DWNYC

Hey guys,

I bought my GS 350 AWD with 29k miles. It runs as expected (with the rattles which for the most part are fixed) but once in a while, I smell something burning.

I did a search and it seems like they are relate to break in period. Obviously mine is not the same. The smell resembles something like hot machine oil (not burning engine oil and not electrical burning smell).

The smell seems to be noticable only when I driving it hard in snow (i.e., patchy snow on the roads) when the AWD system is probably engaged. Anyone experience this? Seems odd that a smell would come from making the AWD system work. Just want to make sure I'm not burning something up. Note, I'm not actually driving it that hard in snow but was testing out the handling in snow up slight hill etc during the snow storm in PA. I'll probably mention it to service person at next oil change but wanted to see if anyone has any insight or any thoughts on some other cause.

Thanks.

BinaryJay

The AWD system is always engaged regardless of traction. That's why it's called AWD and not 4WD. So you can disregard that.

If the car has been recently sprayed with rust proofing oil, then it's going to stink for a while if the place it was done is anything like my place (Krown). They spray everything, engine bay and exhaust components. They get hot, and burn the oil off for a while.

Go smell your exhaust (sniff it, don't start enjoying it too much) and see if it smells like what you're describing. Use your nose and smell around the car to try to locate where it's the strongest.

Obviously check for leaks under the car after driving and all of the fluids are hot. Could be, I suppose, that one of your differentials is running dry. I don't know what burning transmission fluid smells like, but you can try to see if it gets worse by going to sportshift mode and shifting it up and down a lot more than usual to see if the smell gets worse.

*Batman*

I sometimes get a burning smell from my brakes, but that happens on every car I drive when I drive aggressively.

DWNYC

I figured someone would say this. What I meant about AWD being engaged is that the system obviously is working more when surfaces are slippery. Only perfect roads with tires at equal pressure and same tread depth, the AWD system probably is in its neutral state (i.e., doesn't have to redistribute power). I was concerned that prolonged driving on slippery roads with different traction on left and right wheels would be tantamount to driving a prolonged distance with tires are different pressures or different tread depths. Of course I wasn't driving that long but trying to figure out the smell that seems to only appear when I was driving around in the snow. I wasn't doing too much breaking either. Perhaps the AWD system uses breaking to control tire spin....

BinaryJay

All trac systems use the brakes to control wheel spin etc. There isn't really a neutral state for the AWD system. Default is 70% rear 30% front and it can change that up to 50/50, but I wouldn't say the system is working any harder in any given situation.