Slight engine knock on cold start?

SD-KJ · **Posted:** Fri Nov 03, 2006 4:08 pm

Ok, I have been dreading asking this and quite honestly i don't know if there is anything that can be done if there actually IS a problem.

Since it has been getting colder out in the morning i get a slight engine knock until it warms up a bit. Its not very loud (heck my dad couldn't even hear it), but i can tell its something different since its been cold out. When its just sitting at idle you cannot hear it but when you accelerate you can hear it. I am running AMSOil 5w-30.

Anyone have any clue? I really hope that this is just a normal cold engine sound but I want someone who really knows something about the 3.7 to confirm this.

Thank you for your help and input.

-Nick

FLJeep · **Joined:** Wed Oct 18, 2006 7:27 am **Posts:** 84

There's been several threads about this same issue. As it get colder and colder the engine starts a little rougher. From what i can tell it is pretty normal. Now with it knocking after accel, not aure about that

k99jk99j · **Posted:** Fri Nov 03, 2006 6:48 pm

welcome to the club! it doesn't seem to hurt anything. no body knows what causes it but some front runners are, heat sheilds expanding and contracting, piston slap, or "noisey valves".

mine goes away after a minute of idling. also pester your dealer about it. i plan on pestering my dealer when i get new ball joints. mike

Jeepjeepster · **Posted:** Fri Nov 03, 2006 6:50 pm

It does seem this is normal.. Weve had many threads and everyone says they can hear it when its cold.. Mine was doing it the other morning and it went away when it warmed up.. Ive never heard it this loud and it did get my attention.. I only have around 22-23k and I know it wasnt this loud last winter.. I guess its normal break in? :lol:

waddy whiteguts · **Posted:** Fri Nov 03, 2006 7:13 pm

I don't know about the 3.7, mine doesn't do it, but you should drive a VW through a Winter! I've had several and they all clatter like mad for a few seconds when starting below 20°F or so, and I've gotten over 150k out of all of those without engine damage or any sort of oil consumption.

I always assumed it was the oil pump or valvetrain making the noise.

Jeepjeepster · **Posted:** Fri Nov 03, 2006 7:21 pm

waddy whiteguts wrote:

I don't know about the 3.7, mine doesn't do it, but you should drive a VW through a Winter! I've had several and they all clatter like mad for a few seconds when starting below 20°F or so, and I've gotten over 150k out of all of those without engine damage or any sort of oil consumption.

I always assumed it was the oil pump or valvetrain making the noise.

I would say your right with the valve train..

SD-KJ · **Posted:** Fri Nov 03, 2006 8:17 pm

Well this is what i was hoping to hear. The thing thats weird is that it does it until the temp gauge shows it 1/4 the way to normal temp. And it doesn't just do this for a few seconds either...

I have about 66k on it now so hopefully it will last.

Next question, is it bad to drive it like this? Usually i give it about 30 to 60 seconds to warm before i back out of my garage and start driving...naturally when its colder out i let it warm up a little longer.

-Nick

priell3 · **Posted:** Fri Nov 03, 2006 8:43 pm

Mine does it also when it's cold outside. I just take it easy on the RPMs until it warms up.

Jeepjeepster · **Posted:** Fri Nov 03, 2006 8:50 pm

Yea, its not good at all to start a cold engine and drive off. I always let it sit for at least 60sec then put it in N for around 15sec before going to D or R..

It amazes me how many people start the engine and drive off like they stole the car. I pity those little engines..

SD-KJ · **Posted:** Fri Nov 03, 2006 11:37 pm

priell3 wrote:

Mine does it also when it's cold outside. I just take it easy on the RPMs until it warms up.

Yeah, thats what i do, I just let it settle a bit and then take it easy until it warms up. All my morning driving is on city streets in light traffic so nothing really bad....

-Nick

Slight engine knock on cold start?

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