1luckyduck

my girlfriend just got a 1986 rx7 base model, the motor is strong and the compression is very good , but one problem the top rad. hose gets hard and kinda hot fast on warm up, its like the coolant
not circulating. I have no idea what to do. I got a new water pump and added a electric fan to, same problem.

freemanrx7

Whats the problems then. The hose will become hard when there is coolant pressure. Heat will happen to. SO whats the problem?

w0ppe

On probably all vehicles, the radiator hoses will get very hot. They should be somewhere around 75*C....
Did somebody buy an FC without knowledge of vehicles? You're going to be in the rough course I'll say that much

1luckyduck

I have an 1985 rx7gsl and a 1991 rx7 s5 and they both run fine so I now if somthing doesn't seem right with my girlfriends car, I'm thinking the motor has a clogged, she bought it from a shop that put water in the rad. so it has alot of rust in the hose and water neck it self, thats why I change the water pump and some of the gaskets, its kinda hard to explain, and where I live if the seals are bad then the motor is bad, no one can repair it here. so we trash the motor. im asking for help not an a-hole. so its over heating not fast but it does

freemanrx7

Thermostat?

Radiator caps should be replaced. Try using the cap off your 91 and see if that solves the problem.

texFCturboII

iTrader: (17)

+1

change the thermostat, change the rad cap, flush the radiator. BLEED ALL AIR.

still getting too hot? check the waterpump weephole, anything leaking outta there? replace the waterpump.

Aaron Cake

iTrader: (1)

http://www.aaroncake.net/rx-7/cooling.htm

The link above is a step by step troubleshooting guide for the cooling system. Though I am still not sure what your problem is as you have not been specific.

ericgrau

iTrader: (1)

Standard operating temperature is 180 degrees. Hot tap water is 140. 180 is hot enough to burn your hand if you got coolant on it. 180 is on the low end for a car, in fact. Other cars run hotter. Coolant will not circulate through the radiator on any car until it gets up to operating temperature. If it still doesn't circulate, then you need a new thermostat.

Doesn't seem like you have a problem. Try learning more about cars?

13bturbofc

iTrader: (4)

first replace thermostat and rad caps if that dosent fix it, have a radiator shop pressure test the rad

Sideways7

iTrader: (7)

Maybe the rad is clogged. The test procedure is in the link Aaroncake posted.

1luckyduck

thanks guys. I will try all of these out and I'll get back to you on the after math.

90gtrx

Agree here, but is it a problem with just a hot hose or is the temp guage off its ****

1luckyduck

ok, I took off the rad. cap and started the car and all the cool. started to shoot out of the water neck, so I took off the water neck and there no thermostat so its not stuck. I forgot to mention, here on Guam we always remove the Thermostat .
haha its so hot it always breaks and it holds back the coolant and it over heats fast ... so we alway remove the thermostat. to be honest I never had a blown rotary motor. I had a blown sohc 240sx, so I realy don't know what it means when the coolant shoots out of the water neck. but I put everything back togther and did the rad. flush put napa closed so I couldn't buy any coolant till tomorrow.

Saavedro88

iTrader: (1)

Wait...

You've never had a thermostat in your Rotary engines, but you've never blown one? You may not have blown anything yet, but that thermostat is essential to the operation of the car. It may be hot in Guam, but it's not 190 degrees...

You are damaging the car. Maybe not in ways that are noticeable, but nonetheless...

ericgrau

iTrader: (1)

if the engine's just idling then coolant shouldn't shoot out the filler neck. May mean a blown coolant seal if it continues to shoot out non-stop.

The thermostat is not esential. Running the engine hard when cold will merely create increased wear. If you wait for it to warm up before pushing it hard, you won't increase wear. Removing the thermostat will not magically make the car as cold as outside. The cooling system simply isn't capable of that. The thermostat merely helps the car warm up faster and keeps the engine from getting too cold when you're coasting downhill at 90mph in cold weather. The thermostat also helps cooling because it blocks off a bypass passage when it opens. Try a Mazda thermostat to prevent frequent failures like you mentioned. Replace it every 12 to 18 months, replacing the coolant at the same time.

freemanrx7

He's touching them and he said it !!!! GREAT

Aaron Cake

iTrader: (1)

If you started the car cold without a rad cap and coolant immediately began gushing out of the filler neck, that's a definite sign of a compromised coolant o-ring.

Try the test again, but this time rev the engine a little. If the gushing increases, then you certainly have a bad coolant seal.

Saavedro88

iTrader: (1)

Maybe not essential, but critical. I drove my 86 around for a week without the gauge ever moving off the peg, and named it as a sensor error. Cracked open the housing one day and found out I didn't have a thermostat... My engine never warmed up. Now that I've got a thermostat, it'll warm up in less then three minutes...

I just find it hard to believe he hasn't broken anything yet without ever using a thermostat...

1luckyduck

alright I'll buy one tomorow. thanks guys.

Aaron Cake

iTrader: (1)

Before you waste money on a thermostat, first test the engine to see if the coolant seals are junk.