UPDATE: New Turbo

[FSiLeonMike]

OK, I'll tell the whole story.

Turbo blew (bearing gave out, and did the usual, wore the vanes, destroyed the seal, sucked some oil through the air intake system, lots of smoke)

Got me a recon turbo, tried to de-oil/sludge the boost pipes and inlet manifold as best I could.
Fitted new turbo, did an oil change(charged turbo with oil as per instructions) , and when all re-assembled, fired her up, and left her running on idle for 10 minutes.

Then took her for a drive, nice and slow to begin with, kept below 30mph. did about 3 miles like this.
As expected, smoked quite a bit due to oil residue burning up (guessing there is oil in most places it should't, exhaust, maybe in the intercooler etc)

After 3 miles, decided to give it a little gas. Now, heres my problem. Seemed to pull OK, definitely boost there, then it happened, revs shot up uncontrollably, to maybe 5500rpm.

Managed to get pulled over and stop the engine.

Left it for a 30 seconds, then tried to restart, which it was reluctant to do, but then she fired and all seemed normal, so got her straight home. Still seemed to have boost (didn't thrash it, for obvious reasons, but you can just tell if its boosting.)

By the time I got home, smoking much less, hardly at all actually.

Now, my mate that helped me fit the turbo (a recently made redundant mechanic) said its likely that once i stuck my foot down, and she started boosting, some oil we missed when cleaning the boost pipes etc out may have moved and gone through the inlet manifold and made her over rev for a moment.

Do all you TDi experts agree?

Really would like your opinions

 

[mds1256]

i would say he was spot on....

Seen it happen when a turbo goes and engine runs on its own oil, they just rev uncontrollably so yeah that would make sense so in theory you shouldnt get that any more as it should of burnt off most of the oil

 

[FSiLeonMike]

i would say he was spot on....

Seen it happen when a turbo goes and engine runs on its own oil, they just rev uncontrollably so yeah that would make sense so in theory you shouldnt get that any more as it should of burnt off most of the oil

Bl**dy hope so, frightened the life out of me

 

[FSiLeonMike]

I know I only posted yesterday, but really did expect more response.

 

[devonmikeyboy]

What you mentioned about the oil in the pipeline would explain the car suddenly over revving. The oil would have acted as extra fuel.

 

[FSiLeonMike]

Update, We've checked everything over this morning.

Took it out for another drive. (about10 miles) Much less smoke now, in fact hardly any.

Last nights smoke was white (oil residue burning up?), today, the smoke was not so white, what little there was

Seems to be boosting OK

 

[FSiLeonMike]

OK, so a few weeks on, and an update.

Things aren't right, smokes a lot on start up from cold (OK when the engine is warm)

When pulling away cold, lumpy as hell, almost like a misfire if it were a petrol.

As soon as your away and rolling, all OK, no smoke, smoothes out.

Ideas? (other than sell the car)

 

[zach225]

did you flush the intercooler whilst cleaning boost pipes? if not that may still be causing this

 

[FSiLeonMike]

OK, would that make it shitty from cold? Then OK when warmed up? Intercooler is the only bit that didn't get done.

 

[zach225]

lol thats the first bit i would have done as its the only bit that could 'store' the oil.

i could cause the issue but if its had oil through it it would definitely need doing,

you say its lumpy when cold, it isnt just that its bad at idle?

 

[zach225]

lol thats the first bit i would have done as its the only bit that could 'store' the oil.

i could cause the issue but if its had oil through it it would definitely need doing,

you say its lumpy when cold, it isnt just that its bad at idle?

 

[FSiLeonMike]

lol thats the first bit i would have done as its the only bit that could 'store' the oil.

i could cause the issue but if its had oil through it it would definitely need doing,

you say its lumpy when cold, it isnt just that its bad at idle?

Smokes pretty bad when I start it.

I was thinking myybe a burnt out glo plug on 1 cylinder?

Also idles badly when cold, and have to rev it a bit to pull away.

Once rolling, smoke completely clears (like after 10 seconds or less), and then will idle bang on 900rpm, no fluctuation at all.

 

[zach225]

oil going through the engine could definitely cause a glow plug to fail, although i would have thought it would be a constant issue not just something when cold, i'm at a loss mate... maybe swap it for a yaris or something

 

[FSiLeonMike]

Surely glow plugs would only effect a cold engine, as thats their purpose, to heat cold diesel prior to starting. Once the engine is running, they do , well, nothing

Yaris, maybe not, but swapping it is an option

 

[Murf]

I would pop the i/c off and flush it out, my dads turbo blew the same way as yours on his golf and the entire intake system had to be flushed, there was literally oil everywhere!

 

[muddyboots]

Here's a theory, see what you think:

If you lost a fair quantity of oil into the intake, it's probably pooled in the bottom of your I/C - or the hoses if they're any lower than the IC itself. (Assuming it's a side-mounted jobby ?).

Now, when the car's been left standing for a while, all the oil in the intake pipework will all drain back down to the lowest point. If there's a reasonable quantity, it will be enough to block (or substantially impede) the airflow through the intake.

When you start up, the car will start and idle with no boost from the turbo, so instead of air being forced in by the turbo, it's being sucked in by the engine - just as if it was a n/a engine. If oil is blocking, or partially blocking the intake, then without any assistance from the turbo to force air through, the engine won't be able to suck enough air to burn the fuel properly, leading to a lumpy idle, and quite possibly causing the smoke (because fuel not all being burnt).

When you drive off, the turbo will start to generate some boost and force air through, so the engine will start to run OK.
In doing so, whatever oil is in the intake will get blown up through the intake, spread around the walls of the pipework etc, leaving a fairly clear path for the air.
(First time you ran the car, and gave it some beans, then there was perhaps so much oil that some actually made it through to the engine and was used as fuel, causing the runaway that you mentioned. But now there's not so much.).
But then when you switch off and let the car stand, the oil will gradually all drain back down to the low point, restricting the airway again and causing problems next time you start.

Should be easy enough to prove - disconnect the lowest pipe connection to the I/C - or whatever joint is lowest in the system if it's not the I/C.

See what comes out...be interesting to know if my theory is anywhere near the truth or complete rubbish

 

[muddyboots]

Wouldn't have though a glowplug would cause an issue at this time of year, I doubt they'll even be switched on at all at these temps.

 

[FSiLeonMike]

Here's a theory, see what you think:

If you lost a fair quantity of oil into the intake, it's probably pooled in the bottom of your I/C - or the hoses if they're any lower than the IC itself. (Assuming it's a side-mounted jobby ?).

Now, when the car's been left standing for a while, all the oil in the intake pipework will all drain back down to the lowest point. If there's a reasonable quantity, it will be enough to block (or substantially impede) the airflow through the intake.

When you start up, the car will start and idle with no boost from the turbo, so instead of air being forced in by the turbo, it's being sucked in by the engine - just as if it was a n/a engine. If oil is blocking, or partially blocking the intake, then without any assistance from the turbo to force air through, the engine won't be able to suck enough air to burn the fuel properly, leading to a lumpy idle, and quite possibly causing the smoke (because fuel not all being burnt).

When you drive off, the turbo will start to generate some boost and force air through, so the engine will start to run OK.
In doing so, whatever oil is in the intake will get blown up through the intake, spread around the walls of the pipework etc, leaving a fairly clear path for the air.
(First time you ran the car, and gave it some beans, then there was perhaps so much oil that some actually made it through to the engine and was used as fuel, causing the runaway that you mentioned. But now there's not so much.).
But then when you switch off and let the car stand, the oil will gradually all drain back down to the low point, restricting the airway again and causing problems next time you start.

Should be easy enough to prove - disconnect the lowest pipe connection to the I/C - or whatever joint is lowest in the system if it's not the I/C.

See what comes out...be interesting to know if my theory is anywhere near the truth or complete rubbish

Actually, that sounds spot on, thank you

 

[muddyboots]

Actually, that sounds spot on, thank you

Only guessing, be interesting to know if it's right !
EDIT: I wouldn't be too concerned about getting every last trace of oil out of your intake pipework. They're normally pretty oily anyway when everything's OK (just not big pools of the stuff!)