Oil Pressure And Exhaust Smoke

[charlie]

Just rebuilt my engine, but problem is when i start up from cold, oil pressure
stays at 5 bar when idleing even when water temp is 90c and fan comes on.
this is when it starts to smoke. but when i blip the throttle oil pressure drops
down to 2-3 bar and smoke begins to clear. I've got rebuilt K26/27 turbo,
3" cat back Milltek, Cat by-pass pipes, Castrol RS 10-60W.

What can it be? Maybe breather system causing high crank case
pressure or can it be oil pump.

I was told by AET turbo that by removing Cats it reduces back pressure
which allows oil to pass through seal as seal on high-brid turbo is metal
not rubber. Putting cats back on might be an option but Turbo spins
alot better without them.

[charlie]

Same problem as below.or is it a common fault after engine
rebuilt.

http://www.s2forum.com/forum/showthread.php?t=10236

[rotoryboy]

I have the same trouble. It only smokes from cold on idle. If you start and drive it, it never smokes. If you start it and leave it to idle , it would smoke all day.

[Doug_RS2]

If you leave the car to idle for a ocuple of minutes, then give it a hard rev and you get the smoke, it is most likely the turbo oil seals.

The removing cats thing only highlights a problem - it isn't the cause of the problem.

Losing oil and water means the headgasket has not sealed properly (assuming the head is not cracked) - after the rebuild was the head put on dry? If it was oiled then you probably contaminated the layers of the headgasket and you have a path for water and or oil into the cylinders.

How big a rebuild have these engnes had?

[nickhey]

I had an AET turbo ( RS2 hybrid ) that smoked from cold on idle from day one.

Took car back to QST after 2 weeks, who agreed to strip and return the turbo to AET under warrantly.

Picked car up 3 weeks later ( !!! ) and it was slightly better, but not completely cured. Was told by QST that the turbo seals had been replaced ( therefore must have been dodgy ).

Problem got progressivly worse and worse again over the next 17000 miles.

End result was that turbo failed in spectacular style. The shaft broke about 1" behind the compressor wheel, and everything else ( turbine, shaft, seals, bearings etc. ) all went down the downpipe, along with lots of oil. ( never seen a smoke screen like that before!!!)

Managed to get around £300 out of QST after lots of 'communicating', and bought a GT30R from tubo dynamics, whic I fitted myself. This incidently does not smoke, at all, ever.

Moral of story - if car smokes on idle and a new ( recon ) hybrid turbo is fitted, take it back to where it was fitted / take it off straight away and ask for money back or replacement.

I was lucky, no bits of the turbo went through to the engine.

Nick

[charlie]

Leak down test carried out and everything was fine before rebuilt. Reason for rebuild
was that head bolts were stretching every 6 months so complete top end done inc.
stem seals, guides, h/gasket and ARP headbolts , new thermo switches, thermostat,
Radiator, water pump, belts, plugs, ignition pack and turbo sent back to AET just for good mesure . The only thing i've not done is clean the breather system.

Just like Rotorboys if you start up and drive off in a few minutes. No smoke at all.
My impression is that its burning trapped oil or when oil is cold it has higher pressure
and this might be causing it to push by some seal.
But its strange that when i press the throttle it stops smoking.

PS: not losing water, no contamination, head was bench tested to 60 Psi
and left on jig overnight at that pressure, dry headgasket.

[BRY]

I had an AET turbo ( RS2 hybrid ) that smoked from cold on idle from day one.

Took car back to QST after 2 weeks, who agreed to strip and return the turbo to AET under warrantly.

Picked car up 3 weeks later ( !!! ) and it was slightly better, but not completely cured. Was told by QST that the turbo seals had been replaced ( therefore must have been dodgy ).

Problem got progressivly worse and worse again over the next 17000 miles.

End result was that turbo failed in spectacular style. The shaft broke about 1" behind the compressor wheel, and everything else ( turbine, shaft, seals, bearings etc. ) all went down the downpipe, along with lots of oil. ( never seen a smoke screen like that before!!!)

Managed to get around £300 out of QST after lots of 'communicating', and bought a GT30R from tubo dynamics, whic I fitted myself. This incidently does not smoke, at all, ever.

Moral of story - if car smokes on idle and a new ( recon ) hybrid turbo is fitted, take it back to where it was fitted / take it off straight away and ask for money back or replacement.

I was lucky, no bits of the turbo went through to the engine.

Nick

Did you see any paper work from AET for your turbo?
I have been told by various people that they are top blokes, and speaking to them has supported this. I am waiting for turbo from Germany to arrive and then they will be looking at my 3.
Face to face is always best

[Habib]

Do a compression test first, If its got good compression on all cylinders then its most likely to be the crank breather pipe that runs along from the back of the head to the side of the block (cranckcase). I had the same problem a while back the hose got clogged up when I did the RS2 mods. A replacement pipe costs approx £10 from the dealers, alternatively you could replace the stock breather system with an oil catch tank.

[charlie]

Just spoke to Grant at AET turbo. He informed me that RS2 has forged pistons and
normally blow by is by cylinder 1 and/or 5. he asked me to check breather system
and then do another leakdown test and inform him of results. He adviced me to carry
out two tests one when cold and second when hot and compare both %.
watch this space. :mischeif:

[rotoryboy]

I'll wait with baited breath

[charlie]

Right. I stripped down pipework before throttle body in order to gain access to the
two breather pipes behind the rocker cover and then sripped down most of breather system at all joint upto crankcase.
To my suprise it was quite easy and most pipes were quite clean
I cleaned the half dome/mushroom pipe in carb cleaner ( or petrol would do)
I then replaced all pipes but not mushroom.
To my suprise the inlet pipe before the throttle body and Samco hoses to the
intercooler were pretty clean. I cleaned the throttle body with Carb cleaner
while i was at it.

Grant at AET asked me to run car withiut mushroom to see how the crankcase
was breathing smoke was slightly better but it was intresting to see how much
smoke came from crankcase as engine got hot. I can definately see an
advantage of having a catch tank cause its amaising how much oil vapour is pushed back into the inlet side of turbo. well i've put everything back together and might take it out for a run and see if it does it tommorrow.

[charlie]

Problem Solved

Read some old threats about catch tanks and it got me thinking.
Stripped down the complete breather system and cleaned it all down.
replaced what was required and installed a motal 1 litre catch tank.
after alot of blood and sweat and swearing in 10 different languages
problem solved.
Car runs alot better obviously no oil fumes being put back into the engine.
Condensation coming out of exhaust ( de-catted)

[BRY]

Have you got any pics?