Engine problem

[walkie]

Hello all, I have a serious engine problem. The engine was noisy, low on power, tappety noises etc., so I changed the camshaft and co. (timing, rocker assembly, tappets), manifold gaskets, ignition parts. Unrelated, but also changed the clutch as it was slipping. As fired up first, there was some tappet noise for a few secs, but thats normal for new tappets, then all the noises gone and I was smiling like that cheshire cat. For about 2-3 mins... Then came the cold shower. The engine started to knock. From somewhere inside, deep metallic knocking noise. And got louder... When the engine warmed up completely, the knocking became very loud. I had proper oil pressure, the fans and the water pump worked, the engine was good as new, bar the knocking.
Here's the sound, when the engine is warm: http://www.brandavenue.hu/eng.mp3

Please help me locate the problem, there's no garage around with TVR knowledge so I'm on my own now...
Could this be:
- camshaft bearing
- big or main ends
- conrods
or other sinisters? The engine is a 500 with 62k on the clock.
Oh, forgot, when its cool, there's no noise, only when warm, also nothing under load, just when idling or keeping the rpm without load.

[Pupp]

walkie said:

Hello all, I have a serious engine problem. The engine was noisy, low on power, tappety noises etc., so I changed the camshaft and co. (timing, rocker assembly, tappets), manifold gaskets, ignition parts. Unrelated, but also changed the clutch as it was slipping. As fired up first, there was some tappet noise for a few secs, but thats normal for new tappets, then all the noises gone and I was smiling like that cheshire cat. For about 2-3 mins... Then came the cold shower. The engine started to knock. From somewhere inside, deep metallic knocking noise. And got louder... When the engine warmed up completely, the knocking became very loud. I had proper oil pressure, the fans and the water pump worked, the engine was good as new, bar the knocking.
Here's the sound, when the engine is warm: http://www.brandavenue.hu/eng.mp3

Please help me locate the problem, there's no garage around with TVR knowledge so I'm on my own now...
Could this be:
- camshaft bearing
- big or main ends
- conrods
or other sinisters? The engine is a 500 with 62k on the clock.
Oh, forgot, when its cool, there's no noise, only when warm, also nothing under load, just when idling or keeping the rpm without load.

Exhaust manifold gaskets can sound very 'mechanical' and often get louder with heat. Worth a shot before assuming anything nuclear. Good luck

[Ribol]

A bit of guess doing it this way but it sounds like the ends to me.

I certainly wouldn't run it like that any more than you need to, the first thing I would do is a proper oil pressure check.
After that I would do a compression test and see if that throws anything up.

[Barkychoc]

Did you do the tappet pre load check with your new cam fitted?

Scroll Down this ---- http://www.rpiv8.com/engine-4.htm

[walkie]

Barkychoc said:

Did you do the tappet pre load check with your new cam fitted?

Scroll Down this ---- http://www.rpiv8.com/engine-4.htm

Yes, the preload is within tolerances.

[walkie]

Pupp said:

Exhaust manifold gaskets can sound very 'mechanical' and often get louder with heat. Worth a shot before assuming anything nuclear. Good luck

Checked the exhaust manifolds and the gaskets, but they're fine.

[walkie]

Ribol said:

A bit of guess doing it this way but it sounds like the ends to me.

I certainly wouldn't run it like that any more than you need to, the first thing I would do is a proper oil pressure check.
After that I would do a compression test and see if that throws anything up.

Thats's what I fear from... The oil pressure is 30 lbs at idle when cold, drops back to 15 when warm, according to the gauge, but we can't trust them, right?
I'll do a compression test later today or tomorrow.

[JonathanT]

Mine makes a similar noise - totally different to a leaking exhaust manifold. Does it go away when you rev the engine very slightly (say to 1200rpm)?

My local reckoned that it was "camshaft slap", describing that the camshaft is allowed to float front to back with the timing chain normally holding it in place except that mine is moving a little more than expected. They said that it was ok but would make this knocking sound. Cure was to add a retaining plate - I assume it's like this one?

http://www.thetvrshop.com/TVR/Parts_details/TVR%20...

Maybe that's what you have?

Edited by JonathanT on Tuesday 12th August 11:32

[GreenV8S]

Is it possible you have the wrong cam? The serpentine front end is different to the preserpentine, and needs a different cam. If you don't have the right end stop on the cam, it possible that the cam will walk endways until the lobes stop it. If the problem isn't obvious, I'd be inclined to drop the sump and make sure the bearings were OK before running the engine for long.

[walkie]

GreenV8S said:

Is it possible you have the wrong cam? The serpentine front end is different to the preserpentine, and needs a different cam. If you don't have the right end stop on the cam, it possible that the cam will walk endways until the lobes stop it. If the problem isn't obvious, I'd be inclined to drop the sump and make sure the bearings were OK before running the engine for long.

I'll check the cam for movement, I bought it for serpentine engine and has the correct front end for the retaining plate. Maybe the old plate is worn or a bit out of tolerance with the new cam.

[v8 racing]

That sounds way too harsh to be cam related, if it is quiet and definetly cant hear it when it is cold i would guess at the little end, it is not that uncommon on the 500's to be honest

[Pupp]

v8 racing said:

That sounds way too harsh to be cam related, if it is quiet and definetly cant hear it when it is cold i would guess at the little end, it is not that uncommon on the 500's to be honest

That's interesting Rob... what is it that actually fails with the little ends? Aren't the pins tight in the rod eyes with the 'bearing' being at the pin/piston interface? How's it fixed?

[v8 racing]

Pupp said:

v8 racing said:

That sounds way too harsh to be cam related, if it is quiet and definetly cant hear it when it is cold i would guess at the little end, it is not that uncommon on the 500's to be honest

That's interesting Rob... what is it that actually fails with the little ends? Aren't the pins tight in the rod eyes with the 'bearing' being at the pin/piston interface? How's it fixed?

Hi mate, yes the pin in the piston is normally ok, the wear is usually between the pin and the piston, the piston wears more than the pin, a bit like the rocker arm on the rocker shaft, it is caused by the short rod to crank angle on the 500's

[Pupp]

v8 racing said:

Pupp said:

v8 racing said:

That sounds way too harsh to be cam related, if it is quiet and definetly cant hear it when it is cold i would guess at the little end, it is not that uncommon on the 500's to be honest

That's interesting Rob... what is it that actually fails with the little ends? Aren't the pins tight in the rod eyes with the 'bearing' being at the pin/piston interface? How's it fixed?

Hi mate, yes the pin in the piston is normally ok, the wear is usually between the pin and the piston, the piston wears more than the pin, a bit like the rocker arm on the rocker shaft, it is caused by the short rod to crank angle on the 500's

Cheers for the info. Are the pin lands on the pistons generally made with holes to allow additional oil ingress? Heve seen Cosworth bike pistons done like this and imagine it might be a possible mod to improve longevity if not...

[JonathanT]

Walkie, any update on your noisy engine?

[walkie]

Nothing yet, I've been too busy with other things in life
Maybe this weekend...

[Boosted LS1]

That sounds like a proper knock to me so, if the rods etc were fine before I'd expect them to be fine now and you have good oil pressure. Also I assume you didn't remove the heads as there wasn't any need to do so.

You haven't got a loose bolt rotating in there somewhere? Or have you fitted a long bolt where there should be a short bolt resulting in metal to metal contact? Have you fitted any long bolts into the timing gear by mistake? They'd hit the block as the gear rotates.

[MikeTVR]

That sounds pretty serious to me. Did you notice whether there was any oil pressure when the engine was started after the cam change? The Rover V8 oil pump needs priming or certainly rotating for a long time before it starts to pump. Big ends don't last long without oil pressure.

Sorry to be a pesimist but I wouln't use it until it's been properly diagnosed.

Mike

[Boosted LS1]

The OP hasn't clarified if this is a new knock or the noise he had before? Clarification may be helpful.

[walkie]

I had a similar noise before (much louder and complex), but thought it was the camshaft, which turned out was in very bad shape. One of the lobes was completely circle, guess there wasn't any valve movement there. Also two rockers were found damaged and the bottom of one tappet was concave, about 0,08" deep in the middle. I haven't pulled the heads yet and not planning to do so before I check the compression.