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Q: The car idles rough when in drive with the brake applied.

asked by on March 03, 2017

I just had a shop replace the head gaskets because there was an external leak. The car was picked up from the shop and seemed to run fine, the next morning the intake manifold gasket failed and the engine took the coolant into cylinders and quit running. The mechanic replaced the intake manifold gaskets and returned it to me with a rough idle and low compression in one cylinder bank.

My car has 123000 miles.
My car has an automatic transmission.

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Hi there. It is quite possible that during the head gasket replacement, a fuel injector or ignition system component may have been improperly installed. It is also highly probable that the mechanic installed the old spark plugs instead of new ones. First, I wouldn’t visit this mechanic again, but I would recommend having a professional mobile mechanic come to your location and complete an engine is misfiring inspection.

Mercury
V8-4.6L
1997
Grand Marquis
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