E36 S50B32 rough running/ smoky exhaust

[nzodea 25]

Bizzare situation.

qualified the car at a recent race day and it ran great temp/oil pressure all in place.

filled up with gas for the main 1 hour endurance event drove to the dummy grid basically at idle. turned off engine. turned on to go onto track and there was a plume of smoke out the back. did one lap with it spewing smoke out and pulled in.

no obvious hoses off. temp and oil pressure all good. very rough idling. gotten progressively worse

Decided to turn it off and try and diagnosis later. very rough idle now which gets worse each time it starts (barely starts now)

No obvious sign of a head gasket gone (no oil in water system, no milkyness in oil when pull the oil filler cap). drained the fuel system - no obvious contamination.

does anyone have any thoughts or ideas before I take it in to get looked at??? Wondering if there is some sensor, breather or something that might be a known fix.

any help is appreciated.

[kerry 10]

hi. you are positive you put petrol in it not diesel !

[hybrid 1039]

Pull the plugs and have a look, fire some photos up here (800x600 res) they should be greyish in colour with mild carbon build up.. not oily or burnt

What colour is the smoke?

Have you had it scanned .. my bet by now is the o2 sensors would of at least throw an error? can help out if your stuck with the scan.

yeah as kerry said .. did ya chuck desiel in ?

other things to check are vacum inlet pipes (post MAF and intake plenium boots)

Are you still running your emmissions pump and lines ?

[Jamez 2147483647]

I have blown two headgaskets on my s50b32 and both times it made no sense at all and never smoked. The only way I know it has blown the headgasket is when it over heats when revving over ~5500.

Also if the plugs are dirty the S50 really struggles to idle. My S50 sounds like a rotor with dirty plugs.

[swordfish 30]

Hey mate are you in Christchurch? What colour is your car? To me it sounds like a gasket as well to be honest! Have you revved it before you turned it off? Maybe it was very warm? I usually let mine run for 5-7 minutes if I stop on the pit stop on the track before turning it off... Just to cool it off!!!

[nzodea 25]

hey guys

thanks for your feedback and help. out first thought was a gasket. but we drained the petrol tank to check the fuel and we found the fuel was a different color from another jerry can sample. I tried to load a picture of the different color but the system will not let me sorry

looked OK but when compared obvious difference.

was BP ultimate 98 from BP stockburn.

Swordfish - yes in CHCH.

thanks for your help.

going to the trackday tomorrow hopefully with some fresh petrol and some injector cleaner. Don't get behiond me for the first 10 or so laps!!!

[Greg111 13]

Obviously you've checked all air hoses etc, my one got a big gulp of oil in the plenum last year at the track which in turn blew the breather hose from the sump to the plenum off, these engines along with a lot of others don't like air leaks, will run very rough with a leak.

[swordfish 30]

hey guys

thanks for your feedback and help. out first thought was a gasket. but we drained the petrol tank to check the fuel and we found the fuel was a different color from another jerry can sample. I tried to load a picture of the different color but the system will not let me sorry

looked OK but when compared obvious difference.

was BP ultimate 98 from BP stockburn.

Swordfish - yes in CHCH.

thanks for your help.

going to the trackday tomorrow hopefully with some fresh petrol and some injector cleaner. Don't get behiond me for the first 10 or so laps!!!

Awesome!!! Good news! Good luck tomorrow!

Edited October 13, 2011 by swordfish

[nzodea 25]

Awesome!!! Good news! Good luck tomorrow!

So my mate/co-owner goes out and does a 1.39 in it after only ever having done a 1.41 before.

so I think we can say issue solved. thanks for your help

[swordfish 30]

So my mate/co-owner goes out and does a 1.39 in it after only ever having done a 1.41 before.

so I think we can say issue solved. thanks for your help

That is good to hear. Not a bad time as well. What track days do you usually go to? (e.g. BMW ones or from the club?)