So my overheating issue started when I changed from clutch fan to electric fan on my 86 Mazda B2000. I drained the coolant from the radiator and installed the coolant fan switch in the bottom of the rad. Before that, the temp gauge would show 1/3 even on the hot summer days. After the e-fan swap, it would go past 2/3 and sometimes it would almost reach the letter "H". So I switched back to the clutch fan, thinking that the electric fan didn't provide sufficient cooling, but the problem persisted. So I drained the coolant and bled it in numerous ways: I parked the car on an incline, with the heater on max and radiator cap off and just letting the bubbles out. I even rocked the truck from side to side and jumped up and down in the back of the pickup bed to let out all the air that may have been in the system, but to no avail. So I thought that maybe somehow my water pump went out, so I replaced the water pump, thermostat, coolant sensor, and rad cap but still the gauge would show high temp, so I removed it and ran water from a garden hose through it and it seems to flow fine. Ah temp. I even changed the thermostat twice because I thought maybe it's faulty. I also changed the upper radiator hose because it was swelling and looked like it was about to burst (that didn't happen before the fan swap). So then I thought that maybe my radiator became clogged, when the truck reaches high temp and the thermostat opens I can feel the lower radiator hose is lukewarm to the touch, compared to the upper rad hose that's very hot, so it seems that the fan is cooling the radiator sufficiently? My truck doesn't smoke, so I don't think the coolant is getting into the combustion chamber and it feels fine driving and I don't feel any power loss or anything. The only indication of overheating is the temperature gauge next to the speedometer. I have a cheapo laser thermometer and can check the temperature of the different engine parts while it's hot, but I don't have anything to compare it to. Part of me says that I should just drive the truck till it dies and part of me tells me to fix it. The truck has an original 116k miles on it. I converted the truck from carb to EFI using all Mazda parts from B2200 and it's quite a nice ride. I'm out of ideas on what to do. Any advice would be appreciated. Thank you.

 

I'd they no it's a dirty radiator clogged. Maybe try some vinegar.or clr cleaner. Then flush real good. The best would be to replace with an automatic transmission radiator with two rows.and an oem thermostat that's two valves.i had some trouble and the combination of both new radiator and thermostat made is run perfect. Especially not taking forever to heat up.

 

I would install a new radiator, and make sure you have all the fan shrouding, important. I also have the "automatic" 2-row radiator in my own 1988 B2200 even though mine is a 5-speed truck. I'm in Arizona, Cab Plus, AC on most of the time, and never gets to half way up on the gauge even in 115F temperatures.

So I'd go with Jerry C's recommendation. I only replaced my radiator when mine started running hot, and a chemical flush (done by me) didn't help. If you do overheat the engine, you risk a head gasket failure and cylinder head warping.

 

Thanks for your advice. Where would be the best place to get a two-row radiator? Would you still think I should run the electric fan or keep it stock? Thanks!

 

If your after mpg or power leave the electric but stock is the best. I got my radiator from eBay I make sure to pay the best price not necessarily the cheapest quality part but best price. From csf radiator. I also replaced all the hoses I did have to drive around then add more coolant I hope you figure out the issue

I got mine on ebay like a month ago so listing should be fresh

This is the the thermostat I got.ive posted elsewhere an people tell me to just use stant 180 one but it takes way too long to heat up with it. This one take five min to heat up and still keeps temp like barely over low temp line on coolant guage.

 

Also I've no experience with them but I've read the only sure way to power an e fan correctly is using a universal fan controller. I've also heard some volvo have a stand alone unit you could pull from junkyard. But like I said Its armchair knowledge lol not first hand. I kinda like to smoothness the fan and shroud adds to the way the engine revs

 

Liland Radiator LIL865AA All-aluminum 2-row radiator. Google, RockAuto....
I have an all-aluminum 2-row radiator in my B2200, Arizona. Mounted right in, I did need to drill holes for mounting the plastic fan shroud in my 5-speed, apparently the automatics had slightly-different fan shrouds. The two ports at the bottom intended for ATF are simply not used.

 

Cusser and Jerry C, thank you for your replies. I will start by getting a new 2-row radiator. I found CSF rad at Summit Racing for around $160, I believe they offer free shipping. I had a new Stant 180 thermostat in my Mazda but I thought it was faulty, so installed a Murray thermostat from Oreilly instead, It seems to work ok. If it still overheating with the new radiator I will try the thermostat you suggested.

I used an electric 2-speed fan from Volvo S70 with all the relays and fuses it came with, and a 180F degree fan switch, and it was almost plug-and-play on Mazda stock radiator after I trimmed the shroud a little bit and flipped it upside down. I know most people go with Ford Taurus fan for their e fan swaps. I also have a 90 amp alternator instead of a factory 55 amp.

 

My own experience:
Arizona desert, we've had high recorded temperatures up to 118F the past year, over 110F is not uncommon in the summer (and that's measured in the shade)
2-row all-aluminum radiator since 2011, Hayden replacement fan clutch (important for cooling in the city/idling), 192/195F Stant thermostat, Cab Plus (heavier) truck, about 150 pounds of stuff in cross-bed tool box, 15-inch wheels/tires, AC used pretty much full time, heater hooked up and works great. My truck does NOT overheat, even on highway uphills at 75 mph, the temperature gauge NEVER goes above 40% up on the gauge.

My factory radiator did not leak, but about 2010 would run real hot on highway travels but never had an actual overheat situation, but I did have to make an emergency summer afternoon trip and drove (yes, in Arizona summer) with heat on full blast to get there. Running hot on highway typically is an indicator of a radiator that needs chemical cleaning or replacement, if coolant system is otherwise OK.

 

Your welcome dude it's been a learning experience for me. I tried holding out for the aluminum radiator to be back in stock but I figure the brass one can be repaired on the road.i plan on traveling in my truck.