Cadillac Deville speeds up by itself

golflady80

I have a 1998 Cadillac Deville that just yesterday would speed up on its own while driving on a rural road. I had to keep the breaks on intermittently to reach my destination. After about 1 hour it way time for the return trip home. NO problem untill the same time had passed it did it again. My breaks were smelling and I had to put it in neutral as I stopped. The engine raced and I cut the engine off and then put it in Park. Have any of you experienced anything like this? It was scarey! What should I do?

bolivar

Yes, I have.

It was the floor mat bunched up and catching the accelerator.

I'm not kidding, this is the very first thing I would check if you are having 'unexpected acceleration'.

Other than that, has anyone worked recently under the hood? Could have messed up the linkage under there.

And, looking again at your message, I see it's a 1988 vehicle. This is a 19 year old car. The linkage could be failed/failing because of the age of the car.

tamade

my 94 DeVille (43K miles) has the same problem on local street or the interstate. It will accelerate by itselt even I do not press down. It usually happens when gets to 33-35MPH speed, I have to brake often to "calm" it down.

The car hasn't been driven regularly for 2 yrs.

maxymyllyn

I have had the same issue. I have a 1991 Cadillac Deville. It just started today. The engine rev's up and there's a loud 'tick-tick-tick' coming from the steering wheel assembly. Also, the check engine light just came on as well. It's very disconcerting since it feels like if I just let up off the brake the car is going to lunge forward. Once I hit a straightaway it works itself out, but there doesn't seem to be a rhyme or reason for it.

I'm going to take the car in within the next few weeks. I hope the engine revving on the Cadillac Deville is not indicative of larger and more costly repairs.

bolivar

You probably do NOT have the Northstar. The 4.9L non-Northstar motor (I think this is the motor size) has 2 'motors' on the throttle linkage that are prone to failure and cause this problem. They are the Idle Speed Control and another one with a similar name.

There are ways to diagnoise this and see which one has the problem. Replacing is no big problem, but getting the new part 'set up' is somewhat complex. You just can't tighten or loosen a screw to set it up.

Find an independent garage that has worked on early-90's Cadillac and has seen this problem. They should be able to replace the part and get the new one set up.