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Running hot

How about we back up for a second? Mine is running hot for my taste. Drove
Blue Oval Trucks for years so I base my opion on that. (95 XJ ,4.0) replaced:
t-stat,cap,coolant sensor,have temp sensor and am debating a REAL gauge,coolant looks good,no appartant head problems. Runs up to "about" 3/4 on factory gauge after a jaunt to work(15 miles, pretty open roads)lots of good air! electric fan will kick on when it "gets" hot.have talked w/ other XJ owners and have gotten various responses. also talked w/ service manager at local stealership. He thinks this normal.I'm quessing maybe 235-240 degrees if the factory gauge is correct or close. Sorry to babble but one last thing. Have a couple of 96 and a 98 in a local yard pretty much intack. whats the good year on the intake and is there anything else I could look for. THAKXJ
 
my 87 always ran hot, real hot when wheeling. the guys i wheel with who drive XJs say theirs run hot too. seems like they were designed that way to me. mine would get hot enough to "tan" your hand if you leaned on the hood after wheeling. good place to cook dinner when camping. haven't had the new XJ out in traffic and heat enough to see how it will behave yet.
 
Talyn said:
I've owner 5 4.0 Jeeps. Anything above 220 is not a good idea. jeeper95xj, have you replaced the radiator?
Click to expand...

Were they XJ's?

ZJ's, WJ's, YJ's and TJ's all run cooler than XJ's. It's well-documented in these forums... I knew about it before I even bought my Jeep.

Running up around 220 is NORMAL for these rigs. Is it good? Dunno. Probably causes some premature failure of hoses and plastic stuff... but it's quite normal for the vehicle. It can also be hell on the paint on the hood.

Honest.

You can probably put in an aftermarket 3-row radiator or better fans or any number of other things to bring the temp DOWN some -- for a price -- but the rest of us are content to live with the higher temps.

Den
 
anyone running one of the cowl hoods? seems like that would let some heat out, cool air in. if i ever do headers i'll do the wrap on em to keep the exhaust heat going out the pipe.
 
Talyn said:
I've owner 5 4.0 Jeeps. Anything above 220 is not a good idea. jeeper95xj, have you replaced the radiator?
Click to expand...
no but it has crossed my mind.it's ok until I park in the lot at work.After about 30 seconds or so the gauge starts creepin up and the electric fan will kick on.It runs at 200? according to gauge up to this point. Has never cooked over I've never seen the gauge go past 3/4 (my point on a real gauge to see what I'm really at).A couple of guys (XJ owners) haved even mentioned the heater core? And just giving the whole system a good flush.
 
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Talyn said:
I've owner 5 4.0 Jeeps. Anything above 220 is not a good idea. jeeper95xj, have you replaced the radiator?
Click to expand...

2 XJs, 2 ZJs. My 1991 XJ with 200k miles never broke 210.
 
UPDATE

Yesterday I changed out the thermostat for a Stant 195* one. It was fairly warm today and it didn't move from 210. Also found out that the fluid isn't as clean as it should be. Taking care of that in a week. So, despite the fact I wanted a new rad one appears not to be needed.

But, how can people run a high flow water pump, high flow t-stat and high flow t-stat housing without having the issuse I have? I was thinking about it and I think it is because of the fact that I am still using the stock radiator. Most of the ones they go with have more rows and hold more fluid. Which equals a slower flow through the rad. Does that make sense?

Thanx Rev Den

-Chris
 
Re: UPDATE

Talyn said:
But, how can people run a high flow water pump, high flow t-stat and high flow t-stat housing without having the issuse I have? I was thinking about it and I think it is because of the fact that I am still using the stock radiator. Most of the ones they go with have more rows and hold more fluid. Which equals a slower flow through the rad. Does that make sense?

Thanx Rev Den

-Chris
Click to expand...


All I can say it this, My GDI three row was wider than my stock RAD, and now I have a CSF 2 Row which is thicker than the old POS GDI. Right now with a stock pump and a high flow prestone 180 T-stat I'm cruizing at 180 according to my highly accurate OEM guage. When at idle it is lucky to get to 200. I used distilled water and just water wetter, no coolant.

So, can your RAD effect your coolant flow, absolutely. I don't think it's a size issue, no it sounds like it is just plugged up.
 
I haven't read every post in this thread but something that happens, in general, if your cooling agent (water/anti-freeze) moves through your medium (radiator/engine) too fast, there is not efficient temperature transfer, so over heating is noted. Hope this isn't a redundant post.

Spelling mistakes can be blamed on Southern Comfort, trying to kill a cold... or myself........not sure which.
 
Re: UPDATE

Talyn said:
Yesterday I changed out the thermostat for a Stant 195* one. It was fairly warm today and it didn't move from 210. Also found out that the fluid isn't as clean as it should be. Taking care of that in a week. So, despite the fact I wanted a new rad one appears not to be needed.

But, how can people run a high flow water pump, high flow t-stat and high flow t-stat housing without having the issuse I have? I was thinking about it and I think it is because of the fact that I am still using the stock radiator. Most of the ones they go with have more rows and hold more fluid. Which equals a slower flow through the rad. Does that make sense?

Thanx Rev Den

-Chris
Click to expand...


I was getting sorta warm until I drained over a gallon of coolant out and replaced it with vinegar (as I mentioned on the other thread). This cleaned out the entire cooling system extremely well, loosened up all kinds of crud all through the system. Now I stay right at 190* no matter what, and I don't even have a mechanical fan or an electric replacement for the mech fan. I'll put one on this summer, but for now the system stays cool with just the AC electric fan. In stop & slow traffic the fan is on about one minute out of every 5. Clean system and coolant are pretty important, ime.


EDIT: I only left the vinegar in for 7 days then flushed twice, replaced with water and antifreeze 50/50
 
When you replaced the head, was it with a stock unit or had there been porting work done on it? I've seen heads with extensive port work on the exhaust side cause an engine to run hot - not enough meat between the exhaust ports and the coolant jackets. Since it's been doing it SINCE you replaced the head, and not until, I would either suspect something with the head or gasket (possibly wrong gasket not letting coolant flow properly) ... Are you 100% sure that the engine is actually running hotter and that the gauge isn't off?
 
titan4u2c said:
'91 xj with 200k and never broke 210....? Was it a lightly used 2wd 2.5L with a super duty rad? I'd like to see that, no offense haha.
Click to expand...

No, it was a well cared for 4.0 4x4. Used a lot on the beach, daily driver, etc. Itw asn't driven gently, but maintenance was 100%.
 
FWIW:

I'm on my 3rd 4.0 Jeep.

The first was a low (under 45k) mile 95 XJ. Had no idea how hot it ran because there was no temperature gauge. I could tell how much gas was in it, down to the ounce, because of the enormous gas gauge.

My 97 XJ, which just turned 95k the other day, has always (in the 68k miles since I've owned it) ran at "about" 210. A hair below in the winter, at 210 in the summer, and it creeps up at idle (esp in hot weather) towards 220 until the fan kicked on. Always has.

This is before AND after a new radiator, water pump, t-stat, coolant flush, hoses, fan clutch and belt.

My 00 TJ ran at 210. All the time.

My two 2.5 YJs' temps varied like my 97 XJ.

It's a Jeep thing.
 
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Unless you bought it new and used nothing but distilled water + coolant in the radiator, I can almost guarantee you the radiator core is clogged. I had the same problem and replaced everything else first. Tried radiator flushes and even lime-a-way. When I busted a end cap off the old rad, it was completely full of deposits. With the new CSF 3 core, the temp never goes over the half way mark on the gauge...even when towing with the AC on.
 
sorry for the huge bump, but is there any way to test if your t-stat is working properly?

btw, where is it located? :dunno:
 
And you needed to bump this old thread why?

You tstat is located under the tstat cover on the front of your cyl head, just above the water pump. There is a large radiator hose connected to it.

You can test it by removing it and immersing it into a small pot of water on your stove. When the water temp hits the setting for your tstat, you'll see it open. Turn off the heat and slowly add cool water and you'll see it close.
 
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