Maitlandtron

I have been driving this 84 gs for about two months now and t has ran with no glitches. My temp has always stayed at 1/4 sweep no matter how long I sat in traffic, and I live in phoenix(115 degrees). Just recently i took a 50 mile trip and my temp went to the halfway mark, i thought this was odd but it was still in the normal range. I got to my destination and i didn't notice anything odd. On my way back, just 5 miles in I smelled coolant and it started boiling. I stopped, let it cool down. Refilled the radiator, but i had a leak coming from pne of the heater hoses. I replaced it and went on my way. My temp needle was still at the halfway mark the whole way home but it didn't overheat. About a mile from my house the top radiator hose exploded. I towed home replaced the hose and thermostat and since then it has been incosistant. Sometimes it will stay at the 1/4 mark all day, then sometimes it will overheat. But I have no leaks. Sorry for the long story. any suggestions?

I was thinking of getting a new radiator, and adding an electric fan. Would that help? How about the water pump? should i replace it? Thanks for any help.

mjm4jc

Did you re-fill the radiator to the brim and make sure that there is adequate fluid in the reservoir? I have had vehicles with similar problems. For some it was just low coolant, which allowed the car to appear normal as long as I was moving. For other cars, the system developed an air pocket, especially if the system was opened. Make sure the fluid in the rad is filled to the very top. Do this when cold. After you run the car, let it cool back down and re-check. keep adding if you have to.

Rotospeed

iTrader: (8)

when the car is cold... remove the rad. cap, fill the water, start the car, let it warm up so you can see the water flowing in the rad., top off the water with it running, put the cap on and go for a test drive.


what part of phoenix are you in??

Maitlandtron

I'm starting to think there is an air pocket that needs to be worked out. After it runs hot, I let it cool down and relieve the pressure and add water and it seems to help a bit. When i open the radiator cap it doesn't seem to flow like it used to. It kinda bubbles up. Its not steam though.

By the way. I'm on the west side of phoenix, 67th ave and bethany home.

LongDuck

You might also look at replacing your thermostat - anytime an overheat condition occurs, it can damage the thermostat such that it won't operate consistently thereafter. On install, be sure the 'jiggle pin' is at the top, which will allow air to escape the system as it warms up again.

Good luck, and try to keep the engine as cool as possible - any overheating AT ALL damages a rotary engine to some degree.

jinxed4dub

iTrader: (7)

don't buy crappy part store thermostats. they suck. don't hold up for more than 6 months. Get one from the dealership. Its like 30 bucks for the thermostat and gasket, but at least it works.

Rotospeed

iTrader: (8)

do you have the tin under tray installed........you need it.

i think i have an extra one if you need it. im out by the 101 and peoria

gsl-se addict

iTrader: (3)

Could be an air pocket, but I'm concerned that it might be something more.

1. When you said that the coolant was boiling over, you didn't say if the meter ever got into the 'H' region. You might be running hot all of the time and you just have a faulty sender/connection/meter that is telling you it is cooler. Check this out or try an aftermarket setup.

2. Bursting hoses tells me that you are probably having some pressure buildup issue.

- It may be as simple as a faulty rad cap. The rad cap is supposed to provide a relief as the coolant expands and pressure builds. The excess coolant flows into the reservior and is sucked back in when the system cools back down.

- Could be a faulty t-stat not opening. This will kill cooling ability and could allow pressure buildup. The coolant is not flowing in the rad in this case, so the rad cap does little to relieve pressure. However, your rad must be getting pressurized as the top hose is past the t-stat. Could have just been a rotten hose, but I think there are bigger problems.

- Worst of the bunch.. Blown coolant o-rings or warped housings allowing combustion pressure into the coolant system. This will cause a massive pressure buildup and can cause the engine to run hot as the gases in the coolant reduce the heat transfer area. Take off the rad cap and start the car. Look in the rad for "champagne bubbles". The system is cold at this point, so any bubbles are not due to boiling, but from combustion gases. This will typically force most of the coolant out of the rad cap and into the reservior. If you are missing coolant when you overheat, this may be the case (assuming the hoses are not leaking).

When you refill with water/coolant, you should do so after things have cooled down. If you add when the engine is still warm/hot, you should have the car running while adding water and add the water slowly. Dumping a bunch of cold water on the overheated irons/housings is asking for trouble (warping or worse).

Maitlandtron

I did replace the t-stat when i replaced the top hose, but unfortunately it was an autozone one. I do have the tin on the bottom and i also have the shroud. When I start the car with the cap off it overflows out for a second or two then it stabilizes. But i don't see any bubbles. Only on initial start up. When I shut the car down after its been running with the needel at about half of the sweep, I can hear coolant flowing to the resevoir tank.

This has really got me confused. I don't notice any lack of power or any weird smoke out of my exhaust. There are no leaks, I'm stumped.

gsl-se addict

iTrader: (3)

It depends on where the o-rings have failed (if it is the problem). If it is on the intake part of the housing, coolant will go into the engine and give off a white smoke. However, if it is in the combustion area (near the spark plugs, for instance), then coolant will not go into the engine as pressure is high there. Only compressed air, combustion gases, etc. will go from the combustion side and into the coolant system.

I would start with the simple things first. Replace rad cap. They are cheap and can cause problems if they are stuck open or closed. Toss in an OEM t-stat. Test the sender/gauge to make sure it is reading properly.

Are you using straight water or are you using coolant mix? When you have to add water, how much to you need to add and how often does it happen? Have you noticed any coolant weeping from the water pump? Is it only in certain conditions when this happens? In traffic? Cruising down the highway?

When you fill the system, it is important to get the air out. Squeze the upper and lower rad hoes as you fill. This will help to work out air. Start the car with the cap off and turn the heater on full bore (get air out of heater core).

There are several possibilities. Start with the simple stuff and go from there. The more you can answer on when/how this happens, the better we can narrow things down.