My Sister InLaw (its always the sister Inlwa) has problems with a 2005 Honda Acord. Recently traveling from her house to hours (Northern NJ to Northern Va) she ran into engine problems (she said was a clunking noise). I drove up to meet her in Pennsylvania and found the following:
1) It was clunking because the engine was downshifting
2) The downshifting was being caused by the engine racing from about 1200 to 2400 RPM’s and back again.
3) If I came to a stop the car would stall, so I shifted it into Nueteral quickly and feathered the gas - keeping the engine more steady.
4) Note that the RPM fluctuations would also happend downhill.
5) The engine light was on and, like all good drivers I used black electrical tape to mask the indicator (OK just kidding). The codes indicated misfires on all cyliders at random times. Also engine speak indicator.
Since this is reproduceable only after prolonged drives (and after at least 2 hours of driving - though I guess it could happen sooner in stop and start trafic) could this be ‘heat soak’…maybe its ‘heat stroke’ any thoughts would be helpfull (PS one garage changed her plugs and ignition coils…coils? when did cars start having more than one?)
OK…English is my second language (I am not sure what my first one is)