VR6 Intermittent Burning Oil Woes.....Page 3.

[leigh_harty]

It might be worth noting you cant use a standard ring compressor on the vr engine

[Gti_Jamo]

He's doing an ABF engine.

It might be worth re ringing the block after Honing with a flexhone. It doesn't necessarily need a rebore as rings can wear faster than the block. A bore micrometer can show you how much wear.

Flexhones are fairly cheap off eBay and you can do it with a drill and some paraffin. 

Then put some new rings in and that should give you some peace of mind.

You will have to run the engine in to bed the rings in though

My engine had a slight lip at 123k but when measured it was only 0.03mm and was well within wear limits.

Well thats all mine has, slight lip across the range but more apparent on the outer edges. Just by feel. Like I dont need the engine to be perfect, just better than the 190,000 mile one I have now. Its dying more with every run. Don't have the money to do much to the bottom end.

It might be worth noting you cant use a standard ring compressor on the vr engine

Yeah I read that. Doubt i'll remove pistons though.

[Gti_Jamo]

Well the engine is built back up and fitted over weekend. Sounded rough and was real smokey on initial start up but after 10 mins it sorted itself out. Used the inlet manifold from my bad engine and would have had some traces of oil from the excessive crank case pressure caused by the bad rings. Anyway despite my new engines bore lips it runs like a dream, compression test showed 165psi across the range give or take a few psi. No smoke on start up, accelerating or overrun. Hydraulic lifters and chains are quiet. The car feels much quicker. Everythings top notch so i'm happy.

Will update my dub rides thread with pics when i get time. Cheers for the advice.

[tshirt2k]

How did you do the compression test? warm? full throttle? Sounds a bit low. Although if they are equal it should be fine.

[F17BAD]

Remember folks

The Tshirt Knows... How to Diagnose...


 

[Gti_Jamo]

I may have spoken to soon unfortunately. Some more info to follow. 

And yeah compression test was done up to temp with open throttle. Cranked 6 times.

[Gti_Jamo]

Ok then,

So anyway got it fitted and running and ran as sweet as a nut, no smoke. Nice and quiet. Pulls really well compared to my old engine so was really happy that I have a strong one.

However after running it for 100 odd miles I noticed a wee bit of blue smoke on overrun that gradually stated to get worse as the journey continued. Was gutted!! Basically its not until the throttle is closed then I start to smell the oil building up then once I get back on the throttle the smoke is released. Yesterday morning I had a wee bit of smoke on start up but nothing this morning and never started to smoke until it was right up to temperature. Does not smoke driving normally, only when throttle is closed for a period of time.

So this afternoon I done some tests first being another compression test. This was a hot / dry test and the results are as follows.

Cyl 1 - 164psi - No oil on plug
Cyl 3 - 165psi - No oil on plug
Cyl 5 - 162psi - No oil on plug
Cyl 2 - 165psi - No oil on plug
Cyl 4 - 168psi - No oil on plug
Cyl 6 - 175psi - Oiled up plug

With number 6 being higher and oil on plug I turned the engine over with the plug removed to clear any oil and ran the test again on that cylinder and it gave me 162psi so all pretty level and not particularly low.

Then I done a leak test on each cylinder at tdc. Pumped 6 bar into them and could hear a slight hiss from the oil cap on each cylinder, none anymore worse than others. Would a slight seepage be normal? I would think it would be.

Put the car all back together, took it for a 20 mile blast and got a tiny bit of blue smoke on one occasion despite me letting it coast down a big hill in 5th I couldn't get the smoke to appear nor could i smell it building up. It makes no sense considering yesterday I done the same thing on the same road and i could barely see behind me from blueness. I know when the blue smoke is going to appear as i can clearly smell it before I get back on the throttle.

So what do you guys think. A worn bore or ring? If so should it of not been smoking since its first ran? Duff stem seal perhaps. Or something i'm not aware off. The seals I got came with the headset and more or less just pushed on the valve guides pretty easy. I know I should of went to vw for them. Its just strange how it appears to be intermittent, usually engines either burn oil or they don't, not sometimes, like mine appears to be doing.

Just need to know where to begin. I don't mind removing the head again and doing the stem seals as its no big job but don't particularly want to do it if its not going to fix the problem. As for the bottom end, well I don't really have the money to start getting that redone. I'm a vr6 novice so not too clued up on these problems. My old engine smoked in a similar fashion but done it all the time and was way down on compression in cylinders 1 and 6 and was about as slow as my old 8v but this engine goes really well despite this problem. Put the smile back on my face anyway.

So in my opinion its either the seals or the rings/bores but would like to believe the seal on cyl 6 has had it or i damaged it when fitting. Or it could because they are cheap and nastys. I should of put proper ones in, I hold my hands up for that error.

Sorry for the essay, just want to give as much info as possible.

Give me your knowledge. Cheers

[gazareth]

yeah its probably only smoking when its up to temp as that's when the oil is thinnest and can be drawn down the guide. maybe one of your seals has came loose or maybe it was damaged on fitting? did you by any chance distort the top of the valve guide when pulling the old seal off? them seals can be darn tight! doubt its your piston rings though.

[Gti_Jamo]

yeah its probably only smoking when its up to temp as that's when the oil is thinnest and can be drawn down the guide. maybe one of your seals has came loose or maybe it was damaged on fitting? did you by any chance distort the top of the valve guide when pulling the old seal off? them seals can be darn tight! doubt its your piston rings though.

Hi mate, yeah but its strange how it never smoked bad on my journey home. It was upto temp and should of done it on request almost. Was really carefull removing seals and the new ones seated will with little force. Usually the seals are quie tight to go on from experience with other engines. Maybe a problem with the head gasket or a head bolt near cylinder number 6. A crack between cylinder and oil chamber. All have crossed my mind. I wish I could rule out the ring/bore wear but I cant properly check it just by looking at it.  But visually it looked ok. No different to the rest. Also it wouldn't have taken 100 miles for the problem to arise if it was already there. But, thinking back, when cleaning the valves that exhaust valve on 6 did have a little more burnt on carbon compared to the others. Not much though.

[tshirt2k]

Remember folks

The Tshirt Knows... How to Diagnose...