Possiable bad thermostat or fan clutch or gauge, or pump?
#16
12-25-2016, 10:18 PM
Update.
Well I finally got time to change the thermostat.
My test track is a 5 mile stretch on the interstate were I can run 75mph. 2.5 miles of that is up a medium grade with a truck lane. The outside temperature today was 70f.
With the 195f Napa thermostat the base temperature was 195f and 205f at the top of the uphill grade.
With the Motorcraft 192f thermostat the base temperature is 192 and 198 on the same test track.
One differance is that with the NAPA 195f the temperature would steadily rise to 205 and hold there till I topped the hill.
With the Motorcraft 192f, the temperature would rise up to 198f then fall back down to 194f, then back up to 198f and back down to 194f. It did this 3 times while pulling the hill. Once over the top of the hill, the temperature fell back to 192 to 193.
I didn't have time to see how it did in city driving but will do that tomorrow.
Idling temperatures were 192f in park and 195f in drive.
I am thinking that with the stock dash gauge hooked back up, that I would never notice a 6 degree fluctuation.
I don't remember what I used on the thermostat housing bolts when i installed them last year (thought it was anti-seize) but I had to use a wrench on them all the way out to the end. Of course that bottom one on a 302, you cant get your fingers on it anyway.
A tip for getting that bottom bolt on the thermostat housing in far enough to get a wrench on it.
Well I finally got time to change the thermostat.
My test track is a 5 mile stretch on the interstate were I can run 75mph. 2.5 miles of that is up a medium grade with a truck lane. The outside temperature today was 70f.
With the 195f Napa thermostat the base temperature was 195f and 205f at the top of the uphill grade.
With the Motorcraft 192f thermostat the base temperature is 192 and 198 on the same test track.
One differance is that with the NAPA 195f the temperature would steadily rise to 205 and hold there till I topped the hill.
With the Motorcraft 192f, the temperature would rise up to 198f then fall back down to 194f, then back up to 198f and back down to 194f. It did this 3 times while pulling the hill. Once over the top of the hill, the temperature fell back to 192 to 193.
I didn't have time to see how it did in city driving but will do that tomorrow.
Idling temperatures were 192f in park and 195f in drive.
I am thinking that with the stock dash gauge hooked back up, that I would never notice a 6 degree fluctuation.
I don't remember what I used on the thermostat housing bolts when i installed them last year (thought it was anti-seize) but I had to use a wrench on them all the way out to the end. Of course that bottom one on a 302, you cant get your fingers on it anyway.
A tip for getting that bottom bolt on the thermostat housing in far enough to get a wrench on it.
#17
12-29-2016, 06:53 PM
update on city driving.
Hwy driving the temperature just bounces from 192 to 195 and back down depending on conditions...
City driving in a hilly area the temps bounce anywhere from 191 to 200f seems to hit 200 when cursing up hill at 35mph in 3rg gear then coming to a stop. I hear the fan clutch cut out around 25 or when it shifts to 3rd. If I remember it used to stay engaged will around 35 to 40mph.
Am thinking that the fan clutch is the next easiest part to change and has a life time warranty. NAPA said to just bring it in and they would swap it.
after that, perhaps water pump, perhaps the impeller is eroded .. I don't see much flow with the cap off.
Hwy driving the temperature just bounces from 192 to 195 and back down depending on conditions...
City driving in a hilly area the temps bounce anywhere from 191 to 200f seems to hit 200 when cursing up hill at 35mph in 3rg gear then coming to a stop. I hear the fan clutch cut out around 25 or when it shifts to 3rd. If I remember it used to stay engaged will around 35 to 40mph.
Am thinking that the fan clutch is the next easiest part to change and has a life time warranty. NAPA said to just bring it in and they would swap it.
after that, perhaps water pump, perhaps the impeller is eroded .. I don't see much flow with the cap off.
Thread
Thread Starter
Forum
Replies
Last Post
natewoz
1999 - 2003 7.3L Power Stroke Diesel
19
02-09-2008 11:36 PM
dbalfa
1994.5 - 1997 7.3L Power Stroke Diesel
4
11-01-2007 03:33 PM