My '82 was overheating. I replaced my thermostat and it's still overheating, what else could be the issue?

Radiator? How can I tell if it's bad?

Thanks!

 

Cold be the water pump and/or the fan clutch. If there over 75,000 since new I do both since you have to take the fan clutch off for the water pump.

Do a test: with the engine cool, remove the radiator pressure cap (which should be replaced in time). Start the engine and wait for the ypper radiator hose to get hot. If the water pump is good you should see water circulating. If it flows fairly well the pump is good.

With the engine cool the clutch fan should spin a little with a slight resistance. If it spins very freely it is bad.

When you start the engine, if water spews it chold be a cracked waterjacket or head gasket issue.

Good luck.

 

check to make sure your radiator pores arent clogged. my 82 had the same problem, i got the pores cleaned and the radiator flushed and that took care of the problem. i can drive this thing through hell if i want to now.

 

I had the same problem with my 82 when I bought it. It turned out to be the radiator. I would just replace it. They aren't that expensive and it is very possible that that is your problem. I tried that chemical cleaner stuff and had no luck, so I just replaced the thing.

 

What tires and gear ratio are you runniing? I had 33's and factory 4.10 gears, overheated the motor twice because it just did not have the power to push the big tires.

 

Work your way from "cheapest and easiest to replace" to "expensive and time consuming." Here's the best chronological way to go about it.

Replace the radiator cap. Cheapest part.

Replace thermostat (you already accomplished that).

Replace the fan clutch. About $60-70$ for a good name brand part.

Replace the radiator last.


I've never seen a faulty water pump cause an overheating problem unless it has locked up. The only other possibility is that cooling system has a serious electrolysis problem and it ate the impeller up. Very common to late 90's Ford Taurus's because of its design, but not an issue Toyota pickups of this vintage.

 

Could be the water you are using is to hot that will cause an engine to overheat, just kidding have you had your system flushed? if so you might consider an acid bath for the radiator it really is a step one step two kind of deal : step 1 thermostat Step 2 flush system step 3 acid bath radiator is the water clean? or is it brownish rust in color? well good luck with it, i did the three step program to mine 3 months ago, runs great now. 84sr5yoty follow his list make sure to spent the extra money for the dealer clutch i ate through 4 auto zone ones, TGF warranties! but the dealer one is going for 3 years now.