You’re correct. There is a “wearing out period” The video I posted is the end result. His may be at the beginning of wearing out.
Jeep is overheating at idle
- Thread starter Jonas Menges
- Start date
You’re correct. There is a “wearing out period” The video I posted is the end result. His may be at the beginning of wearing out.
The factory cooling system is more than up to the task. If you overheating, something is wrong. Replace the broken parts..... no need to add anything.
An electric fan would be a significant downgrade to the factory serpentine belt driven fan in the TJ's case. Us desert wheelers learned that many years ago.
Brandon Casey0
New Member
Update, I changed the fan clutch, the problem is still there. I think the fan clutch was about to go out anyways.
Brandon Casey0
New Member
I'm going to try the water pump next if I find that my radiator isn't clogged.
I doubt it, that belt needs to be changed though asap before your in a bad spot and it breaks and leaves you stranded. I would also clean that idler pulley and get all that old belt reside off of it.
My TJ was recently idling higher than usual (like halfway between 210 and the red zone) and today I went to a spray bay and blasted all my radiator fins out with high pressure water and it idles way lower now, right where it should be. I think this is something you should be doing routinely. Though my fan clutch could use an update i'm sure...
Keep in mind that cracks going across a serpentine belt are absolutely normal, they will form within a short time after installing a brand-new belt. Cracks running lengthwise along the belt are the bad cracks to watch out for, they're the sign imminent failure.
http://www.agcoauto.com/content/news/p2_articleid/117
Some dishonest mechanics will point at a serpentine belt with cracks running across its width and tell you it needs replacing. They don't usually indicate that at all.
http://www.agcoauto.com/content/news/p2_articleid/117
Some dishonest mechanics will point at a serpentine belt with cracks running across its width and tell you it needs replacing. They don't usually indicate that at all.
I have a 1998 TJ and I put an electric fan with a 180 thermostat in and it keeps it around 210 while driving but if I let it sit and idle for 5-10 minutes it will overheat. Any ideas?
A few... first, that electric fan was a definite downgrade to the cooling system where the 4.0L and 2.5L engines are concerned. It can't, truly, pull as much air through the radiator as the OE serpentine belt-driven fan can. I usually wheel in desert areas where it gets hot and the OE cooling system is good for anything our deserts can throw at us. If it wasn't, we'd have all converted to something else long-ago. And when I come across someone in a Wrangler with an overheating cooling system, more times than not it has been converted to use an electric fan in the mistaken thought it'd cool better. They don't, at least not in our TJs with the 2.5 and 4.0L engines..
Then, the cooling system needs to have a 195 degree thermostat installed, not a 180. First, running a lower temperature thermostat cannot and will not magically force an engine to run cooler except on extremely cold days. In warm or hot conditions, the engine will run right at 210 whether there's a 165, 180, or 195 degree thermostat installed. And with a lower than specified thermostat installed, the engine will take longer than it should to warm up, and it won't warm up enough on cold days. A lower temp thermostat can even cause a Check Engine light since the PCM is programmed around the specified 195 degree thermostat.
Overheating at idle usually means the fan is not pulling air through the radiator as designed. That is usually from the fan's clutch having gone bad, the shroud is damaged, or someone cluelessly removed the fan shroud which is crucial to good cooling when the Jeep is stopped or being driven very slowly.
Personally, I'd go back to the original fan and figure out what the problem was... like a bad fan clutch, something wrong with the shroud or it's missing, perhaps the radiator has some of its cooling fins packed with dirt. Or perhaps someone mistakenly mixed the coolant with tap water instead of distilled water which will start clogging the radiator with mineral deposits causing marginal cooling ability.
The bottom line is that when it's working as designed, the TJ's factory cooling system can cope with anything our Jeeps will encounter. When it can't, just find and fix the problem... no need to convert it to a different design. And if nothing seems to help, odds are very good someone installed an aftermarket store brand radiator which are well known to not have as much of an (if any) excess cooling margin like the OE Mopar radiator with its all aluminum core does.
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I put a 4 inch lift on it. Once I did that a little later the radiator head cracked so I got a 56mm full aluminum 3 row core radiator and put it in. There has only ever been 50/50 pre-diluted coolant run through it.
While this may seem counterintuitive, keep in mind more rows don't necessarily or even often mean better cooling. Absolutely.
In fact, Jeep changed the TJ's original 2 row radiator design in the late 90's to a 1 row design (including an all aluminum core) and picked up significantly better cooling characteristics. Typical 3 row all aluminum radiators don't cool nearly as well,it takes a very expensive one to even equal it. And most all aluminum radiators rely on an epoxy internal coating to stop leaks. The problem with that is the epoxy lining reduces the coolant capacity reducing its ability to cool.
As said above, it is very hard and rare for a store brand aftermarket radiator to even equal the cooling capacity of the OE Mopar, let alone perform better which would require an expensive design and very high quality which isn't sold by auto parts stores or discount radiator sites.
In fact, Jeep changed the TJ's original 2 row radiator design in the late 90's to a 1 row design (including an all aluminum core) and picked up significantly better cooling characteristics. Typical 3 row all aluminum radiators don't cool nearly as well,it takes a very expensive one to even equal it. And most all aluminum radiators rely on an epoxy internal coating to stop leaks. The problem with that is the epoxy lining reduces the coolant capacity reducing its ability to cool.
As said above, it is very hard and rare for a store brand aftermarket radiator to even equal the cooling capacity of the OE Mopar, let alone perform better which would require an expensive design and very high quality which isn't sold by auto parts stores or discount radiator sites.
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I'm having same issue.. changed engine a couple months ago cause piston slap. But it did same thing with old engine. Since then put in a new radiator from advance. Water pump, Old one seemed fine. Thermostat, radiator hoses, 2 jeep fan clutches and fans. Now i put a ford explorer fan clutch severe duty and 9 blade fan.. but if i let idle for 10 or 15 min gets hot.. heck i thought i could fix most things but this thing is getting the best of me.. need advice... not much left i can change..
It done it with oem parts also so I'm confused. Oem factory radiator. Replaced cause small leak but also at idle run hot.
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