'97 montero overheats while towing - CEL code P0306
 

I know I need to look into this more but wanted to post this in case anyone has experienced the same or has suggestions.
*Sorry if post is long but wanted to cover everything.

Purchased this vehicle about 6 weeks ago so do not know a lot of history on it. I have had the lower oil pan and valve cover gaskets replaced, power steering pump gaskets/seals redone, replaced an axle boot and new air filter.
*I know not all of this applies to the following but this is what was done so far.

Up until yesterday the truck ran fine. Gets ~15 mpg around town. Only oil leak now is a very small leak at the back plug on engine. Would cost too much to fix and it is only a few drops.
Yesterday I rented a 6x12 flatbed trailer from U-haul and loaded it up with stuff. I estimate that total weight minus vehicle was 400 lbs. I am about 2 miles from highway and 1 mile on highway the Check Engine light came on. Temp and oil pressure gauge were still in the norm. I turned around and went back home. Called my mobile mechanic but could not get a hold of him. Checked oil and level was fine, no obvious leaves with oil or coolant. After looking it over some more etc, we tried the trip again. Engine light went off so I was hoping it was just some sensor messing up. About the same distance on the highway the check light came on again and this time the temp guage kept rising to "H". I turned around and took side streets back to house and temp slowly lowered back to the middle.

Upon arriving home I checked oil again (still good). Once cooled I checked radiator and level was fine and overflow was full. (Not sure where it was at before.) Fan has enough tension so that I can move it but not spin it by hand.

Just had code checked and it is P0306: misfire cylinder 6
Would this cause truck to overheat?

Any ideas/suggestions that I could check on before taking somewhere for repairs?

Thanks for any help

Jim

plugged radiator / bad fan clutch / weak hoses / bad rad cap / thermostat

Yes I thought about all those. However, the CEL code said misfire on cylinder 6. When I research that code, nothing ever was stated about overheating etc.
I drove it today to take back trailer and although the light is still on, it never moved the needle for temp once it got just a tic below mid point on temp gauge.

????

Thx
Jim

I have the same problem with my 01 Montero every time I tow my trailer. Usually going up hill. It may be an undersized cooler I really don't know. Does it happen while not towing ??? How is the performance otherwise ??? My truck runs like a champ and has 127000 mi. on it. Just a rust problem now....

I checked all the hoses n flushed the system. TT is just fine. Replaced the OEM clamps with real SS clamps. Rad. Fan works wonderful and still can't find the problem...Good Luck.