Overheating at low speed (new coolant, new tstat, new fan clutch)

[Andy Steiner]

Foiled in my ever lasting quest for perfection!

CHEROKEE: http://www.partsgeek.com/catalog/1994/jeep/cherokee/cooling_system/radiator_fan_shroud.html

Your batting average isn't in jeopardy. You still kick Gehrig's ass.

 

[Andy Steiner]

oh duh!
good suggestion.

On another thread, somebody posted that he rigged a hose to flush the heater core only and going in the wrong direction. He reported finding a big old glob of something that came shooting out of the core.

No problems since.

 

[winkosmosis]

I found an image of the KJ cooling system. Their radiator is 20x20 so I would think the pusher fan is much too big for our 31x11

http://www.jeep4x4center.com/jeep-cooling-system-parts/liberty-kj.htm

 

[winkosmosis]

I'm guessing a 10" fan would fit.

http://www.midwayautosupply.com/p-10422-hayden-10-electric-radiator-fan-3670.aspx

http://www.2kracing.com/Product/2112305.html

This one says 1570cfm and only $23
http://cgi.ebay.com/ebaymotors/ws/e...5ffbf990b&rvr_id=&ua=WVF?&itemid=190414871222

 

[winkosmosis]

http://www.jeep4x4center.com/jeep-cooling-system-parts/cherokee-xj.htm <-- According to this the 2.5L XJ has a 16.75x20.25 radiator. I assume the 20.25 is the height. Does that mean we have room for a giant 31x20.25 radiator?

 

[winkosmosis]

I impulse bought a 10" Hayden fan at Checker today. $58. It looks like there is barely enough room to fit it in. It's supposed to attach with plastic straps that go through the radiator, but I'm not going to risk messing up the radiator with those. I need to figure out how to mount it. Any ideas?? Maybe zip tie through the grill even though I'll have unsightly zip ties?


It's rated for 650cfm which isn't much but I doubt the OEM electric fan is much better. Every bit should help.

I think I'll wire it to the fog light switch with Hella relay the PO was using for offroad lights (the lights died of old age).

http://www.summitracing.com/parts/HDA-3670/ <-- says puller but the blades mount both ways

 

[winkosmosis]

It fits perfect. I think I'll place it so the center is behind the vertical bar, and zip tie it to the bar. I think I need some kind of gasket so it seals better against the radiator (condensor?)

 

[Shorty]

Does that mean we have room for a giant 31x20.25 radiator?

sadly, no. The 4cyl radiator mounts behind (aft) the core support. That gives it more room vertically to mount.

 

[winkosmosis]

It's in place and wired up. I stuck adhesive foam from Ace Hardware around the rim to get a better seal against the radiator. The extra thickness is enough to hold it in place snugly, wedged between the radiator and that vertical bar. I did a test run and it sounds like a jet engine. It feels like it moves more air than the OEM electric fan.

 

[XJPhoenix]

Winkosmosis - Is that in pusher, or puller mode?

 

[Digger87xj]

I too am going to install a ten inch pusher, but I'm going to mount it in front of the mechanical fan. That is the 'hot' side of the radiator, So I want it to get the double cooling effect. I figure it should get the fan clutch to kick in earlier too, but I could be wrong though.

 

[winkosmosis]

It's in pusher mode.

So far it doesn't seem to do anything. Whether I switch it on or off, temp stays the same!! Maybe in hotter weather it will do more.

I didn't realize the right side is the hot side. I thought the water flow was back and forth. Maybe I should try putting it on the right.

 

[XJPhoenix]

Wink - Gotcha. Didn't want to offend, but I did want to ask as the method of reversing the fans always seems like crossing the streams... Did the instructions mention needing to reverse the wires as well? I know some fans do that...

Digger - I also had no idea the right side was the hotter side, good to know!

 

[winkosmosis]

Yeah I think the instructions said to reverse the wires. It's set up from the factory as a pusher, with some text on the fan saying that black is + and blue is - so I didn't have to do anything.

For puller mode you uncrew the blades and mount them the other way.

 

[winkosmosis]

BTW I did the test listed in the FSM for checking the fan clutch. It's supposed to become hard to turn after 5 rotations. It got stiffer, but it was never really hard to turn. Is it supposed to be too stiff to turn by hand?

What about when it's hot, should it be impossible to turn by hand, or just offer a little resistance?

 

[winkosmosis]

BTW I did the test listed in the FSM for checking the fan clutch. It's supposed to become hard to turn after 5 rotations even when cold. It got stiffer, but it was never really hard to turn. Is it supposed to be too stiff to turn by hand?

What about when it's hot, should it be impossible to turn by hand, or just offer a little resistance?

 

[ehall]

The air on the clutch face needs to be 170f (IIRC) for the clutch to engage. A good blowdryer and an IR thermometer are needed. The difference will be noticeable.

Here's an interesting read http://www.peachparts.com/shopforum/showthread.php?t=67800

 

[winkosmosis]

Oops.. I must have accidentally quoted myself instead of editing.

I've tested it cold like the FSM says, and it never gets stiff. When hot, like when the coolant temp is 230F, it's still not stiff.

 

[Jamescad04]

I dont know if i may have missed it or not but have you replaced the coolant temperature sensor? I removed my radiator flushed it and the block then cleaned out all of the fins and it fixed my overheating and the high idle issues I was having.

 

[winkosmosis]

Haven't replaced the temperature sensor. That's where the Scangauge gets its signal from right?