I recently purchased a 91 Volvo 940 Turbo and thus far am completely happy with it. I am noticing some problems though and I was hoping someone may make a suggestion aside from take it to a mechanic.

1. The guy I bought it from said he put in a larger Turbo but that it doesnt have a blow off valve... What problems if any might this cause? ( Ive never owned a Turbo before)

2. Im noticing a burning rubber like smell and when I pop the hood the coolant seems to be bubbling. Im assuming this is bad but I wonder if it may have something to do with the aforementioned turbo.

3. and finally... No thats actually it. I love this car and can't believe the comfort of those seats. Thanks for any help provided.

Chris

 

I can answer your question about the turbo and the blow off valve.


It does have a blow off valve. It is a recirculating blow off valve which returns the relieved air pressure back into the air intake pipe just in front of the turbo compressor to be recompressed. An external blow off vlave simply lets the pressurized air out into the atmosphere and this type is usually the noisey type. (you hear them chatter and hiss when when you let off the gas)

A turbo engine needs a blow off valve to prevent compressor surge which will shorten the life of the turbo.

 

As for point 2: It sounds as though your engine is getting too hot.

At what position on the gauge does the temp needle usually sit?

When does this bubbling happen? After town or highwaydriving?

 

I found the smoke. Seems there oil on the catalitic converter. How it got there I dont know yet. The Bubbly coolant was just low it seems. These cars are alot more comfortable than the MGB it replaced. Im hoping less problematic too.