Continued overheating, coolant spewing from radiator when warming up...

Da6onesupra · 02-18-2011, 06:50 PM

Where is the clutch fan? I do have an automatic transmission... Is it the electric fan right next to the radiator fan? Cause that fan doesn't work, I have to connect it directly to the battery for it to come on...

91ma70 · 02-18-2011, 07:30 PM

I thought it was the fan clutch too but the car overheats on highway too. Did you replace with a used engine, re manufactured or rebuild the old one to be specific? Check the fan clutch which is silver looking thing with small fins attached behind the radiator fan and is driven by the water pump. The small electric fans are for the AC

The fan Clutch can fail in many ways.

1. Any fluid leakage means it's toast.

2. They can seize solid. That's the "sounds like an airplane".

3. They can fail to engage. Engine overheats.

4. With the clutch firmly bolted to the waterpump, any fore/aft play in the fan blades means the bearings are shot. This often happens before the bearings lock up, as in #2 above.

Da6onesupra · 02-18-2011, 08:17 PM

I replaced it with a used engine that the garage claimed had 47k miles on. They also said they had to rebuild some part of the engine, I don't remember exactly. (I've put about 12k miles on it). Ok is the fan clutch connected to the radiator fan? Cause the fan itself works fine. There is still coolant in the reservoir...

cre · 02-18-2011, 08:41 PM

The fan should be resistant to spinning by hand to a certain degree.... more so when it is cold. The fan clutch is the aluminum hub between the water pump and the fan.

A shot fan clutch (which allows the fan to spin too freely), a clogged or restricted cooling system, a missing fan shroud or any combination thereof may cause overheating while the vehicle is sitting idle or moving at low speeds.

Do note that the MKIII's coolant sensor is logarithmic and that beyond the normal operation range the temp is either VERY cold or VERY hot... In other words, if the temp gauge presents a temp more than a couple millimeters from normal, you're quite likely running at damaging heat levels... shut the car down IMMEDIATELY!

Da6onesupra · 02-18-2011, 11:36 PM

Oh yeah I see now that the fan is resistant to me turning it by hand. It looks like the coolant is just not circulating through the engine. It just builds up in the main radiator hose like the thermostat doesn't open...

cre · 02-19-2011, 12:44 AM

So test the thermostat.... just because it's new doesn't mean it's good. There are a number of possibilities here including advanced timing, bad water pump, coolant blockage, missing fan shroud (combined with other minor problems), bad thermostat and BHG. Start testing.

gloreboy89 · 02-19-2011, 05:42 AM

maybe try running the car without a thermostat just so the coolant can run freely. If the thermostat is a problem you will tell

02-18-2011, 08:41 PM	#4
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	The fan should be resistant to spinning by hand to a certain degree.... more so when it is cold. The fan clutch is the aluminum hub between the water pump and the fan. A shot fan clutch (which allows the fan to spin too freely), a clogged or restricted cooling system, a missing fan shroud or any combination thereof may cause overheating while the vehicle is sitting idle or moving at low speeds. Do note that the MKIII's coolant sensor is logarithmic and that beyond the normal operation range the temp is either VERY cold or VERY hot... In other words, if the temp gauge presents a temp more than a couple millimeters from normal, you're quite likely running at damaging heat levels... shut the car down IMMEDIATELY! __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

02-19-2011, 12:44 AM	#6
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	So test the thermostat.... just because it's new doesn't mean it's good. There are a number of possibilities here including advanced timing, bad water pump, coolant blockage, missing fan shroud (combined with other minor problems), bad thermostat and BHG. Start testing. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

02-19-2011, 05:42 AM	#7
gloreboy89 3" Exhaust Join Date: Aug 2010 Location: Atlanta, GA Posts: 68	just a suggestion maybe try running the car without a thermostat just so the coolant can run freely. If the thermostat is a problem you will tell __________________ too lazy to find a funny quote, buuuutttt off the top of my head. "life always= how well you treat your car, put crap in ur car, then car breaks down, then miss important meeting, or work which just so happen u cant miss another day or ur fired... and end up with a crappy life. driving an '88 supra

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Auto Supra Coolant hose pressure and return leak to oil pan and filter area?	rjSupra	MKIII Supra	45	01-18-2011 12:12 AM
Had overheating issue and Coolant leaking from intake Side??	Raysupra	MKIII Supra	6	04-07-2010 05:20 PM
Heater Union (Coolant Leak)	slader99	MKIII Supra	11	12-28-2009 12:29 AM

02-18-2011, 06:50 PM	#1
Da6onesupra Stock Join Date: May 2006 Location: Dallas, TX Posts: 6	Where is the clutch fan? I do have an automatic transmission... Is it the electric fan right next to the radiator fan? Cause that fan doesn't work, I have to connect it directly to the battery for it to come on...

02-18-2011, 07:30 PM	#2
91ma70 3" Exhaust Join Date: Feb 2010 Location: Irvine/Lancaster CA Posts: 61	I thought it was the fan clutch too but the car overheats on highway too. Did you replace with a used engine, re manufactured or rebuild the old one to be specific? Check the fan clutch which is silver looking thing with small fins attached behind the radiator fan and is driven by the water pump. The small electric fans are for the AC The fan Clutch can fail in many ways. 1. Any fluid leakage means it's toast. 2. They can seize solid. That's the "sounds like an airplane". 3. They can fail to engage. Engine overheats. 4. With the clutch firmly bolted to the waterpump, any fore/aft play in the fan blades means the bearings are shot. This often happens before the bearings lock up, as in #2 above.

02-18-2011, 08:17 PM	#3
Da6onesupra Stock Join Date: May 2006 Location: Dallas, TX Posts: 6	I replaced it with a used engine that the garage claimed had 47k miles on. They also said they had to rebuild some part of the engine, I don't remember exactly. (I've put about 12k miles on it). Ok is the fan clutch connected to the radiator fan? Cause the fan itself works fine. There is still coolant in the reservoir...

02-18-2011, 11:36 PM	#5
Da6onesupra Stock Join Date: May 2006 Location: Dallas, TX Posts: 6	Oh yeah I see now that the fan is resistant to me turning it by hand. It looks like the coolant is just not circulating through the engine. It just builds up in the main radiator hose like the thermostat doesn't open...