So those of you who are keenly following the fascinating saga of my Passat will remember that the turbo went recently resulting in loads of oil blowing through the engine amongst other things. Well I bought an old turbo and fitted it – not without faffage – and it kind of works, but I can only get 10psi of boost instead of 14.. however that's by the by.

The car's now taken up smoking. This could be either

a) the oily crud that ended up in the air intake coming through
b) the new turbo's knackered also
c) the car was run low on oil when it was driven home and the rings are knackered.

The smoke was originally blue/white and there was tons of it, now it's just a bit of blue but it smells acrid like burning oil does. It only does it when you blip the throttle, and you only get it when driving when you either floor it or change down to get higher revs. Not really there when driving along.

I was expecting smoke under full throttle because there's now less boost so I need to reduce the fuelling.. but that should be black smoke..?

Turbo blown.

Try posting here – uk-mkivs.net

don't worry about it

Mis read your first post. Are you saying the smoke is getting less? As long as the oil's not going too then it's just cleaning out all the gunk the broken turbo dumped into the system.

Did you flush out the intercooler? They often fill up with oil when turbo's blow.

Definitely got a lot less within the first 5 mins, but is still smokey.

No intercooler, unfortunately.

Any ideas on how to clean out an inlet manifold that's attached to a head? Tried de-coking spray…

Without ripping the engine apart you'll not clean the insides with sprays etc, without going through tons of them. Just drive it and keep a close eye on oil levels for now. Oil on boost and downshift do suggest your replacement tubby might also be dead. You didnt rev it on the first fire-up after new turbo did you? No oil in tubby = dead seals and bearings if you're not lucky.

I gave it a few 30s cranks with the fuel cut-off solenoid disconnected to try and get oil circulating. I also checked the oil which was mysteriously off the bottom of the dipstick. Now it may have all leaked out when I moved the car with the turbo off.. but I can't imagine it ALL did. Consequently I am worried that it was driven with far less than I thought to get it home.

Boost is low, also seems to take longer to get there than it did before. With the previous one the boost needle snapped up to 14psi, now it takes a second or so to climb.

If you didn't fit exactly the same type it could take longer to build boost and get lower boost. You could have a wastegate leak, or an actuator vac hose blockage (less likely). Rule them out before assuming the turbo is dead. Check the wastegate shuts completely and positively with the force of the actuator, and check the actuator hose for blockages.

It was exactly the same in theory – same fittings and whatnot, same manuf code but a few different numbers elsewhere – batch codes or something.

However it had a different shaped wastegate actuator arm (requiring a bodge) and a very slight difference in the exit angle from the compressor, so the tubes are a bit stretched.. might be leaking, explaining less boost I suppose.

Wastegate was a little stiff but I freed it up and cleaned it in the process of fixing it. The hose nipple on the wastegate actuator had broken off, so I used the old actuator off my old turbo. It may have a different throw or something on it.. could be part of it.

I think I'm gonna fix the *ahem* mysterious new oil leak coming from the oil return hose *cough* and then let its new owner drive it smoke and all, see what happens. Good long run might burn it all off.

My dad replaced the line form turbo to throttle body on our old fiat 1.9td with reinforced hose pipe, that got the boost (or at least the indicated boost on the dash) up loads, so presumably it wouldn't take much to make it drop a similar ammount.

My car gets through a lot of oil, but the exhaust is clear almost as soon as its even slightly warm. If its visible/smelling then you should see an apreciable oil consumption.

On a side note, will I die after overfilling my midget with oil? It's 3-4mm over the top line. Miss calculated and put about 100ml too much in, presumably it will just burn it off a little quicker? 🙁

As far as I understand it, overfilling slightly isn't a problem.. your risks are increased pressure over the oil leading to oil forcing out of the crankshaft seal, or.. something else.

You know you can stick a bit of tubing down the dipstick hole and suck some out? Do use clear tube tho, you don't want a gobful of that.

Re turbo, due to the design if anything leaked I'd get more boost not less – the wastegate uses positive feedback.. either that or there'd be no boost at all which I had before I replaced the control hose.

Overfilling can cause issues, but 3-4mm is fairly minimal.

Yup, the actuator releases with positive pressure, so it depends if your 14psi was normal or high and you've fixed the leak 🙂

Different actuator might not be pre-loaded properly so slight leak?

It's the same actuator tho, had to bodge the old one cos the new one was broken.

14psi was as much as I could get out of the old one 🙂 I reckon I must've got a dizzying 85bhp from that… Interesting about fixing a leak. I'm actually usign the same wastegate to compressor hose cos I didn't have one on the new, but maybe I could add some sort of pressure release valve to simulate a leak? Having said that, 10psi max is pretty low, most people can get their k03s up to abotu 18.

I'd ask on the relevant engine forum but they're a bunch of weirdos, I'd rather ask STW 🙂