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Right, starting to loose the will to live with my vr. First the headgasket was gone and started to pressurize the cooling system. So fitted a new headgasket. Cooling system fixed. Then started to puff blue smoke on the over run. Valve guides were work out. So back off with the head new guides and new valves fitted. Problem fixed - for about 3 weeks and its started puffing blue smoke under load and on the over run - not all the time but mostley when hot. So checked my engine breather and it is breathing blue smoke on idle - a fair amount. So is this now the piston rings?? Im telling myself it is now because everything eles had been replaced. Whats you opinions.

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150k. Now I think about it im stupid for not doing them whilst it was out. Just getting frustrated with it being a money pit. Ive done all the work myself and the car cost £1100 and ive spent £2000 in parts - thats at cost price to vw as my mate works there. Now im looking at ££££'s again to do the bottom end. Just to be at square one what I originally wanted when I bought the car - a working low vr6. Im sure ill calm down in a few days and carry on with it just feels like its always the long uphill route for this project. Not to metion last time i rebuilt it the roofers came round and filled the intake with stones after it was freshly built so in the space of 7 months of owning it ive had the head off 3 times and the engine out once to do the chains ggggggggrrrrrrrrrrrr!

Rant over!

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Before I start pulling my lump apart again im just wanting to get a few opinions and sound my thoughts over the last few days.

This 150,000 mile 12 valve vr6 engine has seen better days, its puffing blue smoke from the exhuast. You can make it burn oil by rolling along at say 4000rpm off the throttle and let the revs slowly come down for about 8 seconds then when you gave it a foot full, there was a large cough of blue smoke.

Fitted the new guides and valves and genuine stem seals genuine headgasket. Ran my new cams in and bedded my clutch in for 500miles then started to give it abit of a hoof again. Then the blue smoke started to come back again. In exactly the same way! Fantastic.

Is this signs that the machine shop has reamed the guides too much causing excessive movment again? Its possiblility. I'll need to get a bentley shop manual and mesure the valve play to check the tolerances.

Or is it that the rings on the high mileage engine have come to the end of there life?

The way i saw it was that as the throttle was shut and the vacume in the engine was present at 4000rpm it was sucking the oil through the worn guides. Filling up cylinders and then when you open the throttle up it was causing the oil to burn.

My next step is to remove the oil breather filter and cup the end of the hose to see how much presure is there as the should be very little. High presure is a sign of worn piston rings as the compression from the engine is passing the worn rings and pressurizing the sump pan which in turn is raising the presure and vapour coming out of the filter.

Compresion tests along with checking the plugs would give a indication to which cylinders are at fault.

Either way all the work has got to be re done.

Your thoughts, any pointers or past experiances are welcome. This seems to be a very commen fault with these 12 valves so lets see if we can get a guide together for people experiencing the same faults!

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My 120k engine was nailed. It's obviously had a hard life, was using ALOT of oil and suffered some severe piston slap. Just had a full engine rebuild though, well sourced a 2.8 block and bored it up to a 2.9l and drives amazing now sounds completely different than before, even though I am running it in.

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I would do a compression test on each cylinder and see what results your getting with that mate then that might confirm or deny your thoughts on the rings before going to all the trouble of head off or engine out

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Was your vr using oil too pete? My vr has definitely had a hard life as the rude boy who owned it before took me for a test drive in it and hammered the living death out of it up the road from cold. I knew this was the sort of life it has put up with with the last 14 owners but we all like a little project.

Gordon your thinking along the same lines as me. First step I'm going to pull the plugs out and inspect them for signs of burning oil to hopefully pin point the faulty cylinders and follow it up with a compression test to verify the rings as there should be no faults with the valves.

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It was off the dip stick every 300 miles mate, Vince said it wouldn't have lasted out the summer, there was loads of wear in bore 1 and 6 and some nasty piston slap. Was also way down on power too.

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I'm sure this is worn rings, this is what happened with my series 2 turbo. Would only puff smoke when backed off the throttle. My rebuild on that cost £1300 several years ago, but the performance was fantastic after it was run in.

Sent from my iPhone using Tapatalk

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I have the same symptoms too, real heavy breathing through the breather, after doing a compression test it looks like my bottom end is dead, might be able to save it with a overbore and 2.9 pistons as suggested by you.

As suggested get a compression and leak test done, should point you in the right direction

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.My mk4 12v with 168000 is doing the same I did valve seals and the compression is perfect. Is there such a thing as oil ring on the piston that can go bad but still have good compression? A quart after 100 miles isn't good,but still running really strong??

Any help would greatly be appreciated

Edited by sprkyzappa

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My mk4 12v with 168000 is doing the same I did valve seals and the compression is perfect. Is there such a thing as oil ring on the piston that can go bad but still have good compression? A quart after 100 miles isn't good,but still running really strong??

Any help would greatly be appreciated.

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Even tho this thread is old thought id update you all. About a month ago I forgave the vr6 and calmed down after it being parked for 6 months or so and pulled the engine out and striped it down all the bores were glazed over and fat lip at the top and generally a bit tired. Managed to get a set of 2.9 pistons and sent the block off for a re bore. Also turboing it whilst its apart too.

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That last comment makes me laugh, engine rebuild was quick and not as painful as I originally thought, but that turbo build is still not finished lol. Altho I may hear it run for the first time since I pulled the engine out all those years ago tomorrow last piece of the puzzle is my new fuel pump which arrived today... Lets hope she doesn't smoke like she did 3 years ago!

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Hey sump slammer, I'm super interested in your posts!! I've got a 3.2L vr6 & had nothing but problems Sally year since I've owned it seems Any good I do to it I'm rewarded with terrible symptoms

It's got 200k on the clock, wasn't driven for years before I bought it, did a major on it when I first got it, new fluids plugs coils filters belts vaccuum lines, as you do....

Then the problems arrived ! Serious ammounts of blue smoke At start up,new pcv, newvalve stem seals, was all good for a bit

Did another major engine flush recently to try eliminate any ring lock n things gone bad to worse!

Soo much smoke!!! When it's hot it's all good,the first5kms don't even think of tailgating me!!

The smoke is almost identical to the throttle, put my foot down out comes the smoke! Compression is great! 180-200, leak down all good, alll cylinders at 0

Disconnected the pcv today for fun same problem! Gunna disconnect the egr tomorrow to rule that out after that it's almost looking at a new engine,


Possibly a broken oil ring ??

Symptoms sounds very familiar to yours so thought you sound like the man to shed any sort of light on my situation ......

Any thing u got I'll try!!

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Hey sump slammer, I'm super interested in your posts!! I've got a 3.2L vr6 & had nothing but problems During the year I've owned it, seems Any good I do to it I'm rewarded with terrible symptoms

 

It's got 200k on the clock, wasn't driven for years before I bought it, did a major on it when I first got it, new fluids plugs coils filters belts vaccuum lines, as you do....

 

Then the problems arrived ! Serious ammounts of blue smoke At start up,new pcv, newvalve stem seals, was all good for a bit

 

Did another major engine flush recently to try eliminate any ring lock n things gone bad to worse!

 

Soo much smoke!!! When it's hot it's all good,the first5kms don't even think of tailgating me!!

 

The smoke is almost identical to the throttle, put my foot down out comes the smoke! Compression is great! 180-200, leak down all good, alll cylinders at 0

 

Disconnected the pcv today for fun same problem! Gunna disconnect the egr tomorrow to rule that out after that it's almost looking at a new engine,

 

 

Possibly a broken oil ring ??

 

Symptoms sounds very familiar to yours so thought you sound like the man to shed any sort of light on my situation ......

 

On the positive side he car drives great once past the smoke stage, plenty of power limited misfires, very smooth!

 

There's either something terminal I'm not accepting or something possible I haven't checked, can't rule anything out at this point

 

Any thing u got I'll try!!

 

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