strange overheating problem
 

So today I'm driving and the temp is perfect as usual. After I get out of boost the temp starts to go up quickly. I immediately turn the heat on high on defrost to see if it will relieve some of the heat and the temp stays the same. The with it still on high I switch it to the footwell setting and the temp immediately goes back to normal. Wtf?? No power loss or anything the entire time either.. any ideas?

anyone??? anytime it overheats if i put the car on the footwell setting the temp immediately drops to normal...

try replacing the thermostat. it sounds like it's stuck

If the temperature sensor wire is grounding, it will read maximum temperature. If sounds like there could be some kind of rubbing/interference issue that has worn the insulation and is grounding the wire when the temperature control is moved.

If you have MS or some other ECU, you might be able to monitor the ECU coolant temperature to see whether it agrees. IIRC, the gauge uses a different sensor than the ECU.

im running a link.. new thermostat.. bottom rad hose is pretty cool when im at temp.. and it only overheats right after boost..

BTW- when you have the vent system on defrost, it automatically turns the air conditioning on (this dehumidifys the air and removes the condensation from the window you are trying to defrost- even with the heat on full blast), which puts a nice hot condenser in front of your radiator...increasing the temperature of the air going to the radiator.

Slightly OT: Is that an NB2 only thing? I can run the vent set at defrost and the a/c does not turn on, this is on my '99 and my '95 was the same way as well. If I manually hit the a/c button, then it kicks on.

sooo... i think i must have some sort of electrical goblin.. seriously... so i turn the car on about an hour ago and the charge battery light is on (new alternator, battery and terminals btw) and the oil pressure is at like 30 psi at idle. (norm at 15).. after driving for like 15 mins the charge light and psi go back to normal.. the when im in 5th gear under boost 20psi the motor shuts off and then turns right back on... wtf!! i checked every fluid in the car right after, perfect, not overheating one bit, no loose anything as far as i can see.... any ideas??

Mine does it, Jenn's car does it and I'm about sure that my 99 did it too. Even with the a/c button off, I can hear the compressor pop on when the defrost setting is selected. You could always crank your car up, with the vents off, check the compressor and then turn the defrost on and check the compressor again to see if it's engaged.

sooooo now its getting worse.. driving not in boost around 55 mph the motor shuts off then turns right back on... also feeling slight hesitation during acceleration.. any ideas?

What's your setup? Year, ecu, ect? Check some grounds, should have a strap from the firewall to the head, this sounds like a grounding issue.

Custom 16g,link, 550s built motor. I checked most of the grounds and stuff last night. While doing that I discovered that the wire to the o2 sensor is completely ripped out. Its not touching anything though.would that cause the bad idle and motor to shut off?

WB or NB? Not familiar with the Link, but if it is expecting a good O2 signal and is not able to fail gracefully . . . you bet.

Check the hotside of the harness for the o2 that got ripped off. If one of those 12v wires contacts one of the grounds, all hell will happen. Been there.

Stock nb sensor.... nothing is touching.. I used a bread tie and tied it to the coolant line That goes into into the turbo

not bad idle, but I will tell you a loose battery which is shorting out momentarily will cut your car off and on like you are saying.

Not sure if you have the o2 wired directly from the battery or on a fuse circuit, but I would take a gander that your battery tie-down is loose or its the wire (at least for the shut offs).

Also, just to add on to the temp. sensor earlier, its the SAME sensor for both the ECU and the gauge. Gauge is just biased to display flat (165*-225* is flat) and has a ton of dampening fluid in it.