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1992 SC, 5-speed, 101K miles.

New head gaskets, new water pump, new radiator, new thermostat, new coolent temperature sensor, and tonight I swapped out the IRCM with the same label, and. it's. still. over. heating!

Can anybody tell me what to check and how to check it so I can get this SOB to run without overheating? :mad:
 

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Yep, stock, runs strong!

Gradually builds temp, thermostat opens, temp sorta stablizes then it starts to climb.

I been running the AC eventhough it needs a charge, and with the fan forced deu to the A/C it seems to maintain. This led me to swap out the IRCM since the fan doesn't seem to want to turn on when the temp starts to climb.
 

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So this is probably the head gaskets, given that a healthy SC simply doesn't operate at a temperature where the fan's have to kick on the control the temp.

I've been driving around in my 89 after doing a HG and water pump job, just like with this car. And the temp never rises above the "O" in norm on the guage. Where on the 92 SC the temp rises to where the thermostate opens and then it keeps rising.

After consulting with DD he advised this may a combination of using MLS HG's and not putting a perfect surface on the block.

Regretfully I suppose it's back into this one to re-replace the MLS with a standard Felpro gasket.

Live and learn, ... hopefully!
 

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I would test to see if you are getting combustion gases into the coolant before ripping the heads back off the motor. If not, then it probably is not your problem. Also, even if the HGs are bad, the fan should still come on once the temp comes up. Maybe replace the coolant temp sensor first? If it isn't giving the right reading to the ECM, then it might not command the fan on until the temp is way up.
 

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i believe he said he changed that,before i would tear back into it i would be certain that the guage is really giving you correct temp.You can get one of those radiator caps with the temp guage built into it i have one on my 66 t bird because the guage was so unreliable.
 

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fan

On my 89 it was running hot, and I clipped #14 wire on the fan control (behind the passenger's side headlight) The fan is on low with the key on, you could try it or put a switch inside to turn it on. Also under the front bumper there is a small air dam that is suppose to pull the air up to the radiator
 

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Chris my availability has changed since we last talked, I will be available next Saturday after 3 and all day Sunday more than willing to come by and give you a hand. I can't do it this weekend cause I'm moving.
 

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I may fool around with it this weekend some more.

I'm a little fed up with this SC, the 89 seems to be running well though so I got that going for me!

Steve I have my Granddaughter visiting the weekend of the 10th so I may not be interested in spending too much time on cars but we'll see give me a call when it gets closer and we'll assess the situation and make a plan.
 

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Work schedule is a set schedule now, I work from 8-6 Monday - Friday and Saturday 8-3, so let me know when and what you need help with so I can make sure I grab the needed tools before I leave work.
 

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Well I dug into the 89 in order to check the quality of work recently performed during a head gasket R&R. Both fuel pressure regulator and bypass actuator were running w/o vacuum lines attached.

Fixed that Saturday! BIG Thanks To Matt XR7-4.6 for helping out. Always a pleasant and capable assistant or point man. PS Poly tubing max temp withstand, 125F :( replaced the bypass actuator tube with the proper rubber vac line (capable of withstanding the underhood temps) but didn't have the motivation to dig down to the FPR again. Instead I tore apart the passenger door window regulator, replaced it with a good motor I had on hand instead of the beat up reman'd unit at Pep Boys. I guess I should lay in another passenger side window motor from RA just in case.

Dropped the 92 off at Pep Boys Sunday to test the coolant/fans/etc... for the overheating condition. Hope to hear from them today.

A few parts I need:
Wiper motor assembly.
Passenger door lower window guide.
If anybody has these or comes across them, please let me know.
 

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So Pep Boys calls me up yesterday and asks me what the problem is and what's been done to the car leading up to dropping it off with them. So I explain all the stuff I had already explained to the service manager when I dropped the car off Sunday to the Monday service manager! Wait till later in the day and acll him back to hear... "you car is definately overheating, but we can't figure out what's wrong, there was no combustion gas contaminantes in the coolant, maybe you should replace your t-stat? No charge, cause we couldn't find or fix anything..." Now the whole no charge thing makes me enormously suspicious that they messed up something, or they just don't want to work on an SC. regardless I'm no further with the diagnosis unless I can trust them regarding the "not bad head gasket" diagnosis.

I'm planning on dropping it off at another speciality shop that I think might know more. moreover this shop is who did the water pump in the first place.

I still question if the fans are coming on at the right time (temp), I did pull the thermostat housing off and verified the part number and even boiled the state and verified it was functioning as it should. Reassembled it and drove it to work this morning, still overheating, still somewhat controlled by running the A/C (forcing low speed fan to operate).

If anybody have some detailed diagnostice advice, especially ringing out the pins and what they should be indicating for proper fan operation, that would be very much appreciated. I would supply this information to my next shop in the hopes they could pin down the problem once and for all.

Thanks in advance for your kind and knowledgeble advise.

Chris/Plat0
 

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How hot does it get? Does the coolant boil? Will the car overheat cruising down the highway? If so, that pretty much rules out the fan. If it overheats when sitting idling, will the fan ever come on before it overheats? Does the system hold pressure? Is there a noticable temperature difference between the upper and lower hoses? If you turn on the heater, do you get heat? If so, can you notice a temp difference between the 2 heater hoses with the heat on?
 

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Which T-stat do you have? If 180 with stock EEC this may be the problem.
 

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Maybe the sensor is out of whack. Get something that can read the sensor the computer sees.
Never mind. I missed that part of the first post. I'd still read the other sensor though
 

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Thread at SCCoA...
http://www.sccoa.com/forums/showthread.php?t=131090

How hot does it get? Does the coolant boil? Will the car overheat cruising down the highway? If so, that pretty much rules out the fan. If it overheats when sitting idling, will the fan ever come on before it overheats? Does the system hold pressure? Is there a noticeable temperature difference between the upper and lower hoses? If you turn on the heater, do you get heat? If so, can you notice a temp difference between the 2 heater hoses with the heat on?
Gauge indicates over "M" (NORM), swapped the gauge sending unit, same result. Fan starts with AC on or when ECT connector is pulled, New Thermostat checked in a pot o water. New Radiator, new ECT, new water pump new (2 years ago MLS Head Gaskets with no problems up till the water pump was replaced).

Sorry for the no replies I've been occasionally trying to sort out this problem along with a host of other life issues and I'm not the best diagnostician around. The fans will not come on despite the gauge indicating they should (by comparison to the other 89 SC I have that is operating normally.
 

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Check all grounds and power wires. I was having similar issue and found mouse damage (wires not even related to the EEC or cool) repaired them and car is much better and indicating a temp I more used to.

I'd make sure you are really seeing over heating (get a mechanical gauge to check against best would be at the gauge sending unit, ECT and Radiator).

No obstructions in front of the A/C?
 

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OK, so the fan doesn't come on at all when sitting idling, but it will come on with the AC on. I'll look up the wiring diagram and see exactly how that is controlled/triggered. Will the car overheat sitting idling with the AC on? If so, then you have another problem besides the fan. You say this started when the water pump was replaced? Why was the pump replaced? Do you have another pump you can install to see if perhaps the one you got was defective?
 

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It was a new bosch water pump, I had it replaced by a shop.

The AC system isn't properly charged, I was using the dash control to force the fan in order to just use the car to/from work (6 miles). During this drive it will get over the M on the guage. If I force the fans with the AC it'll just barely keep it at the M.

Right after I had the water pump replaced I drove the car from Chicago to St. Louis. it was overheating while in traffic, but when I got it out on the road it seemed to be ok. No idea if the fan was working at all during this trip.

If I run it idling in the driveway it'll eventually climb over the M.

Mikey, I appreciate you're continued advice. I'm currently driving the 89 so I can let the 92 sit until I find another diagnostic I can try. I'm trying to get one of the loal TCCoA club members to stop by with more diagnostics chops than my feeble attempts.
 
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