Here's the situation;

The thermostat housing on my brothers '89 GTU recently blew up while he was driving. Apparently the previous owner had JB welded a section of the housing back on after it had some how cracked off.

My brother already replaced the housing and t-stat with new mazda parts. Now the car constantly over heats. The coolant goes in to the reservoir boiling, one of the radiator hoses is constricting and collapsing on itself, and temps go into the red.

His car is by no means in good condition. The car previously would dump a lot of white smoke in the morning when it was started and showed other signs of a failing o-ring. It still spews lots of smoke, but only when warming up and stops after. From what he's telling me I'm guessing that the car overheated when the t-stat housing blew and shot the o-rings. However I thought I'd ask and see if there was any chance that they didn't install the housing or thermostat properly.

Sorry that I can't be more descriptive, but I'm going on what my bro is telling me and haven't seen the car myself since he lives about 400 miles away.

BTW, already read this http://www.aaroncake.net/rx-7/cooling.htm and he doesn't seem to have a clogged radiator, bad water pump, and the t-stat is new.

Thanks in advance for any help you guys can give.

 

sound like your coolent seals are deff fried not if the temp went into the red

 

Check the orientation of your thermostat. I had installed mine upside down, which prevented coolant from going back into the radiator and thus cooling the engine.

 

^^^ what he said. its almost definately in upside down.

there is no guessing about blown coolant seals...it is very very obvious. as in, i had one that would burn all 2 gallons of coolant in 30 seconds. that is a huge white cloud.

pat

 

Yeah...Ive seen them upside down before also. Very easy/common thing to do.

 

Thanks for the responses guys. I already told my brother to check and make sure the orientation of the t-stat is correct.

felixwankel88, are you saying that they are definitely not fried since the temps went way up, or that they are definitely fried?

Sorry for the noobness of these questions, but haven't had problems with coolant seals, or t-stat housing blowing for that matter, before.

Thanks again guys.

EDIT: The problem is his seals probably were already done before this happened. My bro refills his coolant and oil almost every other day. That's not near as bad as what you're describing, but his obviously aren't in good shape.

 

Oh, and have him read the cooling section of the factory service manual. Not only does the thermostat need to be oriented "right-side up," but there's a jiggle pin on the thermostat that needs to oriented between 12 o'clock and the right-hand bolt hole on the thermostat housing. The FSM explains it better than me.

 

Sorry Rex i typoed i ment to say the odds are that the coolent seals are DEFF fried if the temp went up to the red

 

This could be a possibility too since he swears that he installed it right side up. Unfortunately my brother doesn't have a FSM or internet access at the moment to look at the online ones. I'll see if your explanation is enought for him to get it installed correctly.

Thanks for the clarification.

 

could also be a clogged radiator ... one check for this is is the top side hot and bottom cool (well one way I have used before). another is waterpump could be shot...hmmmm several other things besides coolant seals being toast or passages being clogged...

food for thought anyhow

 

not really true. more likely that they are fried, but not a definate thing. it is possible to overheat a rotary without blowing the seals. you can even do it multiple times.

if he has to add oil and coolant every day, tho, sounds like its on its last legs.

pat

 

One indication that the thermostat is working is to check the upper radiator hose. If the engine has been running for a few minutes and the thermostat opens, the hose should get hot. If it's still cold, coolant isn't flowing back to the radiator.

 

Yea, Pat, I'm pretty sure the car isn't gonna last much longer. He actually has overheated the car several times. The car is just a transition car that was given to my brother from our Dad. My Dad has been in horrible medical condition and hasn't had the ability to maintain any of his cars which is why the car is in bad shape. My bro just needs it to last a couple more months.

He said that one of the radiator hoses (I'm assuming the upper) was collapsing on itself. This wasn't continuous but would collapse then go back to normal and collapse again. Is this an indication of anything?

My bro said he was gonna check out all the previous recommendations tonight, but he isn't very mechanically inclined so we'll see how successful he is.

 

Just thought I'd update. Apparently the T-stat was installed correctly as the car is having no overheating problems now. Unfortunately it is eating up coolant like no tomorrow. Looks like he blew a coolant seal after all.

Thanks to all that provided info to trouble shoot this problem.

 

Did he properly burp the cooling system? Im not sure if its too late now but if theres air trapped in the cooling system, it will cause the coolant to boil. Thats probably why the coolant was going into the overflow tank.

 

I told him how too, but I can't be sure if he did it properly.

Thanks for the input.