RV8 Big Bang Theory!?!?!

[RichDyne]

Help!!!

250 mile trip and on the way home had smoke coming from the bonnet. Pulled over to take a look and it looks like an oil leak from the rocker cover or dipstick tube - smoke was due to oil splattering on the exhaust manifold.

Limped home

Cleaned up the oil and took her for a short spin today to try and see where the oil was coming from and noticed under acceleration a hugh amount of smoke coming from the passenger side exhaust. Engine runs fine but am worried I have blown the head gasket on the left bank (as seen from cockpit) and its burning oil.

Has anyone else done this to a 3500 RV8? What was the answer?

Cheers
Rich

[Sidecarbod]

First thing to do would be to pull the spark plugs out and try and narrow it down to a cylinder or cylinders.

Check for signs of water in the oil, and maybe do a compression test.

Also check that things are still mechanically OK like the valve gear working correctly when you turn the engine over by hand.

If you still can't sus out what the problem is then it might be time to take the head off which is not a massive amount of work.

I'm sure others will be along shortly with more suggestions that you can try before pulling the head off.

You could get a sample of the coolant checked for combustion gases.

Good Luck,

Pete

[RichDyne]

Thanks Pete,

Have geared myself up for removing the head however if I do that and find I didn't need to I would not be too impressed with myself

Should be a fun day tomorrow.

Am hoping someone else has had the same symptons from an RV8 before.

Cheers Again
Rich

[Purple AK]

Rich. Had this on a 3 Litre Capri many years ago. Before you completely pull the head, Check the valley gasket Chances are it's leaking oil (being sucked) into the inlet port/s on that side Tip. After a fix it will take several miles to burn off the excess oil still left in the exhaust!!!! But it does go away

[RichDyne]

Ahhhhhhh nice thinking - had not thought about that at all as the oil I am seeing is coming from the outlet side of the engine.

Could the oil leak be a sympton of pressure in the engine? The oil pressure guage is reading normal though...

[Sidecarbod]

Chris has a good point.

When you take the inlet manifold off if it is leaking oil into an inlet track you should be able to see the oil in the track.

The tin valley gaskets don't seal too well, but if you clean them up with solvent then put a thin smear of silicone sealent round all the ports and waterways on both sides of the gasket that usually sorts it out. (let the sealent semi cure before you torque up the manifold bolts.

The tin head gaskets are also bad for leaking, if you've got them fitted you will see brown blow by marks on the gasket when they start to fail. the cure is to fit composite ones and get the heads skimmed if you are worried about the .5 compression ratio loss due to their thickness.

(You can get coated valley gaskets but the silicone trick works OK).

Regards,

Pete

[Sidecarbod]

Originally Posted by RichDyne

Ahhhhhhh nice thinking - had not thought about that at all as the oil I am seeing is coming from the outlet side of the engine.

Could the oil leak be a sympton of pressure in the engine? The oil pressure guage is reading normal though...

I thought the smoke was comming from the exhaust? If the smoke is just due to oil on the outside of the exhaust then it can't be a major problem, maybe just a rocker cover gasket or something similar.

You may have an adaptor plate under your rocker cover to allow the fitment of fancy covers, these can cause leaks.

There is no oil pressure in the rocker cover but they can still leak.

Regards,

Pete

[RichDyne]

Do you recommend replacing the valley / inlet manifold gasket as a matter of course once going through all the effort to remove the EFI system?

Are these the sort of gaskets that never really re-compress once untorqued?

Luckily my wife is working all day tomorrow and the weather looks like its going to be great - perfect for pulling the top of the engine to bits.



Thanks for your advice guys - you have both helped a great deal.

[Purple AK]

Originally Posted by RichDyne

Ahhhhhhh nice thinking - had not thought about that at all as the oil I am seeing is coming from the outlet side of the engine.

Could the oil leak be a sympton of pressure in the engine? The oil pressure guage is reading normal though...

Unlikely as any excess pressure would be vented to atmosphere or back through the PCV system dependant on which you use. But a smallish leak into the inlet tract is subject to quite a high vaccum and will pull a suprising amount of oil

[RichDyne]

with the amount of smoke I don't think it is coming from the light splatter on the manifold.

Think I may have two problems here. Trouble is I don't believe in co-incidence when it comes to engines - and struggling to connect the smoky exhaust with the oil leak which is coming from very high in the engine - like you said - rocker gasket.