mmtoy1 Posted August 21, 2009 Share Posted August 21, 2009 I have a 87 sunrader with a 22 re 4 cyl when I operate it at highway speeds with the ac on the temp gauge goes to the top white line. It is on the line any more and I would be in the overheat zone. But when I slow down or operate at low speeds the temp is in the middle of the gauge. Is this normal or is there a problem or should I just turn off the ac. Yesterday I did that and put on the heat and the temp went to the middle. I am planning a long trip and would like to use the ac any suggestions or is this ok. mm Quote Link to comment Share on other sites More sharing options...
Maineah Posted August 21, 2009 Share Posted August 21, 2009 You might check the fan clutch mine is is pretty noisy at high way speed you can defiantly hear it. If it is turning free it will get hot with the A/C on. Quote Link to comment Share on other sites More sharing options...
WME Posted August 22, 2009 Share Posted August 22, 2009 Start with cheap and work your way up. Clean radiator and A/C condenser, check fan clutch, check fan belt tension, check hoses for firmness, change thermostat. After that its a water pump, then a radiator replace/repair Quote Link to comment Share on other sites More sharing options...
mmtoy1 Posted August 22, 2009 Author Share Posted August 22, 2009 I have anti freeze in it, the belts are new , the radiator is clean and so is the ac condensor, the hoses are new also did them and the belts togther about 2000 miles ago. I dont know how to check the fan clutch can someone explain looking at the fan it looks ok is there somthing I can do to test it. As for the thermostat , the fact that it is not overheating but running hot with ac on only would that not mean the thermostat was ok, if not I will change it as it is the easiest change of the whole system. Is there a way to test the water pump as I said the condition is only with ac on at highway speeds is there a test to see if thats it. Also I read that the mixture of anti freeze to water could cause this if not enough water is mixed in, is this true, I have never had this happen to me in any car and I have run all anti freeze in the past. But I do have more antifreeze that water in my toy. thanks for the help mm Quote Link to comment Share on other sites More sharing options...
Kathy Laurin Posted August 22, 2009 Share Posted August 22, 2009 I have an 88 18" same engine. My AC was a Toyota add on. I had the same problem at high speed or with the engine under heavy load (climbing steep passes). I did not have problems overheating but the needle would be so close to the red zone it certainly caused alot of worry. I have done all of WME's suggestions as part of ongoing care/maintenace/repair. I did replace my radiator with the largest core that would fit, and replaced the water pump at the same time. Also changed the thermostat. The AC has been serviced as well and the engine is well tuned and cared for. This helped but did not eliminate the problem. I still take precautions. I do not run the AC when climbing steep hills nor do I use it at idling speeds for any extended time. High altitude is also hard. If I stay at 55-60 mph it is fine. If I drive any faster the needle on the temp gage rises to the top pretty fast. I have not had any problems overheating but I do watch that temp gage pretty close. Quote Link to comment Share on other sites More sharing options...
Maineah Posted August 22, 2009 Share Posted August 22, 2009 What WRE is referring to is the inside of the radiator, the tubes, over the years they can get clogged with yuck and that reduces the cooling capacity of the radiator. As far as your fan clutch when it is warm it should move a lot of air, warm the engine up and rev the engine a bit you should hear the fan. When it is cool the fan blades should have a bit of resistance with the engine off turn the blades by hand a see if it gives you a bit of resistance if it turns real easy or spins free the cultch is probably toast. As far as anti freeze 50% is about tops pure anti freeze is not real good for your engine but it should not make it run hot. Quote Link to comment Share on other sites More sharing options...
Tom W Posted August 22, 2009 Share Posted August 22, 2009 Used to work with large compressors stationary and portables when we had heating problems and called for help one of the first things they asked was how much antifreeze,too much doesn't cool as good as plan water but is needed for freeze protection and corrosion. Fan clutch's are hard to check on mine I did everything rodded the radiator which when checked was ok did it anyway + thermostat and fan Clutch I think it was the fan that did the trick. I try'ed a photo tack on the fan clutch not very positive results. With all this done with ac on 100deg day pulling for all its worth its barely over half way on gauge. Quote Link to comment Share on other sites More sharing options...
WME Posted August 23, 2009 Share Posted August 23, 2009 OK I've got a mild hot rod engine in mine. I installed a 3 row radiator and a big external automatic transmission cooler. The factory transmission puts a lot of heat into the radiator. I regularly pull a 750lb trailer over 10,000 ft passes in the summer with the needle staying around the 1/2 mark, the trannie temp is just under 210. On level ground It runs more than 1/3 but less than 1/2 mark, with a trannie temp of 190. I have a 195 stat. Quote Link to comment Share on other sites More sharing options...
mmtoy1 Posted August 23, 2009 Author Share Posted August 23, 2009 Well with the motor off I turned the fan and it turns with minor resistiance. it is just a lottle tight, I am not sure if its good or not but when you run the motor it is turning does that mean its of. The fan runs as soon as you start the engine and continues to run?, I am going to change the anti freeze tomorrow. thanks mm Quote Link to comment Share on other sites More sharing options...
Bodybagger Posted August 24, 2009 Share Posted August 24, 2009 If it was bad, it would spin, wobble, and sound like a worn out roller skate. Definitely change your thermostat! Flush your cooling system with prestone or peak radiator flush. It contains citric acid and dissolves a bit of the gunk out of the radiator. But don't be surprised if it starts leaking afterward. It's old enough that it might just do that. The part where you said that using the heater brings down the temperature leads me to believe that the thermostat is not opening completely. Change it and report your results... Quote Link to comment Share on other sites More sharing options...
McShank Posted August 26, 2009 Share Posted August 26, 2009 I live in the desert southwest where the temps are always 100+ during summer and climbing steep highway grades with the ac on always sends the temp guage higher than I like to see it. One simple thing I did was to attach water spray nozzles (like you use with drip irrigation) to the inside of the front grill so I can shower the radiator and trans cooler as I drive. Create my own rain storm. I use a windshield washer pump and draw from my water tank, running it in one minute intervals as I climb and the temp guage goes back to normal for about five minutes before starting to heat up again. Repeat as necessary. I only use about two quarts of water per minute and although I rarely have to use it the cost in time and material was minimal and the effect is great. Has anyone else done this? Seamus McShank Quote Link to comment Share on other sites More sharing options...
mmtoy1 Posted September 1, 2009 Author Share Posted September 1, 2009 Well I got to this during the weekend , I flushed out the system with one of those preston kits, I put in a new thermostat and new 50/50 antifreeze. I took it on the highway with the ac going full blast and the temp gauge never went over a quarter. The only thing is the outside temp has been a little cooler than it was last week but I think the problem is solved. Not sure which one it was but seemed like all three things had to be done at the same time and the cost was very little. Well next week I am taking the toy to montana so I am hoping all is ok. Thanks for the help to all. mm Quote Link to comment Share on other sites More sharing options...
nibs Posted September 1, 2009 Share Posted September 1, 2009 I have a sprayer on the rads on my bus, but there is a problem with it, over time minerals are deposited on the fins of the rad on the outside, further lowering the cooling efficiency. Quote Link to comment Share on other sites More sharing options...
turtle Posted September 2, 2009 Share Posted September 2, 2009 I remember back in the late 50's when I was young my parents would travel across the US on Route 66 to visit family (we lived in L.A. and the family was in Virginia). We carried a flax water bag and my dad would close the hood of his Buick Roadmaster on the rope that held it and it dangled in front of the radiator. Being flax it leaked and the air going over it kept the water inside cool to drink (and the evaporation cooled the engine). Quote Link to comment Share on other sites More sharing options...
mirage Posted February 23, 2010 Share Posted February 23, 2010 I have a 87 sunrader with a 22 re 4 cyl when I operate it at highway speeds with the ac on the temp gauge goes to the top white line. It is on the line any more and I would be in the overheat zone. But when I slow down or operate at low speeds the temp is in the middle of the gauge. Is this normal or is there a problem or should I just turn off the ac. Yesterday I did that and put on the heat and the temp went to the middle. I am planning a long trip and would like to use the ac any suggestions or is this ok. mm One thing that is important that you all missed is engine Timing. Working on Old ford Flatheads , they always had a heat problem. When you had the timing just right they cooled down. It's the same with any engine, even a lawnmower ! (Of course the flywheel key would have tobe broken) Get the timing right and you just might see the temps come down Quote Link to comment Share on other sites More sharing options...
Homer Posted February 24, 2010 Share Posted February 24, 2010 (edited) I'm new to the site with a 86 Sunland Express and live in NC. Sure are a lot of good info here. I have never heard of the spraying the radiator with water and that washer pump sounds like a great idea. It sure sounds logical. I haven't seen one of the water bags in years My uncles used to go to Calif. and Wash. from NC and that was a good way to have cool water. Also my aunts would wet towels and hang in front of air vents (before AC) to keep cool. I enjoy all the good info on this site and am learning a lot too.We have tent camped most of our lives and then in 2000 bought an Apache Ranger hardside popup and used it up until now. Then purchased the SLE in December. Am looking forward to the many adventures we will be making in it. 'Homer' Edited February 24, 2010 by Homer Quote Link to comment Share on other sites More sharing options...
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