Dave Jenkins Posted May 20, 2007 Share Posted May 20, 2007 We just bought a 1990 Sunrader V6 3.0 96,000 miles that was just tuned up, new radiator and timing belt replaced. The engine is heating up to the red line on the temperature gauge when climbing a 7% grade with the outside temp being 75 degrees. To climb the hill I shifted down to second gear (auto trans) and was cruising at 40-45 mph. Does this seem like it's running to hot? Thanks Dave Quote Link to comment Share on other sites More sharing options...
keitholivier Posted May 21, 2007 Share Posted May 21, 2007 Dave How is your radiator, A/C condenser and oil cooler configured ? On my Dolphin, the oil cooler is at the front, followed by the condenser followed by the radiator. In my opinion, this is a very bad setup for high temperature operation. In the hottest weather, one will be running the AC and the tranny will be pumping out heat through the oil cooler. All of this heat raises the temperature of the air before it even reaches the radiator, thus the heat transfer from the radiator to the air is made innefective. To transfer heat, there needs to be a temperature differential. If the air hitting the front of the radiator is nearly as hot as the water in the radiator, there is no way you can cool the water down. Right now my AC is down, so that lightens the load. Furthermore, I am going to look for one of the long narrow oil coolers that can be mounted in the free airstream below the radiator. This way, both the radiator and oil cooler get air at ambient temperature. I also intend to bypass the oil to water heat exchanger at the bottom of the radiator (which is another way that heat gets from tranny fluid into the cooling water. Disadvantage is that at low temperature the transmission oil will not be heated by the cooling water, so will take somewhat longer to reach operating temperature. This is not a big factor for me, I don't use the Dolphin for commuting..... best of luck keith Quote Link to comment Share on other sites More sharing options...
Dave Jenkins Posted May 21, 2007 Author Share Posted May 21, 2007 (edited) Yes mine is the same! Does your temp gauge get as hot as the pict I uploaded above? How is your radiator, A/C condenser and oil cooler configured ? On my Dolphin, the oil cooler is at the front, followed by the condenser followed by the radiator. Edited May 21, 2007 by Dave Jenkins Quote Link to comment Share on other sites More sharing options...
nolan Posted May 21, 2007 Share Posted May 21, 2007 We just bought a 1990 Sunrader V6 3.0 96,000 miles that was just tuned up, new radiator and timing belt replaced. The engine is heating up to the red line on the temperature gauge when climbing a 7% grade with the outside temp being 75 degrees. To climb the hill I shifted down to second gear (auto trans) and was cruising at 40-45 mph. Does this seem like it's running to hot?Thanks Dave Personally I would say its running on the hot side from the gauge picture. Theres a number of possible answers, faulty gauge? sending unit? bad thermostat, fan clutch not working properly. You mentioned a new radiator, timing belt and tune up, did you have it done or was it done prior to you buying the rig? If prior to buying it might have been good maintenance or trying to fix or mask a problem that was already there. Timing could be set wrong during the tuneup, or worse case the timing belt was installed a tooth or so off, would still run but not as good, possible head gasket problem which the V6 is famous for. Is it losing water from the radiator slowly? puffing any white smoke? I would try to verify the actual water temperature compared to the gauge reading and proceed from there. Quote Link to comment Share on other sites More sharing options...
Tom W Posted May 21, 2007 Share Posted May 21, 2007 I have about the same thing in texas but temp is ok I did have the radiator roded replaced the fan chutch and just about everything infront,it was running a little hotter before doing all this,I kind of think it could have been the fan clutch. I've pulled grades 6% or more in 95 plus weather I Manually Shift down in 2nd gear at about 40- 45mph. the gauge a little over 1/2 under these conditions. Tom Quote Link to comment Share on other sites More sharing options...
turtle Posted May 21, 2007 Share Posted May 21, 2007 We just bought a 1990 Sunrader V6 3.0 96,000 miles that was just tuned up, new radiator and timing belt replaced. The engine is heating up to the red line on the temperature gauge when climbing a 7% grade with the outside temp being 75 degrees. To climb the hill I shifted down to second gear (auto trans) and was cruising at 40-45 mph. Does this seem like it's running to hot? Does the gauge go down if you open the heater valve? sliding the heat lever will engage the heater coil and add that additional circulation to the cooling system. I have never been a fan of hot/cold gauges. How hot is hot? When the gauge hits the red line are you getting coolant into the overflow bottle and past onto the ground? Quote Link to comment Share on other sites More sharing options...
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