Jeep Enthusiast Forums banner

Another overheating thread

2K views 15 replies 10 participants last post by  JS97ZJ 
#1 ·
I've searched and searched and can't find the answer I'm looking for. Maybe starting a thread will help.....

WJ-4.7 ~21,000miles on the engine, ~213,000 on the body, ~10,000 on the tcase.

Ever since the temperature has risen (75-95 average outside temp), my temp gauge sits just above the 210 mark. It will sit and idle at this temp all day long. When I start driving, the harder I drive, the higher the temp gets. Pulling a heavy trailer, and it climbs up pretty quckly. Driving hard on the interstate will make it climb as well. (I live in "The Mountain State") There's no such thing as flat ground here, so the engine is almost always under a load.

A few months ago I replaced my fan clutch, as it locked up. About a month ago, I had the dealer replace my malfunctioning elec-fan (under TSB :2thumbsup: ), hoping that would solve my problems. When it didn't, I took the fan clutch back to advance auto parts for exchange. It's still having the temperature issue.

I'm not losing any coolant as far as I can tell, and the engine runs strong, with the exception of an occasional idling issue that I believe is just the IAC needing cleaned.

I don't know if it makes a difference, but while sitting still the A/C works great, and when driving 70 it seems to not be as cold.
 
See less See more
#4 · (Edited)
You sure you didn't put the fan on backwards? I've got the 4.0 so I don't even know if it'd be possible to put it on backwards without the fan blades hitting the engine, but it does explain both the cooling and A/C issues. Basically it would cause the fan to push air from the engine back through the grill instead of pulling it through. Essentially when you're moving, the fan and your momentum would be fighting, reducing the amount of air flowing through.

If the fan is on correctly, then it's most likely a flow issue (clogged rad or heater core, collapsed hose, faulty water pump, etc...)
 
#5 ·
im voting for a flow issue. What have you checked in that area?
 
#6 ·
I'm positive the fan is on correctly, as for flow issues, 21,000 miles ago when we built the engine, a new water pump, thermostat and radiator hoses were put on. I never had an issue with the heater during the winter, and after it rained the other day, and the outside temps were ~70ish, it sat right on 210 where it belongs.

I've actually been leaning towards just replacing the radiator anyway, and possibly doing the taurus fan swap, I was just wondering if anyone else had similar issues...
 
#14 ·
+1
Also it might be a good idea to get a coolant flush done. Mine was running @ 223 deg F all the time, after the flush its down to the 198 mark on a hot 95 deg day.
Make sure you replace the thermostat before getting the flush done, they did the flush and didn't say that they could not flush it properly and when i left and i got down the road aways and it overheated on me, fortunately i was a few blocks from a friends repair shop and made it in there and replaced the thermostat and no more over heating issues since. The thermo could been the problem in the first place, as i tested the old one and it wasn't opening up at temp. :duhrock:
 
#8 ·
Is it a stock transmission cooler? If so, the cooler is routed into radiator.... So, an elevated transmission temp would also elevate coolant temp and therefor engine temp. Maybe its time for a transmission fluid/filter change.

I guess I'm basing this on the "harder I drive" and "more load, i.e. pulling a trailer" statements.
 
#10 ·
If you put the aftermarket (which is usually a "fluid to air" cooler), put it on the return side of the radiator such that trans fluid flows through radiator cooler first, then air cooler.
However, unless your jeeps has mods, the original cooler should work well for most situations. But if the fluid is old and filter/lines are plugged then extra heat is the result. I would change fluid and filter first.
I used a pump to pump fresh fluid into the system, while catching the old fluid out of the line into a bucket. This worked well to flush things out.
 
#11 ·
i just bought a 99 with 4.7.. it runs a little over 210, as does my tj with the 4.0
 
#12 ·
Have you looked at my thread called "towing makes 4.7L too hot"? It from awhile back but will describe a similar issue.

I still have not gotten it back to a perfect tow rig after 4 years or so, but it's better and the thread will tell you what to do next.

Bottom line: Do Not Let That 4.7 get hot!

Run the heater full blast when it does....does the temp come back down? Yep? There's your sign...
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top