Could this cause valve damage?

[A900ss]

You may have seen on another thread some poor garage work on the trumpets of my cars and I think this 'may' have damaged my valves.

Over the past couple of months I have been getting smoke on the overrun but have put this potentially down to loads of different things (decat Y, fuel regulator, oil weight) and have not really considered valves as I had an engine rebuild last year including the valves all being machined.

Smoke on the overrun is classic valves but I have discounted it as the work on the top end is so recent.

My current thinking is that the wrong adhesive was used as I can see it down the ports of the inlet manifold. It's quite think down some ports, maybe 2mm all around the port. All ports have some adhesive in them but in some ports it is only a trickle.

This adhesive COULD have then got into the valve stems/guides meaning that they are not closing correctly and oil is getting into the cylinder on the overrun vacuum.

I guess any adhesive that did get into the cylinder would go straight out the exhaust valve/exhaust manifolds in a gas form as it would be so hot.

I'd really appreciate people's thoughts as my current thinking is to get the garage (or another garage) to strip down the top end (at their cost)

Original post with photos here.
http://www.pistonheads.com/gassing/topic.asp?h=0&a...



image by a900ss, on Flickr

Untitled by a900ss, on Flickr

Edited by A900ss on Saturday 17th May 14:11

Edited by A900ss on Saturday 17th May 18:33

[carsy]

Hopefully not but difficult to say.

If the same garage that did those trumpets did your top end rebuild, god knows what they have done to your top end, if anything at all.

[ChilliWhizz]

Er, might be a really stupid suggestion, but it might be worth removing some of the adhesive and heating it up with a blow torch, would simulate what happened to it when it melted/went runny in the engine... If it melts straight into something really runny then there's a good chance the engine would have just breathed it in and spat it out..

Nothing to lose anyway.....

[spend]

It won't get into your guides, they are a good fit around the valves unless they were shagged before the 'silcone'. The only real worry is how much is in the inlet manifold & possibly injectors (but a good clean off with solvent should suffice).

I think the only real concern is if some bits of silicone lodge in the piston rings or valve seats ~ you wouldn't need to interfere with either for very long to get odd wear patterns.

If it was mine I'd want to pull the heads off & check.

Oil presence in plenum/trumpet base is likely to be lack of drainage, so when liberally applying sealant they blocked the drainage holes and oil is pooling in the bottom.

[EGB]

Check the compression on all 8 cylinders. If all about 170psi then valves and piston rings about ok. Mine are an average 170.3psi after an indicated 56k miles. No oil smoke or excessive oil use. Let us know.

[EGB]

Check the compression on all 8 cylinders. If all about 170psi then valves and piston rings about ok. Mine are an average 170.3psi after an indicated 56k miles. No oil smoke or excessive oil use. Let us know.

[A900ss]

carsy said:

Hopefully not but difficult to say.

If the same garage that did those trumpets did your top end rebuild, god knows what they have done to your top end, if anything at all.

Different garage to the rebuild and they are very reputable.

[A900ss]

spend said:

I think the only real concern is if some bits of silicone lodge in the piston rings or valve seats ~ you wouldn't need to interfere with either for very long to get odd wear patterns.

If it was mine I'd want to pull the heads off & check.

I didn't think it would get into the rings but if it has got into the valve stems, could that cause overrun smoke?

I was thinking it would get onto the valve stems when it was drawn in with the air in the plenum.