Engine is cold

[shrike]

ok, first a little backstory:
I had the truck last winter, with the original heater core and 1 speed on the fan (basically on or off) and it seemed to warm the truck adequately. I also had no working temp gauge.

This summer, I installed Vintage Air (which includes a new heater core and fan) and put a new intake manifold on (including a new thermostat) and installed a temp gauge.
ever since then, the temp gauge read really low unless I was sitting in traffic for like 30 minutes in the summer with the air on. Then it would creep up over 200. Most of the time it would run at 150 or less.
I thought it was possibly a bad temp gauge (and I am going to replace it, Im not happy with it for other reasons) but just lately we have had a cold snap (in the 30's) and the heater will not blow even warm air unless I have been driving the truck for 45 minutes or so and the gauge reads at least 150. Most of the time, driving around town the gauge is sitting at the bottom, not even moving and the heater blows cold air.

I am guessing the thermostat is either defective or installed wrong but I thought I would post and see if anyone else had any ideas.

[cdowns]

use a knon good thermometer and take the temp of the coolant in the radiator

[MrDude_1]

engine thermostat.

replace it first (its like $6)

[ksjh1316]

Originally Posted by MrDude_1

engine thermostat.

replace it first (its like $6)

I agree 100% sounds like it is stuck open. Had a Toyota this happened in froze my rear off for a month before I got to the thermostat

[Jacfourteen]

X3 on the T-stat. I usually throw the new one in a pan with a thermometer and boil it to see when it opens and if it opens all the way. They are just so unreliable now, its good insurance to see that they work before installing. Oh the spring goes down toward the block, since you said it may be in wrong.

[Zeke's Garage]

x1.5 million on the Thermostat. I'm of the mind that folks stay away from the MotoRad 'Failsafe' models that lock open when they 'fail'. I've got one in my '67 That stuck open, and now one in my '99 Suburban that's 'failed' open.

I pulled the one out of my '67 that was stuck open, released the little locks on the plunger to close it again,and put it in a pan of heating water. Whereupon it snapped locked again at 160 degrees (The opening temp). Any one else have problems with these? I got mine at Oreilly's but I'm sure they're sold everywhere.

[shrike]

Dont remember the brand, but I got mine at oreillys also.
Well, thanks for the input. I guess I know what I'll be doing this weekend!

[Stubbs67]

pick up an OEM thermostat. I hate aftermarkets. The oem ones are 1 million times better than the autoparts specials. The ones from auto parts stores are all low quality isreal or pakistan made junk, here is a comparo, the awesome brass one is OEM subaru, the other is "oem replacement" from allimport auto parts



my heat was cold, and my car ran hot on hill pulls... junk.

[grs]

I think Stant is a good thermostat. I agree you should check it before you install it.

[shrike]

where can I get a OEM thermostat? The Dealers near me all show that it is discontinued...

[MrDude_1]

Originally Posted by shrike

where can I get a OEM thermostat? The Dealers near me all show that it is discontinued...

fact is.. dont worry about it.
from the best thermostat to the cheapist... they're all so stupid simple that if it works at all, it will continue to work for the next decade without issue.

some people get all worked up over nothing. its a SBC.. you literally have hundreds to choose from...
if you're worried about it just get a "stock replacement" stant one. they're the most popular name brand replacement, and will be on the shelf everywhere.

[Stubbs67]

Originally Posted by grs

I think Stant is a good thermostat. I agree you should check it before you install it.

stant is probably as close to oem as you will ever get. Their QC is really good. I have seen so many Oreilly's and duralasts suck right out of the box, and one killed my old suby motor, just 2 months after i installed it. It was stuck shut... and it did NOT do it progressively, it just leaked out its wax and snapped shut.

You could also go with performance quality aftermarket. Good options there too.

[AustinScott]

Originally Posted by Zeke's Garage

x1.5 million on the Thermostat. I'm of the mind that folks stay away from the MotoRad 'Failsafe' models that lock open when they 'fail'. I've got one in my '67 That stuck open, and now one in my '99 Suburban that's 'failed' open.

I pulled the one out of my '67 that was stuck open, released the little locks on the plunger to close it again,and put it in a pan of heating water. Whereupon it snapped locked again at 160 degrees (The opening temp). Any one else have problems with these? I got mine at Oreilly's but I'm sure they're sold everywhere.

YEah i went thru 3 of these "fail safe" garbage T-stats. I did the same thing when testing them & right about 180 it opened to far and snap the lock, not allowing it to close... what garbage.

[Ed 72 Sierra Grande]

Bought one when I got the truck in July. Going for the stant oem type after reading this on the fail safes. I'll take it back and exchange it.

Thanks to all for that one.

[shrike]

Went and bought a Stant on the way home and installed it last night. The old oreilly one had locked open.
I boiled the stant with a meat thermometer to verify it opened and closed correctly before I put it in.
It worked great, had plenty of heat on the way in this morning.
Thanks for the replies!

[Stubbs67]

no problemo!