A4 on Highway

[Jaymatic]

I just had an oil change, coolant flush, and tune up and am still getting crappy gas mileage. Just to make sure my TCC in my A4 isn't bad, what do you guys with A4's have for RPM's at 65 mph on the highway. My car is a 1996 stock 3.8L and cruising at 65 on the highway I am at 2,000 RPM's. I would say that is normal but I just want to make sure. I think I saw somewhere in a post a while ago that 2,000 to 2,200 RPM's on the highway is normal. My car also shifts a little hard too, not real hard, just harder than any other automatic I've driven but I've always assumed it was the nature of the car since my friends 1990 5.0L automatic Camaro does the same thing.

I am also going to check my catalytic converter this weekend to make sure it is not clogged or anything.

[Dekay]

Check your o2 sensor?

[Linxs]

Change your fuel filter lately?

[hawgs]

2000 for 65 is about right... but that also depends on gears.

With 3.42s at 65-70 I am about 2000 RPMs.

How is the air in your tires? Low? The other posts are good things to check too.

[Jaymatic]

I have 3.08's with the open differential. My tire air pressure is about 33 psi. I am pretty sure the fuel filter was recently changed but I can check again. And yes, I am going to check my o2 sensor along with the cat this weekend.

[Dan Vincent]

You're locking up pretty good according to your RPMs - I'd say the culprit is 02s (if they haven't been changed, it would be a good idea to), and how's your intake/air filter? PCV Valve?

[Jaymatic]

Originally Posted by Dan Vincent
and how's your intake/air filter? PCV Valve?

Didn't think of that. Thanks man, thats something I will check.

[chas]

to check your tcc just get up to 65 or so and watch your rpms. now, lightly (enough to just light up the lights in the back not stop) tap the brakes. this will make the pcm release the tcc and your rpms should go up by a couple hundred for a few seconds and then the tcc will engage again and the rpms will drop back to the previous reading.

oh yeah, for those in colder climates the tcc will not lock up unless the transmission is at 'normal' operating temperature (10-15 minutes of running).