I picked up my 4runner brand new back in '02. I moved back to Las Vegas a month ago from the East Coast and for some reason It's overheating now. The temps haven't been that bad here either. (upper 90's-109) It's mostly when I'm sitting in traffic and goes down to about 2/3 when I'm driving. I don't dare turn my A/C either because it the gauge will go totally red. (it gets up to the mid-upper red range right now)

I took it to the dealer and they said my radiator cap wasn't sealing correctly. They put a new one on and sent me on my way. It's of course still overheating.

Does anyone have any idea what might be going on? I'm going back, but I'd like to have them look at something specific because they seem to feel that there is nothing wrong. Any suggestions would be greatly appreciated.

Blocked Heater Core? Or Thermostat maybe....

thanks. I'm taking it in tomorrow morning. That gives me a good place to start at least. They seem to feel that this is perfectly normal, but I'm very positive that there is something wrong.

I agree, my 4Runner has not experienced any problems with over heating. Tow quick things come to mind, faulty thermostat or water pump. Hopefully you have oil changed regularly and it is not gummed up. Also, make sure your radiator fluid is full. I hope it is something simple.

You need to check you fan when you start up cold. You will hear a loud roar under the hood, and feel the fan pulling air for the first 30 seconds. If that is not happening, then your fan clutch is bad. If it does work, you might have a clogged core in the radiator that is close to the center of the fan clutch. This will cause the fan clutch not to engage and not cool your truck when it's at idle.

Mike

The fan definitely starts up and runs for a bit when I first start it up cold. I went in for an oil change on Friday, while I was there I had my coolant flushed. It was fine the rest of Friday and all day Saturday, but Sunday afternoon while sitting in traffic it started heating up again. I had to turn off my A/C to keep from completely overheating. I thought I might get away with skipping the dealer visit, but I think I might be taking that trip anyway.

I'll mention the possibility of a clogged core. I just wish the overheating was more consistant so the problem could be more easily identified.

Is your reserve tank full or empty? Is your coolant full? I think you have an air pocket in your coolant system and need to bleed it.

Mike

Well, if you had the radiator cap replaced, the coolant flushed and changed (I hope reverse flush), then the obvious other things are fan belt and/or clutch, thermostat, and radiator core. If they check out ok then I'd look for an internal head gasket leak. Have them do a leak down test.

Pattin22,

Which dealer are you using in vegas? I lived there for 8 months and went to three dealerships before I found the best. Desert on Sahara.

i was thinking fan clutch too. but sounds like it runs......bad thermostat maybe?......definatley not normal though....have you been using toy red for coolant?

i used to go to desert toy for years too, (ever since it was toy west) but am using centennial now, and have had good luck there!

hope you get it sorted out soon, as its gettin hot here huh?