carl_9_9

(87 rx7 na both cars)i changed the thermo(its a stant) and pressure checked the system. it runs ok no leaks and pressure loss. but it runs around 10 to 15 degrees higher than my rx7. i have a temp gun on it check. the biggest difference is at the thermostat, it shows the highest temp around 15 to 20 but no longer that for 20 secs. my car barely goes that high. mine rus at 180ish and it runs at 190ish to max200. the radiator plug to blead is stripped out i was bleeding it when it was running and it seem to melt. is it the radiator or the water pump. a seal cant be busted cause there was no pressure loss for up to 30 pounds.

RX7MAVEN

Beware of pressure testing a cooling system on a 20 year old car at 30 pounds. You could blow the heater core or radiator. Never check more than 5 pounds above the cap rating. If the cap works right, your cooling system will not exceed the cap pressure ratings. Are both thermostats the same temperature ? The higher temp could be the difference in the thermostats. One could be 180 and the other 195. Both are available.

carl_9_9

ok well i tested til 20 then the hoses started to leak. what is the oe temp suppose to be.

carl_9_9

the one i got was 190.

carl_9_9

i drove it home 15 miles and it stayed at 1/2(on highway) when i got on the streets it like 90% so i shut it off and rolled into a parking lot and my girlfriend pushed me. oh yeah.... with her truck. so why isnt it cooling good enough. is it a rad or th 190 stant thermo, or the waterpump that looks new.

MaczPayne

iTrader: (5)

Did you use the oem thermostat?

krosLy

the temp doesn't go up for highway driving, but it goes up for street driving? (slower speed, stop/starting)

carl_9_9

yeah it stays a little higher than my original rx7, i have 2 rx7s one that runs fine stays around 1/4. this one on the highway is at half exactly. when i was on the streets for even a few minutes it was going up. so yeah exactly what u said.

carl_9_9

no i have to order one, i was just using one to get home

krosLy

alright well I was reading a while back and came across this..

"Overheating In Traffic (Stop and Go, Low Speed Driving)
Overheating in traffic and low speed driving has one common cause: the fan. During stop and go, low speed "creeping" and low speed driving, there is not sufficient flow of air through the radiator. Therefore, the engine has a fan to draw air through the front of the car. This fan operates off of a viscous fan clutch. Basically, the fan clutch is mounted between the fan and the engine. As cold air flows over it, the clutch loosens up, allowing the fan to freewheel on the shaft of the engine. The fan then hardly turns. As the air flowing over the clutch heats up (as the engine transfers more heat to the radiator) the clutch tightens up, spinning the fan faster and drawing more air through the radiator. The cycle continues as long as the car is running. Over time, this fan clutch can wear out, causing the fan to freewheel whether it is hot or cold. This causes reduced airflow through the radiator, and therefore high operating temperatures during low speed driving. This theory is easy to test, because once you get on the highway the car will cool right down.

Testing the fan clutch is pretty easy. Simply start the car and allow it to warm up to normal operating temperature. Shut it off, then give the fan a good flick with your hand. If it rotates more than about 1.5 turns, then odds are the fan clutch is worn. However, I have found this test to be a very bad indicator of the true condition of the clutch. A much better test is to simply pick another one up from a local wreckers (they are cheap and available) and swap it on. If this solves your problem, then the fan clutch was obviously the culprit.

As mentioned, replacements are available at many wrecking yards. You can also purchase a new unit from Mazda, but I don't even want to think of the cost. If your fan clutch is bad, you might want to put some serious thought into just replacing the stock fan with an electric unit. It will cost less than a new fan clutch from Mazda, and offer slightly less drag on the engine resulting in better throttle response. Good fans to use are made by Flex-A-Lite and are available from Summit Racing. "

here is a link to the whole page if you would like..
http://www.aaroncake.net/rx-7/cooling.htm

krosLy

I am new to the rx7 scene, so don't hate me if you've already looked into this :P