hey guys, i have a 91' 740 turbo wagon and when im on the freeway or doing like 70mph+ the revs are start getting really high, up to like 5000 (not accelerating) is this normal, i know this car has only 3 gears, but is there anything i can do? It seems to be buring ALOT of fuel, after like 10 min on the freeway, i can see the fuel gauge go down a good amount, maybe 1/8 - 1/4 tank gone. I also dont mess with the overdrive and the overdrive off light is not on.

thanks

 

I have a similar problem with my 240, but about 3600 RPM at 110kph, it's turning out to be either a faulty overdrive relay or the overdrive soleniod.... 5000RPM sounds quite high in your case though. Could be the overdrive has stoped working, or it might be the gears are not changing... Do you hear any gear changes? It might be stuck in first or second gear... Check that the transmission fluid levels are okay...

 

It is switching to 3rd fine, if i dropped to 2nd at those speeds, the engine would blow.


The overdrive light under the gauges should be off right? (that little orange arrow facing up on the bottom right)

 

Yes, when the orange light is off the overdrive is on, so the RPMs should be higher when the overdrive is off (i.e. orange light on), if there is no difference either way then I think something is wrong with the OD.... When did the problem start? Air leaking into the engine can effect fuel consumption, and revs too? Anyone know? (or correct me if I'm mistaken...) My OD is not working on my 240 and I get 4000RPM at 130kph (hoping to get it fixed next week though!)...

 

the engine did overheat once when racing on track, and the seals could be messed up

 

I just found that my Volvo jumps to nearly 6500RPM if I put the peddle to the floor... Don't think I will be doing it again though!