Hey guys. I have a 1990 745T. Today I had some intermittent problems with a rough running engine. Found a corroded battery connection. Cleaned it up and it runs good again. Funny how it's enough juice to easily engage the starter but not enough to smoothly sustain the engine running.

As I was under the hood reving the engine I noticed that every time I dumped the throttle for a quick rev the hose going from the top of the intercooler to the intake would collapse and then open up again as soon as the waste gate kicked in. IS it supposed to do this? It's only made of rubber. I seem to remember all the intake parts from the intercooler on my Saab were made of hard plastic or aluminum. I'm thinking this is causing me to lose a lot of power and also probably contributing to my poor fuel mileage.

Randy

jmars is correct. This should be a rigid aluminum tube. You can probably get a properly sized tin can and cut off both ends and stick it in the hose to keep it from collapsing but it should be replaced. Tighten a tiewrap around it to keep it in place.

I really don't understand which hose you are talking about. My turbo has a short coupling hose at the intercooler then a longish (18"±) aluminum pipe with an outlet for the CIS system and then a bellish shaped rubber coupling to the throttlebody. If your aluminum pipe has been replaced with a rubber hose you should scour the junk yards for a replacement. Good stable inlet plumbing is crucial to turbo operation.

Randy, that hose is definitely not supposed to collapse so your diagnosis IMO is correct.

Good time to check other turbo hose plumbing for holes/excessive softness.

I used to recommend the cheapo MTC hoses from Fcptgroton.com but it seems a few folks have problems with fit. FCP also carries OEM hoses too for about $145.
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Norm Cook; Vancouver BC; 1989 745T 206,000KM