You can do a compression check to see if the engine is damaged. The 800 had a thing for eating water pump impellers.

 

I work with a guy who has a lot of experience working on UTV/ATV and especially Polaris. I'll get with him tomorrow and maybe have him take a look at it. Replacing a thermostat, cooling fan, or water pump I can handle. If the engine is toast it's a different story. I only have $5,500 invested in the 800 including the tilt trailer.

 

The RZR will go into limp mode when you get that hot..,. I want to say 240 degrees, but I think my light comes on at 230. I was having overheating problems . Thought it was my impeller... replaced it with a billet impeller. When I went to refill and circulate the coolant, the thermostat wasn’t opening. Replaced that and it is good to go. Both are easy jobs and fairly cheap.


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Thanks for the info. Isn't the impeller part of the water pump and would be replaced as a single part? I'll probably replace the thermostat just for the hell of it even if the problem is the water pump or cooling fan. Where is the thermostat located? You normally find them near the radiator but I didn't see it. Looking at some parts diagrams it seems to be at the back near the engine. I haven't pulled the bed off yet. Seems fairly simple but a lot of screws to remove. Do you have to remove the fenders or do they come off with the bed?

 

The thermostat is right on the engine. Pull the plastic cover behind the seats and you will see the hose coming out near the top of the motor with the thermostat hosing. Two bolts to take it off. You don’t need to remove the bed. The impeller comes out of the water pump. Just unbolt the cover, take the nut off the impeller and change it out. All you will have to do is pull the passenger rear tire to give you a little better access.

If you ever do remove the bed, it is just the four? bolts in the bed, the two in the rear wear the bumper would mount, and then then plastic clips connecting the fenders to the passenger side. I think that is it, it has been a while and I am going off of memory.


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I noticed during my short ride today that the cooling fan never came on. Maybe that's the problem.

 

If my fan only runs for 15-20 seconds when I unplug it from sensor, is that a problem? I was told it is supposed to run continuously

 

That is the first thing to check an fix.

 

It'll be a process of elimination. Most mechanical problems are. Start with the simplest solution first and go from there. I spent 20+ years repairing 35mm cameras before digital ruined everything. Canon, Nikon, Minolta, Pentax, Olympus, etc. I like the little stuff. With engines I'm lost.

 

Also, if you want to do some diagnosis for the fan and thermostat, turn the digital consol to temp. You should see the temps rise until the thermostat opens (I want to say it is around 195) and you should see a drop in temp.. then as that cold coolant circulated and normalizes the temp will begin to rise again. Fan should come on around 205 I think and you should see a drop in the temp again. Also, you can feel the return hose at the top of your radiator and it should be hot if your thermostat is opening at the prescribed temp.


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Wow! Thanks again!

 

RZRs are not as complicated as SLR, but just as frustrating.
Impeller is behind Water pump housing.

Thermostat (J)

Thermostat housing

Water pump

Impeller

 

Thermostat (J)
View attachment 658726

Thermostat housing
View attachment 658727

Water pump
View attachment 658724

Impeller
View attachment 658725
[/QUOTE]

RZRs are not as complicated as SLR, but just as frustrating.
Impeller is behind Water pump housing.

Thermostat (J)
View attachment 658726

Hopefully I'll track down the problem and be riding next weekend. I just left it idling for a while but not enough to get the temp up. I'm going to go down the road a bit and try to get it hot enough to check the cooling fan. Thanks again for the info.

Thermostat housing
View attachment 658727

Water pump
View attachment 658724

Impeller
View attachment 658725

 

Hopefully I'll track down the problem and be riding next weekend. I just left it idling for a while but not enough to get the temp up. I'm going to go down the road a bit and try to get it hot enough to check the cooling fan. Thanks again for the info.

 

I'm not sure happened with my last attempt to post but ignore it . Anyway I got the 800 out on the road to try to heat it up. I found out the thermostat is working. Wasn't able to get the temp much above 190 until I got home and revved it sitting still. Finally got up to about 230 and got out to look under the front fender and saw the cooling fan moved a little. Not sure if it was moving faster before I took a look. I suspect cooling fan or relay. Now another problem that somehow must be related. The thing is bogged down. Seems to be running at half speed. At one point it picked up like normal and then slowed down again. I've heard of limp mode but thought that would clear up on it's own. I'll probably order a cooling fan and relay and replace those but the bogged down running is worrying me. Any thoughts on that?

 

I would check the fan circuit breaker before ordering a fan. They have a nasty habit of rusting the connections off! Piece in the yellow outline, will be below the driverside seat.

 

With motor cool and key OFF, the fan should spin freely, by hand.

Fan should kick on around 205 degrees, and kick off around 194 degrees.
It turns fast enough that you can here it over the motor.
Light comes on at 235ish
Limp mode at 240ish

If it spins freely, I would start with the circuit breaker, as mentioned by Brian (Clothier).
Not sure why, but Polaris located CB where it can lay in water, and when I was a kid I learned that water and electricity don't play well together.

 

I'll check the fan manually. Can you bypass the relay and connect power directly to the fan to see how it spins up? Pretty stupid location for the relay but then again I'm surprised the battery is not better protected. I've been able to avoid locations where my battery might be submerged. Mine is just sitting there under the seat with no case to keep water out. I heard today that a RZR 900 burned up Saturday night in the area I normally ride. Burned to the ground was description I got. Suspected electrical problem. Scary. We have some deep holes if you want to play around in them. I normally try to go around. After Hurricane Sally came through I though conditions would be worse but that was not a problem. One of the usual creek crossings was actually almost dry. I was hoping to use the Polaris next Saturday for getting around a local MX track to shoot photos but probably ain't gonna happen. I'll end up going around the course on foot most likely. Or ride on my Honda 230F with the camera gear in a backpack. I was also planning on doing some drone photography but I can fly from my truck in the parking area.

 

Circuit breaker is under drivers seat, relay is in fuse panel (under dash)

If you disconnect temp sensor, fan should turn on.
See ECT sensor test below.

 

Circuit breaker is under drivers seat, relay is in fuse panel (under dash)

If you disconnect temp sensor, fan should turn on.
See ECT sensor test below.
If my fan only runs for 15-20 seconds when I unplug it from sensor, is that a problem? I was told it is supposed to run continuously
View attachment 658802

 

I recently had it in for a cooling fan problem and then. . .

So. . . . What was the fix?

 

Apparently a relay. I had swapped out the one in the fuse box but there was a second on around the battery. The mechanic was a little vague. Got that working and after some mud riding a few weeks ago I realized AWD wasn't working. I'm trying to track that down now. I started a new thread on that and have got some pointers on where to start. I'm riding Saturday without AWD. That's what winches and tow straps are for.

 

I love vague mechanics.
Back by the battery would be the circuit breaker, not a relay.

 

Sounds like what was suggested was the issue.

 

My bad. I meant circuit breaker.