Almost overheated this last weekend

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Joined
Sep 23, 2007
Threads
16
Messages
189
Location
Murrieta, CA
So the run last weekend went great. When we were coming back out of the canyon, up to the road, my AC went out. That has never happened to me. Reid said that the car was overheating, and the AC turned off to save it.

I have a scangauge in the truck, but I wasn't paying any attention to the temps when we were out there. When we were driving up Montezuma grade, I had the AC off, and the windows open. The temp was 229*!!!! YIKES!!

As we got to the top, it went down to 190*, so I turned the AC back on. My question to you all is........

Should I just do a coolant flush with a new TStat, or change the fan clutch also? I was reading about that a bit on the National Board.

Anything I should visually check besides the coolant?

Thanks fellas........
 
Darwalk said:
So the run last weekend went great. When we were coming back out of the canyon, up to the road, my AC went out. That has never happened to me. Reid said that the car was overheating, and the AC turned off to save it.

I have a scangauge in the truck, but I wasn't paying any attention to the temps when we were out there. When we were driving up Montezuma grade, I had the AC off, and the windows open. The temp was 229*!!!! YIKES!!

As we got to the top, it went down to 190*, so I turned the AC back on. My question to you all is........

Should I just do a coolant flush with a new TStat, or change the fan clutch also? I was reading about that a bit on the National Board.

Anything I should visually check besides the coolant?

Thanks fellas........
Darrin,
When I first did the "Temp Gauge Mod" I had hot running issues I didn't know I had. I changed the thermostat, fan clutch, thoroughly cleaned the radiator and had Mr.T do a coolant flush. I run much cooler now. However, I still get hot when the outside temps are high. Late last spring, Steve and I ran Corral Canyon and my A/C shut down during the run. IT WAS HOT! My next move is to do the "Blue Fan Clutch Mod" to get a little more cooling power.
HTH
 
So the run last weekend went great. When we were coming back out of the canyon, up to the road, my AC went out. That has never happened to me. Reid said that the car was overheating, and the AC turned off to save it.

I have a scangauge in the truck, but I wasn't paying any attention to the temps when we were out there. When we were driving up Montezuma grade, I had the AC off, and the windows open. The temp was 229*!!!! YIKES!!

As we got to the top, it went down to 190*, so I turned the AC back on. My question to you all is........

Should I just do a coolant flush with a new TStat, or change the fan clutch also? I was reading about that a bit on the National Board.

Anything I should visually check besides the coolant?

Thanks fellas........

I've been doing a fair amount of reading on the topic and here's what I've come up with, take it for what it is.

First though, here's some wisdom from CDan specific to your A/C cutoff...
"Anything below 217 F is considered "normal" by the engineers because that is the threshold temperature at which they allow the A/C compressor to come back on line. Anything over 226 f is a "threat" because that is the compressor cut-off threshold. In between 217 and 226 it is not hot enough to kill the compressor but too hot to let it come back on."

What I've learned about the causes to high temps is that there aren't very many common variables. Either the block coolant passages are clogged with sludge, the radiator is clogged with sludge, your thermostat isn't operating properly, or your fan clutch isn't operating properly.

Edit: Forgot to mention, I just did the temp gauge mod and discovered I have been running slightly hot. Since I flushed the coolant back in December I wont be draining again until later this spring and will have the radiator professionally flushed then. I just did a mod to the fan clutch this weekend, so we'll see how that goes.
 
Last edited:
MAYBE A DUMB QUESTION:

Does running a snorkel help with this at all or is it totally seperate issue?
 
Darrin,

Hey I wonder if you would measure your lift now in some way. I got the same lift as you and it settled a bit and I wonder how much it was after all. I did add a bumper and winch but even before that. Mine used to look like yours...looks more like 7" lift at first. Did you get the 5" springs front and rear or 5" and 4"?
 
Darrin,
When I first did the "Temp Gauge Mod" I had hot running issues I didn't know I had. I changed the thermostat, fan clutch, thoroughly cleaned the radiator and had Mr.T do a coolant flush. I run much cooler now. However, I still get hot when the outside temps are high. Late last spring, Steve and I ran Corral Canyon and my A/C shut down during the run. IT WAS HOT! My next move is to do the "Blue Fan Clutch Mod" to get a little more cooling power.
HTH

I am going to look at the threads about radiator flushing first, and tackle that in the beginning. Change the TStat at the same time. The fan clutch will wait for a bit I guess. I will see how hot it is running after that.

Being in Corral Canyon in hot wouldn't be too fun, but that place has some nice trails....when are we going? :D
 
I've been doing a fair amount of reading on the topic and here's what I've come up with, take it for what it is.

First though, here's some wisdom from CDan specific to your A/C cutoff...
"Anything below 217 F is considered "normal" by the engineers because that is the threshold temperature at which they allow the A/C compressor to come back on line. Anything over 226 f is a "threat" because that is the compressor cut-off threshold. In between 217 and 226 it is not hot enough to kill the compressor but too hot to let it come back on."

What I've learned about the causes to high temps is that there aren't very many common variables. Either the block coolant passages are clogged with sludge, the radiator is clogged with sludge, your thermostat isn't operating properly, or your fan clutch isn't operating properly.

Edit: Forgot to mention, I just did the temp gauge mod and discovered I have been running slightly hot. Since I flushed the coolant back in December I wont be draining again until later this spring and will have the radiator professionally flushed then. I just did a mod to the fan clutch this weekend, so we'll see how that goes.
Well atleast I wasn't going to blow the thing up this weekend then. That feels good....
 
I went through all of this 1 month after owning the truck. It turned a 3.5 hr trip back home to SD from the High Desert into a 6 hr drive. Driving in the desert in June with the heater on and window down is NOT FUN....
$1000 dollars later at the dealer, (Didn't know the power of this site or the search button at that time) it turned out 90% of my radiator was clogged. I had a flush done 3 weeks earlier but I guess that's what happens when you have a 19 year old kid at the dealer work on you truck rather than John and his boys at SD Trux. The bulk of that $$ was in removing the radiator and re-installing which I could have done in a weekend.
Anyway that is my experience with over heating and the AC cutting off.

P.S. John, I saw Darryl (SP?) yesterday and he took good care of my rig and gave it the once over before I head to Baja this weekend, *Cough* SOLO.
 
I just replaced my fan clutch, T-stat, and water pump this last weekend as PM for the summer and some upcoming Baja trips. I noticed a big difference with the new fan clutch which now blows like a jet engine on start up. (That never happened with the old one)

For the money (C-Dan $120) and with summmer coming I would replace the fan clutch and the T-stat. I think the T-stat was like $12.
 
Snorkel.......anyone.......anyone?:hhmm:
 
Snorkel.......anyone.......anyone?:hhmm:

Since you asked...
I think a snorkel keeps your intake air cooler which leads to more power/efficiency or something, but doesnt have an effect on engine cooling. Could be wrong though.
 
I'd test the radiator for coolant flow rate....if you have clogging arteries, it ain't going to sort itself out.
 
What I've learned about the causes to high temps is that there aren't very many common variables. Either the block coolant passages are clogged with sludge, the radiator is clogged with sludge, your thermostat isn't operating properly, or your fan clutch isn't operating properly.

All of these variables are true and can be cured with some PM, major or minor. One more thing to consider as a cause for over-temp is lack of air-flow across the radiator. Sounds like that may be a contributor in this case.

I experimented with an electric fan that I control from a switch. When slow-going, or sitting idling in the summer, I'll click on the e-fan and it's enough to keep that AC blowing cool. When slow trail driving, it'll be on most of the time in summer just to keep air moving across the condensor and radiator.

A blue fan clutch mod does essentially the same thing except it's less controllable by the driver (fuel economy effects?).

Need insurance? Do all - PM everything and add the blue fan clutch AND the e-fan in front of the radiator.
 
One more thing to consider as a cause for over-temp is lack of air-flow across the radiator.

Absolutely. I shouldnt have pegged sludge as the only potential cause of poor performance. In fact, this is the exact reason I bought the radiator spray wand. I want to make sure air flow around the outside of the radiator is able to contact all those wonderful little fins and take that heat away. A much cheaper item to try before a new radiator.

I also agree, do all of this stuff and you probably have a bullet proof coolant system (add new hoses including a new PHH, of course!)
 

I'm planning at least one or two Baja surf trips this summer. One for sure is in mid-Sept to the Erindira area. A group of guys from my work and I are staying at Coyote Cal's and surfing the area.

I'm still kicking myself for missing your trip Kevin.
 

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