98 Cav. Sudden Drop in MPG

ALGREIMANN

MEMBER
1998 CHEVROLET CAVALIER

98 Chevy Cavalier 130,000 miles, automatic, 2.2 engine (I believe).

The situation is that my MPG have dramatically drop in the period of about a week (took about double normal gas to drive 60 miles of highway).

The back ground is this, my car suddenly started to rumble a bit as if I was driving on rough road. It was also sluggish. This was right after an oil change that was a little late, by about 200miles. When I got the oil change, it was suggested that I should replace the air filter, but they admitted that it'd be okay unitl next time.

So with my car not working well, I took it to the shop. After about a days worth of work, my car had a tune up and the front brakes replaced.

It ran better but not quite up to what it should be. On top of all this, a friend of mine drove the car for about 3 miles with the parking break on. It was through some neighbor hoods, no faster than 30.

Engine has been running slightly higher than normal and heating up fast but it is summer and average temp has been around 85.

Car is still sluggish but really only noticable on highway.

As of now, my only thought is to replace the air filter.

So what should I do next?
What could be the problem?
Any advice on how to increase the MPG and give my car back its power?

Sorry about the length and any confusion. I just wanted to make you got any detail you might need.

1 Reply

SERVICE WRITER

MECHANIC
9,123 POSTS

Let me clear some of the thoughts first.200 miles over on an oil change. Assuming that means 3200 total is not a big deal.

The parking brake issue might have done some damage to the rear brakes. Make sure that is is fully released, may want to check the rear brake linings to make sure there are no cracks. The linings should be sprayed with brake clean to be sure as the dust can fill in cracks. If they are not fully released this will affect gas miliage.

Since this happened right after the oil change.I assume you mean right when you pulled out of the oil change place parking lot. Then you might want to pick up an air filter and change it. The air filter box may not be sealed properly. I have seen the "parts changing" happy quicky lube places, not make a good effort at getting them back togather, causing air leaks that can throw off the air/fuel mixture causing a variety of problems.

Temperture of the car "may" be a concern, As loong as it isn't going into the unsafe red zone, I wouldn't get too concerned. You have to keep an eye on your coolant level and monitor the condition of the oil. IF you are losing any coolant or the oil cap begins to get a yellowish slime on the inside, it can be a sign of trouble.

What tune up parts/procedures were replaced/performed? Tune up is general word that means different things.