Overheating - My Type A Personality

[gunbarrelvx]

Back again. So after the clutch work/$3,000.00 investment, I have returned yet again.

My VX began to fluctuate with the temp gauge. Driving in stop and go traffic, it began to climb and almost peg to the right. I tested the fan clutch and it seemed weak so I have already replaced it. Seemed to help but the problem resurfaced a week ago. As soon as I drive and the fan kicks on, the temp drops.

I have no high idle issues, even when it is hot. The motor doesn't feel overly hot or anything either. Anyone have input on what I should go after next?

I have a trip to Wyoming this weekend for a triathlon and have to take the VX. Kind of nervous.

[tom4bren]

Gunny,

Why don't you just bypass the thermal sensor for your fan & connect it directly to a switched hot wire for the trip. The fan will run alla time but at least you won't overheat. The thermostat should keep the temp up to optimal running temps.

The only other suggestion I would have at the moment is to add an auxiliary fan in front of the radiator. IIRC some members were quite successful in installing a fan (with temp sensor) from a Caravan.

Tom

EDIT:

Here's a thread on the subject (with links to even more threads).

http://www.vehicross.info/forums/showthread.php?t=13846&highlight=electric+fan+conversion

[gunbarrelvx]

K. How hard is it to replace the thermal sensor out of curiosity?

[tom4bren]

IDK. Never even looked for it on the VX. I'll see if I can find it in the shop manual.

[Triathlete]

The system really does not have many parts...though a few are a b*tch to get to. The obvious...coolant (proper mixture, how long since changed), fan, fan clutch (already addressed), radiator (fins clean, no rust, clogged), thermostat, water pump, and the hoses.

[gunbarrelvx]

Hey Billy,

The coolant coolant is fresh, fins are spotless, and hoses look good.

Another thing. I check the oil regularly since everyone on the forum freaks me out about consumption. I am still sitting at a 2/3 full on the dipstick. Not sure if that piece of data helps at all.

Guess that leaves thermostat and water pump. Any idea on how to test either?

[Makocross]

Try to find an infrared thermometer and point it at several places on your engine and radiator to verify it is overheating. It could be sensor or indicator problem.
Mike

[SilverBullet75]

What about adding a small external oil cooler? Tap into the two plugged ports on the oil filter mount.

Something like this:
http://www.ebay.com/itm/Universal-13-Row-8-AN-Engine-Transmission-Oil-Cooler-/180674581248?pt=Motors_Car_Truck_Parts_Accessories&hash=item2a110b5300&vxp=mtr

[Triathlete]

The tranny overheating can also cause overheating

[EVO]

It could be a stuck thermostat.

[tom4bren]

As soon as I drive and the fan kicks on, the temp drops.

That's the part that I'm focusing in on. He's fine as long as the fan is running ... but it doesn't seem to kick on when it should. It sounds to me like the temp sensor that engages the fan clutch isn't working like it should.

It can be a real beeeotch to track down that problem. I know because I've been at it for 2 years with the Eclipse. It keeps burning up the relay that engages the electric fan when the engine temp rises ... but if I turn on AC, the fan comes on. There's only one problem with my Eclipse ... as of tomorrow morning, it's somebody else's problem (I'm turning it in to the auto auction since insurance totalled it).

He either needs to find the right temp sensor to replace or bypass it and run the fan alla time.

EDIT:

I looked it up in the shop manual. The trouble shooting guide lists 2 sensors: Thermo Meter Unit, Engine Coolant Temperature Sensor. I have no idea what the first one is since it's not mentioned anywhere else in the manual. The second one is shown in the other pages I scanned.

[Triathlete]

Tom, our fan is mechanical not electrical. The fan clutch provides that service, which he already replaced. The cluctch has a little spiral wire on the back, much like the one you find on a wall mounted ac thermostat, that controls it.

[tom4bren]

Good to know. Mebbe that's the "thermo meter unit" thinggy that I didn't recognize. IMHO that's a stooopid way of turning a fan on/off in a car though. I wonder if the bimetal spring is adjustable like they are on the home units.

I've got a spare clutch that he can try out if he'd like (prolly not though since he's already replaced his once already).