2011 Dodge GC R/T 3.6L with 6,000 KMs on odometer. Over the last few days, on cold start up, a loud tapping noise that lasts about 3 seconds is coming from the engine. The noise goes away after the 3 seconds and it doesn't appear when the engine is hot. Also, the engine feels like its running rough at idle and misfiring all the time. The van feels like it sometimes hesitates, but then sometimes surges. The first time the tapping occurred, the MIL light and the traction control light lit up on the dash until I turned off the engine. Turning the engine on any other time just produces the MIL light. Sometimes though the MIL light never comes on but the rough idle is always there. I'm taking the van to the dealer this week to have it checked out but I wondered if this has been happening to anyone else with the 3.6L engine. My brother is a diesel mechanic and when he heard the engine tapping noise, he said it sounds like the lifters aren't getting oil or have too much clearance on startup until the oil starts flowing, said it could be issues with variable valve timing mechanics. He's not entirely sure as he's not familiar with the workings of the 3.6L.

Anyone have any ideas what could be causing this?

 

same issue on mine only 2800 miles.....will me taking it into the dealer soon....only happens at cold start up just like you...post your results please....

 

Welcome to DF
The sound you maybe hearing is the timing chain tensioner. They may bleed down after sitting for a while. Then when you start the engine you hear the chains rattle. The 2.7L and 4.7L engine do the same thing. Have the dealers check for any TSB for this problem.

 

Thanks MT, I'll mention this to the techs when I bring it in Thursday this week. Just so you all can hear it for yourselves, I made a short YouTube video of a cold start.

http://www.youtube.com/watch?v=7ZdDZWY-6VY

If you listen close, you can hear the short rattle. It actually only occurs for about a second, then disappears. Previously I said it made the noise for about 3 secs which it doesn't.

 

Not a sound I would like to hear....almost sounds like insufficient lubrication to the upper area lifters. But, not a mechanic hopefully they diagnose it and it isn't a serious problem.
Or you can have the 4.0L and on startup after an oilchange it revs up then drops......I don't like that.

 

thats normal after startup to have engine slightly go up in revs, beleive just oil pump needing to me run higher rpm. now i have a dam squeeing/grunt sound on cold start but only once. can shut off and on and it be fine(ussually after it sits a while).

 

same sound coming from mine, just that mine will do it randomly, some days it starts up fine...Scheduling a inspection for that and for transmission shifting issues... tranny is upshifting intermittently pretty darn hard even my wife noticed it......

 

Van went to the dealer this morning. Right now they are saying the PCM needs replacing. Currently on backorder. Won't be able to speak to a technician till later this afternoon. Any opinions on whether it could be the PCM? Should I be skeptical? Guess I won't know till they replace it and try a few cold starts.

Thanks.

 

tapping noise will not be solved with a PCM, missfires can...

 

Here maybe the reason why the dealer is replacing the PCM. This is just a guess.


Oil Pump/PCM
Issue Description:
If you are replacing these parts due to a DTC of P06DD on a vehicle equipped with a 3.6L engine, please be sure to perform the diagnostic procedure and verify the oil pump is functioning properly. If it is functioning properly replacing parts will not correct this condition. Please clear the codes as a new software change is coming soon to address this concern.