A little help please?

[killwhytey07]

So, my YJ (2.5) has been running funny lately, it would run real hot at first then run at the normal 210 or so. Then after a while it started doing this thing where when it idled it would heat way up, but if I was driving or gave it a little gas 2000 RPM or so it would cool down. Now it's just going straight up and overheating. I put a new thermostat in it, tried it and it overheated... waited an hour tried it again, and it ran fine, tried it the next day and it over heated. Now everytime I start the thing it over heats. I'm at a lose on this. This is the second thermostat I've put in it, in about 6 months. I also drained my radiator (very dirty, rusty looking) and flushed it. I've noticed when it runs the ingoing hose will be hot, but the outgoing will be cool, like no water is actually going through the motor.

Could there be a clog in the system somewhere? Or maybe the water pump is shot?... and any suggestions on a fix?

As always, any help is appreciated!, you guys rock.

-Dustyn

[nagal]

It kind of does sound like a bad water pump to me.

[medicmahem]

It kind of does sound like a bad water pump to me.

ditto here and when was the last time you flushed your radiator.

[TDS SD]

Heating up

On the older 2.5's part of the enging cooling system was the heater core. If the heater core was blocked part of the engine was not getting any coolant. I'm not sure if the later model 2.5's coolant was routed different.

[killwhytey07]

Flushed the radiator before winter to get it ready... it definantly shouldnt be as dirty as it is.

Mines a 92' TDS... I dont know if that qualifies as older or newer... if it were the heater core, how would I go about checking that?

And as for the water pump, is there any way to be sure, or is it just replace, and hope for the best?

Again, thanks a lot you guys!

[TDS SD]

Overheating

Dustyn. I think on later models such as yours the "in" hose for the heater core comes from the manifold and the "out" goes to the waterpump. The out will be much cooler then the in if its clogged. On my Iron Duke 2.5 one of the heater hoses went to the rear of the head and the constant circulation help cool the head.

[killwhytey07]

Does anyone know a website that has a step by step for dealing with the water pump?

I looked at autozone.com, and couldn't find anything

[Dukes69]

buy a factory service manual. You need one anyway.

[killwhytey07]

I know I do, but money is extremely tight.
I found my guide though... tackle that soon, I hope.

[maddmike]

does the exhaust have a sweet smell? is there whitish smoke coming from the tailpipe? are you losing coolant from the reservoir but it's not leaking?

[Dukes69]

So, my YJ (2.5) has been running funny lately, it would run real hot at first then run at the normal 210 or so. Then after a while it started doing this thing where when it idled it would heat way up, but if I was driving or gave it a little gas 2000 RPM or so it would cool down. Now it's just going straight up and overheating. I put a new thermostat in it, tried it and it overheated... waited an hour tried it again, and it ran fine, tried it the next day and it over heated. Now everytime I start the thing it over heats. I'm at a lose on this. This is the second thermostat I've put in it, in about 6 months. I also drained my radiator (very dirty, rusty looking) and flushed it. I've noticed when it runs the ingoing hose will be hot, but the outgoing will be cool, like no water is actually going through the motor.

Could there be a clog in the system somewhere? Or maybe the water pump is shot?... and any suggestions on a fix?

As always, any help is appreciated!, you guys rock.

-Dustyn

I just read the thread so let me ask some questions.

1. Do you have a mechanical or electric temp gauge? If electric, plumb in a mechanical gauge. Electric gauges cannot be trusted.

2. did you flush the motor? if not, try it.

3. when one hose is hot and the other is cool, is the same true for the radiator?

4. is all the air out of the system?

5. what condition is your fan clutch in?

[killwhytey07]

madmike-
I've never had any white smoke until the other day. I pulled into my friends drive way and shut it off, a few minutes later we go to leave, and the thing is smoking like I blew a head gasket. I turn it off and check the motor, and everthing looks fine. wait a few minutes and start it, and it runs like nothing ever happened.... I have no idea what that was.

Also I do lose coolant, but it's mostly through the boil over line. I'm faarly certain there is no leak, because I check the pavement under my jeep and theres never anything there.


Dukes-
1. I'm not sure if it is electric or mechanical. I'm assuming it's electric though, since it only works when the jeep is on. It's the stock
2. I've flushed the radiator a couple times
3. When it overheats, the radiator always feels cool.
4. I'm not sure if there is air in it or not, I've never taken steps to get the air out, I just fill the radiator up till it's full
5. I honeslty have no idea about the fan clutch. The fan is always running though.