Radiator question

[ComancheGrl]

Hi Guys...

This may be a stupid question, if so sorry.

Today I went wheeling at holister. It was pretty warm, probably mid to hi 80's.

We went up a pretty steep rocky grade. It was challenging for me, as I am new to wheeling, and my rig is pretty close to stock.

I have an 89 MJ, 4.0 six cylindar, not HO, and it overheated on the hill. Are there any upgrades, or better stock radiators I could put in it to prevent this from happening again?

Thanks,

Dawn

[Moxj85]

Might be worth tryin to clean out. Take it to a shop and have them steam clean it out and check for leaks. I've seen this make almost a 40 degree difference on some of my radiators. Next option is to get a lower degree thermistat, not sure what you stock on is but try to get on around 160. Last option is to get a new radiator. I've gone through 3 radiators in the last 2 months (large sticks out of the ground are not your friend) and have really good luck with forgien car radiators. Example is a Isuzu pick up radiator - didn't even need a fan, it cooled so well. Another was a old Celica radiator did about the same thing. I didn't even clean those, just threw um in and ran. All i looked for was something the right size and had the right sides for the in and out puts.

[kajeepxj]

Just get a GDI 3-core. great upgrade and i got mine for 100 bucks delivered. i think you call 1-800-radiator and thats where to get them from.

[moveaside]

specialtyparts 800-504-jeep their in No. Cal they'll set you up with a 3-core rad that should solve that prob and you might want to take a look at your weight on your rig like what's necessary and what's gotta go. You can also change the thermostat to a lower temp. Sure sucks overheating on a hot hill and then watching your buds tearing it up while you sit there?

[Ropeburn]

I know on XJ s of that vintage, they run on a crappy closed loop cooling system that is very prone to overheating. Tiffs had one, I swaped it over to the newer style system and it took care of those problems. Check this out:

http://www.off-road.com/jeep/cheroke.../radiator.html
http://www.off-roadweb.com/archives/...1_tech01.shtml
http://www.geocities.com/bigbadxj/Op...em_switch.html
http://www.olypen.com/craigh/cooling.htm
http://www.angelfire.com/my/fan/electric.html
http://www.olypen.com/craigh/auxfan.htm



or take a look at hers at the meeting.

Mike

[ComancheGrl]

Thanks guys!

I will definately look into both the steam cleaning and getting a 3 core.

As for extra weight on the truck, I dont think there is much. I dont even have a tailgate on it at the moment and its a light rig to begin with.

Mike I do want to see what you did for Tiff. We ended up cutting the day short. We stopped and filled it a couple of times on the way home and it seemed to do OK. I really hope I didnt do any damage.


Thanks again!

Dawn

[four_by_nut]

I had an '87 MJ for about 6 years. I live in Phoenix, AZ and only ran into an overheat problem once. I was in Rocky Point, Mexico. I was running up and down the beach in low range pulling about 3 or 4 guys "surfing" on boards on the sand from behind the truck (Oooooohhhhhhhhh the college years) and the outside temp was about 95 - 100F. The idiot light came on after about 30 minutes of this. I shut it down and let it cool. Never happened again.

I would recommend making sure what you have is in tip-top-running condition before dropping money into new stuff. May be that you'll do good with what you got if it's just cleaned up and in good working order.

That having been said, if you find the radiator is really plugged and needing replacing, obviously, upgrade it. But make sure what you have is working well before moving forward.

[Ropeburn]

By all means try all of the cheap things first. These are upgrades for XJs and ended up being a god send for Tiffs rig. Let me know if I can help in anyway. How was Hollister?

[PYRO]

Originally posted by Moxj85
Next option is to get a lower degree thermistat, not sure what you stock on is but try to get on around 160.

Wrong!!!! don't run anything less then a 190 thermostat. Motors are made to run around 210, anything less then 190 and the proper tolerances will not be reached and the life of the motor will be decreased. The motor temps will run up and down from 160 to 220 over and over depending on load, very bad for the motor. Also, FI motors need to operate at a set temp(195) for proper sensor function.

Replace the thermostat(cheap and simple)Check your elec fans and the coolant temp sensor(turns elec fans on and off at certain temps through the computor).
If it still gives problems, As was said, you may want to upgrade to a '92 radiator. This year Jeep went back to the open system(filler neck in the top of the radiator). You'll need to add the '92 heater valve also but it all fits without any fabrication.

[ComancheGrl]

Wow! Thanks!

Im going to take it in on Friday and have someone completely check it out to make sure its ok.


I thought it was odd that the idiot light never went on to show that it was overheating. Also...the electric fans never came on, so something must be mucked up there.

We have the dash gauge cluster from an XJ that shows temp etc, but havent put it in yet. The stock one on the MJ just has idiot lights.

I am thinking that even if (which doesnt seem likely) the cooling system is working correctly I will still need to upgrade because once I upgrade to bigger tires etc. wont that make the engine work harder so it will be prone to getting hotter, right?

Hollister was great...I was really having a blast until the steam started pouring out. <sigh> But at least I have a lot of info to go on now. It was a great day. I started to take pictures, but since I had the camera and I had to get out to take the pics I couldnt on any of the good trails, so there isnt really anything to post. Eric got a pretty good pic of someone stuck in the mud pit. They had to get yanked out.

[stemp]

Originally posted by ComancheGrl

Also...the electric fans never came on, so something must be mucked up there.

There is a big problem right there. If your electric fans didn't come on then you are not moving any air across your radiator fins which transfers the heat out of your coolant.

[/B][/QUOTE]
I am thinking that even if (which doesnt seem likely) the cooling system is working correctly I will still need to upgrade because once I upgrade to bigger tires etc. wont that make the engine work harder so it will be prone to getting hotter, right?
[/B][/QUOTE]

If you are worried about having problems in the future then just invest in a 3 core radiator and think about an additional electric fan as a pusher in front of your radiator.

I just fixed the problem I was having with my CJ by replacing the radiator with a 3 core and adding twin 12 inch electric fans. The elctrics work so much better than a flex fan with crawling since the engine is turning at low RPMS. The electric fans are controled by an adjustable temperture sensor so I control when they turn on and turn off. I also put in a cut-off switch for water crossing. Total projest was less than $250. Hope it helps.

Stemp

[4Bangler]

Don't buy aftermarket electric fans, go to the junk yard and get some factory jobs out of front wheel drive cars, way better than any race unit or aftermarket piece. My fan is out of a Pontiac 6000 and it will suck a shop rag off my winch and through the grill. I wired mine to a ignition switched hot, but I need a relay, cuz when I shut it off the fan becomes a generator and back feeds my ignition, the Jeep will run for a minute after I take the key out.

[ComancheGrl]

Thanks again for all the input guys. I really appreciate it.

Dawn

[SeanP]

Dawn,

Been there done that. My XJ runs (ran) very hot whenever crawling in 4 LO. I have done ALOT of research on this subject. Stick with the 195 T-stat. Your cooling system has the crappy plastic overflow bottle which needs to remain pressurized for the system to work. These are notorious for getting cracks and leaking pressure.

The best advice that I can give you is to change out to the HO (91+) cooling system that has the radioator cap on the filler tube. The poster above has some good links to this project. The 3 core GDI (brand name) radiator from 1-888-radiator should be about $100. If the y qoute you $130, just mention an internet special group buy that was set up thru NAXJA or a local jeep club. They always throw out a price, then come down. They ship from Benecia, by the way.

Also, if you can get a dial temp gauge, this would help a lot. If you see the engine creeping above 200*, you can manually turn your electric fan on. The fan is normally wired to come on at 219*, but usually that is too late for my engine. Wiring the manual switch is pretty straight forward. You can test your electric fan to see if it comes on when your AC compressor coes on (it should). Search for Daless2 posts on this board as he did a nice write up/schematic for me when I did this project.

The NAXJA OEM forum has more info, plus there are a lot of MJ/XJ guys in NorCal that can help in a pinch.

Best,

SeanP

[IndyCJ]

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[ComancheGrl]

Hey Thanks Sean!

We looked at what Ropeburn set up in his g/f vehicle, and I think it is the same thing that you are talking about and that's the way I think we will go.

Eric pulled a stock gauge set out of an XJ that has an actual temp gauge on it and we want to install that. Right now I just have idiot lights, which dont do much good, since it didnt come on at all.

It doesnt sound terribly expensive, and I want to make sure I dont have this problem in the future. I have plans for this baby.

Dawn

[ComancheGrl]

Originally posted by IndyCJ
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