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Jason, he's saying it doesn't matter what temp the thermostat opens; the temps would be in that range regardless of thermostat since both open at a lower temperature. As I'm sure you know, the rating for the thermostat just determines when it opens, not the temperature of the coolant after it is opened.
The things that make coolant cool are the radiator, fan, and the water pump (and absence of air in the coolant lines or a closed thermostat). If your temps are high after the thermostat opens, those are your culprits.
I'm still not sure your temps are high, though. That sensor ...
I installed a low temp thermostat (LAND ROVER DISCOVERY 2 1999-2004 THERMOSTAT AND HOUSING SOFT 82C / 180 PART: PEL500110) and the coolant temps are dramatically reduced.
Cruising at 45: 198f
Stopped at stoplight after traveling at speed: 207f
Idle after a few min: 202f
I am much relieved to be running these temps and now feel comfortable putting some break in miles on this new engine and addressing any other little issues.
Are we comfortable with these temps or should I explore other options to reduce temps more?
I will update my New Engine thread, but I am happy to report that I did a 50 mile oil change with Rotella T4 15w-40 and Comp Cams break in additive. Boy, that stuff is pretty thick! Also I upgraded to the brass bleed screw. Looks cherry.
New brass bleed screw High ZDDP conventional oil and additive for more break in miles.
Those temps are perfect. The only way, IMO to get them lower is inline thermostat mod, but they are just fine.
I have gone to Castrol 10w-40 and zddp additive, because of living in the Midwest for the cold weather. In Cali I am guessing you are able to run the T4 all year. That is an excellent choice.
Let is know how she is running! Jealous of those gas flowed heads.
PHEW!! Thanks guys, such a relief to have everything working as expected. Thanks again for brainstorming and talking it though. Yeah it is running really nice so far. I haven't been able to really ring it out or anything since I am still breaking it in but it seems like she has some power.
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.
09-17-2018, 08:19 PM
