Hey Guys!

I am new to this site and have spent most of the day doing research on overheating problems and solutions. A LOT OF INFO! This place is awesome.

Anyway, I am looking to buy a 97 4wd 3.4 4runner. Problem is it overheats. The owners have replaced head gaskets(heads re surfaced), water pump, t-stat, timing belt, plugs and wires, radiator and had the cooling system pressure tested. I have not taken a look at it in person yet. I want to be prepared with a plan of attack and figure out this problem. Where and how do you experts think I should start to diagnose this problem and hopefully get a screaming deal and a clean 4 runner? Or should I just walk and keep looking?
All help and advice is greatly appreciated.

 

Man that's bizarre. If they replaced all of that stuff I don't see how it could still be overheating. Maybe the radiator cap is stuck down? Lol.

 

Sounds like they have already replaced everything cooling system related.

You did not mention hoses... so maybe the lower radiator hose is collapsing?

The coolant passages in the engine could be clogged.

Ask if they used the right temp thermostat? Check the radiator cap?

Or maybe a long shot but there could be exhaust issues (partially clogged Cat) causing heat to build up in the exhaust system and thus the engine????


Did they change the head gaskets due to overheating? Or did it start after the HG change. Maybe they put them on wrong and blocked the coolant passages on the head????

It could also be a faulty gage. need to check the real temp not just what the gage says.

 

why does it overheat ? is it the indicator saying itis hot or does it
actually fill up the overflow tank

automatic transmission ? check ATF fluid for coolant

stay away from anything that overheats, very bad omen

 

Is it actually running hot? A bad gauge or sender can give you false readings.

 

Should I check the hose after it is up to temp?

Can the water jacket be so clogged that you need to take the engine apart to clear it, or will back flushing do the trick?

How can I check if the cat. is clogged? Smog test? Feel exhaust coming out of the tail pipe?

I have a infared thermometer, where is the best place to check "real" temp? Radiator hose @ t-stat?

Thanks!

 

Is their a fool proof way of checking that the gauge or sender is reading correctly?

 

there are 2 temp senders

one for the dashboard indicator

one for the computer to run engine management

use an OBD-II tool and get the temp reading from the ECU