Oil contamination, turbo surge & intermittent heavy smoke.

[Saab93TiD]

Saab 93 SS 1.9tid 16v (150bhp) 2005

Hi all,

I'm a little stuck to say the least and could use a little help.

The problem:
Currently i am suffering from 3 issues amd dont know where to go.

1st issue - Turbo surge. Occassionally under acceleration i am experiencing a lot of surge, however this doesnt happen all of the time. Under heavy driving the engine appears to lose all power and go into what can only be explained as "limp mode" however of i turn the ignition off and then back on the issue is resolved.

2nd issue - Diesel in oil. Oil all over EGR and TB, i clean these often.

3rd issue - Lots of (white/grey) smoke out of the exhaust after around 20 minutes, loss of power, MPG drops rapidly.

Before anyone suggests its the DPF, let me tell you, its not. I have tried 3 different DPF's.

Aside from the issues above, the car runs amazingly and is very quick day to day with an average MPG of 60 over 1000 miles.

Any help is more than welcomed.

Regards,
Sam.

[Jimmyarm]

The surge is probably the engine picking up the oil/diesel mix that is building up in the intercooler and pipework, the ECU detects an overboost situation and kills the turbo to prevent damage.

I'd start by cleaning out every single breather pipe and replacing any PCV valves and see if it improves. You need to find out why so much oil is getting into the inlet tract, it could be the turbo oil seals going...

[paintman]

Need to sort why diesel is getting into the oil. This MAY be the source of the rest of the problem but it certainly isn't going to do your engine any good having its oil diluted.

[Saab93TiD]

Would a faulty injector seal possibly be the cause of diesel in the oil? I have checked the turbo and it seems fine, however there is a lot of oil build up in the air intake system.

[stevieturbo]

Saab93TiD said:

Would a faulty injector seal possibly be the cause of diesel in the oil? I have checked the turbo and it seems fine, however there is a lot of oil build up in the air intake system.

Not familiar with the engine, but yes it would be possible in some other common rail setups where the injectors dont seal correctly into the head, and the injectors are inside the rocker/valve covers.

[bearman68]

I would imagine the fuel in the oil is a major concern, and prob the root cause of the whole lot of issues.

Injectors are leaking directly into the combustion chambers, diluting the oil, possibly passing through the turbo seals. The injectors leaking make fuel pressure control in the common rail unpredictable, and outside the normal ECU parameters, so it goes into limp mode.

I would suggest checking the signal wire from the common rail pressure sensor with a multimeter. You're looking for about 1.5v on idle.
Switch it off, and the ignition immediately back on - you should see a gradual decline in voltage (pressure) from 1.5v to 0.5v in about 10 seconds. If you are getting an immediate pressure drop, it might be that something is wrong. (Sometimes this test needs to be considered with caution as the ECU will dump pressure)

[350zwelgje]

Does it have a diesel particle filter?
If yes and old generation: ecu pumps additional diesel in the engine to burn the filter clean.
This system has many drawbacks and can cause all of your issues:
- too much diesel and it ends up in the oil even to overfill the engine that could kill it
- white smoke is unburnt diesel that should be burnt in the filter, if not white smoke
- engine sensors go mad due with ecu and turbo doing what you are experiencing....
Ecu reprogramming, as done by the manufacturers, could cure this.
Best to check saab sites/specialist/ diesel specialists that can help you.

Rob