1G Overheating Issue

[mrkost]

I bought a 1990 Eagle Talon TSi AWD a couple months ago and finally got it driving. I’m currently dealing with an over heating issue. I do not have A/C and my heater core is looped. I drive it for 10mins and it almost rises to red. I turn off the car before it reaches so I do not cause damage to the engine. The car was sitting for around 4 years in a garage.

Any ideas? I haven’t done much diagnosing yet.

 

[Anfurnyy]

Well first off, if you haven't replaced the coolant definitely do that and burp the system really well.

Well also need to know, what kind of radiator fans does it have, does it have an aftermarket intercooler, and have you confirmed that the fans are coming on?

 

[mrkost]

Well first off, if you haven't replaced the coolant definitely do that and burp the system really well.

Well also need to know, what kind of radiator fans does it have, does it have an aftermarket intercooler, and have you confirmed that the fans are coming on?

I will start with flushing and replacing the coolant. I have a large after market intercooler. Stock radiator and stock radiator fan.

I do not believe the fan is turning on. I tested the fan by jumping it in the fuse box and it does work. What causes the fan to not turn on?

 

[Anfurnyy]

I will start with flushing and replacing the coolant. I have a large after market intercooler. Stock radiator and stock radiator fan.

I do not believe the fan is turning on. I tested the fan by jumping it in the fuse box and it does work. What causes the fan to not turn on?

The fans are supposed to turn on using the coolant temp switch on the bottom of the radiator, right by where there lower radiator hose connects to the radiator.
There might be another one possibly on the thermostat housing too but I honestly can't remember.

 

[CrackedDSM]

The fans are supposed to turn on using the coolant temp switch on the bottom of the radiator, right by where there lower radiator hose connects to the radiator.
There might be another one possibly on the thermostat housing too but I honestly can't remember.

The one on the thermostat housing is for the A/C, and its only job is over a certain degree it won't allow the A/C compressor or A/C system to kick on. The only one that really matters is the one in the lower radiator.

Whether you have A/C or not, if you have the relays and the fuse in the fuse box on the upper driver's side in the engine bay, if you turn the inside fan on and press the A/C switch until it's green, both fans should kick on.

 

[dwb]

Does the upper radiator hose get hot? If not, replace your thermostat.

 

[mrkost]

Does the upper radiator hose get hot? If not, replace your thermostat.

What type of thermostat should I order?

 

[dwb]

What type of thermostat should I order?

A stock equivalent would be fine.

 

[jed344]

Run it at idle up to temp. If the both rad hoses are not hot then thermostat is not opening. Parts store ones are fine we have used car quest ones for 15 years without issue. Heck my own car has a 10 year old 10deg cooler napa one in it, if they both get hot then thermostat is not the issue.

Make sure the fan turns on but after a certain speed say 30mph there should be plenty of air flow that without a fan it would stay cool. If the fan turns on then i would check if its pushing coolant out the overflow as it could be a bad radiator cap not raising the pressure to increase the boiling point of the coolant, if all of this all checks out then the signs point to a not so good issue.

 

[TerminalTalon]

Make sure the system holds pressure. (pressure test)
Make sure it circulates. (waterpump and thermostat)
Make sure the fans come on at operating temperature. (sensors and fan assy’s)

 

[mrkost]

Run it at idle up to temp. If the both rad hoses are not hot then thermostat is not opening. Parts store ones are fine we have used car quest ones for 15 years without issue. Heck my own car has a 10 year old 10deg cooler napa one in it, if they both get hot then thermostat is not the issue.

Make sure the fan turns on but after a certain speed say 30mph there should be plenty of air flow that without a fan it would stay cool. If the fan turns on then i would check if its pushing coolant out the overflow as it could be a bad radiator cap not raising the pressure to increase the boiling point of the coolant, if all of this all checks out then the signs point to a not so good issue.

Might be a dumb question. What is the removal process to take out the temp sensor at bottom of the radiator fan. Or is there any good way to test it without removal. The fan is not kicking on but I jumped it and know it works.

Thanks

 

[dwb]

Drain coolant and remove sensor. Then:

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Also, if the thermostat is not opening, the radiator is likely not going to reach at least 180F when you expect it. Which won't trigger the sensor in the radiator to turn the fans on.

 

[1990TSIAWDTALON]

You can dip it in boiling water and see if it makes the 2 wires have continuity with a DMM. If it does, and then it doesn't when it cools off, the switch is good.

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[steve]

Disconnect the thermo sensor (#9) in the bottom of the radiator, short the two pins and the fan should turn on. If it doesn't you have an issue with the power, wiring, or relay. If it does then the problem is with the sensor. The wiring diagram gets a little complex due to the AC but if you follow the basic radiator fan you'll see it gets power from fusible link #2 via the radiator fan relay and that the thermo switch grounds that relays coil to turn it on.

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[mrkost]

Disconnect the thermo sensor (#9) in the bottom of the radiator, short the two pins and the fan should turn on. If it doesn't you have an issue with the power, wiring, or relay. If it does then the problem is with the sensor. The wiring diagram gets a little complex due to the AC but if you follow the basic radiator fan you'll see it gets power from fusible link #2 via the radiator fan relay and that the thermo switch grounds that relays coil to turn it on.

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Thank you.