My car is running at 4000 RPM at 25 mph. What is going on?

August 21, 2008 10:00 AM

My car is running at 4000 RPM at 25 mph. What is going on?

I drive a 98 Mitsubishi Eclipse. I was having what seemed like fuel line issues before now. After driving on the highway, the car would stall out at stops and need to be restarted, but would drive fine if speed was maintained. I found that turning the overdrive off kept this from occuring.

Didn't really have the money to look into it, so I've been driving it this way, which was maybe a terrible idea in hindsight. This morning while driving the car seized or sputtered, and afterward the car was hitting 4000 rpm's when i was only going 25 mph. It would go higher if I tried to accelerate past that.

A buddy suggested it may be an engine controller, and I've felt like there was a possible fuel line issue for a while, but I'm too ignorant to be sure. Any help would be very appreciated.

posted by bend2squares to travel & transportation (10 comments total)

Try putting it in second, to force it out of first gear.
posted by notsnot at 10:06 AM on August 21, 2008

Sounds like transmission fluid.

Isn't this one of those AskMe threads where the response is going to be "go see a doctor, NOW"?
posted by KokuRyu at 10:11 AM on August 21, 2008

Some automatics (which from the overdrive reference is what you are driving) go into a fail-safe mode when there is a problem with the transmission where it will not let you go out of first or second gear.

I am no mechanic, but i can see the logic. Its enough to get you to limp to a mechanic, but not enough to thrash the hell out of it.

Bottom line is, you are going to have to get someone to look at it. If it is the transmisison then be prepared to take a hit in the wallet. I have just this week had to write off a car that had pretty much exactly the same problem.

So yeah.. i hope its the fuel line too ;)
posted by TheOtherGuy at 10:15 AM on August 21, 2008

damn shoulda previewed:

(which from the overdrive reference is what I assume you are driving)
posted by TheOtherGuy at 10:17 AM on August 21, 2008

Some cars have a "limp home" mode where they run rich and limit you to second gear (in an automatic). Do you have any check engine lights on? But yeah, mechanic.

Other possibilities are throttle body or mass airflow sensors, although that doesn't really explain the high revs.
posted by electroboy at 10:21 AM on August 21, 2008

oops, basically what TheOtherGuy said.
posted by electroboy at 10:21 AM on August 21, 2008

....with the caveat that it's not necessarily a transmission problem. Here's a good synopsis of the "limp home" setting.
posted by electroboy at 10:23 AM on August 21, 2008

Upon further investigation, it looks like you might have the Ultradrive transmission. If a mechanic confirms that the problem is with the transmission, it might be worth some digging to find out whether Chrysler will repair or replace it for you.
posted by electroboy at 10:31 AM on August 21, 2008

It is possible that the kickdown cable is stuck. This cable goes from the throttle to the transmission, and if it is stuck, the transmission will think that you are flooring the gas pedal and stay in lower gear longer. (4000rpm at 25mph sounds like first gear.)

Have you tried accelerating closer to the redline and seeing if it will eventually shift into 2nd gear This would support the stuck kickdown cable theory.
posted by qvtqht at 10:49 AM on August 21, 2008

(1) Limp home mode (as discussed above)
(2) Fuel issues:
____(a) fuel line
____(b) spark plugs/wires - are all cylinders firing?
____(c) fuel injectors
(3) Not enough transmission fluid? Too much? There may be a dent in the transmission fluid pan which would functionally increase the amount of fluid creating different shift points.

Honestly, if you can't get an error message from a code scanner (Auto zone or Kragen will probably let you borrow one) then you may need the attentions of a qualified mechanic.

Alternatively, you can call Car Talk! (or check their website for the Mechan - X-files for a good local mechanic).
posted by unclezeb at 11:44 AM on August 21, 2008