Discussion
Okay, I have been told by a respected specialist 'its nothing to worry about' and I believe him, BUT, having put up with pin/piston noise and spent a fortune having the engine rebuilt 3500 miles ago (by one of the recognized top 3) I want to enjoy the sound of my engine. Okay I know I am being paranoid and will be told by the PH massive to just get on and enjoy the car, but the tapping on tick over is spoiling it for me.
Its had a new cam (Powers 885), new old stock lifters, new (genuine LR) rockers and new old stock rocker shaft and adjustable push rods fitted 10000 miles ago, together with cam shaft bearings.
Then a few thousand mile later a head gasket went, so had both replaced with a very light skim.
After this the ticking on over run started, that was the pin/piston wear problem (probably the extra compression accelerated this)
All sorted by a total rebuild, new pistons, top hat liners, cross bolting, internal crank balance, the works....
All great 300hp and 350lbft (little piston slap when cold).
But just recently a tapping has started when warmed up. I have been told its not manifold (by the previously mentioned specialist) and I think I agree. He said things do settle after a while. (It wasn't him who rebuilt the engine by the way)
Its difficult to tell where its coming from (even with the belt of) but it sounded slightly louder on the right.
So off with rocker cover off, there is nothing obviously wrong ( no missing pads or lose lock nuts on the push rods)
When running with the rocker cover off the noise seems to come form the middle (ish) but I cant pin it to one rocker.
Shall I try inserting a 5 thou feeler between rocker and valve whilst running ?
Or will this (if I can get it in) cause piston valve collision (cant be that close surely)?
I have tried pushing down on each rocker, but this didn't make any difference.
Any thoughts how to identify the culprit ?
Its had a new cam (Powers 885), new old stock lifters, new (genuine LR) rockers and new old stock rocker shaft and adjustable push rods fitted 10000 miles ago, together with cam shaft bearings.
Then a few thousand mile later a head gasket went, so had both replaced with a very light skim.
After this the ticking on over run started, that was the pin/piston wear problem (probably the extra compression accelerated this)
All sorted by a total rebuild, new pistons, top hat liners, cross bolting, internal crank balance, the works....
All great 300hp and 350lbft (little piston slap when cold).
But just recently a tapping has started when warmed up. I have been told its not manifold (by the previously mentioned specialist) and I think I agree. He said things do settle after a while. (It wasn't him who rebuilt the engine by the way)
Its difficult to tell where its coming from (even with the belt of) but it sounded slightly louder on the right.
So off with rocker cover off, there is nothing obviously wrong ( no missing pads or lose lock nuts on the push rods)
When running with the rocker cover off the noise seems to come form the middle (ish) but I cant pin it to one rocker.
Shall I try inserting a 5 thou feeler between rocker and valve whilst running ?
Or will this (if I can get it in) cause piston valve collision (cant be that close surely)?
I have tried pushing down on each rocker, but this didn't make any difference.
Any thoughts how to identify the culprit ?
phazed said:
Sounds like an exhaust manifold gasket.
A minor blow can be hard to identify and it will increase under load.
Try having a listen with a bit of tube around each joint.
Happy to have a listen sometime.
I have done the hose trick and even a stethoscope and endoscope (looking for tell tail carbon from a blow. A minor blow can be hard to identify and it will increase under load.
Try having a listen with a bit of tube around each joint.
Happy to have a listen sometime.
Considering rockers again, I have the nearside cover off at the moment (was easiest.Stethoscope is good but you can only put it on stationary parts and noise is loudest on rear and centre post bolt heads. Hose is good because you don't have to touch anything and it confirms rear rockers are louder, but no specific one.
Extra (experienced) ears would be most welcome indeed Peter.
When are you around ? (Dorking way aren't you ?)
phazed said:
Sounds like an exhaust manifold gasket.
Exactly what I thought when I read the OP's post. My MGB V8 has suffered with this over the years with tubular manifold which go walk-abouts easily and cause a ticking noise at the drop of a hat. My money's on this as the cause. I get an exhaust smell inside the car when stationary if a gasket is leaking.Sorry Wedger, but I agree with Distressed of Dorking et al.
I have had endless exhaust manifold issues.
I have had the gaskets replaced three times this year, by an increasingly frustrated Mat Smith, TVR Guru of my parish.
Then, when he took the engine out recently, he spotted a half inch crack on the underside of one of the manifolds and welded it up. Big shouts of "Yessssss!!"
In the past I have also had the classic exhaust leak both sides - where the 4 pipes go into one. You won't be able to see it, but you will be able to hear it with the old rubber hose trick (so loved by the Gestapo).
And lastly, you can get a slight leak where the manifold joins the Y piece, and as your noise started immediately after the engine had been hokey-cokeyed, that's one of the first places i would check.
I guess what I am saying is that there are several opportunities for exhaust leaks, and hence "ticking", apart from the manifold gaskets.
Go visit the Dorking Dervish - he loves nothing better than an excuse to abandon his desk and hit the garage. You will be doing him a favour.....
I have had endless exhaust manifold issues.
I have had the gaskets replaced three times this year, by an increasingly frustrated Mat Smith, TVR Guru of my parish.
Then, when he took the engine out recently, he spotted a half inch crack on the underside of one of the manifolds and welded it up. Big shouts of "Yessssss!!"
In the past I have also had the classic exhaust leak both sides - where the 4 pipes go into one. You won't be able to see it, but you will be able to hear it with the old rubber hose trick (so loved by the Gestapo).
And lastly, you can get a slight leak where the manifold joins the Y piece, and as your noise started immediately after the engine had been hokey-cokeyed, that's one of the first places i would check.
I guess what I am saying is that there are several opportunities for exhaust leaks, and hence "ticking", apart from the manifold gaskets.
Go visit the Dorking Dervish - he loves nothing better than an excuse to abandon his desk and hit the garage. You will be doing him a favour.....
What oil are you using.
I tried a slightly thicker viscosity oil and contrary to popular belief my top end got noisy.
Changed the oil back to the specked oil of my engine builder, did a trackday which I think helped pump up the lifters and it's been very quiet ever since.
On the thicker oil I'd get a slight rattling on shut off as the engine was dropping past 1700 revs.
I first thought this was cam follower tapping, but after much advice and some reading I came to the conclusion it was more like little end rattle, the little ends are known to suffer from lack of lubricant, I think the thicker oil couldn't get through and caused even more starvation.
I put the thinner 10/40 semi synth back in and it quietened down.
It's more likely a gasket or exhaust leak unless you can clearly hear the metallic tapping.
The hose thing or even a screw driver touching the metal surfaces near the noise can show up odd knocking at tapping quiet well.
Has the engine been stood awhile, just wondering if you have a slight bleed down on a lifter.
I tried a slightly thicker viscosity oil and contrary to popular belief my top end got noisy.
Changed the oil back to the specked oil of my engine builder, did a trackday which I think helped pump up the lifters and it's been very quiet ever since.
On the thicker oil I'd get a slight rattling on shut off as the engine was dropping past 1700 revs.
I first thought this was cam follower tapping, but after much advice and some reading I came to the conclusion it was more like little end rattle, the little ends are known to suffer from lack of lubricant, I think the thicker oil couldn't get through and caused even more starvation.
I put the thinner 10/40 semi synth back in and it quietened down.
It's more likely a gasket or exhaust leak unless you can clearly hear the metallic tapping.
The hose thing or even a screw driver touching the metal surfaces near the noise can show up odd knocking at tapping quiet well.
Has the engine been stood awhile, just wondering if you have a slight bleed down on a lifter.
Boosted LS1 said:
jojackson4 said:
Fill the manifolds with water that will tell you if and where there's a leak
Interesting, can you elaborate on this?[/quoteIf your pulling the manifold to cut it up to mend something that may not be there
Before cutting fill with water and stand back and watch if you go damp /moist
You have a problem and it tells you where it is
If it stays dry no problem and no cutting giveing you 3 hours more in the pub
Nothing wrong with water, me and a mate was about 12/13 years old respectively, put a big knee dink in the tank of our Gilera 50 moped crosser 
Heard a story so tried it,
Blocked the filler cap and made it fairly air tight,
Half filled it with water, turned the tank upside down put a pushbike pump nozzle on the fuel on/off pipe and pumped like buggery, boom, it worked.
No crease line or anything, we was stoked
Sorry to digress.
It can only be exhaust/gasket leaks or something not quite right in the heads valve train.
Adjustable rockers , maybe ones moved slightly.
Heard a story so tried it,
Blocked the filler cap and made it fairly air tight,
Half filled it with water, turned the tank upside down put a pushbike pump nozzle on the fuel on/off pipe and pumped like buggery, boom, it worked.
No crease line or anything, we was stoked
Sorry to digress.
It can only be exhaust/gasket leaks or something not quite right in the heads valve train.
Adjustable rockers , maybe ones moved slightly.
Hi all thanks for the interest.
The ticking is not on over run, its there all the time (on tick over at least - difficult to hear at revs).
It ok cold but appears as it warms up (not what you get with a manifold leak - so I have read)
I have tried 20W/50, 10W/40 and now on Vavlvoline VR1 20W/50, no difference.
I am going to try to pop over to Peter's this morning. I will give him a ring in a minute or 2
The ticking is not on over run, its there all the time (on tick over at least - difficult to hear at revs).
It ok cold but appears as it warms up (not what you get with a manifold leak - so I have read)
I have tried 20W/50, 10W/40 and now on Vavlvoline VR1 20W/50, no difference.
I am going to try to pop over to Peter's this morning. I will give him a ring in a minute or 2
Right an up date.
Peter (phazed) kindly lent his ear to the problem over a nice cup of tea (thanks Peter) and agreed the noise sounded mechanical, but commented how quiet he thought my engine actually was.
I guess most of the while I have been listening to it in my garage where everything sounds louder anyway.
I may whip the other rocker cover off when I have nothing else to do (ha ha), but I now know I am being super critical.
Thanks again for your time Peter, and the chat about all things RV8
Peter (phazed) kindly lent his ear to the problem over a nice cup of tea (thanks Peter) and agreed the noise sounded mechanical, but commented how quiet he thought my engine actually was.
I guess most of the while I have been listening to it in my garage where everything sounds louder anyway.
I may whip the other rocker cover off when I have nothing else to do (ha ha), but I now know I am being super critical.
Thanks again for your time Peter, and the chat about all things RV8
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