OK, so I went through the search and read a lot on overheating. However, my specifics seem to be somewhat different.

1. I know my fan is slightly damaged from mudding, since last time I mudded it made a squeaky noise. However, it still runs and pulls air, albeit it seems to run now more on high, and very noisy.

2. Did a Radiator Flush at dealer, as they suggested it as part of preventive maintenance.

3. Overheated in a hilly stop and go traffic jam:




4. Opened Rad cap and found it completely dry!!!

5. Reservoir was full, so it seems it is not puling coolant into the rad.

6. Filled up with coolant, and again got an overheat in stop and go, but not as bad;

7. No overheating if stopped or when moving at more that 15 mphs.

8. Red light or warning never came up;

9. No codes thrown.

So I think:

1. Radiator cap is not fully sealing, causing a leak in the vacuum and then not letting coolant to flow from reservoir;

2. Maybe dealer did not fill up radiator after flush;

3. Need new fan assembly.

Your thoughts are appreciated, since I will not take it to the dealer!!!

 

I would suggest that you go ahead and replace the cap, thermostat, water pump, and replace fluids. If you are having all of that happening then I would spend the 100.00$ that it would take to do all of that preventative maintenance. I had a similar problem in my truck and until I did everything to the cooling system, it was like a band aid on the problem. I would also say replace hoses but I know some folks at Dayco and they said OEM are the best unless you spend tons on new. So if you are low mileage wise and they have not sen that much wear I would not bother. Hope this helps.

 

Thanks. Will start with t-stat and cap. Hoses look like new. If t-stat and cap do not slve the problem, I'll take a look at the water pump. Seems 36 K are early for a pump failure.

 

Don't know if you tried this already, didn't read it if you did, but take your fan out and use the hose from the inside engine bay with a little water pressure. Shoot the hose from the inside out for about 45 minutes cleaning all the dirt caught in the fins. I had all the same issues and this worked for me.

 

Yeah it does seem early. I have seen some threads about it going out prematurely. But if that is the problem it does seem to be inexpensive to fix DIY. Good luck!

 

Thanks, tried that, as I took out the fan asseby for a nice wash. But, will do it again.

 

Thanks,m will let you know!

 

Took the cap off and turned on the engine.

It had air inside, as it started "breathing" and the round area that the cap covers started filling up to the neck after "bubbling". Before this, there was movement of the coolant in the bottom of the neck.

Put the cap on, left it idling, and after it heated up to operating range (middle of the gauger), steam started coming from the cap. You could feel the boil, and two seconds after shutdown the boiling went away. So, maybe a leak in the cap is responsible for:

1. Drying up the radiator;
2. Not letting flow from reservoir?

Thoughts?

 

It sounds likely that is it. The system has to operate under a certain pressure and if that is not sealing then it will not build up the required psi it needs. If the system was operating correctly and it was boiling it would kore than likely throw it out of the res. overflow tube.

 

Why should he replace the water pump if it's not leaking and still moving the coolant? I'm sorry but that's a waste of money and time. Diagnose the actual problem instead of throwing parts in it.

It sounds like the dealer left an air pocket in your cooling system and that is why the coolant is low. Make sure that the transfer hose between the radiator and reservior isn't plugged or kinked. A bad radiator cap not allowing the coolant to transfer over will cause this to happen. A t-stat will make you overheat at ide or on the move so that is not your problem. Think logically here, you didn't have any problems until the dealer touched your cooling system. Take it back to them for warranty work (they'll probably sell you a cap).