Slideshow86

I have searched and found some solutions but am wondering if theres anything better out there.

-93 Pickup
-Radiator (says GM on it?)
-No clutch fan, has 15" electric fan
-Heater works soo good it will burn you (well close)

*Heres my daily runthrough*

-I warm up the truck at 6:45 and outside temps are around 40-50 F (in sept)
-Heater is kicking when I get in and drive away.
-I drive a few miles through town and watch the temp guage move to the middle (like it should)
-I drive out of town through the woods for 45 mins to work.
-Just as I get out of town I watch my temp guage move down to about 1/4 way, sometimes lower.
-My heater still work great.
-My Idle goes up to 1800-2k rpms when I stop and am not warm ( and my exhaust rattle buggs the crap out of me)
-On my drive home its between 65-80 F.

*Solutions*
- Cardboard over radiator
- Hotter T-stat
- Smaller Radiator

What else is there?

What do you guys do?

I just dont want to R&R card board every day.....

Stuwy123

iTrader: (1)

Make a manual switch for the electric fan.
Or
Wire it so it turns on when you reach operating temperature.

Slideshow86

Fan was on a switch when I got the truck.

I put in some cardboard to see how it will be on the way home from work and it it just fine. If it makes a difference on the drive to work then its fixed. Ill just make a rubber flap that I can put in the winter months and it wont wear away with water.

Jay351

remove and inspect the t-stat.

Make sure the electric fan is not staying on too long.

How big is your rad??

abecedarian

which engine?

Slideshow86

I never really need to turn on the fan. Ive only really turned it on a hand full of times in the month ive owned the truck and that was when it was 100f outside.

Radiator seems to bee 2ish inches thick and fits in the factory radiator mounts but says GM on it? (....... Pix or it didnt happen. lol)

22re

Jay351

defantly some pics would be good.

You sure the previous owner didnt do a chevy mod to your thermostat (drill hole in it)?

Slideshow86

I have no idea. I know he had a shop do most the work and paid way too much for it. Looks like it needs to come out though.

Pix will be up in 10 mins.

JaredL

I own a 93 as well with the GM radiator (it is stock). I put in a higher temp t-stat and it seriously heats the cab in less than 3 minutes. Running the blower on high will bake me even in sub-zero temps.


Now my 4runner on the other hand has a clogged heater core so it does not heat as well. Maybe something you can check too.

JARED

Jay351

It can't be a GM radiator...

Slideshow86

Heater still works like a champ.

Here are the pictures. Looks like a stock radiator.

JaredL

From what I read, Toyota and GM did a joint venture back in the early to mid-90's. GM received Toyota engines for their small cars (that's why some GM cars are reliable) and Toyota recieved GM radiators. Very weird I will agree but it is stock. I have owned my truck it's entire life so I know it was stock. It is the only plastic part under my hood

So far it has not broken ...knock on wood.

Jay351

Thats pretty lame...

Slideshow86

After some testing.

If the out side temp is 67-70 or lower, Cardboard covering half of the radiator works like a champ. Ill just make something out of rubber and it will be good to go for the winter.

ovrrdrive

no matter how well your cooling system is working it won't ever overcool your engine if the tstat is working properly...

Marc

x2 tstat

yodta

yeah, x3.
the temps you're talking about aren't even close to anything that should prevent you from staying at operating temp.
I could see it doing this if you had a lower opening t-stat, but even then, I don't think it wouldn't get hot and then go cold? I installed a lower opening one, iirc, on my other vehicle, and it would just take forever to get hot.

sounds like at the very least it's just not cycling properly.

and you're sure that fan's not wired to come on with a temp trigger?

Slideshow86

Very cool, Ill get the correct temp T-stat just to get a new one anyway and see whats going on. I guess I figured since I tested it in neutral with my hand held pyrometer when I first got it and I think it opened around 185ish I just figured it was ok.

If the heater core isnt the issue and I change the t-stat. Where is the next place to check for improper cycling?

As for the fan. Im sure its not.

Im was almost thinking temp sensor/connection issue but the symptoms would be more inconsistant. It was very predictable. Well it was untill yesterday when I was wheeling a little with my wife and I turned the fan on so I didnt have to watch the temp guage. After about 25 mins of driving it was 1/4 way up the temp guage. I turned off the fan and left the truck running while I jumped out and walked around checking out a hill climb. I got back down and attempted the hill climb once. When I needed to make another attempt, I noticed the guage was in the red? WTF?? Thats new?

Im going to flush the system and get a new t-stat but any other ideas?

yodta

wow, that really is doing some weird stuff.
along those lines though, I've had screwy behavior due to bad thermostats in the past.

the cooling system really isn't very complicated. those issues used to freak me out, but if you think about it, there's only

• the radiator
• the water pump
• thermostat
• coolant itself
• fan

radiator can be suspect in overheating issues mostly; slow overheating due to deposits on the cooling fins inside.

water pump will usually be dropping water from the weep hole

coolant itself -- oh, okay, well there's something so obvious no one's mentioned it here. are you running a 50/50 mix, or straight coolant?

that fan. I was going to switch to electric fans, but then read about stuff like this, having to wire it in, or keep an eye on things and flip it manually. I haven't much experience with electrical stuff, so I decided to skip it. did your truck have a mechanical fan before? got any good salvage yards nearby? I've found myself going back to stock for a lot of the upgrades I've made over the years that just didn't perform or were troublesome.

Slideshow86

UPDATE- ITS FIXED!

I finally got around to getting a new T-stat and o-ring. When I removed the old t-stat the previous owner had removed the inner flap that actually moves, to open and close the passage when the unit gets up to temp. All the gutts were still there but just the flap was missing.

After replacing it everything works as it should. I suspected the t-stat at first but because it was acting so weirdly I figured I would ask. Now I know to go with what I know.