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tman4024 02-02-2010 07:05 PM

Engine knocking
I give my Jeep about 5-10 mins to warm up but when I come out I notice the engine has been making a knocking noise. I drive it to work about 10 min drive and no knocking. I need to unflash my CMR and see if that makes any difference, but I thought I would get some opinions as well.

Could it just be from the cold or should I take it in to the dealer?

Scottina06 02-02-2010 07:13 PM

Re: Engine knocking
like a lifter click?

tman4024 02-02-2010 07:15 PM

Re: Engine knocking
It may be... a couple months ago my dad said he heard it knocking a little and said it could be a lifter. I didn't really notice anything at the time, but it could be the same thing he was hearing just louder now...

Scottina06 02-02-2010 07:18 PM

Re: Engine knocking
what oil are you running?

tman4024 02-02-2010 07:26 PM

Re: Engine knocking
5-20 mobil1

Scottina06 02-02-2010 07:48 PM

Re: Engine knocking
hmm......08 right? Warranty?

tman4024 02-02-2010 09:47 PM

Re: Engine knocking
Yeah, still under warranty.

blackpepper 02-03-2010 04:32 AM

Re: Engine knocking
All HEMIs knock a little I think... I would start simple with some fuel injector cleaner and see if that helps.

HemiJeep4x4 02-03-2010 07:07 AM

Re: Engine knocking
Its only the MDS it knocks at idle because its running as a 4 cylinder.But deffinately Mobile 1 isnt what it used to be they changed it.I myself use Royal Purple 2/20 no issues better fuel economy but if idleing long enought it has a slight knock if its the hemi its the cylinder deactivation you hear thats knocking.

LTrainGC 02-03-2010 10:00 AM

Re: Engine knocking
I'm pretty sure MDS doesn't activate if the vehicle is in park. I can't confirm this though. However, I have MDS disabled and notice not what I would call a knock - but more like a light tick/tap if I let the truck idle for an extended period of time.

Also, isn't the consensus that it isn't good to let the engine warm up for an extended period of time? In the mornings and after work I'll start it and give it maybe 20-30 seconds and then off I go.

Scottina06 02-03-2010 10:47 AM

Re: Engine knocking
its not the MDS...that doesnt kick in till like 52 mph....right?

tman4024 02-03-2010 10:49 AM

Re: Engine knocking
MDS can activate any time while in drive. Not sure if it kicks in when in park. I've never actually checked the EVIC. I'll try to remember to check that tonight when leaving work.

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