theexbrit Posted October 3, 2012 Share Posted October 3, 2012 Hi all, just got back from a couple of trips & my engine was close to overheating on several occasions. It's been very hot here in So Cal, 100+ on these trips, but still shouldn't get that hot under the hood. When I'm driving at road speed (anything 30mph or above) the truck is fine, it just gets really hot when going slow uphill. I've had to turn the heater on & that helped it stay below boiling but made it a little "uncomfortable" in the truck :laugh: It has a new water pump (about 6 months old), new radiator (it was overheating before the new rad), electric fans (which saved the day on each over heat occasion) & correct mix of water/anti freeze. I'm wondering if a high capacity water pump is a good investment as it seems that it only gets really hot when it's under load. Link to comment Share on other sites More sharing options...
MAXPATH Posted October 3, 2012 Share Posted October 3, 2012 You didnt say anything about your Thermostat. When was the last time you replaced it, could be sticking a little. Link to comment Share on other sites More sharing options...
Towncivilian Posted October 3, 2012 Share Posted October 3, 2012 Did you reuse the old rad cap or use a new one? Link to comment Share on other sites More sharing options...
XPLORx4 Posted October 3, 2012 Share Posted October 3, 2012 New or old fan clutch? Link to comment Share on other sites More sharing options...
theexbrit Posted October 3, 2012 Author Share Posted October 3, 2012 Sorry, new thermostat (180f open) about 6 months ago, new 13lbs rad cap, no fan clutch (electric fans that come on at 190f), heater blows hot. Link to comment Share on other sites More sharing options...
Towncivilian Posted October 3, 2012 Share Posted October 3, 2012 What brand thermostat & radiator cap? Did you test the thermostat in a pot of boiling water before installation? Link to comment Share on other sites More sharing options...
XPLORx4 Posted October 3, 2012 Share Posted October 3, 2012 (edited) Do your fans cover all of the radiator, and are they shrouded? Did the fans keep the engine cool last summer? Edited October 3, 2012 by XPLORx4 Link to comment Share on other sites More sharing options...
theexbrit Posted October 3, 2012 Author Share Posted October 3, 2012 Stant rad cap & thermostat, no I didn't test it first. My bad. It does take quite a while to warm up & the top of the rad & top hose gets to about 160f when warmed up. The fans cover the whole rad width wise & I adapted the stock shroud to fit the fans. The electric fans were on pretty much all the time in the desert & stopped it from boiling over, although I did have to stop once to let it cool down. I'll get a pic of the rad shroud & fans if you want. Link to comment Share on other sites More sharing options...
Trogdor636 Posted October 3, 2012 Share Posted October 3, 2012 How's the coolant look? Is it really dirty/rusty? Link to comment Share on other sites More sharing options...
XPLORx4 Posted October 3, 2012 Share Posted October 3, 2012 Did the fans work at slow speed previously when it was 100°F+ out, or is this the first time the fans have been used in these conditions? It is possible that the fans cannot pull enough air through the radiator on their own, when there is an insufficient ram-air effect from driving fast. 1 Link to comment Share on other sites More sharing options...
devonianwalk Posted October 3, 2012 Share Posted October 3, 2012 Did the fans work at slow speed previously when it was 100°F+ out, or is this the first time the fans have been used in these conditions? It is possible that the fans cannot pull enough air through the radiator on their own, when there is an insufficient ram-air effect from driving fast. x2 .. Exactly what I was thinking. Link to comment Share on other sites More sharing options...
XPLORx4 Posted October 4, 2012 Share Posted October 4, 2012 Did the fans work at slow speed previously when it was 100°F+ out, or is this the first time the fans have been used in these conditions? It is possible that the fans cannot pull enough air through the radiator on their own, when there is an insufficient ram-air effect from driving fast. BTW, when I go off-roading (4LO, 1st gear, ~6000ft elevation, ambient temp > 85°F, A/C on high), the engine often starts to run towards the upper range of "normal" (up to 225°F, monitored by a Scan-Gauge II), even with the stock belt-driven fan, because at idle the fan doesn't pull enough CFM through the radiator. In 4LO, the engine has to do a lot of work climbing up steep terrain, but speeds are typically under 10mph, and the engine RPM is also usually not very fast. If I shift to N and rev the engine to ~3000rpm, the fan makes all sorts of crazy loud noise and the temperature starts to drop. I'm pretty sure the stock fan pulls a ton more CFM through the radiator when the clutch is fully engaged than any electric fan could. I am not sure how cool things would be in 100°F+ temperatures. When I have time, I may install a 10-12" aux. electric "pusher" fan in front of the A/C condenser to help keep air moving at low speeds to compensate. Link to comment Share on other sites More sharing options...
Tungsten Posted October 4, 2012 Share Posted October 4, 2012 I'm leaning toward the electrical fans not providing enough air flow. You can also try ditching some of the plastic cover junk inside the engine bay. Link to comment Share on other sites More sharing options...
theexbrit Posted October 4, 2012 Author Share Posted October 4, 2012 The coolant is clean, I changed it when I changed the radiator. I never ran it in these temps with the stock fan so I don't have anything to compare. The fans are supposed to pull 2,500cfm I think, I'll have to dig out the specs. They seem to pull a ton of air through & they stopped it from overheating a few times. I'm wondering if an aftermarket tranny cooler would help or maybe an oil cooler. Link to comment Share on other sites More sharing options...
XPLORx4 Posted October 4, 2012 Share Posted October 4, 2012 I'm wondering if an aftermarket tranny cooler would help or maybe an oil cooler. The oil filter location on the VG33 R50 makes it impossible to fit an oil cooler sandwich adapter, so that's not an option. A tranny cooler will help keep the AT fluid cooler, but won't have much effect on the engine temperature. Link to comment Share on other sites More sharing options...
fixinto Posted October 27, 2012 Share Posted October 27, 2012 The oil filter location on the VG33 R50 makes it impossible to fit an oil cooler sandwich adapter, so that's not an option. A tranny cooler will help keep the AT fluid cooler, but won't have much effect on the engine temperature. Oil filter relocation kit is for the win!! =) Link to comment Share on other sites More sharing options...
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