Stumped by cool engine temp

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S

saltrig

10 Year 15 Year
Joined
Mar 15, 2008
Threads
7
Messages
71
Location
Eastern LI
'91 pickup, 3VZE

I had my head gaskets done on recall about a year ago. Ever since then my truck's temp gauge barely ticks above the white line. I've replaced the thermostat (twice) and water temp sensor. The truck blows pretty warm, but I wouldn't call it hot. Can't remember if it ever did blow hot.

Any ideas what else this could be causing this cold running?
 
what color smoke is coming out of the exhaust?


could the Tstat be in backwards?
 
Could be the gauge, bad sender, or a poor connection.

Take an infrared thermometer, take some readings around the engine with it up to temp, see what you get.

I don't think the thermostat can be installed backwards. But it is possible that it's not installed at all.
 
can he warm it up and put a tester on the sensor and find out? (that would trouble shoot anything from there up, wouldn't it?)

the heater not blowing hot is what's bothering me. But I think he would have noticed the smoke if its burning as rich (lean? hell, IDK) as I think it is to be that cold.

hmmm.....




could the valves be way out of adjustment? Timing can't make it run THAT cold, could it?
 
White exhaust when warming up, blows clear after that. T-stat is in right, I did the second one myself. Although it probably could fit in backwards you'd have bigger problems in your life if you actually installed it that way.

Valves probably could use some adjustment but engine runs great, no pinging, and my gas mileage is pretty decent for an old 3.0.

I swapped in a new instrument panel two years back from a 4runner. I don't think it's the gauge because it does respond to fluctuations in temp. Engine feels a little cool when it's fully warm. Could it be my fan?
 
no on the fan...unless it's 4 feet tall and about 1,000 CFM....


You're either burning way too much fuel, your timing is way to retarded (doubt), you have no restrictions in your coolant path or your gauges are lying.....



yo, this is an episode straight outta House, yo.....


YouTube - House - Teardrop :hhmm:
 
My 94 22RE runs cold, has since we bought it. The top end has been rebuilt before we bought it. Gets 27 mpgs, runs good, but just never really warms up that much. The idle is a little because of it.

Have not had any time to track the problem down as well. Aside from a stuck fan clutch, or a stuck thermostat I am not really sure what would cause it.

I know it runs cold just getting out the truck from a 2 hour drive the hood will hardly be warm.
 
You might have issues with your heater core.

As well, you might have a t stat that is not recommended for your climate i.e. they do have different temp grades. Maybe try getting one with a higher temp rating?
 
I have the exact same problem on a 1991 FJ80, the heater will start pumping out cold air, the temp gauge reads as though the vehicle is off, and my gas mileage nearly doubles (some problem, huh) I have not played with the tstat yet, but planned to until my wife said, ""Wow, we just came 200 miles on a half tank, that's crazy!"
Is there a potential down-side to running cold? The problem is intermittent. Anyone, anyone?
 
cruiser88 said:
Is there a rubber O-Ring on top of the thermostat like the 60 series?

If so that would make it run cold.
Click to expand...

KLF said:
Nope, it's not like that. There's only a ring that surrounds the t-stat, and it's actually in the face of the water pump, on the BOTTOM hose. Such a joy to change too. :rolleyes:
Click to expand...

cruiser88 said:
gotcha
Click to expand...

aarondotnet said:
I have the exact same problem on a 1991 FJ80, the heater will start pumping out cold air, the temp gauge reads as though the vehicle is off, and my gas mileage nearly doubles (some problem, huh) I have not played with the tstat yet, but planned to until my wife said, ""Wow, we just came 200 miles on a half tank, that's crazy!"
Is there a potential down-side to running cold? The problem is intermittent. Anyone, anyone?
Click to expand...




aarondotnet, I don't know to the extent of your problems, but just so you know, you DO have the motor that needs the rubber O-ring 88 is talking about...
 
The danger of running cold is that your ECU will dump fuel into your EFI system to try to get it up to temp. Crappy mileage. And a cool running truck will cause more wear on internal engine components. I still haven't tracked down my cause. But I don't really care since the heater blows hot and my thermostat works. Heater core gurgles though.:confused:

Anyway if you're gonna have a problem its not a bad one to have. If your heat doesn't work though it means your thermostat is shot or you have a blocked heater core. I would take care of that.
 
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