Community Forums

vogey · 08-10-2018, 10:08 PM

after a hellish 48 hours getting the rex home (bought a bigger inline pump, drove 150 miles to rv, installed it, worked just long enough to move it too end of driveway, were pump fried. so i ran to parts store, bought the in tank pump, spent hours droppin tank (finished at midnight to find the part store sold me wrong pump, had to spend night in rv no bedding no pillows no clean clothes nothing) take pump back with original have to order but there same day) get new pump in. runs great. hook up toad (99 jeep cherokee) and pass front caliper stuck blowin smoke. crimp off line get down road the temp gauge will stay at the m in normal all day get on the highway and it goes up to a..... then l n creeps past pull over let it idle and it goes back down to m... on highway again samething. no jeep it will go pretty far on a n creep to l, then driver front caliper stuck. i always stopped b4 it hit red and it never boiled. antifreeze looks fresh and rad looks new. what can i do to drop the temp, every 460 ive ever had ran on the n. even usin same rad the 351w used b4 460. only time guage ever moved was when it was over heating

**JohnRR** · 08-11-2018, 01:08 AM

So many possibilities one that comes to mind is does it have a fan shroud?

hoakken · 08-11-2018, 01:34 AM

Lower radiator hose collapsing at speed ? Repaired a coach on a gm chassis with big block with what seems to be similar to what you are having. Customer had replaced water pump, radiator cleaned, fan clutch with no success . Hose was missing a spring like coil that prevents hose collapse .

vogey · 08-11-2018, 06:51 AM

it does have fan shroud, i had my wife crawl under while i pushed gas in park, (no tach but by ear had to have been spinnin 3k) she said hose wasnt collapsing. motor runs great, has good power, and seems to be getting pretty good mpg. the rv has basically been unused for 3 years, he started it and moved it now n then. but literally never slept in the rv. just took it on a couple day trips to the lake by sounds of it. i kinda suspect the thermostat though it cooling itself back down idling throws me off the thermostat idea. the plan for now is pop the center outta the stat. and get a aftermarket temp gauge (weres a good place to mount temp sensor on a efi 460, the ridiculously small dog house opening dont leave much for "exploring") everything about were the needle sits is wrong to me. never seen a fords needle sit straight up in the middle of the gauge at idle/operating temp and never really seen them move once its warmed up

56safari · 08-11-2018, 09:22 AM

Lot of options for overheating at highway speed. In the old days, a lean mixture would be a suspect, but with EFI that shouldn't be an issue unless there is a vacuum leak somewhere. More likely is a partially clogged radiator, external junk clogging up the radiator fins, air flowing around the radiator and not through it,lower rad hose partially collapsing or a thermostat not fully opening. Your guess about the thermostat is where I would start after your sure the radiator fins are clean and there there is nowhere for air to go around rather than through the radiator. A thermostat stuck partially open would be able to keep the temp down at low speeds but not enough flow to keep things cool at highway speeds.

Good luck and welcome to Rexhall family!

vogey · 08-12-2018, 12:24 AM

gonna pop the center outta the stat, see if that makes a diff, the rad looks new nice clean straight fins. if it dont help im flushing the rad, on that note.. how much pressure can the rad take? i wanna get some "flush" run it drain it, do 2nd flush with water then take my cheeta and fire it into lower hose to blast anything in there out backwards. have any of you capped off the little recirculating hose that goes to pump? im told hot rodders do it to run cooler

Dutch Star Don · 08-12-2018, 03:38 AM

I'm not sure what year they stopped installing converters on the exhaust. My 1991 had one still. If it does have a converter, they can fail and close off the exhaust once you get moving and cause overheating. At lower speeds they're not an issue.

vogey · 08-12-2018, 02:52 PM

dutch star, no converter. the thought had crossed my mind of plugged exhaust. though i figured had that been the case, it would have ran poorly or eventually smell burning (nuts, sticks, ect what ever something might have packed in the pipe) but none if that happened