Cold Engine Knock

GregB · **Posted:** Mon Jan 15, 2007 7:29 pm

Just looking for a little advice. This is the first winter I've noticed an engine knock on cold start-ups in my '02. Also, the fan seems loud on cold starts and the fan revs when I rev the engine. It may have always had that fan noise when cold, but I'm just now noticing it.

Anyway, just wondering if there is any tip or general maintenance I should do to make the knock go away or if the fan noise is unusual.

Just a side note, we had a bad ice storm here in December and I used my KJ to pull the neighbor's stuck F-250 out of his driveway. I wish I had pics ... it was beautiful :wink:

jason thompson · **Posted:** Mon Jan 15, 2007 7:33 pm

GregB wrote:

Just looking for a little advice. This is the first winter I've noticed an engine knock on cold start-ups in my '02. Also, the fan seems loud on cold starts and the fan revs when I rev the engine. It may have always had that fan noise when cold, but I'm just now noticing it.

Anyway, just wondering if there is any tip or general maintenance I should do to make the knock go away or if the fan noise is unusual.

Just a side note, we had a bad ice storm here in December and I used my KJ to pull the neighbor's stuck F-250 out of his driveway. I wish I had pics ... it was beautiful :wink:

the knock is normal
hyd. lifters not getting oil in them only if it goes away when it gets warm
the fan I m assumeing is a mech fan if so then I would wach it I had a work truck that started doing the same thing and by the summer the fan cluch went out

meh_kick · **Posted:** Mon Jan 15, 2007 7:56 pm

I had an oil change done during a cold spell last winter. I noticed, what I can assume, is the same knocking. Turns out I was almost a quart low on oil when cold. Even though when the engine was warm, it was just within the cross-hatched marks on the dipstick.

With any luck you're oil level migh just be on the low end of acceptable when warm, falling below the mark as the engine cools.

sleeve84028 · **Posted:** Mon Jan 15, 2007 8:42 pm

My 02 knocks all the time... it's a noisy Jeep in the winter and a little bit in the summers too.

renegadekj · **Posted:** Mon Jan 15, 2007 10:58 pm

Iam not sure about the knocking , But the fan noise wont harm anything( it happens to my kj in
-30 to-40. Last winter my kj use to make a loud squealing noise so i brought it back to the dealer ship and they changed out the power steering pump( under warranty), they told me they have that problem alot with the kjs it seems fine now!

GregB · **Posted:** Tue Jan 16, 2007 12:12 am

meh_kick wrote:

I had an oil change done during a cold spell last winter. I noticed, what I can assume, is the same knocking. Turns out I was almost a quart low on oil when cold. Even though when the engine was warm, it was just within the cross-hatched marks on the dipstick.

With any luck you're oil level migh just be on the low end of acceptable when warm, falling below the mark as the engine cools.

Thanks, I just double checked that oil level when it was cold. The oil level was fine though ... I think she's just getting a little old. I'm thinking I might start going with a synthetic oil.

Jeger · **Posted:** Tue Jan 16, 2007 6:00 am

Definantly go with a synthetic oil, I think it is well worth it. Also what weight are you running?

GregB · **Posted:** Tue Jan 16, 2007 8:57 am

Jeger wrote:

Definantly go with a synthetic oil, I think it is well worth it. Also what weight are you running?

Not sure what weight, I still have about 2 years of free oil changes from the dealer I bought it from.

sleeve84028 · **Posted:** Tue Jan 16, 2007 9:26 am

I will say that this winter I finally switched over to synthetic oil (5W-30) and the motor does seem to be a little less noisy and it starts a wee bit smoother. But before than, the past 3 winters, I could really hear either a lifter ticking away or rocker working a valve. At first I didn't like the noise but then I got used to it.

Jeepjeepster · **Posted:** Tue Jan 16, 2007 10:59 am

I use mobil 1 syn and I get the knock. Normal

The roar you hear is caused by the cold fluid in the Viscous clutch for the mechanical fan. It will go away when the fluid warms up.

I take it you have the towing package? If not, I hope you have the mechanical fan. :wink:

Guyute1210 · **Posted:** Tue Jan 16, 2007 3:30 pm

GregB wrote:

meh_kick wrote:

I had an oil change done during a cold spell last winter. I noticed, what I can assume, is the same knocking. Turns out I was almost a quart low on oil when cold. Even though when the engine was warm, it was just within the cross-hatched marks on the dipstick.

With any luck you're oil level migh just be on the low end of acceptable when warm, falling below the mark as the engine cools.

Thanks, I just double checked that oil level when it was cold. The oil level was fine though ... I think she's just getting a little old. I'm thinking I might start going with a synthetic oil.

Hit up JJ for some great lubes from Amsoil. Or check my sig for his site, HotRodOil.

Blue KJ in PA · **Posted:** Tue Jan 16, 2007 3:33 pm

Dino does have bad cold knock...switched to Mobil one syn last winter knock became less noisy and shorter time in length right away.

GregB · **Posted:** Wed Jan 17, 2007 9:36 pm

Jeepjeepster wrote:

I use mobil 1 syn and I get the knock. Normal

The roar you hear is caused by the cold fluid in the Viscous clutch for the mechanical fan. It will go away when the fluid warms up.

I take it you have the towing package? If not, I hope you have the mechanical fan. :wink:

No factory towing, all self installed towing, but I thought all KJ's had a electric and a mechanical fan?

Cold Engine Knock

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