Over heating issue.

Jimmyspy · #1 03-05-2016, 04:35 PM

2002 4.0L. ~165,000 miles.

So I was out playin around today (local trails, not really pushin the truck, but a good hour creepin around under 10mph. Heat was only on half the time.). When I was gettin ready to leave, my ultra gauge started yellin at me. Looked down and my temp gauge was pegged in the red. Shut the truck off for a second then fired it back up and cranked the heat. Heat was blowin cold and the gauge climes right back up to the red. Let it sit for a while, fired it up again and the heat was blowin hot and the gauge was back near normal (ultra gauge was reading between 199-210). I've had the intermittent heat issue for a whole now, but this is the first time I've had the over heating issue. I'm thinkin it's the thermostat (based on the intermittent heat issue and the fact that it over heated while the heat wasn't working).

So, what do you guys think? Am I on the right track with the thermostat?

Ranger Danger 1998 · #2 03-05-2016, 04:38 PM

When you go drive it normally and the temp reaches about 195 do you see the temp decrease because the thermostat opens?

shawn_house102 · #3 03-05-2016, 05:04 PM

Quote:

Originally Posted by Jimmyspy

2002 4.0L. ~165,000 miles.

So I was out playin around today (local trails, not really pushin the truck, but a good hour creepin around under 10mph. Heat was only on half the time.). When I was gettin ready to leave, my ultra gauge started yellin at me. Looked down and my temp gauge was pegged in the red. Shut the truck off for a second then fired it back up and cranked the heat. Heat was blowin cold and the gauge climes right back up to the red. Let it sit for a while, fired it up again and the heat was blowin hot and the gauge was back near normal (ultra gauge was reading between 199-210). I've had the intermittent heat issue for a whole now, but this is the first time I've had the over heating issue. I'm thinkin it's the thermostat (based on the intermittent heat issue and the fact that it over heated while the heat wasn't working).

So, what do you guys think? Am I on the right track with the thermostat?

You could test the thermostat by putting it in boiling water around the operating temp of the thermostat.

Jimmyspy · #4 03-05-2016, 05:44 PM

Quote:

Originally Posted by Ranger Danger 1998

When you go drive it normally and the temp reaches about 195 do you see the temp decrease because the thermostat opens?

Honestly, I couldn't tell ya. Next time I warm it up from a cold start I'll have to watch the ultra gauge

----------

Quote:

Originally Posted by shawn_house102

You could test the thermostat by putting it in boiling water around the operating temp of the thermostat.

I'll have to try this.

Although, I have a feelin that if I pull the thermostat, I'll prolly just end up replacing it. Haha

smokinAMD · #5 03-05-2016, 06:42 PM

What's your coolant level?

Jimmyspy · #6 03-05-2016, 07:50 PM

Went out and checked the coolant level. Over flow bucket was dry (as always) and the radiator itself was low. So, I ran up the store to pick up a jug of antifreeze. When I left, engine temp was 55 (ambient air is around 25). She warmed up to 160 then dropped to 130. It hovered around 130-140 for a few minutes, then started to climb. It peaked at 210-215, then settled in at 195.
I put 2/3 of a gallon in the radiator at the store, then took the long way home. Temp started at 180 when I left, climbed a few degrees then bounced in between 183 and 189 for a few miles, then stuck at 186 for the rest of the trip home (5-6 miles). I didn't run the heat on the way, but did on the way back. Put out heat the whole way.

MNRANGER2002 · #7 03-05-2016, 07:55 PM

wow, you were that low on coolant?

Jimmyspy · #8 03-05-2016, 07:57 PM

Quote:

Originally Posted by MNRANGER2002

wow, you were that low on coolant?

Yea, 2/3 of a gallon. ( that's two-thirds, not two or three)

smokinAMD · #9 03-05-2016, 08:03 PM

Figured that would be the problem....now you need to find the leak.

MNRANGER2002 · #10 03-05-2016, 08:05 PM

Is that what 2/3 means, not 2 or 3? 2/3 of a gallon is a lot for a small cooling system like a ranger

Jimmyspy · #11 03-05-2016, 08:06 PM

Quote:

Originally Posted by smokinAMD

now you need to find the leak.

THAT sounds fun. Haha

Could the over flow bucket be a suspect? (It's been cracked since I got the truck. At least I assume it's cracked, as it's never held fluid).

MNRANGER2002 · #12 03-05-2016, 08:09 PM

rent a pressure tester, you'll have the leak find in no time

smokinAMD · #13 03-05-2016, 08:13 PM

Quote:

Originally Posted by Jimmyspy

THAT sounds fun. Haha

Could the over flow bucket be a suspect? (It's been cracked since I got the truck. At least I assume it's cracked, as it's never held fluid).

Yes, and no. Overflow bottle wont let the radiator get that low.

Pressure test is the key. Thermostat housing is a distinct possibility.

Jimmyspy · #14 03-05-2016, 08:29 PM

Quote:

Originally Posted by smokinAMD

Yes, and no. Overflow bottle wont let the radiator get that low.

Pressure test is the key. Thermostat housing is a distinct possibility.

10-4 I'll have to do a pressure test on it. Thankfully its not the daily anymore, so I can park it for the time being. Thanks for the help!

Ranger Danger 1998 · #15 03-05-2016, 08:31 PM

Quote:

Originally Posted by Jimmyspy

10-4 I'll have to do a pressure test on it. Thankfully its not the daily anymore, so I can park it for the time being. Thanks for the help!

did you say the needle was on the red?