HELP!!:Over heating issue

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KimIsAGuy

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My car is over heating, head gasket was recently, so that's not an issue. My issue now is that when it's hot out, or when I use the AC the car will come close to overheating. It will continue to climb as well.

My question is that could it be my radiator going bad? Coolant level is good, I have green coolant color. I don't know if that matters. What other factors can cause this?
 
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If it overheats at low speed or idle and cools off at highway speed, then it's your viscous fan clutch.
 
Could still be your fan clutch. Try to turn the fan after the truck is fully warmed up. (turn the engine off 1st :der: ) Should be hard to turn by hand. If that's OK, check your air flow through the radiator and A/C condenser. Might be restricted. Bugs, dirt and such. Radiator and/or cooling system could also be restricted internally too. One other thing, does it overheat without the A/C on?
 
JRZEE2000TR4LTD said:
Could still be your fan clutch. Try to turn the fan after the truck is fully warmed up. (turn the engine off 1st :der: ) Should be hard to turn by hand. If that's OK, check your air flow through the radiator and A/C condenser. Might be restricted. Bugs, dirt and such. Radiator and/or cooling system could also be restricted internally too. One other thing, does it overheat without the A/C on?
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Okay, air flow is good. Clutch fan works, when engine is off, the fan spins with some resistance. A/C Condenser looks clean of bugs, but I rinsed it just for the heck of it to be sure. At this point, I'm thinking of the radiator is failing. The Runner does have 280k on it, and that's the original radiator. I'm going to pressure check it, and see. The car will heat up but stabilizes, but if I'm driving up a steep hill, it will continuously heat up. If its hot out, maybe in the high 80's, if the A/C is on, it'd heat up and continuously climb.
 
KimIsAGuy said:
Okay, air flow is good. Clutch fan works, when engine is off, the fan spins with some resistance. A/C Condenser looks clean of bugs, but I rinsed it just for the heck of it to be sure. At this point, I'm thinking of the radiator is failing. The Runner does have 280k on it, and that's the original radiator. I'm going to pressure check it, and see. The car will heat up but stabilizes, but if I'm driving up a steep hill, it will continuously heat up. If its hot out, maybe in the high 80's, if the A/C is on, it'd heat up and continuously climb.
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When I start my truck in the morning, it sounds like a jet engine, but after a minute or two, it quiets down. That's the fan clutch working. When you say some resistance, it should be pretty hard two turn. Some have used the rolled up newspaper at the base of the fan (not the fan blades!!) to try to stop the fan from turning when it's warm. If you can, the clutch is bad.
Is your thermostat ok? Jiggle valve at 6 o'clock?
Beyond that, yes your radiator could be failing, probably from internal restriction. Before you put a new radiator, I would flush the cooling system with some good flush or descaler. That may even fix the problem.
If none of these help, you may have to make sure the head gaskets were done right. I've never done them but I've read that you need to get left and right correct or a coolant passage gets blocked.
 
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Check the Thermostat housing. Is there any residue around it? If so it maybe cracked.
Personally went in a viscous cycle to change everything under the hood related to cooling, WP, TB, Radiator, Fans, timing and so on. Simple $10 part will piss you every time!
 
JRZEE2000TR4LTD said:
When I start my truck in the morning, it sounds like a jet engine, but after a minute or two, it quiets down. That's the fan clutch working. When you say some resistance, it should be pretty hard two turn. Some have used the rolled up newspaper at the base of the fan (not the fan blades!!) to try to stop the fan from turning when it's warm. If you can, the clutch is bad.
Is your thermostat ok? Jiggle valve at 12 o'clock?
Beyond that, yes your radiator could be failing, probably from internal restriction. Before you put a new radiator, I would flush the cooling system with some good flush or descaler. That may even fix the problem.
If none of these help, you may have to make sure the head gaskets were done right. I've never done them but I've read that you need to get left and right correct or a coolant passage gets blocked.
Click to expand...

Per the FSM, and experience of many on here, the 5VZ-FE 3.4L V6 works better with the jiggle valve at 6 o'clock.

How does the top of the inside of the radiator look when you pull the cap?
 
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TheDurk said:
Per the FSM, and experience of many on here, the 5VZ-FE 3.4L V6 works better with the jiggle valve at 6 o'clock.

How does the top of the inside of the radiator look when you pull the cap?
Click to expand...

Edited, Sorry 'bout that. Don't want to perpetrate any bad info on here. I just did that repair too and I put it at 6 o'clock. Go figure. Thanks for the correction.
 
KimIsAGuy said:
My car is over heating, head gasket was recently, so that's not an issue. My issue now is that when it's hot out, or when I use the AC the car will come close to overheating. It will continue to climb as well.

My question is that could it be my radiator going bad? Coolant level is good, I have green coolant color. I don't know if that matters. What other factors can cause this?
Click to expand...

Not sure about many on here but I have always run TOYOTA RED COOLANT in my rig. I have dealt with Toyo expert mechanics from New York to Florida and they all say the same thing; Toyo red and nothing else. It's pricey at the stealership but apparently it offers better corrosion protection than the "off the shelf" crap. I believe I have even seen a video somewhere with the dis-assembling of two Yota engines with one running the green stuff and the other with the Toyo Red. The difference was pretty remarkable. The green stuff corroded almost everything and the Toyo Red left everything looking like new.
 
When they replaced your head gasket did the head get checked for square, cracks, flat surface. In most cases if a head gasket needs to be replaced due to a failure the head needs to be resurfaced if it passes a magna flux test.

These types of problems are really a cart and horse story, did a bad radiator create the problem that overheated the motor to fail the head gasket or did the head fail and was not truly resolved with the gasket was replaced. I get be tough and costly process. At 280k miles, radiator, water pump, fan may all be on the failing side of life.
 
Well when I did the head gasket, they're new heads, mine were cracked. I think its really the radiator problem, due to the fact that only on heavy load/stress or driving through really hot weather, it'd heat up.

I checked the cap portion, radiator looks fine to me, but I'm no mechanic. Can barely do a brake job... In learning process.

I did a full water pump and timing belt, new heads gaskets and heads, thermostats is new.

At this point, my girlfriend's dad is saying check the radiator shroud because apparently, it makes a big differences with pulling air in.

Also, I'm going to get it pressure checked this Monday, see if there's a leak, which I doubt it. See if they can see if there's anything wrong with the head gasket job they did, and see if they can figure out if my radiator is failing or not. Also, I do need to check that thermostat pointing at 6 o'clock, idk why that even matters...
 
KimIsAGuy said:
Well when I did the head gasket, they're new heads, mine were cracked. I think its really the radiator problem, due to the fact that only on heavy load/stress or driving through really hot weather, it'd heat up.

I checked the cap portion, radiator looks fine to me, but I'm no mechanic. Can barely do a brake job... In learning process.

I did a full water pump and timing belt, new heads gaskets and heads, thermostats is new.

At this point, my girlfriend's dad is saying check the radiator shroud because apparently, it makes a big differences with pulling air in.

Also, I'm going to get it pressure checked this Monday, see if there's a leak, which I doubt it. See if they can see if there's anything wrong with the head gasket job they did, and see if they can figure out if my radiator is failing or not. Also, I do need to check that thermostat pointing at 6 o'clock, idk why that even matters...
Click to expand...

It most certainly matters and causes the exact problem your having. Search jiggle valve and you'll see peoples experiences with it.
 
Okay guys, its the radiator that's failing. At this point, which radiator should I replace it with? The mechanic that looked at it, said he's going to replace it with a Denso radiator, suppose to be the OME replacement. Any inputs?
 
KimIsAGuy said:
Okay guys, its the radiator that's failing. At this point, which radiator should I replace it with? The mechanic that looked at it, said he's going to replace it with a Denso radiator, suppose to be the OME replacement. Any inputs?
Click to expand...

Denso is OEM that's the one you want
 
KimIsAGuy said:
Okay guys, its the radiator that's failing. At this point, which radiator should I replace it with? The mechanic that looked at it, said he's going to replace it with a Denso radiator, suppose to be the OME replacement. Any inputs?
Click to expand...

Lots on here have used the Koyo A1998. I'm still on my original, but I have a 5-speed and am immune to milkshakes. I take care of my coolant and I'll run it until I have some sign of trouble.
 
I have run the Koyo 1998 for five years and had zero issues. I believe some folks who have ordered such recently received one made by TYC (both are cut from the same cloth IMHO).

If you have the extra $$$ for an OEM, get it.
 
Is there an upgraded radiator to put into our cars? Dual staged cooling or something. haha

Also, while we're all here, I'm thinking of doing the trans cooler. My question are the pros and cons. I'm worried about it blocking a portion of the radiator, will my engine stays cooler since my transmission going to have its own reservoir coolant, etc.
 
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