Help - Cooling System Problem

boblyon1 · #1 (**permalink**) 01-30-2008, 09:43 AM

My SPF is #1399, made circa 1999, with about 6K on the engine. It has a Southern Automotive 351W & Tremec 5 speed. It always ran on the cool side, with the fans coming on rarely around 94 deg C. In colder weather it rarely got about 85 C, even when idleing. All of a sudden, on a cool-weather run with very little stop-and-go traffic, it overheated (without the fans coming on) and warped the head. I suspected that the thermostat (180 degree F I think) froze up. Well, now my mechanic has resurfaced the heads, put a cooler thermostat in (160 F) and it is still running up to 115 deg C with the fans coming on intermitantly, but not always when they should. Any ideas?

Bob

mr0077 · #2 (**permalink**) 01-30-2008, 09:57 AM

Maybe lower radiator hose collapsing (sucking shut) at cruise RPM, or water pump impeller came loose from the pump shaft?

Flyin_Freddie · #3 (**permalink**) 01-30-2008, 10:14 AM

It could also be a bad - or at least misbehavin' - fan relay or the temp sensor. You should be able to see if the lower radiator hose is collapsing. I'd suspect the fan relay or temp sensor first. Both these have had some history of failure with the same symptoms you're reporting.

Also...you have SPF#1399....made in 1999? I beg to disagree. Mine is #770, and I have Q/A documents from the factory in Port Elizabeth dated June 2000. Mine is an Olthoff prepared car, that was delivered in October 2000. I suspect your car is a late 2001, if not a 2002 car.

boblyon1 · #4 (**permalink**) 01-30-2008, 10:24 AM

My beast is SPF # 633 - what was I thinking. Thanks to both of you for your suggestions. Anyone else have an idea? -thanks.

oleyellar · #5 (**permalink**) 01-30-2008, 03:08 PM

The fans are controlled by the temp sensor in the radiator. I have changed mine twice since 1998. The temp sensor closes the relay coil starting the fans, I have replaced two of those since 1998. All seperate failures at four different times. I have since wired a manual switch to activate the fans incase either fails again. Sensor is in the radiator the relay is under the dash.
Good luck

thudmaster · #6 (**permalink**) 01-30-2008, 03:15 PM

The new superformances now have a manual overide switch on the dash for the fans. I have 2742 with that switch. My old spf 0995 just had the temp controlled relay. I think superformance fianally figured it out. My two cents says change the relay and install a manual switch for backup.

boblyon1 · #7 (**permalink**) 01-30-2008, 04:03 PM

Thanks to everyone who gave input, especially mr0077 who nailed it. The water pump impeller was just spinning freely on the pum shaft.

Bob In Ct · #8 (**permalink**) 01-30-2008, 06:33 PM

Running a 160 in place of a 180 will not keep any car from over-heating. When the engine is producing heat faster than it is being taken away you overheat. This can be caused by too small a radiator, fans not running correctly, bad thermostats or in your case no (or low) coolant flow. The thermostat just regulates the temperature of the coolant in the water jacket. Your oil would prefer the 180.

Just my $0.02

Bob

McObra · #9 (**permalink**) 01-30-2008, 06:45 PM

I agree with Bob in Ct. The 160 degree thermostat is too cold. Put a 180 degree
stat back in. The way it is, the engine won't be able to get to normal operating
temperature and sluge will form in the oil due to condensation.

Blas · #10 (**permalink**) 01-30-2008, 07:51 PM

Use a balanced thermostat. It fails open. and be sure the little hole drilled on the edge is at the top when you install it. Be sure to purge all the air out of the system too. You can also get a lower temperature fan switch for the bottom of the radiator, but it's no fun to install...

mpanten · #11 (**permalink**) 02-08-2008, 08:16 AM

I agree with the gremlins in the relay post. You can always try the manual switch route. Cheap, easy, and insurance in case further problems.

Bartruff1 · #12 (**permalink**) 09-15-2008, 02:30 PM

Quote:

Originally Posted by oleyellar

The fans are controlled by the temp sensor in the radiator. I have changed mine twice since 1998. The temp sensor closes the relay coil starting the fans, I have replaced two of those since 1998. All seperate failures at four different times. I have since wired a manual switch to activate the fans incase either fails again. Sensor is in the radiator the relay is under the dash.
Good luck

My fans (SPO 2811) come on around 85C and keep the engine cool...no problem, both work and suck air in...when I turn the engine off the fans will come on and then turn off when the water temp gets to below 80 except on a couple occasions when I have gone back out to the garage and they were running at 60C...on a couple occasions, they have ran the battery down ??? I have a manual switch on the dash...I guess my question is what is your guess, the temp sensor or the relay or what ??? If so, where do I get the parts ??.....to tell you the truth, I would just as soon do away with the automatic feature and just use the manual switch but I suppose, nothing is simple anymore ?? Thanks in advance for any advice...

FWB · #13 (**permalink**) 09-15-2008, 02:51 PM

Quote:

Originally Posted by boblyon1

Thanks to everyone who gave input, especially mr0077 who nailed it. The water pump impeller was just spinning freely on the pum shaft.

just for the insight....how many miles are on the water pump and what brand
is it?

Fred

boblyon1 · #14 (**permalink**) 09-15-2008, 05:10 PM

Fred - This problem surfaced about nine months ago and has been resolved for me. This thread has been essentially dead until revived today by Bartruff1 who has a related problem. I had about 8K miles on the car, engine from Southern Automotive. Goodluck Bartruff - You should get some good answers here.