I have a question for the panel about a problem that I haven't dove too far into yet. A friend of mine has an 88 4runner with a 3.slow, which is an engine I'm not familiar with. It has a serious overheating problem at idle. While he's driving the engine is fine because it's constantly taking in air, obviously. However, when he's not in motion, the gauge rockets nearly to the top. My first thought was the thermostat, but as I said, I'm unfamiliar with these engines and their nuances, so is there another common problem I should look into?

 

Get it checked out. The 3.0 are known for blowing Head G's. I would not drive it till finding out the problem. If the HG is good now, it will not be if it overheats................

 

Maybe its not the head gasket? Check out the clutch fan maybe its bad.

 

Thermostat is the most obvious. I was having the exact same thing happen with mine. Tried the thermostat, nope try again. After much , I noticed my radiator fins were clogged. Just at the bottom, like the first 2" up from the bottom. I hit it with a high pressure water jet, blasted the crud out quick like. Every thing A O.K. now boss. Forgot to mention my hypothesis, fan shroud holds mud from mud hole well. A good 2" worth if your not carefull.

 

Well, I do know that the head gasket was replaced within the last 5 years by the PO through the recall. He hasn't taken it off-roading yet because of the overheating. He's also having a problem with a radiator that's supposed to be fairly new. It blows coolant out around the cap in small amounts, even after trying multiple caps, including a dealer-purchased one. I think I'm going to start with the thermostat and radiator if he can get one from a boneyard.

 

Ditto, I always just go through it. Check clutch, check fins and blow out the junk, remove dead squirl or cat, if it looks dirty inside, take it to a shop and have them give it a once over, replace the thermostat, fresh coolant. Then see where your at. If that doesn't fix it your having real issues.

 

I'd check the fan clutch FIRST. If it's only overheating when there's no air flowing through it, that would be the obvious choice. Next, I'd see about flushing the radiator at a minimum. It's possible there is something clogging it up inside. I'd only go with a new radiator; you can get an all metal one at www.radiators.com for about $140.