Archived Temp gauge jumping around.

[BBeckmann]

Okay everyone, maybe u can help me. Just got done redoing head after old gasket blew at 235,000. #@$%! But ever since temp. gauge will show a slow warm up then after gettin on the road it'll go up 2 bout 190 then start dropping down 2 160ish maybe 150 then if i continue 2 watch it it will start doin the same thing. Very lil oil residue in top of radiator Thinkin maybe thermostat r sensor? tried taking sensor off n sprayed a lil wd-40 in then reconected but still does it. Also, how do get all oil out of coolant system? Had Radiator boiled at shop, blew water thru all that i could n flushed several times then ran with plain water n cap full of dawn several times. R is the lil bit of oil no big deal? Thanks alot. O, and if it helps 2 know '97 12valve 5spd

 

[HCannon]

It didnt do that before the head gasket? I have three (94 and two 98s) and they all do that. I put a new thermostat and new fan clutch on one and if anything, it made it worse. It may be the nature of them, I just dont pay it any attention now and drive them. If you find the answer please post it.

 

[RHestand]

I have to ask this question. Since I've read so many posts about the temp. gauge fluctuations, and my 98 12V doesn't do it, is there something wrong with mine? I also had an 06 2500, and it didn't do it either.
Under normal driving conditions, both of these trucks would reach operating temp. (170*/12V and 190*CR) in about 10 miles ( a little further in 0* temps. ), then stay right there. My 06 would sometimes go up to 200* on a hot day, pulling a steep hill hauling my 31' Air Stream. My 98 reaches operating temp. , and never moves from there.
What do you guys think, is this unusual?
TIA, Ray

 

[BBeckmann]

No it always went to around 160 and stayed there unless pulling a tralier then it wuz around 180 and never moved up and down all the time and before the head gasket i had 2 replace the fan clutch cause the old one was locked in and killin my mileage. Mite try a couple things and c what happens. And as 2 ur question RHestand- since my trk didn't do it 4 235,000 miles and my brothers '92 with 160,000 on it and dads'01 with 150,000 and a friends '02 with 136,000 doesn't do it i guess ur trks are normal.

 

[HCannon]

Wish mind didnt do it, couldnt be good on anything with temp. jumping around like it does. When I changed the fan clutch and thermostate I got them from a Dodge Dealer.

Ray, bet yours is the way it is suppose to be. Something I am over looking here I would think. I really quit thanking about it till I read your post. All of mind have a lot of miles on them, 275K on one-225K on one and 190K on the other.

 

[1995Dodge...]

Here's a little background on the Ford Powerstroke thermostat...



203* IS THE TEMPERATURE THAT NAVISTAR DESIGNED YOUR TRUCK TO RUN AT. THIS IS THE THERMOSTAT THAT WAS AND STILL SHOULD BE IN EVERY POWERSTROKE 7. 3L. Until 1996, all 7. 3L Powerstrokes that were manufactured used an International water pump and an International short stem 203o thermostat . In 1996, Ford changed to a lower degree 195o thermstostat. They changed water pump designs at this time as well. The new pumps required the new long stem 195o thermostat in place of the short stem to properly seat the bypass disk. All 1996-2003 Ford PSDs now come equipped with a long stem 195o thermostat. Recently the factory replacement thermostat available at the parts counter changed to 192o. Our Dieselsite 203* uses the correctly sized t-stat with the correct temperature spring so that we no longer have to give up the benefits of running our vehicles where they were meant to run.



Engine temp info... hmmmmmmmmmm...