Cooling Fan Glitches COMP?

[tgsho]

Hey guys... Okay, I think I had this in the wrong section, so I am going to try it again and be more descriptive.

Before I decided to do a 60k on the car, it was running hot.. in the "O" part of "NORMAL" and started vommiting out of the overflow tank after it had been runnung for about 15 minutes. I ran codes and got - 51 - ECT engine coolant temp is way too high. I am almost complete my 60k, and I want to make sure I fix this problem before I start the car again. For clarification I need a brass only ECT sensor, the plastic one is NO GOOD?
My cooling fan is also not wired to the computer anymore. It runs right into the fuse panel and is grounded on the fender. I have a feeling this has something to do with the computer. I have searched and I cant find the information I need... or its there, but I dont understand what I am looking for yet. Any help please....

Does it make a difference if my heater core is by-passed right now, becuase it is. I also know thats not right... but how does it effect the car? Apparently the last owner tried fixing it with "rad leak" or something, it got in the heater core and needs to be cleaned out - thats why it is by-passed...

I also strongly believe that the last owner had the t-stat in backwards. What does this cause, and how do I know which way to put a new one in?

 

[projectSHO89]

The "point" of the t-stat should point in towards the engine. If it were backwards, the engine would overhear. "O" is not overheating since it's still in the "NORMAL" range. Puking out the overflow bottle, OTOH, isn't a good sign, either. I'd be replacing the radiator cap for starters, then a complete flush of the cooling system.

Brass/plastic makes no difference. Just make certain you replace the two-wire sensor, not the single wire one.

The heater core makes no difference.

DTC 51 means that the computer is sensing the ECT as open. That means it cannot control the fans. It also appears likely the PO didn't know how to fix it so he just rigged the system. The fans aren't wired to the computer anyway, they're wired to the IRCM box which is controlled by the PCM.

The IRCM/CCRM post sticked to the top of the Electronics forum has much of the detail you need.

Steve

 

[tgsho]

So basically, I should be able to replace the ECT sensor, and then re wire the fan to normal wiring... Then that code (51) should be gone.. I hope.

I checked that sticky out... very awesome. I thought the guy just rigged the fan to by-pass the IRCM.