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my heater doesnt blow hot

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bcrosby

20+ Year Contributor
75
0
Jul 11, 2002
Des_Moines_Iowa
What would make my heater not blow hot? Now that its getting cold out ive noticed that my heater just doesnt blow hot. Could it be the thermostat? Any ideas would be appriciated.
 
my gauge just bounces around becaues i have an aftermarket water temp gauge installed. and that reads fine...ill check the coolant now and replace the thermo real quick and get back to you

thanks for the help
 
well i changed the thermostat and had to change the housing too because it broke while tightening it back down.....dam dsms. and i went for a 10 minute drive to see if the heater got any hotter and it seemed like it did...but on the way back i did a 2nd and 3rd gear pull because i had a huge leak on my injector o-ring and i started smoking and could smell burning coolant.

I popped the hood and it seemed like smoke was coming from below the housing. like by my clutch shatter shield area. and i could hear hissing from the thermostat area and it got louder at i squeezed the upper radiator hose. im guess the gasket i (resused) is bad? but what else would this be? is there a wrong way to install the thermostat? cause i wasnt sure if i had it at the right angle
 
im guess the gasket i (resused) is bad? but what else would this be? is there a wrong way to install the thermostat? cause i wasnt sure if i had it at the right angle
The thermostat must be installed with the heat sensing copper element side (usually has the opening temp engaved on it's end) down into the engine (triangle support structure up) and a NEW gasket between the thermostat and the thermostat housing (not under the T-stat). There's usually a groove the T-stat fits into on the engine side. I also lightly coat the gasket with Permatex Ultra Blue RTV Silicone Gasket Maker to prevent any leaks. Remember to only torque those bolts to 12-14 ft-lbs (sounds like you found out the hard way already).
 
im worried that i did it right because i was hoping i just had put it in backwards but im 99 percent sure i put the ''jiggly" thing to the top (towards the firewall) when you say towards the enging you mean facing to the right when your looking down at it right?
 
If the T-stat goes in horizontally (eg. 2g) the jiggle valve must be up but I believe on your 1g it goes in vertically on a horizontal surface (according to the backup manual I have) so it doesn't matter about the jiggle valve. What matters is the heat sensing element MUST always be towards the engine side (not the hose side) and the gasket MUST be between the T-stat and the T-stat housing (on top of T-stat).
 
dam well i just gasketed it and everything...you say heat sensing element??? what do you mean i looked at the thermostat and it looks identical on both sides aside from the jiggly thing which i placed up top....the only way i can mount its other than that is to put the jiggly thing on the bottom but since the thermostat itself isnt a perfect circle its wont seal up correctly with the housing so im 99 percent sure its in the right way cause that basically the only way it will go in and seal up properly with the housing....which is the way i had it the whole time....the gasket was shot and its too late to go buy a new one so i used a shit load of rtv and its drying now. could a leaky gasket be the problem i was having?
 
Yes it easily could. The jiggle valve is for when it's mounted horizontally [it's easy to get confused as to what direction is what so let me say horizontal is when you put it in moving your hand left or right so the round disc part that touches the housing is in a vertical plane. The jiggle valve then lets air thru for burbing (since air rises and would be near the top of the T-stat)]. But yours I believe is a vertical mount so the round disc part is horizontal so the jiggle valve position doesn't matter - get it? If the round disc part is not horizontal, then rotate the jiggle vavle to be as high up as possible. Often the rotational position is fixed which it sounds like you're saying. But make sure the whole thing is not flipped over the wrong way which is what I'm saying is CRUCIAL. For this to be correct the heat sensing element is in the middle, round, about 1/2" diameter and protrudes out one end. There usually is a large spring around the outside of it. That end must go towards the engine side.
 
oh i get what your saying...ya mine is horizontal....and the heating element...im guessing the sping part is on the under side.....(the side that goes to the engine not the side thats coming from the radiator...in other words its not upside down LOL then i must have it right it might just be that crappy gasket
 
Does it get hotter when you rev your engine or drive it high rpms? If that was the case the water pump may be going out. Just had that happen recently.
 
no, always luke warm LOL.....new problem though haha im not sure what hose it is but its the hose thats under the thermostat that goes behind the engine and into the firewall.....it ripped somehow and now my car isnt holding coolant it just pours out so i give up tonight its too dark to work right now but how do i go about changing that hose for tomorrow?

DAM DSMS i started the night with a small job of removing a broken fuel rail bolt and ended up with my car not holding coolant....only in a frickin dsm OMG
 
could it be that it burst from pressure??? which means i must have put in the Tstat wrong but its the only way it could go in.....should i just leave it out? it doesnt get Toooo cold in california
 
So it has finally gotten cold and I go to turn on my heat in the eclipse when it is fully warmed up and it is hot for about 4 seconds and then goes lukewarm to cold and this is while I am driving and if the car is sitting also. What would be the cause of this?. I don't think it is the thermostat because my temp gauge stays a little under the 1/2 way mark. The coolant resovior bottle is at the full mark also.
 
Heater suddenly stopped working on my way home today. It just blows cold air now. The blower flows better when temp. is turned down. Also, at the same time, the lights for my heater knobs went dim. No overheating issues. I'd really like to get this taken care of soon since it's getting cold! Any ideas would be appreciated.

Thanks guys.
 
Happened to me when I had a coolant leak (no overheating but coolant was low) and happened to me again when my thermostat got stuck open. This would'nt explain the dim controll lights though. I have never heard of a heater or blower motor go bad in a 2g, but check the coolant level then the T-stat since these are easy to check or repair
 
If you aren't low on water, your thermostat is probably leaking. If you weren't getting any heat at all, the suspect would be the heater air door inside the heater assembly. What are you guys getting for "cold" down there, in the forties?
DSMs usually get to full-operating temperature in about three miles of easy driving.
 
Heater air door, I'll look into that. Do you guys have any idea why the lights went dim? I suspect that is directly related since it happened at the exact same time.

It's getting into the 40's during the day and the 20's at night here.
 
I haven't had this happen on my dsm but on some older chryslers (spirits, omnis, and such). The heater cores were plugged and at the same time we replaced the thermostats and it helped the problem considerably. big_d
 
Yeah its easy to flush your heater core, remove the two lines going into the fire wall and blast a hose thru it for a minute and wash it out..

And the dim lights? its only on the center dash? gauges are fine? did you play with your dimmer?
 
Hmmm dim lights sound like a short, i would check your fuses with a voltmeter and see how much power its drawing. My truck's heating/ air motor went bad and it melted, causing it to draw massive amounts of power because of it rubbing on the housing.
 
Yeah its easy to flush your heater core, remove the two lines going into the fire wall and blast a hose thru it for a minute and wash it out..

And the dim lights? its only on the center dash? gauges are fine? did you play with your dimmer?

Yeah, all other lights are fine. I played with the dimmer afterwards to see if it would fix it, but it didn't change anything.

Hmmm dim lights sound like a short, i would check your fuses with a voltmeter and see how much power its drawing. My truck's heating/ air motor went bad and it melted, causing it to draw massive amounts of power because of it rubbing on the housing.

I'll check this out.


Thanks for the help guys. I appreciate it.
 
Ok, i have searched and searched, i may be typing in the wrong things but i cant figure out why i have no heat. k if i missed anything in my profile my fan is constantly on everything in my cooling system is ok i think. Coolant level is good overflow tank full. I unplugged my fan and went for a drive it warmed up pretty fast of course but the needle stayed were it always does in the middle. And still no heat. Now were i am in jersey its about 32 out side, but even when it was warm out their was still no heat.:cry:
 
Has you heater core been bypassed? Is your fan blowing air into your car? If so hot or cold?
 
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