I'm putting a new thermostat in my car every 1-2 weeks. It's getting rediculous. Everytime I take a old thermostat out it is stuck open. Every time. It's getting too cold to ride around with no heat.

She's got a new waterpump, radiator, all new hoses, new coolant temp sensor and coolant switch, 50/50 coolant mix, and I've tried every grade thermostat and it's the same story every time.

It's turbo, on 8lbs, a lot of aftermarket goodies but none of which would mess with the thermostat like that. Coolant remains a neon green.

Any ideas?

Where are you getting your 'stats?

Is there any buildup or corrosion on the stat? Are you overheating?

Double post

Are they all the same brand?

Getting them from autozone, since I work there. The thermostat that came with the motor was stuck open. The 1st duralast thermostat worked for two weeks. The first failsafe (Lifetime thermostat) lasted about a week and a half. Then this 2nd failsafe lasted all of maybe 2 days. They are all getting stuck open.

Car is not overheating at all. In fact, my problem is the opposite. It's cold as hell and it wont go past the "C" line on the gauge. No heat whatsoever.

I only have the condenser fan in now so when I start the car the fan runs constant with the heat on. I cut the fan off and it takes like 15-20 minutes of idling to start warming up. Today I decided to leave the fan off when I left work, in the city, and with the stop and go and traffic lights it finally warmed up to operating temp. Cut the fan on and it drops down to C.

Interesting note though, on the ride back home, the trip down the highway at 65-75mph I left the fan off and after it was in the normal operating temp from the city driving it stayed there until I got home and blew pretty warm. It's still not blowing hot, but the blower isn't blowing it fast either. I turn the blower on hi and you can hear it blowing hard in the dash but only a little heat is coming out.

The amount of heat you feel coming from the heater core is not an accurate way to tell if your engine is warm. The gauge is a tell tale sign, but again it is not 100% reliable. I would suggest measuring/logging the coolant temps with a standalone gauge or even one of those pocket IR temp devices. What are your ambient temperatures?

Well when the gauges is reading cold, cold air comes from the heater core. When the gauge reads normal operating temp, warm air comes from the core. As far as ambient temps, if you are referring to the temp outside, it's around... FREAKIN COLD! Like 20 degrees in the morning, 45-50 during the day, and around freezing before midnight. I have a glowshift temp gauge I haven't installed yet since I still haven't ordered my gauge cluster pod, but as far as I can tell, the temp gauge works properly.

One thing that I noticed today when I felt the heater hoses after I got home was one hose was really hot, about as hot as the radiator hose, and the other was hot but I could definately tell at least a 20-30 degrees difference on my burnt hand-o-meter.

I've never had a thermostat fail on any car, ever, so I am a little suspicious. Could you post a picture of your next thermostat "as installed" and one of the failed thermostat? Maybe they are giving you 4G63 thermostats or you are putting them in backwards (seen it done). Also, shouldn't the condenser fan turn on when the A/C compressor kicks on, not with heat only? That's the way my car works anyway.

Corbin
'95 ESI-T

Now with more power and fewer leaks



Humble servant of the Wiki

I'll see if I can post pics up when I take this one out. As far as the 4G63 stat, no I get them from the shelf myself. I triple checked the way it goes in after the 2nd one and they're going in good.

I don't know if the 98 is different from the 95-96, but with that little "snow flake button" on the climate control depressed, when you cut on the blower motor whether the heat or ac is on, the condensor fan should cut on. That's how mine works anyway. When I hit the button again to make it pop back out, the condensor fan shuts off.

The snow flake button is the A/C button. The temperature control just blends in air from the heater core, if you ask it to. The only good reason to run the A/C compressor with the heat on is to defog the windsheild. Otherwise, you are cooling the air just to heat it (and over cooling your radiator with the condenser fan on).

Corbin
'95 ESI-T

Now with more power and fewer leaks



Humble servant of the Wiki

Actually the car will cycle the AC with the defrost on anyway to help control the humidity inside the cabin. I had been wondering for a while why my gas mileage kinda sucked when I ran the defroster compared to when I would just crack the sunroof and blast the heater on my feet. I finally let the car sit and idle with the defroster on and I watched the AC compressor kick on and off.

Originally posted by RoninEclipse2G
Actually the car will cycle the AC with the defrost on anyway to help control the humidity inside the cabin. I had been wondering for a while why my gas mileage kinda sucked when I ran the defroster compared to when I would just crack the sunroof and blast the heater on my feet. I finally let the car sit and idle with the defroster on and I watched the AC compressor kick on and off.

My car does not cycle the A/C with vent selector in defrost mode. I would definitely know because I often leave the vent in defrost mode and the A/C compressor causes wicked oscillation in my MS2 controlled stepper IAC (it will stall the car after a while). The 1995 had a different control system for the A/C. I have the weird three position "snow flake" button. In any case, leaving the A/C button depressed in the winter will certainly tend to overcool your radiator. The thermostat should still be able to accomodate that and direct flow away from the radiator to maintain temperature.

Corbin
'95 ESI-T

Now with more power and fewer leaks



Humble servant of the Wiki

Strange. Malachi is a 95 as well. August 94 build. I have the weird 3 pos snowflake button too. I'm pretty sure that was a hold over thing from the 1G's because my mom's 94 had the same settings.

Maybe just odd inconsistancies between 95's? Seems like every 95 I've messsed with was just a little different from the others.

Ronin, I still think you're on crack. Are you sure that the A/C button wasn't in econo mode (amber)? That will cycle the compressor every so often. There would have to be a microswitch that senses the knob being rotated into the defrost position. I'm pretty sure that selector is all cable driven, with no switches. The 1995 owner's manual also makes no mention of the defrost position cycling the compressor. It actually tells you to press the A/C button and put the selector in defrost to dehumidify the cabin.

Corbin
'95 ESI-T

Now with more power and fewer leaks



Humble servant of the Wiki

Well I definately narrowed it down to the heater core. I cut the car off today when I got home and heard massively hot air pressure bubbling the hell out of the overflow tank. I grabbed the upper radiator hose and it was hot as hell and kind of stiff. Grabbed the bottom hose and it was warm. Grabbed one of the heater hoses, it was warm, and grabbed the other and burnt my hand.

So, question is, when I swapped motors I couldn't remember which hose went to which pipe. Does the direction of coolant into and out of the heater core make a difference? Is the core directional or can it flow both ways. Also, if that's not the case, what can I do to unclog the core without taking it or the motor out of the car?

And yes, that just happened. "Snow flake" button is the new name for that thing.

Well I searched the other day and the heater core is not directional. I did decide to switch the heater hoses to see if it would unclog the core by pushing the crud the opposite way. It kinda worked I guess. I'm not getting alot of pressure buildup. But it won't stay hot either. It gets warm at idle, rev it to around 2k and it gets hot. Then let it idle again and goes back to warm.

Took it for a short ride and when moving at a decent speed it steadily goes back to cold again, like the tstats stuck open. I haven't pulled it out yet to see but that's my guess. It got down to like 15 degrees here yesterday. It's way too cold for this.

Suppose you jumpered around the heater core and connected the hoses together? That would eliminate the possible heater core blockage as a source of your problem. you would probably want to put in a new thermostat at the same time. If the car doesn't overcool, you know it was the heater core. You can get a new one from RockAuto for $118.

Corbin
'95 ESI-T

Now with more power and fewer leaks



Humble servant of the Wiki

Yeah, I'll give that a shot. Can't hurt.

Originally posted by RoninEclipse2G
Actually the car will cycle the AC with the defrost on anyway to help control the humidity inside the cabin. I had been wondering for a while why my gas mileage kinda sucked when I ran the defroster compared to when I would just crack the sunroof and blast the heater on my feet. I finally let the car sit and idle with the defroster on and I watched the AC compressor kick on and off.

I cannot find the thread about this right now, but this has come up a while back. My 99, prior to having the heating and A/C gutted, would cycle the a/c compressor to dry the air when in the defrost or defrost + feet mode. There is a switch behind the vent position on mine. Even if the snowflake (2 position on mine) is in the "off" position, the green LED will remain off however the compressor will cycle. As mentioned, presumably to prevent overly humid air from being blown onto an already foggy windshield.

If I recall correctly, part of the discussion was the benefit this had as owners that did not use their A/C for 4 or 5 months straight would still benefit from the compressor oil being pumped through the system, lubricating the appropriate o-rings and seals. Keeping the A/C system in use regularly promoted system longevity and potential breakdown of internal seals.

The difference in 95 model years is something new to me however and may act differently.