Hot?

[techninja]

Maybe the rear heater core is plugged?

Even if it were clogged, I don't see how just connecting it, and having it off, would restrict the flow. When I did hook it up, it worked great.

When I first connected it, I ran water through it, and it flow w/o a problem; I don't need it, but it bugs me when stuff doesn't work.

I forgot to mention that at least once a day, the temp gauge just flies up to the red, then almost immediately it goes back down pretty quickly.

If the is an intermittent open on the wire, do you know if that is what I would see?

I just don't know if the temp sender has more resistance when the temp goes up, or when it goes down.

Thanks.

 

[jvazquez53]

Mine doesn't go completely to the red, it goes past 3/4. I replaced the sending unit and still get the same reading. Starting today, I'm going to use the truck without thermostat and I'll see if there's any significant change.

 

[BlueBoxFJ60]

i had a similar unsolveable overheating problem, long story short replace the radiator!!!!radiatorbarn.com fast and good customer service.
Search my post history or pm me for more details.

 

[JLH911]

Even if it were clogged, I don't see how just connecting it, and having it off, would restrict the flow. When I did hook it up, it worked great.

When I first connected it, I ran water through it, and it flow w/o a problem; I don't need it, but it bugs me when stuff doesn't work.

I forgot to mention that at least once a day, the temp gauge just flies up to the red, then almost immediately it goes back down pretty quickly.

If the is an intermittent open on the wire, do you know if that is what I would see?

I just don't know if the temp sender has more resistance when the temp goes up, or when it goes down.

Thanks.

The pegging of the temp needle is a known problem.

Do a search and you'll see that most people install a mechanical temp gauge and bypass the stock one.

 

[jvazquez53]

Removed the thermo, drove to work back and forth (20 miles), and the truck ran like new no high temp issues. Since I have no need for the thermostat, it is going to a box.

 

[techninja]

Thermostat

Removed the thermo, drove to work back and forth (20 miles), and the truck ran like new no high temp issues. Since I have no need for the thermostat, it is going to a box.

What I heard/read is if you remove the thermostat, you starve the rear water gallery, and can overheat #6. Don't know if that's fact, but I think a mechanic @ Man-A-Fre said that as well, but I don't recall exactly where I got that info.

I'm thinking mine is the sender/spliced wire/gauge thing. Now I just have to find the parts for a mechanical. It's getting the fitting that concerns me...not to mention where I can mount the thing.

 

[jvazquez53]

What I heard/read is if you remove the thermostat, you starve the rear water gallery, and can overheat #6. Don't know if that's fact, but I think a mechanic @ Man-A-Fre said that as well, but I don't recall exactly where I got that info.

I'm thinking mine is the sender/spliced wire/gauge thing. Now I just have to find the parts for a mechanical. It's getting the fitting that concerns me...not to mention where I can mount the thing.

I don't know but here, the unwritten rule is if the vehicle is carbureted and does not have a computer, the thermostat can come off. Same applies to the heating system; remove it. I have done this for years and so far I haven't have any problems. All 6 cylinders work, no overheat. Our environment temperature is 80-80 degrees all year around.

 

[jvazquez53]

While fixing my truck overheating problem, my wife's van developed a similar problem. Hers was easy to pinpoint, or at least I believed I knew what the problem was. I thought that the thermostat stuck in the closed position, so far I was on the right track. Actually while it stuck close, the pressure build up made the thermostat blew up inside the housing. The picture shows what I found it inside the van's thermo housing. After this happened, overheating was gone water was flowing freely, I replaced the thermostat and now hopefully I will not have any more exploding thermostats.

PS Overheating in the FJ is gone, running thermostatless.