Burning Smell and Performance Improvement

[Simon P]

Hi all,

My ongoing relationship with my 1998 V40 2.0T has taken another interesting turn.

I had mentioned some problems with an apparent flat spot (see here) which has now gone, the car feels much more responsive and I get a muce more apparent feeling of boost from about 2.7K-3.5K which I had not been aware of for a long time. The only thing I have played with was the take up one turn of "slack" in the waste-gate actuator hoping to seat the bypass more firmly. There was no apparent change immediately after this tweak, but after several days/weeks it's got more consistently better. I was wondering if this might be because of the EFI system taking some time to adapt to the change in engine conditions? Also now, if I drive the car hard, I have much worse fuel economy than I used to get - but the new power is worth it!

This all sounds good, but the downside is that I have started noticing a burning smell when I stop the car and get out (to me it's a combination of a burning plastic/oil smell). I cannot trace exactly where it's coming from, I've tried smelling each wheel, and under the bonnet and there's no single place that the smell seems to be coming from. If I stop, get out and restart the car (like when refueling) then there is a strong burnt smell in the cabin, so my personal feeling is that it could be under the bonnet, although there's no signs of any smoke.

Could these 2 things be related, and my new boost is causing oil to leak and be burned off somewhere? What do people suggest I can check?

Finally in relation to my old fuel/power problem (here) this seems to be less apparent also with the new increased power/boost I'm getting - again I've not replaced the fuel pump/pressure reg yet. Is it possible that my fuel system has "fixed" itself, and the improvements in power are related to this?

All advice, suggestions gratefully recieved

Thanks

Simon (loving his Volvo again!)

[Simon P]

Sorry for the shameless bump on this, does anyone have any thoughts or suggestions? I have the opportunity to have a good nose around under the thing this weekend, would like some ideas of things to check.

Thanks

Simon

[Rooster]

I used to get same thing with my 2.0t, usually when driving steady through town, but it didn't have any oil leaks anywhere on engine,

Could just be things been warm i suppose, i never managed to trace what it was

[TicklyT]

Had similar with our Renault Kangoo a while back. Flat spots, hunting at idle cutting out when cold, and odd smells.... Sometimes it smelt like we were running the engine on creosote!

It turned out the lambda sensor had died, and had eventually taken the cat with it

[Mutley1]

I sometimes get that burning plastic/oil smell on my 2.0 t as well. It normally seems to come from near the rear. I haven't tracked it down yet either.

[Rooster]

I don't have a cat on mine so its not that

[Simon P]

The smell is not that kind of eggy smell I've always associated with catalytic converters, and the smell is not stronger when I approach the exhaust. It's due for an MOT within the next month, I guess a duff Lambda senson/toasted Cat would show up in the emissions test?

[wa666ou]

Maybe turbo oil return line is leaking? It's cheapest fix...
You can see it best from under the car.

[Simon P]

I'm definitely thinking that it's an oil leak somewhere, the car's never consumed oil in the past, but today I checked the level and it needed about 2L to top it back up. I'll get it up on ramps, and see if I can see an obvious leak. Hopefully it'll be a cheap fix. Will post findings here.