cooling system problem

[gasisontheright]

Ok, here the situation. 89 SHO. Manual trans. 167k miles, I just bought it Monday. This problem just started yesteday. When driving the temp guage stays below the "l" in normal(seems a bit low to me). When it stops, it starts going up. Its gone up at high as the "m". If I drive it a while, it starts spewing steam and it comes from the middle of the intake manifold, it runs the whole length of the intake. When it happened the first time coolant was dripping. It appeared to be coming from the thermostat housing, but I think it was just running down the center of the intake and exiting there. What all could it be? Where is coolant running under the manifold? I don't really wanna take the manifold off. Looks like a LOT of work.

 

[sdpatt]

There is a steel tube that runs the length of the intake from the output of the
water pump (center of the "V" on the belt side) to the thermostat housing. I have not heard of that tube corroding to the point of leaking (but anything is possible), but the leak is likely from the O-ring seals at the pump end or the thermostat end. The water pump (basically a timing belt service job) must come off to remove this "crossover" tube. Only you can determine where the leak is coming from.

The most common cause of the temperature staying below the normal range is the thermostat not fully closing and allowing the trickle of coolant to pass that will keep this very temperature efficient engine from reaching the normal range unless there is no air flowing through the radiator.

You can get a stock 180 degree replacement thermostat from AutoZone 492-180. Do not use much torque on the aluminum 10mm unts on the housing or any RTV on the mating surface of the metal parts. There should be a rubber seal around the outside perimeter of the thermostat.

 

[gasisontheright]

I found 2 leaking hoses that I've replaced, I've also got the thermostat and gasket I'm going to do tonite. I have also found out the cooling fan isn't turning on so tonite I'm going to do some tests to see why it isn't coming on. Since replacing the hoses it hasn't steamed at all, just overheat because of no cooling fan. I'm thinking the temperature sending unit isn't working because the guage quit working yesterday also. Perhaps is was showing such a low temperature because the TSU was bad. Does the fan turn on by the TSU, or does something else control when it kicks on?

 

[sdpatt]

There has been a good post in this Forum regarding the troubleshooting method to determine why the fan motor isn't running. You may want to search for that post. If you set the climate control to A/C and the fan doesn't run, the fan motor is at fault - most likely worn brushes. Don't get stuck in traffic.

 

[gasisontheright]

There has been a good post in this Forum regarding the troubleshooting method to determine why the fan motor isn't running. You may want to search for that post. If you set the climate control to A/C and the fan doesn't run, the fan motor is at fault - most likely worn brushes. Don't get stuck in traffic.

would it matter that the AC isn't hooked up? The previous owner cut 2 wires to the canister underneath the battery.

 

[gasisontheright]

I ended up snapping one of the bolts for the water outlet off. I'ma have to get a stuff extractor now.

 

[gasisontheright]

cooling fan motor is fried.