TR6 engine noise ?

[tr6driver]

Hi folks.

 

How much noise do you have from your TR6 engines ?

I ask this because I have some noise from my engine,it sounds like one of the valves are not correct adjusted.

Like tapping noise.

It has an overhauled cylinder head with new valves and guides , and new rocker gear.

The valves are adjusted to the recomended specification,but still there is tapping noise.

The engine have a good oil pressure and equal compression on all cylinders.

On the other hand the engine appear to be healthy , easy to start,very low oil consumption.

 

I have listed some questions:

Can the noise come from worn cam followers or the camshaft chain ?

can the distributor make noise like this?

I have also checked the ignition timing ,that is also correct.

Can it come from the fuel, low octane , 95 ?

Is it posible to do any modification on the rocker gear?

 

Oystein

Edited May 6, 2008 by tr6driver

[PILKIE]

Evening Oystein.

 

Theres lots of things it could be!!

 

Is this noise there on tickover?,when you rev it?,or when you drive it and pull away putting the system under load!??

Your ignition timing may be correct by the book,but it will need adjustment to compensate for low octane fuel!

If you start the car,then turn the distributor a little left then a little right until you get the fastest possible tickover,then back it off,,retard it, just enough to slow the engine a very small amount,this should cure whats called pinking rattle, that happens when you drive the car,especially if you try to pull away in too high a gear,if it still has this pinking,retard it a little more,road test,bit more,etc, till its gone.

I went for a drive in mine to tune it out,adjust it,drive it,adjust it,drive it,till it went and it now ticks over smooth and really pulls well!

 

Dave

[jemgee]

If the car is stationary but you cannot tell what is causing the noise I suggest the old stethoscope trick - a large wooden handled screwdriver agianst the ear and the business end against the various engine components. Make sure you do not have any loose clothing etc flapping around near the engine eg scarf or tie

[tr6driver]

Evening Oystein.

 

Theres lots of things it could be!!

 

Is this noise there on tickover?,when you rev it?,or when you drive it and pull away putting the system under load!??

Your ignition timing may be correct by the book,but it will need adjustment to compensate for low octane fuel!

If you start the car,then turn the distributor a little left then a little right until you get the fastest possible tickover,then back it off,,retard it, just enough to slow the engine a very small amount,this should cure whats called pinking rattle, that happens when you drive the car,especially if you try to pull away in too high a gear,if it still has this pinking,retard it a little more,road test,bit more,etc, till its gone.

I went for a drive in mine to tune it out,adjust it,drive it,adjust it,drive it,till it went and it now ticks over smooth and really pulls well!

 

Dave

 

Hi Dave.

 

When the engine revs on idle the ticking noise is low , but from 1200 rpm and up , and when the engine pulls under load the ticking noise is higher.

Does that mean that my ignition timing is not correct ?

So what you are suggesting is that I only adjust the timing to minimum pinking ,doing it the way you did?

I also have a lumenition electronic contact breaker in the distributor,can that also magnify this problem ?

 

Oystein

[PILKIE]

Evening Oystein.

 

I would suggest that you check the tappet clearances again to be sure! Its easy to miss one or get its position wrong when checking it! Do it step by step as the book says!

One thing I do to see if it IS a worn tappet rocker or pushrod,is,, cover both wings and inner wings,and windscreen with a sheet,make sure its clear of anything like fanblade,alternator! this is to protect it from oil splashes,as you will need to remove the rocker cover. Start the engine,and on low tickover,insert a thin feeler guage into the rocker- pushrod gap,this will take up any wear that might be present,and you will find the one thats ticking when it stops ticking when you insert the guage!! It will destroy the feeler guage,so thats why I use an old set!,and keep my best ones for adjustments!! If you find a worn ticking one,you can carefully adjust it bit by bit,till the ticking stops.

Also get freindly with a local nurse and obtain a stethoscope! for listening to the rocker cover and other engines parts,places for where noises are located!!

Its one of those noises that is almost impossible to diagnose on a forum!! only an experienced person,on hearing it, will be able to say its this or that!

It could be a sticky valve! as it is an overhauled head, one valve could be a little tight,and will loosen up and the tick will dissapear in time!

Keep us up to date.

Dave

[88V8]

Engine stethescope..... stethoscope..... whatever.....

 

http://www.toolsandhardware.co.uk/index.ph...36bc2d3828c94f4

 

and elsewhere no doubt....

[BrianC]

Engine stethescope..... stethoscope..... whatever.....

 

http://www.toolsandhardware.co.uk/index.ph...36bc2d3828c94f4

 

and elsewhere no doubt....

I saw these on an autojumble stall at the Old Warden Shuttleworth Classic Car Show on Sunday for £3 each.

Like a prat, I forgot to go back and buy one (along with other heavier items), before we left - Doh!

[Tom Fremont]

My engine had tappet-type ticking noise off idle both times the cam went bad. This was not detectable at the rockers.

 

Unless great care and diligence is used with non-standard valve train/ cam fitment there is a fair chance of failure.

 

A sure way to check the cam is to remove the sump and inspect the lobes from below

[tr6driver]

Evening Oystein.

 

I would suggest that you check the tappet clearances again to be sure! Its easy to miss one or get its position wrong when checking it! Do it step by step as the book says!

One thing I do to see if it IS a worn tappet rocker or pushrod,is,, cover both wings and inner wings,and windscreen with a sheet,make sure its clear of anything like fanblade,alternator! this is to protect it from oil splashes,as you will need to remove the rocker cover. Start the engine,and on low tickover,insert a thin feeler guage into the rocker- pushrod gap,this will take up any wear that might be present,and you will find the one thats ticking when it stops ticking when you insert the guage!! It will destroy the feeler guage,so thats why I use an old set!,and keep my best ones for adjustments!! If you find a worn ticking one,you can carefully adjust it bit by bit,till the ticking stops.

Also get freindly with a local nurse and obtain a stethoscope! for listening to the rocker cover and other engines parts,places for where noises are located!!

Its one of those noises that is almost impossible to diagnose on a forum!! only an experienced person,on hearing it, will be able to say its this or that!

It could be a sticky valve! as it is an overhauled head, one valve could be a little tight,and will loosen up and the tick will dissapear in time!

Keep us up to date.

Dave

 

Hi

 

Can worn pushrods make this noise ?

Have any of you experienced that ?

 

Øystein

[PILKIE]

Yes thats why I do the trick with the feeler guage!

Hard to describe,>SEE PIC DIAGRAM<,but if the wear is a certain wavy shape on the end of the pushrod,the feeler guage will not totally fill the gap when being set up,there will be a few thou of wear not taken up.This can be enough to cause a ticking tappet!

Fairly common on pushrod engines.

 

 

[tr6driver]

Yes thats why I do the trick with the feeler guage!

Hard to describe,>SEE PIC DIAGRAM<,but if the wear is a certain wavy shape on the end of the pushrod,the feeler guage will not totally fill the gap when being set up,there will be a few thou of wear not taken up.This can be enough to cause a ticking tappet!

Fairly common on pushrod engines.

 

 

 

Very interesting.

 

If I change the pushrods on my TR6 engine do I also need to change the cam followers?

I have read somewhere that it is possible to change them by using a magnet to pull them up without removing the cylinder head,is that correct ?

 

Oystein

[88V8]

If I change the pushrods on my TR6 engine do I also need to change the cam followers?

I have read somewhere that it is possible to change them by using a magnet to pull them up without removing the cylinder head,is that correct ?

 

Don't change the cam followers

 

Putting new followers on an old cam will ruin them both.

 

Yes, I have read that you can pull them out with a magnet - you could do that to check the wear pattern on the follower, but the followers must be put back in the same position, and if you change them you must also change the camshaft.

 

As regards valve clearances, the wear will be in the pushrod, and more so in the pad of the rocker arm. If you change the rocker arms it might be a good idea to change the rocker shaft, although I have read that some of them are poorly hardened, so I would take advice on that.

 

I have a tool that automatically compensates for rocker wear, I bought it in the 70s and used it recently on the TR. Checking against the feeler gauge it closed up the clearances by about 2 thou only, which is not enough to make a difference to the noise, unless you have a Roll Royce engine.

So I think you have to look elsewhere for your noise, but it's still a useful tool, made by SPQR, it's called the Tappet Adjusting Tool.

You see them on eBay - > Cars, Parts & Vehicles> Automobilia> Vintage Tools

 

Maybe you could make a video of your noise and post it on YouTube....

 

Ivor

[88V8]

Hello again

 

Sorry, didn't read your first post properly, I see you have new rockers, so there shouldn't be any pad wear to give misleading valve gaps.

 

Try again:

 

You can replace the pushrods without replacing the followers.

 

If the noise exists at idle, it is not pinking.

The Lumenition (good!) will make no difference, it only fires the spark it does not affect the timing.

 

Noise that is worse under load, hmmmm, the valve train is more loaded at speed, but this would make the noise even if you rev the engine when the car is stationery. It makes no difference to the valve train if the car is moving or not.

 

Noise that varies with load suggests pistons or bearings, if it is a light tap, could be a little end.

 

Did the noise exist before you replaced the cylinder head?

Was any other work done at the same time?

 

If you run the engine without the rocker cover, as Pilkie has suggested, you will be able to find if there is a sticking valve (ie slow to close) , by using a stethoscope/long screwdriver you will able to pinpoint the noise source.

 

Good luck.

 

Ivor

[Tom Fremont]

If it were mine, I'd sleep a lot better eliminating cam failure 1st - of course discovery of failure here could impact sleep as it dooms one to ~ 20 hours of fun replacing it. Worn pushrods is a new one on me - never saw this myself.

 

I've never been completely happy with noises on my 73,000 miles-since-rebuild '250 engine. Some clattering about ( like little hammers deep within ) was evident when not fully hot in the 1st few thousand miles. This gave way to a barely audible knock which can just be heard ~ 1500 rpm though not elsewhere in the range. Sound of a wayward tappet can be heard at idle unless fully hot or cold. Sometimes I hear a rattle ( if I listen hard ) 3000<>3500 rpm under load which I ascribe to bizarre timing needs ( don't have a mapped ignition - just a low advance 7 degree dizzy with points ). Tappet clearance is 0.010" cold. To be fair, it was rebuilt from a motor which was unknown to me ( never ran it myself ) so who knows what it sounded like originally.

 

My new engine makes no untoward noises at all so far ( which is not very, 160 miles ). Tappet clearances are 0.014" / 0.016". Go figure

[Andy Moltu]

Cam followers cannot be changed without lifting the head off - they are too big to fit throught the pushrod apeture in the cylinder head.

 

Changing cam followers won't in itself damage the camshaft however it would be unusual for the cam follower to fail and the camshaft remain healthy. Having said that some of the poor quality reproduction cam followers don't last long & if you are lucky enough to see a little crazing on the follower when the head is off & you can get to look at the followers they can & should be replaced. The original chilled iron ones were far, far better than many of the reproduction ones.

 

However 19 times out of 20 if the cam follower is damaged the cam lobe will be too. - measure the lift - they should be the same - if not it's time for a new cam & followers.

[88V8]

Cam followers cannot be changed without lifting the head off - they are too big to fit throught the pushrod apeture in the cylinder head.

 

Thankyou for that.

I think now that the thread TRDriver and I are recalling, was in connection with changing the camshaft, the suggestion was that the cam could be taken out by lifting the followers clear with magnets, and not that the followers themselves could be removed.

 

The problem I would be looking for in the followers is a wear pattern showing that they have stopped rotating - that might give early warning, but as you say you have to be lucky and catch them in time.

 

However, I have to disagree about followers being changed separately from the cam: I think I am right in saying that the pressures between the cam and the followers are the highest sustained mechanical pressures in the engine, at any rate the parts soon wear in conformity with each other. If either is changed in isolation, a period of rapid wear will ensue while new and old parts find an accomodation. At best, this will disperse metal fragments all round the engine - and when one considers that the filter only filters down to about 20 microns, which is larger than some of the working clearances in the engine and so the engine has to act as a sort of expensive rock crusher until these particles are ground down - and at worst will wear through the case-hardening thus leading to rapid destruction of cam and followers. Personally, I would never fit new followers to an old camshaft, or vice versa.

 

Interesting what you say about some new followers being of poor quality - I have seen recent comment on the Rover V8 by a specialist supplier, to the effect that they were having such trouble with repro followers they had stopped supplying them, some had failed in as little as 20 miles. I wonder if they are made in the same place as the TR's?

 

Ivor

[Andy Moltu]

The workshop manual advises replacement of any followers that show signs of pitting.

Like you I'd be suspicious that a pitted follower is a sign of a worn/damaged cam lobe.

 

If you have to change the cam then it is essential to fit new followers - even if you could work the cam out and a new one in you will doom your new camshaft to death by worn followers. (I doubt you can get the followers high enough to clear the cam bearing journals but this might just be possible with the shortened race followers)

[tr6driver]

I have ordered new pushrods.

 

I will post an answer here at the forum about the result after I have changed them.

 

Oystein

[Robert Price]

Oystein

If you hear this ticking noise at tickover especially inside the car just make sure its not the rev counter spindle, it can make a real racket. But you may have established it is from the rocker box.

Rob