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2014 Polaris Sportsman 400 HO "HOT ENGINE" light

23K views 28 replies 7 participants last post by  bitNine  
#1 ·
back story:

Changed the oil , removed screen, so I primed the pump by clamping the hose coming from the oil box.

No problems, let it run for 20 minutes that day, no light came on.

overflow and rad full!

Today I started it, hot engine light comes on, didn't let it run long enough to see if fan would come on.

Unplugged the coolant temperature switch? I believe on the drivers side below the oil filter, and the light goes off?!

what is wrong, what should I replace if anything?

here is a video of what its doing

 
#4 ·
havent had a chance




Havent had a chance to dirty the rad!

haha!

Used it all last season for hauling logs to the yard to chop firewood there.

No problems whatsoever.

what else could it be?

i'm going to call the Polaris dealer tomorrow morning and see if they will tell me.

the last time I got oil there I got a discount on the oil and filter because that's where I bought the fourwheeler from.
 
#6 ·
oh I forgot to mention.

I got a new front "cab" plastic from PartZilla,

Cut a tree on the four wheeler last season, no light on then though.

Got around to putting the plastic back on, everything bolted down now.

When I went to start it, that's when the light started coming on.

my question now is,

do you think when I put the plastic front cover on, I could have shorted a wire,

causing a short to ground,

making the HOT ENGINE light come on.

when the wire is hooked up, light flashes on speedometer and warning light indicated.

unplugged, no problem.
 
#7 ·
called the Polaris dealer.

first thing they said was thermostat or sensor,

then they said "ecm" but said nevermind that when I told them it was a 2014.

I tired to check for a short, but couldn't find one.

is there a way to test with a DVOM the coolant sensor?

where is the thermosat located?
 
#9 ·
theromstat

Your thermostat is in the tiny housing above the temp sensor.

View attachment 26517

Pm me your email address, I have a factory 2012 service manual, will gladly email you a copy.

Sent from my Z30 using Tapatalk
I used the boiling water trick on the thermostat.

The brass top rose when put in boiling water, and after taking it out the water and it cooled went back to normal.

Has anyone tested the coolant temp sensor on the block, I get readings from the DVOM, but not sure what to reference in numbers.

Are there any other sensors that control the coolant fan?

It doesn't give the over heating message everytime I turn the key on, just when its been running. If I unplug the sensor the fan doesn't come on, and the fan hasn't come on at all.

I'm not sure what else to check.

Thermostat is ok, not sure about the coolant switch, any other switches or relays or fuses control this?
 
#12 · (Edited)
On mine the fan is controlled by a temperature switch in the bottom of the radiator. The sensor in the engine just turns on the warning light.

I tested my fan by unplugging the connector from the rad and putting a wire jumper between the two connections on the fan side of the connector. If it doesn't come on it's either not getting power or the fan motor is shot. Since your bike is newer it may be different, so you'll probably want to check the maintenance manual or wiring diagram first.
 
#13 ·
I'm having the same problem with my 2013 500. I put a jumper across that plug, the relay clicked but the fan did not come on. My fan is good because I hooked it up direct to power source and it works.
 
#16 ·
Maybe mine is a combination of the two sensors.

Its been hours and when I turn the key 'on' the HOT ENGINE light comes on, its been hours, there is no way its still that hot. Its cold to the touch.

I'm going to order a 'aftermarket' sensor about $50 less than the OEM Polaris sensor using this part number 3085352 from Polaris you can find them on the net.

at least the fan is cutting on now though.

I had this happen to a 80's model Ford when both the coolant sensors, on the intake and bottom of the motor whentkapoot.

I cant believe something this new is.

I hope by changing the sensor on the block I will quit getting 'false hot readings'
 
#21 ·
part ordered




I ordered the part tonight, its coming from Minnesota to VA so I hope its here by Saturday. if not, by next week sometime.

Its coming from QuadLogic, I ordered it off of Ebay for a 400 HO. its the same part number for 2012 models, which is still the same part number for my 2014 model.

the part is the temp sensor that gives the HOT ENGINE light. I was going to get a replacement from Polaris, but this aftermarket sensor is suppose to be more heavy duty than OEM.

I think somehow for some reason unknown to me, that both sensors went out at the same time.

If I unplug the engine block sensor the light stays off. if I leave the sensor plugged in, engine cold, just turning the key on , not starting the atv, I instantly get the HOT ENGINE light, which is a false hot reading.

but when I do let the engine run, and cut the atv off, and turn the key back to on, the fan will kick on now since I changed the sensor that's in the radiator. (let the engine get hot)

so far, I have not had to take it to the Polaris dealer where I got it from, the labor rate is $75 a hour. and for under $100, I have replaced both sensors.

Which I don't understand because its a 2014, and the only thing I have done to it is cut a tree down on it. HAHA. I really did, because I use it to haul logs out of the woods to my log splitter. should have moved the atv before I cut the tree down! the only thing it did was bust the top lid, which I stitched together with zipties, and fiberglassed and painted the only big 'chip' back. and it busted the front cab, which I got a another front cab, I could ramble on about that but

I changed the oil 1time because the manual says change the oil at a certain interval, but Polaris Synthetic oil is expensive and should last a long time, so I will probably change it again next season, because I really only use it to ride around the house when I'm not cutting timber.

it just blows my mind both sensors went out at the same time, right after I changed my oil. I'm not a happy camper right now with this 4 -wheeler.
 
#19 ·
Had a similar issue. Fan circuit breaker was bad. Never had a problem when moving, but when I was crawling on a rocky trail, it would overheat. One day my wife had to pull me up a trail with her rzr. I was pissed since it has like 250 miles and about 25 hours.

See the end of this thread: Cooling fan Breaker - Polaris ATV Forum
 
#24 ·
ok so this is the thing I changed: radiator temperature sensor.

before the fan wouldn't kick on after about 5-10 minutes and HOT LIGHT would come on.

I changed the radiator temperature sensor and still had the HOT LIGHT, but after turning the 4-Wheeler off the fan kicked on.
 
#25 ·
note: I was still getting HOT ENGINE lights just by turning the key to on. to a cold motor, hadn't started the atv or anything.

so:

I got the engine block temperature sensor in the mail today from quad logic.

I immediately plugged the block sensor from quad logic in the harness. and just turned the key on a few times to see if the light would come on. it didn't.

I then went and got something to eat to think this over.

I went and plugged the harness into the old temperature sensor that was still in the block and turned the key on and off to see if the HOT ENGINE light would come on. it didn't.

so that's what confuses me, maybe mouse gremlins? maybe a miracle?

but since I had already bought the block temperature sensor from QuadLogic I went on and put it in the old temperature sensors place.

and guess what?

let the ATV run for 5-10 minutes no HOT ENGINE LIGHT and the fan kicked on. I let it stay on until the fan went off and turned the atv off.

I haven't looked at the wiring diagram to see if there was a fuse like in the photo above, but I want to thank Will for sending me a copy of the service manual , and if this happens again, that will be the first thing I check to see. If this atv has a fuse block near the battery or something.

but I think I had a combination of problems with heat sensors, and replacing both fixed my problems.

I had mentioned earlier I have a old Ford Truck and both heat sensors, one for the gauge and one for the block went out one time and I had to replace both. they both work now though.

I also want to thank Old Polaris Tech and bitNINE, thanks guys.
 
#28 ·
Glad to hear you made some progress. Without this forum, I never would have figured out my overheating problem. I think I'm eventually going to wrap my 550's circuit breaker with some sort of heat tape. I've read in a few other places that excessive heat can kill those things. Polaris made a poor decision in where they put that breaker.