Since my car was de-catted in the summer it seemed a little smokey.

 

Doesn't smoke on idle, or when accelerating off boost, or on decelerating, only when under full boost...keeps smoking for as loong as you hold the foot down, disappears soon as you lift off.

 

I'm sure I can also smell oil when this happens, but not sure if I'm imagining that.

 

When car was de-catted they said the turbos had almost no play and seemed in good order.

 

First stop PCV valves?

yep pcv's would be first to check ...

 

but on what your saying its still a big poss its the tubs

the shafts dont have to move to leak oil what mileage your car done

yep pcv's would be first to check ...

 

but on what your saying its still a big poss its the tubs

the shafts dont have to move to leak oil what mileage your car done

 

The tubs are still in my thinking, but no harm in trying the cheap option, I don't really want to think on the cost of getting the turbos done, although timing belt due soon so would make that job easier.

 

76k mate.

 

The only other change on the car which I just remembered was at the same time as the decats got fitted the car was serviced.

I've always used 10w/40 semi synthetic, the garage recommended a 10w/60 full synthetic, but I would think thicker oil would be less likely to leak?

the pcv valves and the change of the exhaust doesn't have any thing in common to give you problem ..

 

however the Exhaust will on the turbos taking the cats out will free up the exhaust back pressure on the tubs

as they use a dynamic oil seal it could aid in a soon fail of the seal

and i think this is whats happened ... the Cats have been masking the problem a little or Prolonging the failure

 

if it is the Turbos m8 ... Engine out job

 

10w40 >10w60 will be the same thickness at 85c engine running temp .. the 60 in oil grade is what Max heat it can with stand before it starts to come ineffective

10w is the Cold velocity ( thickness )

Edited October 27, 201213 yr by MarkDerby

Cheers for the oil info, after reading that I remember what the different bits in the ratings mean, hadn't thought about it in years.

 

Time to start hunting for a pair of turbos then, and try and find a garage that won't rape me to fit lol.

Could all ways buy my used tubs ... Have them rebuilt or do it your self .. 80quid ;)

Standard used turbos mate? My car was an auto but converted to manual, not sure if that makes a difference?

they are Standard OEM Auto Turbos .. they check out ok but unknown if leak oil it just be Wise to have them rebuilt with new bearings/oil seals or get them hybrid for more power

 

you have Auto Turbos on now and there is'nt much differents in it really

TBH, if the engine does not consume much oil, then I would not worry about a bit of smoke mate! As Mark says, there's no harm in replacing the PCV valves to see if it cures the problem, but if it is the turbos then most likely it is just the rear oil seals that have gone. And so long as it boosts up and performs OK, then I'd live with it until you have to top up the oil every week...!!

 

......................10w40 >10w60 will be the same thickness at 85c engine running temp .. the 60 in oil grade is what Max heat it can with stand before it starts to come ineffective

10w is the Cold velocity ( thickness )

 

Not necessarily matey - the "w" is indeed the cold velocity, but it indicates the ability of the oil to circulate around the engine at start-up; the lower the "w" number the quicker it gets round. So at full temp, a 5w40 is the same as a 10w40; whereas whilst a 10w60 will, like you say, withstand a higher thermal break-down, it is still thicker at full running temp and therefore probably overkill on all but the highest tuned of engines. Unless you're hammering your car on a track, then perhaps a "50" is the absolute highest grade you'd need - otherwise stick to a 10w40 or, if you want a fully synth, a 5w40 will be fine....

 

Richard:thumbup1:

After a fair chunk of reading, I came to some conclusion as turbo failure wise. The most common reason for failure is improper breather system. this is usually pcv related, because without being able to vent the pressure from the crankcase properly the oil passing from the turbo down the return pipes doesnt pass as freely as it should. this causes a back up in oil, it has to go somewhere this is usually past the rear oil seal. its not designed to hold back much pressure really. if the seal is worn this is even easier, now picture the fact youve taken away the pressure that was making this not the path of least resistance the cats.... so now the low pressure behind the exhaust housing is the easiest route out of the system. you can try replacing the pcvs and hope that this deals with the pressure enough to allow the poil to pass into the sump as it should, you could try replacing the cats applying the backpressure and causing the proper route to be the easiest option for your oil to take. this is often why replacing the pcvs reduces things even if it doesnt cure it. obviously if the seal is too far worn it will still leak no matter what.

the other problem with many turbos is that the small gallery at the rear clog sup with crap, burnt oil etc. this doesnt allow the oil to pass from the rear bearing efficiently and forces it out the rear seal due to a back pressure of oil.

in my case i found one of my pcvs was flipped, and the left hand turbo had oil deposits in the exhaust compressor housing, at idle it barley smoked as the oil pooled up and didnt pass, looking in from the rear nothing could be seen out the ordinary, once apart i realised it was pooling up there and only when the car was pushing enough gas through was it pushing it up into suspension. hence the reason it smoked like a chimeny at 2k but barley at all at idle.

i hope this helps you to solve your problems just by working out a little more the whys.

(personally i wasnt happy just finding the problem i wanted to know the why had it occurred)