98 Cobra: Recent Engine troubles

5

5.Ohhno

New Member

Dec 30, 2003

17

0

0

Aug 30, 2004

#1

• Aug 30, 2004

• #1

After a long week of driving (1000+ miles in 8 days) my 98 cobra with 54,000 miles on it picked up a rough idle (feels like a miss), has had a drop in gas mileage, and the last time i got on it, i thought i heard some detonation, and around 5k rpm at WOT it felt as if I hit a wall in acceleration. The exhaust tone changed and i lost so much power.(Felt like i hit the rev limiter at 5k) I ran it again up to redline, and didnt hit that wall again but power does seem down still. Im afraid to run it up hard because i dont want to cause anymore damage. I know its not bad gas because ive gone through 4 tanks.

What do you all think is my problem? Ideas, suggestions? Thanks!

 

COBRA90GT

Mustang Master

Sep 22, 2001

6,654

0

87

HOCKEYTOWN ® , MI

Aug 30, 2004

#2

• Aug 30, 2004

• #2

Pull the plugs & examine them...

 

E

EJ23

New Member

May 17, 2004

25

0

0

Aug 30, 2004

#3

• Aug 30, 2004

• #3

Bad Cat, Cats?

 

U

URDONE

Founding Member

Sep 9, 2002

133

0

0

Chicago

Aug 30, 2004

#4

• Aug 30, 2004

• #4

It could also be one of you coil packs.

 

ShakeandBake

New Member

Jun 9, 2002

40

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0

Morgantown PA

Aug 31, 2004

#5

• Aug 31, 2004

• #5

Sounds like plugs or wires to me...

-Chris

 

M

MacDiesel

New Member

Feb 5, 2004

74

0

0

Aug 31, 2004

#6

• Aug 31, 2004

• #6

i had about the same problem with my 98 and i put a new set of wires on it and bam...it ran like a dream

 

F

FasterIsBetter

New Member

Aug 16, 2004

26

0

0

Pittsburgh Area

Aug 31, 2004

#7

• Aug 31, 2004

• #7

I am having a similar problem with my 97 Cobra. There is a rough idle and the power curve around 3200 rpms seems to be gone. I loved the extra boost the car got when it hit the right rpms. Just changed the fuel filter today in case it was flowing poorly. I am looking into new plugs and wires to see if that might work. The car has 48,000 miles on it. Hope it works for the both of us. Will let you know.

 

9

98svtconvert

New Member

May 26, 2004

85

0

0

va beach, va

Sep 1, 2004

#8

• Sep 1, 2004

• #8

i have a similar problem. i just pulled out the plugs yesterday evening and found that the gasket on the valve cover around the plug was pushed into the holw for the plug. so the plug had some oil on it. not where the spark occurs but around the side of it just below that. i am thinking that avery few passes oil is getting to the spark element and causing it to miss and sputter at high rpm's. for the idle thing. if it isn't the plugs, check you idle control valve. i think that is what it is called. it is on your throttle body and controls the airflow at idle. if it is gunked up it will cause your idle to be all messed up. good luck and please post your findings.

 

5

5.Ohhno

New Member

Dec 30, 2003

17

0

0

Sep 2, 2004

#9

• Sep 2, 2004

• #9

Thanks for all the replies. Let me know if all those things work for those having the same probs. Im glad it's not just my car so it cant be too bad. I just did the fuel filter yesterday, and it runs much better. Has'nt gave me any trouble, but I really havnt got on it yet either. As i change things, I'll keep you updated.