2001 Cadillac DeVille with Multiple Misfires

This engine was running flawlessly. On a fairly long highway trip, it started to misfire. By the end of the trip I am pretty sure that there were two or more cylinders misfiring. Please note that I had never experienced *any* misfires before this event. I want to make this clear because I think this diminishes the likelihood that plugs are involved, although the plugs have not been changed in some time. Plugs are very expensive to change in this car and only the dealer will change them. As the car has 150K miles on it and has other non-engine problems, I am trying to avoid spending money needlessly. If possible, I would like to examine all the less expensive possibilities first, ruling out everything but the plugs before I "bite the bullet." (Around $400.) Could someone list all the other possibilities that might be making this engine misfire on multiple cylinders, and that could cause this to occur suddenly? Many thanks for your help! Frank

Reply to
frank1492
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Sounds like moisture in the gas to me. Get some heat or similar product.

Reply to
RamrodSteel

R> Sounds like moisture in the gas to me. Get some heat or similar R> product. R>

Plugs,... or plug wires.

When dark, and "injun" fully warmed up and running, spray some water mist over the plug wires. If you see "lightning" under the hood, you have bad plug wires.

If plugs and/or wires have never been replaced, @ 150Kmi, I'd seriously consider doing it. Nowadays these last a long time but not forever. The plugs (or at least one or two) can be difficult to replace but every semi-reputable mechanic can easily do it, and for a lot less than the dealer.

By the way, if it really was a misfire that should've set a code, which can prolly be pulled using the HVAC cluster. I know how to do it for my '97 STS, but this might not be the same for your 2001. Google for it.

Reply to
BG

The code was 300- multiple random misfires. The dealer diagnosed the problem today- it was the coil. $465 + $100 diagnostic. Thanks to all for your help! Frank

Reply to
frank1492

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