Hi to all,

this is actually my first post/thread on the forum, though I've been reading here for quite a while.

I've got a 2010 JK Unlimited Sahara (3.8 automatic), and in the first regular service in my local Jeep garage (in Switzerland) they said that the water pump was leaking, so they will have to replace it. Ok, fine. I had never noticed any issues with the Jeep, but I had seen a few drops of water on my parking lot below the Jeep, so it makes sense.

It took 2-3 weeks before they got the pump, and changed it. Very soon I realised that in slow driving, the temp gauge went close to the red-zone, so something's not right. On a highway the gauge needle was fine in the middle.

So, I took the Jeep back to them. They kept it for 2 days, and the outcome was, "there was still air in the pipes, so the thermostat didn't work properly, it's fine now". Thanks a bunch I thought.

It's better now, but still at a standstill when the engine is fully warm, the temp gauge needle goes up to about 3/4, and the cooling fan is blowing like crazy. Only after driving further a while, it goes back to the middle.

I contacted the garage again about this issue, but they are telling me that it's normal! I've never had this in any of my cars, including the JK before the waterpump was changed. I also here more waternoise than before in the cockpit when the coolant circles the system. At least I think so, or I'm just loosing it.

Does this happen to anybody else here? Is it ok that the engine overheats up to about 3/4 at standstill? Any thoughts?


There is also another issue with the radio, sometimes it goes dead for a day, then the next day it's fine. I'm having that also replaced on warranty. But I don't see any way how that could be related.

 

Mine has never done that. The needle goes to the half way point on the gauge and stays there in all conditions. Last weekend the temperature was 108 F and the needle never moved after getting to the half way point on the temperature gauge.

There could be some air still in the system, or there could be some debris in the cooling system from removing the old water pump.

The only way the radio and radiator are connected is through the electrical system. If there are electrical problems, that would prevent the fan from turning on. But you said that your fan is turning, so I don't think there is an issue there.

 

I have had my JK for four years and never have seen that temp gauge go over the halfway point, ever.

After that cooling fan kicks on, it stays on for about two to three minutes. But the temp gauge stays at the halfway point.

Still stock water pump and all cooling system is stock as well.

 

I am not really sure on this, but assuming the JK has a thermal spring and disc style thermostat.

I would suggest changing the thermostat or at least pulling it and making sure it is clean. Could be an issue there and should be a cheap thing to start with, you could also run a cooler thermostat to see if the needle drops slightly and holds.

Or, short term you could remove it all together and see if the needle settles in a cooler position and holds.

These are just suggestions to try and locate you problem.

 

Thanks for your input (to everyone), it sounds like that to me too. I.e. there must be either air or some other stuff in the system, not enough fluid, or then just something wrong with the thermostat.

I just informed the "Customer Service" dude that it's really not normal, and if their garage is unable to fix it, I'll go find someone who is able to.

It's not the first time they messed something up though, so it really could be a time to find a new garage.

I've still got more than 2 years left on the warranty, so I'm not worried about the costs, I just hope someone gets it fixed.

It's just a bit of letdown all these problems with the JK, we have a 2007 Commander and it's been running like a dream since day 1. Not a single problem with it, ever, and we've thrown a LOT of heavy duty tasks at it. Always pulled through without a whine.

Oh well, I'll let you know what happens with the issue, and hopefully what was finally the cause.

Thanks again!

 

My 2007 Unlimited just started the same thing this week. Does anyone know if the fan has two speeds or just one? Sometimes it seemed before as if it were running faster at times (at idle with A/C on). 53000 miles. It just seems odd for this to happen this early.

 

Couple things to try:
1. With engine COLD, open radiator cap and then run the engine until the fan comes on and let it run for a bit more to burp the system of trapped air...you should see bubbles. Wait until no more bubbles come up and then turn off engine and replace cap.

2. With engine COLD and the rad cap on, run the engine until the fan comes on and then carefully check the upper radiator hose to see if it's hot and solid. This will let you know know if the thermostat is open and letting coolant flow in the system. If the the thermostat is not open, it should be cool.

 

Yes the Fan has 2 speeds - 195* Med and 205* High speed

 

You have air trapped in the system for sure, that is why you here water sounds from within the heater core. I work on Fords and we always draw a vaccum on the coolant system after having one open like that to get all the air out of it.

 

I am not different than anyone here. Temp runs the same as all others replying here. The one time my gauge pegged all the way to the red, is when the water pump blew. I got it home on a flat bed, then replaced the water pump and thermostat at the same time.

I'm not sure about this air in the system thing. I'm no mechanic but after I replaced all the parts, I just started the Jeep and added coolant as it would drop in the reservoir. have yet to have an issue.

Good luck.