1998 Impreza Turbo burning smell
 

Hi, I have just bought this car and have a couple of questions. When I was looking around it there was a bit of light smoke coming from the turbo area. This has since stopped but there is a lingering burning smell coming from under the bonnet. Also the air filter was missing, the previous owner had removed the air filter and ran it without (idiot). I have cleaned the maf with contact cleaner and the car runs well, the idle seems smooth and the car is performing well. The check engine light works but has not come on so do you think the maf is probably ok? Could it have survived running without a filter? The oil was quite dirty so I changed it, no doubt not helped by the unfiltered air. It's done 112,000 and has full Subaru history up to 75,000 when it had a belt change.

I know it sounds a dog, but it runs really well and apart from piston slap for 60 seconds when cold (normal?) is smooth and quiet. It's also not as thirsty as I was expecting and has 10 months mot. Hope I'm not going to be told I was ripped off!

You bought a car knowing that the guy before was running it with no air filter?????????

No, I found out after I bought it. The guy was an idiot, but the car seems good apart from what I have mentioned. It was quite cheap

its probably the driver side rocker cover gasket thats giving off a bit of smoke possibly. the driver side always goes because its next to the turbo which gets very hot and perishes the gasket. be about 100 quid to get it changed or diy if ur handy with the spanners.

This.

And yes, piston slap is normal when cold on that age range.

The MAF on these cars is far more robust than the later 99-00 so if it is running well do not worry about it.
Running without an air filter? What an idiot, agreed. Not only does crap enter the inlet tract but the car can run very weak.
As advised above, a common fault is a drip of oil from the cam cover on to the exhaust heat shield, usually on the driver side. You then smell the drip burning off on the hot exhaust. We remove seal and replace the cam cover for £30 or remove cam cover, replace gasket and half moon rubber seals for £30 plus cost of rubber gasket and half moons.

Yes a complete imbecile. No doubt a bit of grit entering the turbo could have been interesting. I have looked at the cam cover and I don't think its leaking, the smoke is coming from around the turbo. I will recheck though, where exactly chould I look, or could it be the turbo feed/return pipework? thanks

latest
 

I went for a short drive tonight. When I got home there was quite a lot of smoke, I could see it before I opened the bonnet. The engine temp is stable and the gauge stays just below the middle area. But this smoke production has got me very worried now!

smoke
 

Ok, had a better look and your right, it's oil dripping from the bottom of the rocker cover and burning on the exhaust. How hard is this to change? thanks

I had the same thing. It took about an hour for the workshop to change it.

Probably not a big problem just find a reliable honest garage with Subaru experience. Not always an easy task.