Replaced head gaskets on Ford 4.0 engine. Now getting rough idle at cold start. Could overheated engine cause coolant temp sensor to go bad?
Cleaned maf sensor, throttle body and IAC valve but didn't help.
Trumps fault
Check for a vacuum leak. Check ECT sensor and MAF sensor live data with a scan tool before starting and when engine is running.
Ck. For a leak around the intake gaskets since their new. With it idling, spray wd40 around them, if the idle increases, its leaking.
Coolant sensor is fine, you have a vacuum leak or you missed the cracks in the heads. The Ford 4.0L heads are really, really bad for cracks between valve seats.
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