Hey Guys,

I replaced an bad HG and rebuilt the head on my 88 22RE, and now the temp gauge shows it overheating when I use the heater or defroster. The truck runs fine other than not passing smog due to high CO and HC. That is for another post.

As soon as I turn off the heater the temp begins to come down to normal. Can this be due to air in the system? Any help will be appreciated. Thanks all!

 

Sounds like the classic 22RE Temperature Overshoot problem:
- http://www.4crawler.com/4x4/CheapTri...tml#Thermostat

 

Thanks for the tip 4crawler. It seems like that is a good place to start.
Thanks again!

 

Radiator full? Do you get heat out of your vents or is it cold air?

Looks like 4crawler nailed it on the head for ya.

I've only had the t-stat fail when the coolant gets to low from a cracked radiator (or any loss of fluid) in which case the heater runs cold and the engine hot. Opposite your situation. =/

 

Drew303, I do get hot air from the heater/defroster and the radiator is full. No leaks either. I am going to try 4crawler's tip and go for the new thermostat.
Thanks for your time! I will post the results.

 

The t-stat is getting up to the max, I had to pull over to let it cool down. Tried turning on the heater but cold air comes out. When I finally got home I noticed that the radiator was gurgling or boiling, not sure which it was.

I'm going to check the radiator fluid level and oil level in the morning.

I just had my radiator flushed and refilled about 4 weeks ago so I'm confused as to how it got low, if it is in fact a low radiator. I haven't noticed any leak in the driveway but I will double check in the morning.

Looked at the 4crawler page but I don't think that it is the thermstat causing the problem because the engine was steaming up pretty good, it really seems to be running too hot.

Any feedback would be great, thanks.

 

Sounds like it could be a head gasket (exhaust -> coolant passage) leak. You could have the cooling system pressure tested (look for the pressure rising with engine RPM) or have the coolant tested chemically (NAPA has coolant test kits) to look for exhaust gas contamination.

 

sounds like some air in the coolant system. its real fun to get out too. i had the high temp needle too.....drill a small hole in the flat part of the thermostat.. like 1/8th inch. seemed to work real well for me, cause i am cheap and dont want to pay for a toyota themostat.

 

that was the problem i had thanks for the tip 4crawler

 

Yikes ... I didn't want to hear that but it's better to know and to deal with it ... I will get a NAPA coolant test today and see if there is exhaust gas in the coolant. If this is the problem, can I just replace the seals or will I need a new head gasket?

I looked into the radiator this morning, there is no visible fluid. Should the radiator be full to the top?

Luckily my drive to work is only about 4 miles, so I was able to test it again and see what would happen. By the time I reached work the t-stat was all the way up just before the red zone. Had the heater on full blast but only cold air. (Does anyone know why cold air comes out?) No gurgling when I arrived, I figure it didn't get hot enough (last night I was on the freeway when the heating problem began).

Thanks

 

Yes, rad should be full to the top. Heater blowing cold air is probably due to air (or exhaust gas) in the coolant. Air transfers way less heat than water so no heat transfer to the heater core. If HG leak, replacing the HG often the fix, but check for warped or cracked head and fix/repair any issues leading to the overheating, or you'll blow the new HG as well (BTDT). Coolant low is often due to exhaust gas pressurizing the cooling system and casuing it to blow out past the rad cap and overflow the recovery bottle. Once level drops enough, engine temp rises.

 

Because you're so low on coolant that there isn't any water pumping into the heater.

Basically if your yota is up to "normal" indicated temp and you're not getting any cab heat, something is wrong.

1) Fill your radiator up to the top before you do anything. Fill up the overflow to the proper level also.

2) This problem could be simple (not enough fluid or small radiator leak) to Very Bad [TM] (head gasket with water going into the oil pan).

You need to figure it out. There are a few guys on the board that simply kept filling up their radiators knowning they had issues. For leaks that go into the oil pan, this means you'll eventually pump water through your motor. When that happens, you'll need a lot more than a head gasket....Water goes to the bottom of the pan, so you may not even know it's in there without draining the oil.

 

problem solved for now... we'll see if the radiator level gets low again ... which could indicate an issue as mentioned above

so yes i'm a newbie and yes this is my first yota ... so when i first bought it i took it to EZ Lube to get all the fluids changed: oil, trans, rear dif, and a radiator flush ... they have a guarantee that if any fluids get low, they'll refill for free ... so i took it back to them and said my radiator is low, please refill ... when i came back from walking to the store, they had changed my oil and everything... they had a miscommunication and i got a free oil change ... but after i drove off the engine was still overheating ... pulled over to a gas station, waited for the engine to cool, and found that they didn't put any fluid in my radiator, just the reservoir

I FILLED THE RADIATOR WITH PLAIN WATER ... no more engine over heating (and heater blows warm air as it should) ... but is plain water OK? I live in a hot climate where there is no danger of a freezing temperatures.

Thanks ... I've learned a lot from this experience and from all of your feedback.