Jeep runs hot (very hot)

   / Jeep runs hot (very hot)
  • Thread Starter
#21  
Robert, The 02 sensor is mounted in the collector precisely as holley reccomends they give a pattern for drilling and precise distances and its perfect. Radiators a 4 core custom made for this jeep and application. Timing was checked and adjusted with the installation of the new ignition and injection system 2 months ago its still dead on. Tranny cooler is plumbed thru the frame and its always been there with no heat problems prior to 2 or so years ago the heat problems were present before any of the current mods took place. Pulled the plugs last night just to check they still look brand new. All hoses belts thermostat water pump and pressure cap replaced last night. And the radiator reinstalled after a trip to the radiator shop to have it cleaned out just in case. No bug screen or winch blocking radiator. With the hood up but not off it heats up and continues to climb to slightly above 210. sitting idleing.
Steve
 
   / Jeep runs hot (very hot) #22  
Is the radiator the stock type for that Jeep model with a V-8 under the hood? It might just be too small for that motor. You sound like you've got a good handle on things that they work correctly.
Your running out of options as you mentioned except a different fan set up.
 
   / Jeep runs hot (very hot) #23  
How about just a bad thermostat? Less than $10 to replace, just n case. Bad sender on the gauge?
 
   / Jeep runs hot (very hot) #24  
Steven, Here is a post that might help you out.
fan
If not post this question at this forum, I'm sure you will get some good answers. Von
 
   / Jeep runs hot (very hot)
  • Thread Starter
#25  
Von it sounds like they are building toys this is a ranch work machine I don't think I'll be moving my cooling system out of the engine compartment any time soon. Although it was an interesting read I need to look into the fan they are talking about and see if its rated any better than the fan mans fans that were previously mentioned in the post.
Steve
 
   / Jeep runs hot (very hot) #26  
I read all the replys to you problem and all had great possible solutions but none mentioned acouple of things I learned from experience;

1.) Are you running a "flex" fan? Is it on backwards? (trying to push air thru instead of pull)

2.) Trapped air in cooling system WILL cause an engine to run hot quickly.

3.) MOST IMPORTANT: You said you installed a NEW water pump, CHECK water pump part number, as most parts people don't! A water pump for an engine with a serpentin (single) belt are different than a "standard" pump and are NOT INTER-CHANGABLE!

Hope this may help you in you quest to solve the problem. /forums/images/graemlins/cool.gif

~~~~~ Norm
 
   / Jeep runs hot (very hot) #27  
I keep thinking back to this as a problem that got worse over time. Nothing done so far has affected a fix. I seriously wonder if you have goop building up in the engine over time...

When you had the radiator cleaned, how dirty was it? How about the water pump, thermostat housing, radiator hose connections? Can you easily drain part of the coolant, disconnect a hose, and look inside?

What is the history of this motor? Was it rebuilt when you got it, or? Hi-mileage, or recent build(more than 2 years old obviously)?

Von is right. Check out that Pirates of the Rubicon page a little closer, and ask some questions there. There's folks there that do some extreme rock crawling(Rubicon is a tough trail, but not extreme). They may be more toy than work rig, but these guys have a lot of work in them, and might have some good idea's.
 
   / Jeep runs hot (very hot)
  • Thread Starter
#28  
Well folks I think we got it. I removed the spacer and pulled the fan farther out its about 1/2 and 1/2 in and out of the shroud. Then I took it for a test drive it ran at 180 for almost 30 minutes and then started climbing again to 210 I brought it back to the house and parked it idling and the heat continued to go up a bit to almost 220 I then took Snowridges suggestion and got a big fan and put it in front of the grill it was down to 180 within 4 minutes I then removed the fan and continued to let it idle it climbed back up to 220 within 8 minutes. I'll be ordering the fan tommorrow I think it'll fix it.
Thanks for everyones suggestions. With a special thanks to Snowridge you had a great test idea and it proved without a doubt that I need more air flow.
Steve
 
   / Jeep runs hot (very hot) #29  
Has it always ran hot or is this a problem that just appeared? There are a lot of good suggestions here. I'm inclined to think airflow and/ or timing. Stick a vacuum gauge on a manifold vacuum source ( right on the manifold) and let us know how it reads. You want to set your timing with the vacuum guage, Chevy had a few different timing mark positions so if you have a mis- matched balancer and timing chain cover the marks will be meaningless. You basically adjust the timing until you have the highest vacuum. Then you go out and load it, if it pings, back it off a couple of inches of vacuum. If you can't hear it ping, rig a set of mufflers for tuning purposes.
 
   / Jeep runs hot (very hot) #30  
We must have been typing at the same time. Yep, having the fan too deep in the shroud is another reason it can overheat. /forums/images/graemlins/smirk.gif Still, I'd check the timing. With a custom 4 tube radiator and a thermostat it ought to stay at 180 with that fan. What's it going to do on a 98 degree day?
 
 
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