More heat please

[MylilBowTie]

I need more heat in my truck. It gets mildly warm but nothing really hot. The truck has a new two core replacement (was 4 core copper/brass) aluminum radiator. New clutch for the fan and seems to be pulling tons of air. Rear gear is 3.73:1 with a th400 and 235/85/16 tires. Highway driving seems to have the least amount of heat. City is a little better but not much. I didn't seem to notice the lack of real good heat last year. I have not changed the thermostat but it seems to be operating fine. If it makes any difference the engine is a bbc 454. The temp gauge will get and hover around the first tick mark after the C and stay.

[1BadSS]

What temperature thermostat do you have in the truck?

[MylilBowTie]

Ive never had the thermostat housing off the intake. So I would have to assume that it is the stock 195. Ive only had this truck a little over a year.

[1BadSS]

I'd throw in a brand new stock replacement thermo, its only $4 or $5. Possibly think about a grille wrap to keep the cold air out.

[rayfinseats]

"So I would have to assume that ..." I bet it doesn't have a thermostat in it.

[83burban]

Originally Posted by rayfinseats

"So I would have to assume that ..." I bet it doesn't have a thermostat in it.

Why do you say that - mine with a new 195 thermo in it runs only to the first tick mark and never any hotter. I plan on putting a winter cover onto the front to boost under-hood and heater temps

[spudz]

Id pull the lines off the heater core and flush it out with the hose.

[allengator]

Originally Posted by 83burban

Why do you say that - mine with a new 195 thermo in it runs only to the first tick mark and never any hotter. I plan on putting a winter cover onto the front to boost under-hood and heater temps

Probably because alot of people (at least in this part of country) dont run a thermostat at ALL... especially in their "warm weather only" play toy cars!

[jchav62]

Originally Posted by rayfinseats

"So I would have to assume that ..." I bet it doesn't have a thermostat in it.

That was my guess too...

[78 Chevyrado]

My gauge also stays at the first mark above C on the gauge, no matter what I'm doing or what time of year it is. I think the gauges are just really inaccurate. I don't use the gauge to read the actual temp, I just watch it in case it changes at all.

There could be no thermostat, or the one that's in it could be stuck open.

When the trucks cold, run it on fast idle and squeeze the upper radiator hose really good to block it, when you release the hose, if you feel it surge, the t-stats open, if it doesn't surge the t-stat is closed. the t-stat should be closed when the trucks cold. if you feel the surge, you need a t-stat.

Next on the list would be a clog somewhere, like rust bits plugging up the heater core or something like that.

[rayfinseats]

Because if it has no thermostat it takes a long time to warm up or will not get hot enough. Never assume when troubleshooting anything. That's how most people miss the problem.

[sandorjoben]

I had the same problem, and my thermostat had failed halfway open, replace your thermostat and put a baffle ahead of your radiator. I pulled my grill off and used a piece of foam indoor carpet underpadding, just make sure you you don't block flow through the radiator too much, because your temp gauge will read like your engine is overheating. The piece of padding I cut goes ahead of the radiator and covers the whole front of the radiator but has two 6" x 12" holes cut on either side to allow enough air through).

Dave

[Cue-Ball]

There's an easy way to tell if the engine is getting hot enough. Just drive around for 10 minutes then stop, open the hood, and put your hand on the top radiator hose. If you can grab that hose with your bare hand for more than half a second without burning yourself, your engine is not getting up to temp (which means you probably don't have a thermostat, or the thermostat is stuck open).

If the engine isn't hot, the heater won't put out heat either. If the engine IS hot, then you just ruled out one possible problem. Try putting your hand on the hose running to the heater core. If it's hot too, then either the core itself is plugged up or your heater mechanism isn't working properly (air temp door not moving).

[spudz]

I figured the truck not running hot enough would be a given.

[MylilBowTie]

Going to try and get a new thermostat installed. I would like to back flush the heater core but its been way to cold here to do so. Its been pretty cold low 20s for highs and teens or lower at night around here for a while so not able to use the water hose. May also replace the safety radiator cap as well.

I needed to replace the radiator because the stock one got a small leak in one of the cores. The coolant and everything looked fine, didn't see any rust or other stuff. I did replace the coolant with new antifreeze not knowing how long the old stuff had been used.

The blower works but has to be on high all the time and defrost. It will blow on the floor but doesn't feel like its working at all to heat the cab up. So that is why I leave it on high and defrost.

[sailed2japan]

I know my truck even though the blower was working a new one madea big difference in heating/cooling the cab. I never would have changed it, but a truck I was parting out had a shiny new blower and mine had obviously been around a while. Now I'm glad I did and would do it again even if I had to buy one.

[motornut]

don't forget wind chill,it's not just for Canada ya know
that big block needs lots of cooling in the summer
but in the winter cooling is the problem,
in that the cold air going threw the rad is "super cooling" the antifreeze
so when the heater core (just another rad really)
is looking for heat there is none left to remove
I don't suggest putting anything between the grill and the rad(hard to get at)
put a winter cover over the front of the grill,not just with the snaps(may blow off)
I use bits of wire,what ever you use,make it remove easliy to not over heat
I suggest useing the AC MAX setting as i do to get more heat in the cab,this closes off the outside air,recirculates heat in the cab.then switch to defrost and the window clears quicker...I do this while driving too it works quite well.
short story cover the rad for more heat and don't use cardboard, soggy may clog the rad up

[78 Chevyrado]

Also after you drive the truck, feel both the hoses going to the heater core. if they are different temperatures between the inlet and outlet hose either the hoses or core is plugged.

[wyattglock]

Originally Posted by sandorjoben

I had the same problem, and my thermostat had failed halfway open, replace your thermostat and put a baffle ahead of your radiator. I pulled my grill off and used a piece of foam indoor carpet underpadding, just make sure you you don't block flow through the radiator too much, because your temp gauge will read like your engine is overheating. The piece of padding I cut goes ahead of the radiator and covers the whole front of the radiator but has two 6" x 12" holes cut on either side to allow enough air through).

Dave

X2 on the thermostat failing half open. I just replaced mine due to the same problem. It wouldnt heat up over 120 on the gauge, but the engine was so sizzling hot you couldnt touch it. The thermostat wasnt allowing enough coolant flow to circulate through the system properly. I would change the thermostat for sure, easy $10 and that gets a good t-stat with a Fel-Pro gasket.

[donut]

In addition to making sure the cooling system is up to snuff, check the blower box. The bottom of mine looked like swiss cheese. Also make sure flaps and whatnot are working in the heaterbox. I also would like to mention, on mine, the heatercore itself was 1/2 covered in animal fur and packed full of acorns.

Any holes in the cab?

Other options to check...

[MylilBowTie]

Got the thermostat changed it had a 160 replaced it with a stant 195. Heat seems to be much warmer now the temp gauge sits at the 12o clock position. I did notice that the upper radiator hose still is holding pressure. So I guess the thermostat didn't open up yet.

Maybe the system needs burped?

[GMC Guy]

i have a 195 thermostat, and the temp gauge never goes past the first line (summer and winter). i can actually see when the thermostat opens cuz the needle will drop, but picks back up to the first line, never past. is this normal? should it run warmer? my heater, aftermarket summit brand, blows nice warm air, and gets the cab warm very quickly.
what's the normal operating temp for a sbc350?

[85Bowtie]

When you changed the Tstat you did run the system with the heater in high when you were adding coolant right?

[MylilBowTie]

I may have done it wrong. It was warmed and I released the pressure from the vent on the radiator cap. Used a fluid transfer pump to suck all the coolant out. Removed the thermostat housing and cleaned up the surface. Cleaned up the mating surface on the intake. Then pulled the thermostat out and put the 195 in. New gasket installed, housing bolted back on and hose reconnected. Filled the radiator back with what was sucked out. it filled it all the way back up. Put the radiator cap back on, started the engine, checked for leaks, didn't see any. Put the heat on high and noticed it was warmer than before. Went and ran a few places and noticed the temp gauge was reading higher. Kept a watch of the temp gauge never went hotter than the middle. Got back home felt the upper radiator hose it was hot and felt tight like it has some pressure on it. That was as far as I messed with it was getting to dark out.

I will check it out more in the morning. It could be low on coolant. Alot went into the over flow when I opened the pressure valve on the radiator. So it should suck back in what it needs filling itself back. This was before the new thermostat install not after.

Thinking about getting on of these to help get any air out the might be trapped.

Amazon.com: Lisle 24610 Spill-Free Funnel:...

[ekjunky80]

""Thinking about getting on of these to help get any air out the might be trapped.""


I have the same Funnel set. i love it. i had it for about 7 years. no issues.
used it more on foreign cars though. they go crazy with air in the system.