Overheating problem wth my Ranger

[Russ79]

I have a 2011 model Ranger 800 XP that I have had in the shop twice in the last couple of years with overheating problems. Well it has reared it's ugly head again and about to make me lose my religion! Both times before I believe it was a relay issue. When it started losing power yesterday the temperature would bounce between 250 and 180. It was getting good air flow thru the radiator and was not boiling over. This is making me believe this is an electrical issue. I am getting pretty tired of dragging it to the shop about once a year and spending several hundred dollars for a recurring problem. Anybody else having similar problems?

[91cavgt]

I have a 2011 model Ranger 800 XP that I have had in the shop twice in the last couple of years with overheating problems. Well it has reared it's ugly head again and about to make me lose my religion! Both times before I believe it was a relay issue. When it started losing power yesterday the temperature would bounce between 250 and 180. It was getting good air flow thru the radiator and was not boiling over. This is making me believe this is an electrical issue. I am getting pretty tired of dragging it to the shop about once a year and spending several hundred dollars for a recurring problem. Anybody else having similar problems?

Is the cooling fan turning on at all? When the temp does bounce between 250 and 180, how quick does it go from one to the other? Is that model fuel injected of does it have a carb? How do you know it has good air flow through the radiator?


I know it's a lot of questions but this will help to narrow things down.

[Russ79]

The fan is coming on. And when I say the temperature is bouncing, it will read 235 and then say 180, then up to say 254 and then down to 195, then up to 218 and then maybe up to 235 then back down to 191. It's like it can't decide what the temperature is. I am sure that something in the system says it is at a certain temperature, like around 235, it tells the engine to start shutting down. I have had it in the shop twice already for this problem. Each time I get it fixed it will go about a year and then it will start this overheating problem again. Like I said, I am getting tired of spend all this money on a recurring problem that apparently doesn't have a permanent fix.

[SB09]

You've inspected the oil for coolant and the coolant for oil correct?

Also, make sure when you say cleaned the radiator it is actually clean. They can appear to be clean, but still have mud caked inside the fins where you cannot see it. Best way is to put the Ranger in a place that's dark and make sure a flashlight will shine through the radiator pretty well. If not, there's still mud in there. Visual inspection without a flashlight isn't really a good way to judge if it's still dirty or not.

When is overheats have you touched the radiator? Is it hot too or cold?

This may sound weird. But, have you tried replacing the radiator cap?

The way your temp gauge is acting I almost want to say the water pump isn't working correctly.

[91cavgt]

How quick does the temp go from one extreme to the other? Time wise. Is it 5 seconds, is it 1 minute, is it 5 minutes, is it 10 minutes?


How quick after starting it does it start to do this?

[Russ79]

The change in reading is immediate..it will show one temperature and then less than five seconds later it will read a different temp and so on. I am getting enough air flow thru the radiator that it will suck a dollar bill against it while the fan is running. I can change out the radiator cap first- that should be something cheap I could try, although I will probably have to have the local Polaris place order it for me- they never seem to have anything in stock.

[manwitaplan]

The change in reading is immediate..it will show one temperature and then less than five seconds later it will read a different temp and so on. I am getting enough air flow thru the radiator that it will suck a dollar bill against it while the fan is running. I can change out the radiator cap first- that should be something cheap I could try, although I will probably have to have the local Polaris place order it for me- they never seem to have anything in stock.

Have you ever thought about taking it to another shop for a second opinion?

[hot_rod_eddie]

It is impossible for the coolant to change temps like that. Either your temp switch/relay/wiring/etc is bad, or you have major air bubbles in your system. Take it to a qualified technician who will diagnose the root cause and fix rather than throwing parts.

[SB09]

The change in reading is immediate..it will show one temperature and then less than five seconds later it will read a different temp and so on. I am getting enough air flow thru the radiator that it will suck a dollar bill against it while the fan is running. I can change out the radiator cap first- that should be something cheap I could try, although I will probably have to have the local Polaris place order it for me- they never seem to have anything in stock.

What auto parts retailer do you like to go to? I can cross reference a radiator cap and give you a part number. Will be cheaper and faster than the Polaris house.

[SB09]

It is impossible for the coolant to change temps like that. Either your temp switch/relay/wiring/etc is bad, or you have major air bubbles in your system. Take it to a qualified technician who will diagnose the root cause and fix rather than throwing parts.

I agree. Could be some serious air stuck in the radiator. The way to "burp" them if to lift the front end and start without the radiator cap on it. Let it idle and try and see if you can evacuate any air.

[mattfox]

Could be a bad thermostat

[SB09]

Could be a bad thermostat

That would be least likely in my opinion. I don't think his temp gauge would be acting the way he mentions. Those t-stats either get stuck open or closed, no in between or changing back and forth. If it was the t-stat stuck closed the temp would only rise, not fall and rise then fall and rise. Symptoms just don't point there to me.

I am betting on a bad cap, or air in the radiator. Especially since it's overheated before. That's a prime environment for air to get trapped in the radiator.

[Shiner]

I wonder if the engine is overheating at all. The coolant cannot spike that much that fast. Sounds like your getting a bad reading, like a bad coolant temp sensor, wiring and or computer issue. Try to determine if the engine is in fact getting hot

[Casey]

I am betting on a bad cap, or air in the radiator. Especially since it's overheated before. That's a prime environment for air to get trapped in the radiator.

My 2011 did this to me and "burping" the coolant system solved it. I haven't had the problem since. You'll get more clear instructions by googling, but I basically poured coolant into the radiator with the machine running. I backed out a bleed screw near the thermostat housing (I think) and ran until no more air came out.

[SB09]

I wonder if the engine is overheating at all. The coolant cannot spike that much that fast. Sounds like your getting a bad reading, like a bad coolant temp sensor, wiring and or computer issue. Try to determine if the engine is in fact getting hot

That is pretty viable in my mind. I am trying to google up an instance of this happening, as far as having a computer/wiring issue. Not too much luck as of yet.