smoking on over run
Turbo Mini Forums

This is one Im finding a little odd, and to be totally honest, a little nervous about the cause. I'm now running a "nearly new" 1293 purchased from another tm member late last year as the solution to my fried rings on my 1275. I taxed the car last weekend and have been putting a few miles on it to iron out the usual little teething troubles.
The problem I have is I get a cloud of smoke out of the exhaust on over run. There is no smoke on idle, or on boost, nothing out of the breathers, but it smokes on over run after the engine has been reved higly on boost the throttle shut off then opened. the colour of the smoke is grey (may sound a stupid description) I have followed the car with a mate driving and the smoke doesnt really smell of oil, but a little of fuel, but not greatly. As said the engine is nearly new and the head came from Benross last year to cure the problem I had with fooked guides, so am doubting these are the cause (although still a possibility)
Im thinking that the problem is down to fueling being rich, Im looking for a little guidence and reassurance really. The car is booked in for rr session soon, but just want to ensure its nothing else before I go.
All advice welcome.
Thanks in advance
Shane

Have you put too much oil in the dash pot?

Ive had this problem before

Did wonder that myself, but checked and found level was low. My big fear is it is something major.
Shane

Oil pump filling rocker cover?

Own the day

this sound like a classic turbo fooked seals, what state was the turbo in ?
has it done starship miles ?

shane did you run my head on another engine befor ? to eliminate this ?

My NA did that, valve stem seals, have you got them on inlets and exhaust?

Im with Brmatt. whip the cover off and see if the seals are still nicely inplace.

if you can see them through the springs...

Im with ben fucked turbo

turbo on its way out and less than perfect engine breathing system :)

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

yes Steve the head was ran on my 1275, with no smoke issues untill ring failure.
Shane

I wondered this, had a set fail after low milage in the past.
Shane

Turbo wasnt smoking before rings failed last year. but thinking about it i do currently have the breathers piped into a milk carton as a temp catch tank, this could be an issue.
Shane

Right, gonna look into this a bit more tom eve, I will check
Stem seals are still in position.
Remove breathers from carton to ensure no restriction.
remove turbo to plenum pipe and run it to see if it is the turbo.
Cheers guys
Shane

I had a problem with the stem seal lifting off of the guides started a thread about it back end of last year. Happened 3 times Alan at beechgrove managed to sort me out with some seals that stayed inplace.

Own the day

Managed to get out in the garage this eve, I have tried and checked the follwing.
Stem seals are all in place.
Disconnected c/c breathers, still smokes.
Disconnected boost hose to plenum, smokes but less/
Had a good look in the hose ends, the two 90's that come off the turbo have oil soiling (pic looks worse than it actually is) but the compressor housing is clean which has confused me?
WOuld you say by the look of the oil turbo failure is on the horrizon?
If I get the time tomorrow eve I will remove the hoses and clean them then give the car a run to see if it reappears.

Cheers
Shane

i would say shane, its a light oil mist from the turbo, seals are goosed !

it will only get worse

Ho hum, best start the hunt for a new one then, lol. Does anyone have any suggestions for companies to try. At the moment Im thinking turbo technics, aet, ktec racing, and my local rapist renault dealer.
Cheers
Shane

Or rebuild it with the help of the comprehensive guide posted on here a few days ago.

Valve guides/valves.

Take of your inlet and exhaust manifolds and take a look in the ports in for a penny in for a pound. Also wet oil in the copressor outlet is not a good sign, the seals are loosing their battle and as said it will get worse not better.

Own the day

vegard, shane ran the head on another engine set up and that was ok!

the give away here is oil mist in the compression side of the turbo, so the seals are passing, iam not totall ruling out the guides. but.............. this is where you logically go and the symptoms are a classic of turbo seals Goosed!

Going to start ripping parts off tomorrow to get a better idea whats the cause, will update when I have more info.
Cheers for your help
SHane

if you want a standard replacemnet then turbo teqnics is a good start.

i swapped my .25 ar t3 for a .36 ar exhaust t3 for £350 on my door step the next day.

been very good ever since, but if you want to crank it up near 20 psi in the future then you will need some 360 deg bearings in there.

always looking for them bigger bunches of bannanas

Been ringing round today, turbo technics have got a stage one t2 hybrid with 270 thrust, will be ample for the boost Im plannig on running, all going well will have it at the weekend, or early next week for the folling weekend. will update as and I when I make progress.
Shane

Crumbs! That was more oil than I was thinking in the hose