New engine, High coolant temps on scangauge
#41
09-18-2018, 06:56 PM
Last winter I rebuilt my 2003 with a 4.0 engine. I also had close to or boil-over issues. with temps ranging up to 217F. I changed everything possible (not the worst procedure during a major repair event) it turned out that bleeding system was the really the issue.
I raised the coolant tank above the engine to get the air out and that helped. However, driving the front end up on a snow bank (a curb may be enough) and bleeding the system made the difference. A buddy of mine who works on snow machines says they have to do it all the time to SKIDO's or they overheat.
Today the truck runs in traffic at 186-ish and sitting for a long time about 190-204. I've never heard the fan come on since.
Vapor lock is real.
I raised the coolant tank above the engine to get the air out and that helped. However, driving the front end up on a snow bank (a curb may be enough) and bleeding the system made the difference. A buddy of mine who works on snow machines says they have to do it all the time to SKIDO's or they overheat.
Today the truck runs in traffic at 186-ish and sitting for a long time about 190-204. I've never heard the fan come on since.
Vapor lock is real.
#43
09-18-2018, 10:07 PM
You don't need to raise the tank again. Just open the bleed screw and see if there is any room for even an ounce of coolant. When cold. Uphill parking is optional but parking nose up is what is being referenced here. Raising the reservoir is only for the first step of bleeding, as described in RAVE... the next step is chasing out the remaining air bubbles... the bleeder hole is the highest spot. if you park facing uphill it is even higher, let things settle overnight or longer and simply open the bleeder screw, inspect and add coolant right into the bleed screw hole until it will hold no more... Replace brass screw in hole... Drive your normal routine... Repeat the next morning/day until it is obvious you no longer have to top it up. No disturbing the reservoir at this point. No getting it up to temp and opening anything. Do this only when the engine is STONE COLD and repeat when it is again STONE COLD.
Last edited by Dave03S; 09-18-2018 at 10:10 PM.
#44
09-18-2018, 10:31 PM
You don't need to raise the tank again. Just open the bleed screw and see if there is any room for even an ounce of coolant. When cold. Uphill parking is optional but parking nose up is what is being referenced here. Raising the reservoir is only for the first step of bleeding, as described in RAVE... the next step is chasing out the remaining air bubbles... the bleeder hole is the highest spot. if you park facing uphill it is even higher, let things settle overnight or longer and simply open the bleeder screw, inspect and add coolant right into the bleed screw hole until it will hold no more... Replace brass screw in hole... Drive your normal routine... Repeat the next morning/day until it is obvious you no longer have to top it up. No disturbing the reservoir at this point. No getting it up to temp and opening anything. Do this only when the engine is STONE COLD and repeat when it is again STONE COLD.
#45
09-19-2018, 02:50 AM
Camel Trophy
#46
09-19-2018, 09:36 AM
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The Deputy (09-20-2018)
#47
09-26-2018, 12:48 PM
Stock thermostat:
65mph: 216f
Idle: 220f-224f
(after initial bleed)
65mph: 198f
Idle: 200-207f
(after multi-morning cold bleed)
65mph: 192f
Idle: 198-204f
I am going to also try the following thermostats and will report back:
1. Discovery Soft Spring 82C 180F Thermostat PEL500110
2.https://www.lucky8llc.com/collection...emp-thermostat
Maybe these are the same thing, but we will see.
#48
09-26-2018, 01:35 PM
TReK
#49
09-26-2018, 02:30 PM
Super Moderator
#50
09-26-2018, 04:03 PM
Sounds good. Do you think that 204 is just a bit high at idle? I have seen others posts about low 190s at idle. Do you think I should replace my fan and clutch assembly? Thanks!