Engine Running Rough After Service

[psquared76]

Hi All

I've got a '97 4.6L Grand Marquis. Last Wednesday, I noticed that the temp gauge was running hot, so I took it into the shop. They said the intake manifold had a hole in it and was leaking coolant.

The intake manifold was replaced on Thursday. Immediately, the engine was running rough. I went back to the shop and was told that the coolant which leaked out needed to burn off.

It's now Sunday night and after a full weekend of driving the car, it still runs rough...it does it randomly, not continuously.

Within the past year I have had a tune up (new spark plugs and wires)...and when I drove it to the shop it was running smooth.

Any ideas on what the problem could be?

[way2old]

Somewhere the coolant has seeped down inside the plug well causing the misfire. Need to have it diagnosed. Autozone will read the codes for free. It should be like a P030- The last number will; be the cylinder that misfires. 1234 is front to back opn passenger side 5678 front to back on drivers side.

[psquared76]

Thanks for the reply!

Once I find out which cylinder is missing, do you think I just need take the plug out and dry it off...or should I put a new plug in?

[way2old]

I would replace the coil boot and the plug. Cleaning does not really help much anymore. Replace with OEM plugs.