mvusse Posted August 13, 2008 Share Posted August 13, 2008 The heater control valve has nothing to do with the radiator, just the heater core. If removing the restrictive heater control valve (allowing more coolant to flow through the heater core, which is relatively small compared to the radiator) causes a noticeable drop in operating temperature, I'm guessing the radiator is (almost) completely clogged. First order of business would be to clean out the air passages through the outside, which can ususally be done with a garden hose and spray handle, if that doesn't solve it, take it to a radiator shop to have it flow tested. If bad it will either need reamed out or replaced. Link to comment Share on other sites More sharing options...
HOrnbrod Posted August 13, 2008 Share Posted August 13, 2008 The heater control valve has nothing to do with the radiator, just the heater core. The heater water control valve (or lack therof) allows more coolant to circulate constantly thru the cooling system, so it does have something to do with the radiator, part of the cooling system. Chryco junked the water control valve in 1997. Ever been sitting in traffic on a 100+ degree day running hot, turn the HVAC controls to heat, and watch the engine temp drop instantly? I'm guessing the radiator is (almost) completely clogged. First order of business would be to clean out the air passages through the outside, which can ususally be done with a garden hose and spray handle, if that doesn't solve it, take it to a radiator shop to have it flow tested. If bad it will either need reamed out or replaced. X2. Well said. Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted August 13, 2008 Share Posted August 13, 2008 Rich, I put my new rad in. No change in temp. It's still running hot. Link to comment Share on other sites More sharing options...
PIKE Posted August 13, 2008 Share Posted August 13, 2008 Sounds like you still have air in the system. Did you fill up your plastic overflow about half way? When my jeep is cold the bottle is about 1/4 full, when hot about 1/2 full. It took a while to get all the air out of the system. I had to add some coolant after every heat and cool off cycle for a few times until it stablized. Link to comment Share on other sites More sharing options...
Drahcir495 Posted August 13, 2008 Author Share Posted August 13, 2008 Rich, I put my new rad in. No change in temp. It's still running hot. Not good man. I have the same set-up coming this week. PIKE could be {and probably is} right - air in the system :mad: . Don't lose hope - Rich Link to comment Share on other sites More sharing options...
Motion Offroad Posted August 14, 2008 Share Posted August 14, 2008 The purpose of the engine thermostat is not to keep the engine cool. Its purpose is to maintain a specified minimum temperature. Once that specified temperature is exceeded, the temperature is no longer controlled by the thermostat. A t'stat is intended to keep the engine warm, and NOT to help it cool. Normal running temps for a 4.0L are higher than either a 180 or 195 t'stat. Thus, regardless of which one you have installed, when it's working correctly, and the engine is warmed up, the 'stat is WELL PAST it's full-open temp. Putting in a lower t'stat only means the t'stat opens SOONER during the warm up cycle, thus slowing down the warm up. It does nothing to lower the temp once the engine is fully warmed up, as it's all the way open, be it a 180 or a 195. So for those who think that putting in a different deg. t'stat will help lower your temp; your wrong. Link to comment Share on other sites More sharing options...
possum Posted August 14, 2008 Share Posted August 14, 2008 And a lower temp thermostat can mess with your computer and will sometimes make your vehicle run like crap. I learned on LS1's that you have to use a hand held programmer to set the ECU for the thermostat. I am not one hundred percent sure this applies to Comanches but I figured I would throw it out there. Link to comment Share on other sites More sharing options...
Drahcir495 Posted August 14, 2008 Author Share Posted August 14, 2008 UPS is here I just got the CSF radiator. As soon as I get it installed, I will let you know how it goes - Rich Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted August 15, 2008 Share Posted August 15, 2008 Rich, did you change the waterpump yet? Link to comment Share on other sites More sharing options...
Drahcir495 Posted August 15, 2008 Author Share Posted August 15, 2008 Rich, did you change the waterpump yet? No, I did not. I should probably do that, huh?- Rich Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted August 15, 2008 Share Posted August 15, 2008 Rich, I changed the rad and meade sure all the air was out of the system and I'm still running warm. Since you have the header off and rad out it's really easy to get to it. I just bought one for $35.00 so while you're in there, why not. I also drained all the 50/50 mix again and added Prestone's flush crap that's supposed to clean out a lot of the build-up and rust in the block. Only thing that sucks is I'm supposed to run it thru there for 3-6 hours and drain it out again and replace the 50/50 mix. But since I'm changing out the waterpump to see if it helps I said sure ok. Link to comment Share on other sites More sharing options...
Drahcir495 Posted August 15, 2008 Author Share Posted August 15, 2008 Chico, I just picked up a new waterpump. I can't believe that you are still running warm. I have not started to take things apart. When you say "since you have the header off" you don't mean front clip - do you? I was hoping that there was only that steel peice on top to take off? I guess I will find out soon enough. I can't get mine to run 20 minutes without boiling over, so that 3-6 hour Prestone flush is out for me. Good luck and keep us posted - Rich Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted August 15, 2008 Share Posted August 15, 2008 Rich, I followed LEAD NOT FOLLOW"S DIY post on changing from a closed to open system. He goes step by step on how to remove your rad. It only took about 15 minutes to get the whole front clip off his way and makes working in there really easy. Great detailed write-up with pics. Anyway keep us updated and good luck :cheers: Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted August 15, 2008 Share Posted August 15, 2008 Rich, here's LEAD"S post http://comancheclub.com/forums/viewtopic.php?t=7695 Oh and make sure your waterpump is reverse rotation and is stamped with an R on the back. The moron at Autozone tried to sell me a differnt one. Link to comment Share on other sites More sharing options...
Drahcir495 Posted August 16, 2008 Author Share Posted August 16, 2008 Rich, here's LEAD"S post http://comancheclub.com/forums/viewtopic.php?t=7695 Oh and make sure your waterpump is reverse rotation and is stamped with an R on the back. The moron at Autozone tried to sell me a differnt one. You da-man Chico . Thanks for bringining up the waterpump, it forced me to do it ;) - Rich Link to comment Share on other sites More sharing options...
Drahcir495 Posted August 18, 2008 Author Share Posted August 18, 2008 It was either the water pump, or the new radiator that fixed my overheating problem :brows: . I am at just over 210 {215?} all day long in stop & go traffic. With the electric fan on I am at 210 on the button . I am still using the old plastic bottle with the hose clamp on it {guess it was fine} until the new Mac's comes in. Chico, how is it going for you? I really believe that drilling those two small holes at 6 & 12 on the thermostat did the trick. I did not have to burp the system :nuts: ! I filled up the radiator from the top and through the thermostat housing with the top hose. Ran it until it got hot - filled the bottle after it cooled off. Ran it again {did not get as hot} - then I topped of the bottle. That was it; overheating problem gone 8) . I think the cowl hood helps keep the temp down also - Rich Link to comment Share on other sites More sharing options...
Oizarod115 Posted August 18, 2008 Share Posted August 18, 2008 i'm pretty sure every 4.0L ever needs a radiator by 150k no matter what haha. all we have is 4.0Ls and 4 out of 4 have needed one. and MOST of the time if your waterpump isn't leaking or peeing out of the weep hole its just fine. Link to comment Share on other sites More sharing options...
LEAD_NOT_FOLLOW Posted August 18, 2008 Share Posted August 18, 2008 I will agree that it helps a lot on the closed-loop system to have a bleed hole in the t-stat itself. I remember after I installed the new motor in my XJ and still had the closed loop system how I had a MAJOR overheating issue. I was down right pi$$ed and after several phone calls with the guys at Golen we determined I still had air in the system. They recommended I get a factory OEM t-stat (yeah they are like 5x more expensive, they don't call them the "stealer" for nothing!). They told me that the factory t-stat for a Renix era XJ/MJ had a little hole in it with a ball pinched around some metal. So I went to several local auto stores asking about t-stats and opening up several dozen boxes trying to find an alternative (cheaper) option than the $50 dealer t-stat. After arguing with one local auto parts store about the need to have a hole in the t-stat I broke down and went to the dealer. Almost instantly my overheating issue was gone with the new t-stat that had the hole in it. So I called up Golen, apologized and thanked them for the tip. I never had a temp issue since. So I agree, if you can't find a t-stat with the fancy do-hicky with the hole/ball, drill a small hole in it to let air escape and it'll help bleed the system 10 fold. I will also plug the open-loop conversion at this time, as I see it only fit to do so. :D One of my major gripes with the older closed loop system was bleeding the air out of it so it will effectively cool. I can't count (even with my shoes/socks off) how many times I've been on the trails wheeling and someone has an overheating issue. They blow the pressure bottle (thus letting air into the system); we sit and jimmy-rig something up to get them back to camp, and no matter what we do, we can't get air out of the system and they are left riding with someone else the rest of the day. It seems like EVERY trip I'm on someone with the closed loop system has issues. Bleeding the system on the trail sucks, heck bleeding the system back at camp sucks. Sitting waiting on someone try to bleed the air out of the system on the trail sucks even more when my rig's running fine but I've gotta wait... I've converted ALL my Jeeps to the open system now and never looked back. I've never had an issue since, and quite frankly I think it cools better. I'll leave that argument for another time/place. But I'll tell you that the first time you have an issue not at home (either on the trail, or along the side of the road), you'll wish you would of spent the time/money converting it. OK I'll step off my soap-box now. :roll: 8) Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted August 18, 2008 Share Posted August 18, 2008 Chico, how is it going for you? Rich I finally got the pump in tonight and ran it. I think it's leaking though. No change in temp. 215 to 230. I'm going to wire my electric fan on a switch this week. If that doesn't lower the temp I'm gonna let it run outta coolant and oil and drive it till it blows and catches fire. :D Link to comment Share on other sites More sharing options...
jtdesigns Posted August 18, 2008 Share Posted August 18, 2008 Chico, how is it going for you? Rich I finally got the pump in tonight and ran it. I think it's leaking though. No change in temp. 215 to 230. I'm going to wire my electric fan on a switch this week. If that doesn't lower the temp I'm gonna let it run outta coolant and oil and drive it till it blows and catches fire. :D Just don't kick it... I did that once and was limping around for like a week! Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted August 18, 2008 Share Posted August 18, 2008 Chico, how is it going for you? Rich I finally got the pump in tonight and ran it. I think it's leaking though. No change in temp. 215 to 230. I'm going to wire my electric fan on a switch this week. If that doesn't lower the temp I'm gonna let it run outta coolant and oil and drive it till it blows and catches fire. :D Just don't kick it... I did that once and was limping around for like a week! :jump: :rotfl2: Link to comment Share on other sites More sharing options...
Drahcir495 Posted August 18, 2008 Author Share Posted August 18, 2008 Chico, how is it going for you? Rich I finally got the pump in tonight and ran it. I think it's leaking though. No change in temp. 215 to 230. I'm going to wire my electric fan on a switch this week. If that doesn't lower the temp I'm gonna let it run outta coolant and oil and drive it till it blows and catches fire. :D I think you should try the thermostat trick after you fix the leaking water pump. Good luck :popcorn: Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted August 18, 2008 Share Posted August 18, 2008 Back in the winter when I put a thermostat in because the PO wasn't running one and the truck wouldn't heat up and run like crap I put a 195* in and drilled a whole at the 12 o clock position only. You guys think it makes a differnce I didn't put one at the 6 o clock position? Link to comment Share on other sites More sharing options...
Eagle Posted August 18, 2008 Share Posted August 18, 2008 Back in the winter when I put a thermostat in because the PO wasn't running one and the truck wouldn't heat up and run like crap I put a 195* in and drilled a whole at the 12 o clock position only.You guys think it makes a differnce I didn't put one at the 6 o clock position? Nope. The factory t'stat only has the hole at 12:00 Link to comment Share on other sites More sharing options...
Drahcir495 Posted August 18, 2008 Author Share Posted August 18, 2008 It's all about the hole :roll: Link to comment Share on other sites More sharing options...
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