Any experts on cologne engine rebuilds

[brooky]

So had blue smoke on start up of my 2.8 so decided to change valve stem oil seals, got heads checked whilst they were off, some valve guide oil seals had to be changed and a light skim as had 0.005" out of flatness. Put all back together and now got serious smoking especially when rev hard, also smoking when just ticking over but performance is better than ever. Done 130 miles and used about 1 1/2 pints of oil, it is like a steam train coming down the road when i rev to change gear, etc. Water is ok and not overheating, done compression checks and all around 10 bar and all up on what they were before i took heads off so happy with compressions. I have read that oil control rings can get clogged and let oil into the cylinder but cant see how this can be the problem as it wasnt smoking this bad before heads came off and all was rather clean when i took heads off as only done 5000 mikes with this block

Heads and inlet were put back as described in workshop manual, small amount of sealant on cork on inlet gasket corners, all torqued and retorqued after warm up. Due to amount of oil being burnt and the fact both sides are smoking i was convinced the inlet manifold had not sealed properly and was letting oil enter from the central valley cavity so fitted another new inlet gasket, same again.

Any ideas why i have an engine with good heads and valves, good compressions, good oil pressure, running nicely with good performance yet is eating oil on both sides as shown by smoke from both exhausts and plugs on both sides black with some wet after 130 miles

[Pas28i]

Hi, I'm no expert at all but just had a thought regarding pcv valves / exhaust gas recirculation?

I was watching a YouTube video regarding my golf and the mechanic rebuilding his engine says that many good cars have disregarded because of bad smoking when all it was, was the gauze inside the rocker cover below where the pcv valve was clogged up.

I don't know if the cologne has this but if the valve is blocked or clogged, could the pressure build up and be forced back through the cylinders and out of the exhausts?

It's only a suggestion as I'm no expert but can't think of anything else if all else is ok!

Best of luck.

[Paul G]

From your description I hate to say it but it sounds like the oil control rings are gummed up or worn. Valve guide seals wouldn't use 1 1/2 pints of oil in 130 miles and they don't usually smoke on accelleration.

A few years ago we had a customer with a horrendously smokey zetec engined Focus. When told they would have to have a rebuild or second hand engine they just couldn't afford it. Just as a last resort to try and help them out I took the plugs out and filled each bore with some good old fashioned Redex. I left it in for a couple of days then spun the engine over on the starter to get as much as I could out of the plug holes- made a right mess but ho hum.

Refitted the plugs and started the engine - it popped and farted and smoked like hell for about half an hour after which the smoking stopped. Put a new set of plugs in and cleaned engine then went for a good hard run in the car and -- smoking stopped. The car was fine for over a year when the young lady sold it.

If your rings are gummed this might be worth a last resort try, if not you will have to pull the engine and re ring it I expect.

[Paul G]

Hi, I'm no expert at all but just had a thought regarding pcv valves / exhaust gas recirculation?

I was watching a YouTube video regarding my golf and the mechanic rebuilding his engine says that many good cars have disregarded because of bad smoking when all it was, was the gauze inside the rocker cover below where the pcv valve was clogged up.

I don't know if the cologne has this but if the valve is blocked or clogged, could the pressure build up and be forced back through the cylinders and out of the exhausts?

It's only a suggestion as I'm no expert but can't think of anything else if all else is ok!

Best of luck.

My experience with Golfs is that if that gauze blocks the engine leaks everywhere - rocker cover, cam, crank, jackshaft and rear main oil seals. They are a pig to clean, I've cut open many a rocker cover to get at them then welded them back together. It is true that the high crankcase pressure can force its way past worn rings and cause smoke.

The small engine Golfs and Polos had a breather on the back of the block, known in the trade as the turtle, and when that blocked, or the oil return passage under it, they pumped oil up into the air filter and smoked like hell.

Golfs very regularly have valve stem oil seal trouble and they do smoke terribly with that which could fool some into thinking the rings have gone

[brooky]

Paul

I was reading previous posts about leaking inlet manifolds after heads have been skimmed, as smoke is coming out of both banks do you think it may be the inlet manifold not seating properly. I was thinking of dry fitting and check with a feeler gauge or engineering blue to make sure it is seating fully, if not then a light skim off bottom if too high or sides if not fully down and try again. Also seen various advice on where to put sealant, i have only put it on the cork corners, is this right

Mark

[Peter-S]

Paul

I was reading previous posts about leaking inlet manifolds after heads have been skimmed, as smoke is coming out of both banks do you think it may be the inlet manifold not seating properly. I was thinking of dry fitting and check with a feeler gauge or engineering blue to make sure it is seating fully, if not then a light skim off bottom if too high or sides if not fully down and try again. Also seen various advice on where to put sealant, i have only put it on the cork corners, is this right

Mark

It can be tricky to get the inlet to line up with skimmed heads. Obviously the more skimmed the bigger the problem. The inlet manifold should basically be flush with the cylinder heads where they meet just under the rocker covers. If there is a big step at that point then the manifold is probably not sealing properly around the inlet ports.

Since the whole thing can be a bit temperamental I've always used Loctite instant gasket in addition to the to the valley gasket to avoid any water and oil leaks. Might not be pro advice but that's the way I've done it without any problems.

[brooky]

Thanks peter, will do some dry install gap checks as i am sure this is the problem . If putting some precautionary sealant on, do you put it around all the orifices in the gasket where the orange seals are on the gasket, hope that makes sense

Mark

[Paul G]

Paul

I was reading previous posts about leaking inlet manifolds after heads have been skimmed, as smoke is coming out of both banks do you think it may be the inlet manifold not seating properly. I was thinking of dry fitting and check with a feeler gauge or engineering blue to make sure it is seating fully, if not then a light skim off bottom if too high or sides if not fully down and try again. Also seen various advice on where to put sealant, i have only put it on the cork corners, is this right

Mark

This is feasible, on V engines the inlet manifold does sometimes need machining to get the ports and bolt holes to align. If it's meant to sit flush with the heads and doesn't then that has to be worth looking at. I would also - sparingly - use blue hylomar as a sealant and a smear round the inlet ports shouldn't hurt.

As Peter has had experience of this he may well be right - I hope so as rings are the only other option I can come up with for that kind of oil consumption.

[Peter-S]

Thanks peter, will do some dry install gap checks as i am sure this is the problem . If putting some precautionary sealant on, do you put it around all the orifices in the gasket where the orange seals are on the gasket, hope that makes sense

Mark

Hi Mark,

I've not used a gasket with any orange bits but yes around all the orifices and generally anywhere that looks like it could leak something. As Paul said in another post - sparingly though.

[3 Litre Power]

My 3.0 Essex used to drink oil, changed the valve stem seals and nothing else one year ago, and oil consumption slowly came down to absolutely zero.
If it's burning lots of oil could have stuck piston rings? or maybe even a broken ring, does it blow smoke from the filler cap when the engine is running?
If so that is a clear sign of a broken ring, sadly full engine strip down and rebuild required at that point.

[brooky]

I was not considering rings as compressions are good, all round 145 psi. as it has only started smoking this bad after refitting heads and the fact both sides are smoking a lot the only thing I can think of as common to both sides and would allow a lot of oil leakage is the intake manifold

[Paul G]

I was not considering rings as compressions are good, all round 145 psi. as it has only started smoking this bad after refitting heads and the fact both sides are smoking a lot the only thing I can think of as common to both sides and would allow a lot of oil leakage is the intake manifold

Re - reading through your original post I now see that the block has only done 5000 miles. Was it rebuilt then? If so I think you must be on the money with the inlet manifold unless an oil control ring has broken or been wrongly fitted which I'm sure if you checked or built the engine would not be the case. It's unlikely now having read everything again.

With compression, surely it is the compression rings that ensure compression more than the oil control rings. This said, I now agree that it's something that has arisen during your recent removal of the heads that would cause the problem to suddenly start afterwards and something to do with the valley gasket has to be no 1 suspect.

I think you're going to have to get your tool box out again Mark, it's certainly worth investigating for the cost of a gasket set.

[brooky]

Hi Paul

Yes, whole engine was rebuilt by tickover however I have had problems with the top end after only 5000 miles as had to change rockers and shaft recently and then valve stem oil seals which is when i found some valve guides worn which again I would have thought should have got appeared after just 5000 miles. Had guides changed, new seals and a 0.005" skim to make heads as good as possible. Before heads were taken off, had typical blue haze when starting or accelerating which was linked to valve seals, refitted heads and now smoke both sides and lots of it so my logic is much worse since refitting so thats where the problem is as oil ring contamination was not evident before and pistons and cylinders looked rather clean when heads were off apart from localised carbon build up on top of 2 pistons which i put down to burning oil that had been coming through valves seals/ guides.

Got a new inlet seal, some engineering blue to do some serious gapping checks and some sea foam just in case oil rings are contaminated.

Watch this space for success story or look in cars for sale section for a bargain 280

[Paul G]

Good luck in sorting it mate!

[3 Litre Power]

Maybe the valve guides are not right then, a bit of a mystery.