Hi wondering if anybody on here knows what my problem is given the following fault symptoms. All help appreciated .. :o

I have a MK III Supra Single Turbo, I want to keep it desperately if at all viable. The problem starts perhaps 2-3 days before it gets worse. lets say 2-3 days ago you start it and you get some vibrations as if the timing is out not firing on all cylinders etc. Due to work constraint s you are not able to look at the problem for a further 4 days. Hmm too late perhaps. I am driving to work i am doing 75 mph the turbo is spinning but it is not being caned perhaps 1/2 boost, suddenly with no mechanical noise the exhaust starts blowing extreme smoke - huge cloud. At this point i have perhaps 1/4 mile left then park. Some hours later a friend who knows more about engines than i do takes a look> this is what we discover..

First turn engine over, it starts readily, although friend says it sounds like it is not firing on 6, he says more likely 4/5 cylinders. There is at idle no emissions from the exhaust. As it is Auto we boot it in Park to around 3-4'000 revs, at this point plumes of smoke, the smoke stinks of pure petrol, after foot removed from throttle, small emissions from exhaust more than previous idle. Now i am an amateur, but took it perhaps 400 yds down the car park, the turbo boost indicator needle lifts and there is no excess noise.

From what i know can i rule out..

a) Head Gasket - no emissions at initial idle, no residue on filler cap??
B) Turbo - simply due to the fact the needle still indicates turbo activity??

I suspect something to do with the ignition of fuel that has failed, no emissions intially due to coping with fuel, then 3-4000 revs cant cope with fule volumes and blown thru exhaust? Or is this just wishful thinking? I am thinking it cud be as simple as stripping a couple of plugs or belt teeth are these posibillities or even ignition sequencer chip problems akthough i an fudging around here a bit and have no idea how to test this.

Please if you recognise this, advise me as bin or keep the car to be decided on whether this is a viable repair job or not.

Thanks in advance..

Dave

Hi,

I'm an amateur myself when it comes to all this, but my understanding is this...

Firstly, I don't think you can rule out the Head Gasket given that you say it sounds like it may be running on 4 or 5 cylinders. Whilst the filler cap is a ready indicator, it isn't a definite way of confirming one way or another - for that, you would need to check the compression on each cylinder and also I suggest check the coolant for exhaust contamination (there's some kit that can do this apparently). Hopefully though your assumption here is OK ;)

As for the smoke, I've been led to believe that most "plumes of smoke" incidents are generally turbo-related. I suppose that knowing the colour of the smoke would be a help as this can give a clearer indication - i.e. white, blue, black.

As a novice, I'd hesitate to try to diagnose such a problem myself without more info, but (and I'm sure others can correct me if I'm wrong) I'm guessing that this could be the oil seals in the turbo that have failed. If that's the case, then it's definitely repairable :)

Good Luck!
Tony