Heater only gets warmish. Thermostat stuck open?

[MTBLAZER89]

I have a wheeling trip this Sunday and it's cold and crappy out. Heater is blowing maybe 60-70 degree air.

Engine temp did seem a little low after idling for 20 minutes as well.

 

[GWeakland620]

I'm all ears on this one. Have had the same issue since the day I bought the truck.

 

[sweetk30]

lots of times heatercores get pluged up with junk . need to be back flushed with garden hose .

this guy did a good video .

 

[sweetk30]

lots of times heatercores get pluged up with junk . need to be back flushed with garden hose .

this guy did a good video .

I have a ir temp gun and check inlet / outlet and there should be not much more than 20* max drop 1 side to other . if more its pluged up .

also t-stat housing to upper hose watch the t-stat cycle for its temps . if you find the right spot it will be about perfect to show if its 180- or 190 or higher t-stat . found a few week heat problems this way and also driveability ( bad gas mileage ) problems . computer wants to see a specific temp . if not there would defuel ( like driving with choke on )

 

[GWeakland620]

Mine has a brand new heater core in it.

 

[sweetk30]

then prob weak t-stat or a restricted hose or nipple in intake .

 

[GWeakland620]

Heh, nipple. I shall check them well tonight.

 

[skunked]

Nipple check on aisle 3......

 

[GWeakland620]

Early congrats skunk....

And before this derails more than it already has.

I will do some back flushing this weekend to see if I have a clog.

 

[MTBLAZER89]

My heater core hasn't been replaced in awhile. It isn't leaking either. My passenger door doesn't open so I really really hope it isn't the core. I will also try a flush and possibly a Thermostat tonight.

 

[dyeager535]

Are your blend doors working? Should be pretty simple to figure out, if the engine is that cold, should be able to easily put your hand on it, and hold it there.

 

[MTBLAZER89]

Engine temp showed 150ish 160ish

 

[ryoken]

make sure your coolant is full.. low levels will do it too....

 

[82355]

Mouse nest in your heater?

Martin

 

[dyeager535]

Engine temp showed 150ish 160ish

What's the thermostats temp? Should be 195*, but people insist on using lower ones, so not a given. If you have a 195* stat and temp is truly below that by a significant amount, the thermostat is bad.

 

[GWeakland620]

Mouse nest in your heater?

Martin

I thought about a rat's nest, but I have already been in there to replace the core.

How do we check the blend door?

 

[blazer74]

Just a thought: I've heard some replacement heater cores don't fit or work properly. I think there is a thread on here somewhere.

 

[blazer74]

When I went to an aftermarket aluminum radiator I had to go up to a 192 thermostat from a 180 to get enough heat.

 

[GWeakland620]

Hmmm, never heard of that. I'll have to do some googlin.

 

[dyeager535]

Just a thought: I've heard some replacement heater cores don't fit or work properly. I think there is a thread on here somewhere.

Good point. Those threads may have even been on here. IIRC there was a gap left on one side or the other, so the air could just go around it.