Temp Gauge - Overheating? (1 Viewer)

[LCBC]

The other day i noticed my temp gauge getting close to red lining. Pulled over, felt the rad (wasn't too hot), and waited a few minutes. Fired her up (85 BJ 60 - 3b) and operating temp was normal. I was thinking my thermostat was going, so i replaced it. I drove around and the operating temp was normal, then it shot up again, then dropped??? Anyone had any issues like this? Could it be a faulty sensor?

 

[Gold Boy]

possible faulty gauge

is there coolant in your oil. are you loosing coolant or is there any bubbles in your coolant coming into the overflow tank when your engine is running. if yes could be a cracked head gasket or a cracked head.

 

[LCBC]

haven't noticed any bubbles in the over flow or coolant in the oil. I have lost some coolant, which i think was leaking out from the therm housing.

 

[eleblanc]

The other day i noticed my temp gauge getting close to red lining. Pulled over, felt the rad (wasn't too hot), and waited a few minutes. Fired her up (85 BJ 60 - 3b) and operating temp was normal. I was thinking my thermostat was going, so i replaced it. I drove around and the operating temp was normal, then it shot up again, then dropped??? Anyone had any issues like this? Could it be a faulty sensor?

Install a second gauge, autometer mechanical type. There should be a port not being use in the thermostats housing. I'm not saying your current gauge is wrong, but you will know for sure with a second gauge.

 

[David*BJ70]

When the temperature rises, the gauge climbs. Then the thermostat open, the temperature drop in the gauge down because the coolant in the rad is colder. Then, the thermostat close. Then open, .... It is very clear when this happens with a mech temp gauge. It not supposed to hapen «more» than 2 or 3 times (usualy when it cold outside).

If this product often and exaggerated ... there is a problem. Ait in system, craked head, ...

 

[TAIT]

i just had the identical thing start happening to my truck today (86 HJ60)!!! Only, when the temp. gauge spiked, so did the fuel gauge (told me i had over a full tank, when i knew i was only half tank)> What the fuh!!??

 

[rchalmers3]

My 86 HJ60 also does this occasionally. (fuel and temp gauges move towards max deflection). Each time this happens I first have to calm myself. Then I pull over and cycle the key. It seems to be the solution the gauges need.
I suspect the charging system output, or some relay in the gauge circuit going wonky. I think the problem will be found where a low resistance or high current flow condition is happening. Since it has only occurred a few times, I'm not actively searching for the source.

Rick

 

[TAIT]

My 86 HJ60 also does this occasionally. (fuel and temp gauges move towards max deflection). Each time this happens I first have to calm myself. Then I pull over and cycle the key. It seems to be the solution the gauges need.
I suspect the charging system output, or some relay in the gauge circuit going wonky. I think the problem will be found where a low resistance or high current flow condition is happening. Since it has only occurred a few times, I'm not actively searching for the source.

Rick

hmmm...interesting. i noticed that when i pulled over - and YES! i DID panic and had to calm myself! - and turned the truck off, it was fine when i started it back up. but the last few times on a longer drive back to Revelstoke from Golden it would shoot right back up after driving for another 2 minutes. turning my fan on 'full blast' there was only cool air blowing out the vents.
i have to say, i have read through some other posts where a few people mentioned that it was a blown head gasket...NOW i'm paranoid!

 

[AJAEbj42]

hmmm...interesting. i noticed that when i pulled over - and YES! i DID panic and had to calm myself! - and turned the truck off, it was fine when i started it back up. but the last few times on a longer drive back to Revelstoke from Golden it would shoot right back up after driving for another 2 minutes. turning my fan on 'full blast' there was only cool air blowing out the vents.
i have to say, i have read through some other posts where a few people mentioned that it was a blown head gasket...NOW i'm paranoid!

My 3b 1981 BJ42 does this as well, both the temperature and fuel gauges go to max. I'm pretty sure mine is a grounding problem, but like others have observed. Turn the engine off, and re-start and the gauges work fine. Although not always (one time they spiked right away, but I didn't worry about it because I was sure the engine wasn't over heating). Mine seam to spike when I'm wheeling off road (actually happened today), so not sure if it's the bumpy road or what.

 

[Laughingjackal]

I have the same problem with my 86 HJ60.It only happens occasionally. As others mentioned when I pull over and and check the rad and hoses everything is normal. It starts back up and the temp goes back to normal. I was told it might be the sending unit but haven't worked out the bug yet. At least it isn't really pegged out as the guage indicates.

 

[Frode S]

"Instrument peaking", where the temp. and fuel gauges goes to the top, is a common problem in HJ60. Has happened to me several times, mostly in hot weather. Have also heard it can happen in 70 series, and, to be sure, it can happen in the BJ 60 as well.

The issue has no relation to the mesured parameters (engine temp. and fuel). As far as I know, the issue is caused by a faulty resistor in the instrument cluster. When it gets to hot, the resistance changes, affecting instrumantation as described.

So, nothing really wrong, but irritating none the less...