As I stated does the '87 740 GLE wagon have an EGr valve? It is a 50 state car if that matters.

The reason I ask is that the MPG have been in the 15-19 mpg range and it seems to cut out or stumble when driving near 55 in overdrive.

The car is my girlfriends, I asked my mechanic about it, his first thought was to check the EGR valve, but I can't find it or any thing online saying that it has one.

I keep reading about the flame trap and oil separator. She has all the records from the car and I see nothing about them being cleaned or replaced, so it that something I should do?

 

I was doing some more reading and came across something mentioning vacuum lines for the cruise control. She recently had the front main seal replaced and that is when this issue started. But the car had been sitting for 5 months prior to this. And when she tried to use the cruise control the other day, it did not work.

 

EGR valve should be next to the oil separator directly under the intake manifold #3 runner, IF the car has one. Getting to it and servicing it or replacing it is best done with the intake manifold off...

Vacuum lines along with the rubber t's and l's are the most common cruise control problem. Inspect them for leaks and disconnection: from the pedal switch(s) inside to the pump under the hood, from the bellows at the throttle to the pump. The switch sometimes gets out of practice-work it back and forth to coax it into service...

 

The CC was disconnected at a T. Thanks for the help. I hope it fixes the mileage issue too!

 

No, that won't help you mileage... I'd not be looking at the EGR first... Try a good tune up first... the car should be getting 25mpg on the hwy...

 

Really? I get 16 mpg in mostly hwy driving with an 88 volvo 240 wagon.

If i could get better i would be quite pleased.

 

As they say, 'gas mileage will vary'... But a well tuned Red Block should be able to do mid twenties driven conservatively... My '85 740 with the manual trans does easily 30mpg hwy. But they have to be in good shape: well tuned, good tire pressure, etc. A lot of older Volvos that are worth little get no respect from their owners and are only on the road because they are well put together and the drivetrain is virtually indestructable.

 

Hm, well I only recently got mine (2 months ago) and I have been trying to fix up as many things as I can think of but I still get the miserable mileage. Obviously it's some combination of things I haven't reached yet.

 

Start with a good tune-up. Is the engine relatively healthy? Inflate your tires to 36PSI... Don't drive too aggressively-that's the major difference IF you want to get better economy.

 

Yeah, I suppose a proper tune up is a good place to start. None of this driveway haynes manual stuff for the tune up.

THANK YOU for telling me the PSI. In all the cars I have owned, I can never get straight f*****g answers on the PSI. I guess it's just something so obvious to everyone else, but it's one of those bits of info no one ever shared. Kinda like when you teach someone to drive standard but they can't car started and you rummage around the engine and try various things until it clicks that they wouldn't know to push the clutch in and you wouldn't think of it because it's so basic.

 

Tire pressure is pretty important, and these days few drivers pay attention to it. It affects mileage, tire wear, and the way the car handles: if you got 24 in one, and 36 in another you may get a pull that will make you think you have a major problem... Once a month check tire pressure!