

Thanks.

[roseytvr]

I would check the manifold bolts haven't come loose. I have rigged up a stethoscope with garden hose on the end for listening in the engine bay, you will soon find the area the noise is coming from

[carsy]

Is it a 5ltr. If so have a word with TVR Beaver. Pretty sure his noise, described as chattering on overrun was little ends.

[TVR Beaver]

Sounded more like a bag of ball bearings in oil being shuck up at about 1300 rpm

didn't do it when cold, only when hot... first noticed at 90 deg but over time it started doing it as low as 70 deg...
Pistons changed and noise has gone (for now)

On inspecting the small ends there was little to see.. only thing I did notice was the holes both sides of the piston were slightly out of line with each other (is this because 500 pistons are cut off?)... so feeding the pin in, it appeared quite a good fit when in both sides... however put it in one side only and there was a bit of play with all the oil totaly washed out (and I do mean a bit!).. so may be when hot the pistons change shape and the holes come onto the same centre line.. and then you get the slight play and noise... TBH with oil in there even with the pin in one side only, it felt very nice indeed...
If it is this (and I hope it's not) I'd not be too bothered... just one of thoes noises you learn to live with anyway your profile says 4.5... I do know of two 4.5's that have done this... but at least 50% of the 500 tend to do it so much more in the 500 camp

Edited by TVR Beaver on Wednesday 14th August 23:17

[marks3drtaz]

I spent many days looking for this fault and stripped my engine 4 times, I found that the 2000 rpm drop down rattle is the cam tapping against the locking plate. I presume you have a serp engine as this not fitted to pre serp and they do not suffer the same problem, I confirmed the problem by fitting a spring washer between the cam and locking plate and the noise went. Not an ideal solution and I did remove afterwards as I did not want a bits of worn washer in my engine and I was going to have machined a thicker locking plate but never got round to it as no harm is being done. I would not worry about it as the solution would be unproven an the cam seems happy with a few mm end float.

mark

[fatboychim]

marks3drtaz said:

I spent many days looking for this fault and stripped my engine 4 times, I found that the 2000 rpm drop down rattle is the cam tapping against the locking plate. I presume you have a serp engine as this not fitted to pre serp and they do not suffer the same problem, I confirmed the problem by fitting a spring washer between the cam and locking plate and the noise went. Not an ideal solution and I did remove afterwards as I did not want a bits of worn washer in my engine and I was going to have machined a thicker locking plate but never got round to it as no harm is being done. I would not worry about it as the solution would be unproven an the cam seems happy with a few mm end float.

mark

That sounds like an excellent diagnosis, thanks for taking the time to prove it.
Mine has always done this and I suspected worn push rods, so when I changed my cam I renewed them, guess what, it was worse! So I then assumed it to be the metal timing gear I had installed but the cam shuttling sounds on the money.

I'm pretty sure it has become more noticeable over the years though, maybe the locking plate wears over time.

[v8 racing]

Tvr beaver are you still running your original cam plate?

[TVR Beaver]

missed this... yes I am... why do you ask??

[Chilliman]

TVR Beaver said:

Sounded more like a bag of ball bearings in oil being shuck up at about 1300 rpm

didn't do it when cold, only when hot... first noticed at 90 deg but over time it started doing it as low as 70 deg...
Pistons changed and noise has gone (for now)

On inspecting the small ends there was little to see.. only thing I did notice was the holes both sides of the piston were slightly out of line with each other (is this because 500 pistons are cut off?)... so feeding the pin in, it appeared quite a good fit when in both sides... however put it in one side only and there was a bit of play with all the oil totaly washed out (and I do mean a bit!).. so may be when hot the pistons change shape and the holes come onto the same centre line.. and then you get the slight play and noise... TBH with oil in there even with the pin in one side only, it felt very nice indeed...
If it is this (and I hope it's not) I'd not be too bothered... just one of thoes noises you learn to live with anyway your profile says 4.5... I do know of two 4.5's that have done this... but at least 50% of the 500 tend to do it so much more in the 500 camp

Edited by TVR Beaver on Wednesday 14th August 23:17

This! I had the same (as John knows), drove me up the wall I was advised that it's not uncommon on a 500, and that if I could live with it it wasn't something that needed to be fixed (they all do that sir). I have a different engine in the car now (for other reasons), but had the 'clatter' been the only issue I would have had to have got it remedied, living with it wasn't an option

Chilli

[macdeb]

fatboychim said:

That sounds like an excellent diagnosis, thanks for taking the time to prove it.
Mine has always done this and I suspected worn push rods, so when I changed my cam I renewed them, guess what, it was worse! So I then assumed it to be the metal timing gear I had installed but the cam shuttling sounds on the money.

I'm pretty sure it has become more noticeable over the years though, maybe the locking plate wears over time.

Can also be because correct preload over all valves not possible due to differing valve heights [was on my 2nd Griff]

[fatboychim]

Chilliman said:

This! I had the same (as John knows), drove me up the wall I was advised that it's not uncommon on a 500, and that if I could live with it it wasn't something that needed to be fixed (they all do that sir). I have a different engine in the car now (for other reasons), but had the 'clatter' been the only issue I would have had to have got it remedied, living with it wasn't an option

Chilli

Chilli, you listened to mine at Bedford and said it was nothing like the noise you had experienced. I think there are 2 separate issues going on here.
Some people talk of tapping/ rattle at around 2k rpm on drop off and others talk of a clatter at about 1200 rpm just before settling to idle.
I've had a quick look through the multiple threads on this and most of the 500 boys seem to be in 1200 rpm range whereas 400/450 seem to crop up in the 2k range, maybe one thing is piston chatter and the other is lifter depressurisation/cam shuttle noise.
Mine is a 400 and is noisy around 2k when not under load.
What do you think, decent theory or cobblers?

[fatboychim]

macdeb said:

Can also be because correct preload over all valves not possible due to differing valve heights [was on my 2nd Griff]

Agreed, when I fitted my cam, pre loads were set to best case scenario.

[macdeb]

fatboychim said:

macdeb said:

Can also be because correct preload over all valves not possible due to differing valve heights [was on my 2nd Griff]

Agreed, when I fitted my cam, pre loads were set to best case scenario.

Did I read somewhere on here that someone got around this by using adjustable pushrods?

[Chilliman]

fatboychim said:

Chilliman said:

This! I had the same (as John knows), drove me up the wall I was advised that it's not uncommon on a 500, and that if I could live with it it wasn't something that needed to be fixed (they all do that sir). I have a different engine in the car now (for other reasons), but had the 'clatter' been the only issue I would have had to have got it remedied, living with it wasn't an option

Chilli

Chilli, you listened to mine at Bedford and said it was nothing like the noise you had experienced. I think there are 2 separate issues going on here.
Some people talk of tapping/ rattle at around 2k rpm on drop off and others talk of a clatter at about 1200 rpm just before settling to idle.
I've had a quick look through the multiple threads on this and most of the 500 boys seem to be in 1200 rpm range whereas 400/450 seem to crop up in the 2k range, maybe one thing is piston chatter and the other is lifter depressurisation/cam shuttle noise.
Mine is a 400 and is noisy around 2k when not under load.
What do you think, decent theory or cobblers?

Sounds spot on Andy , my clatter was at a couple of hundred revs above tickover to just before settling back to tickover, so every time I stopped, junctions, roundabouts, traffic lights etc it sounded like some barsteward was juggling bags of marbles under the bonnet

[phazed]

macdeb said:

Did I read somewhere on here that someone got around this by using adjustable pushrods?

I used adjustables on my 4.6.

[macdeb]

Chilliman said:

Sounds spot on Andy , my clatter was at a couple of hundred revs above tickover to just before settling back to tickover, so every time I stopped, junctions, roundabouts, traffic lights etc it sounded like some barsteward was juggling bags of marbles under the bonnet

That's the one I had Chilli, Bloody annoying and for me shouldn't be there.

[macdeb]

phazed said:

I used adjustables on my 4.6.

A Ha, Thanks Peter, new I'd read it somewhere. Was it because of the preload issue?

[phazed]

macdeb said:

phazed said:

I used adjustables on my 4.6.

A Ha, Thanks Peter, new I'd read it somewhere. Was it because of the preload issue?

Yes, just that.

My 5.5 has group B adjustable steel rockers to eliminate the shimming guesswork.