My 88 D100 has a temp gauge that barely moves from C.

I drive it about 3 time per week...maybe 50 miles total weekly. I installed a new radiator 2 years ago and it runs fine but.....

My radiator cap is a 13 lb cap. When I remove tbe cap cold...there seems to always be a little overflow of radiator fluid...not much. So I put a 16 lb cap on tonight and let it run for 20 min. Temp gauge never moved off cold. When I look at my coolant...its clear green with no rust evidence, plus my top rad hose does get hot.

any ideas whats up with this?

Thanks for the help

 

What thermostat do you have in it?

 

I put in a stant lev-r-vent cap, 16 lb.

 

Thermostat, not cap.
My 87 read in the middle with a 190 or 195 in it but reads low with a 180.

 

I have a question about this also and sorry to steal the thread. I have a 88 D 100 with a 3.9 and temp gauge does not work. Had to put in a new radiator and t stat (190 i think). Should i put a new cap on?

 

ok...great. so is ut best to put a 180 thermostat in or 190

thanks

 

Back on this thread again! Temp guage on dash still doesn't move off of cold but maybe 2 marks. I have a 195 deg thermo in it that I replaced in November. Colant levels are fine and coolant is clean. I am wondering if the issue is in the senor on the engine.

Any ideas guys?

 

That's the first thing to check! Take off the the wire and ground it(touch it to engine ground)Look at the temp gauge, It should be all the way up. If it's not you have a gauge or wiring issue. If it does you found the problem(that is if the thermostat is working).

 

Bad gauge?

My fuel gauge only registers up to half full - makes me wonder if I can trust ANY of them.

 

Thanks for the info. Now how do I tell which sensor is the temp? My repair manual isn't clear on it