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oil overheat light keeps coming on

15596 Views 17 Replies 10 Participants Last post by  szembek
I have a 2001 ES 450. It only has 400 miles on it. I ran it all fall deer hunting without any problems. Once about 2 months ago the oil overheat light came on while out on a ride around the lake. It happened in front of my house at the end of my ride, so I didn't pay much attention to it. It happened again last Sunday numerous times while pulling my 2 small kids on a sled (I have used the atv about 5 times since the first time it happened, but for very short distances puilling an ice fishing sled). I had only gone about 6 blocks when it first came on. I'd let it cool for a few minutes (temp was 25 degrees), start it back up, and it would come on again after about 200 yards. After going through this about 3 times, I rode home (about 6 blocks) without it coming on. I checked the radiator last night and it seems clean. I can see through it. I have an extended warranty until this summer, but would like to know if there are any obvious answers. I called the dealership and they basically provided no suggestions. I'm sure they'll have an impossible time reproducing it, so I'm not really excited about driving an hour and dropping it off for some indeterminate amount of time. Help. If there's anything that concerns me it's oil problems.
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Do you have a manual for the bike? If so there are steps they can have you take to help determine the problem, you will need a multi meter as well. But in the front of the manual they have a trouble shooting section. If you dont have this I could possible scan mine for you.
Yes, I have the manual. I dug through it last night and it said very little regarding this light. Basically, if it comes on while riding take it to the dealer. I didn't look at any schematics. It's in my truck, so I'll have it with me tomorrow.

I noticed that there's a hose coming from the radiator. I'm assuming that's to push oil around (?) the radiator to cool it? If so, could my oil pump be shot? If that's how it even all works.
you mean the oil cooler? I dont think you have a radiator on that one, but you should have 2 oil lines coming off that and down to where the oil filter is housed.
You may have done it, but have you check the oil level. Does the oil cooler's fan come on. Its strange that it heats up so fast in that temp, since its an air cooled engine. Sounds like an oil flow problem, with only 400 miles in 5 years you may have oil sludge built up.
I'll reply to both of the posts above.

By radiator, I probably meant oil cooler. Basically, the "thing" in the front of the atv that looks like a radiator. I reviewed the manual for anything regarding liquid cooling, antifreeze, etc. and found I guess oil cooler is the right term.

I did check the oil level. I checked it the day it happened immediately after the light came on and it showed over the fill line. After talking to the dealer about the problem, they informed me to make sure I didn't thread the dipstick in while checking the level (learn something new every day). So, I checked it again the next day after starting it up and running it from the backyard to the garage to warm it up a bit. I still showed over the full level, but I don't remember how much over.

The previous owner said that he had a check-up done on the atv last spring, at which time they changed the oil (and I'm assuming oil filter). Since I'm dealing with the same dealer because that's who the extended warranty was sold through, I hope that I can give them the name of the previous owner and they can tell me exactly what service was done. That would at least tell me it's not an oil problem where I can just change the oil. This build-up problem is interesting, though.

I believe I've heard the fan in the past when it was significantly warmer out (last fall), but I don't know for sure. I did not specifically hear the fan run during the last time it happened. For certain it was not running when I just turned the key on, as the dealer indicated it may stay on even when not running to keep cooling. I know that didn't happen. But, I'm not sure why it would come on. With it only being 25 degrees out, you'd think just riding it would cool the oil cooler more than the fan could (?).
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I would try and change the oil temp sensor.
Did you find the problem? If not, take it out and drive around till the light comes on. Check to see if the fan is on or not.

I haven't found the problem yet.

The fan fuse is fine. I spun the fan manually without any problems.

The next thing is to simulate an overheat condition to see if the fan actually works.
Check the relay. Jump the relay and see if you can get the fan to come on manually.
I dug into this last night and went straight to the sensor. I disconnected the wire to the sensor and applied a gound to it, simulating an oil overheat condition. The lamp and fan turned on. Which to me indicates that everything from the sensor all the way to the fan/lamp is working properly.

The bad news is that I think this points to a "real" problem with the oil overheating, unless the sensor itself is bad. It just seems to me that the sensor is operational because it came on, I let it cool, it turned came on again, I let it cool, it turned off, etc.

If it's a real problem, then that's a bummer because I fully intend on pulling my kids on a sled (or my portable fish house) in the future...and I certainly don't expect this thing to overheat because of that.

I think the only thing I can do is to grab my kids and try to reproduce it, because I'm still not certain the fan turned on when it originally happened.

I'm assuming the sensor provides 2 data points - fan only and then fan AND lamp? Or is it fan only and then lamp only?

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Whats up guys,I just joined the forum today.I would start with the basic checks first.Make sure the fan is working,clean out the oil cooler with a hose and lightly blow air to the front side of the oil cooler(poss resriction of air).I have also seen oil filters fall apart and resrict oil flow on my buddies Big Bear.If that doesnt help i would have to lean towards a oil temp sender(they work off resistance),poss ohm meter and a service manual... HOPE I COULD HELP YA OUT... :
Two things come to mine. look at the fan control unit , located under the front fender by the CDI box. check the conection for dirt,water or corrosion. also the temp sencer wire is know for coming off. i dont know if u have check to make sure the wire was still conected or not. It is located on the rear of the engine. with the skid plate on it is hard to see if the wire is still hooked up. I paied $37 for the last temp. sencer from honda.
Check to make sure the oil filter is not in BACKWARDS.
Well, it's been a year since I posted this and thought I'd follow up. This problem occurred too often this past winter so I finally brought it in (since my extended warranty is about to expire). After much debug, it seems that the fan control unit has been replaced. I'm waiting for the paperwork to complete for the extended warranty before I actually pick it up. Since for some reason this only happened in the winter, I guess I have a few months to wait before I know if that really fixed it.
I was also going to suggest checking the oil filter to make sure it wasn't installed backwards. Chances are that if it was and was installed by the dealer that you took it too, they more than likely aren't going to say anything about it. Hopefully your problem is fixed regardless.
Same problem

I have exactly the same problem for many weeks with my foreman 2001 450 ES. And I am driving it Up North Canada at I'll read all the suggestions carefully... Thanks for your comments guys...

The Clymer manual for the Foreman has a really good troubleshooting section that helps narrow down the cause of the high oil temp light. In my case it was obvious what it was, because the cable coming out of the thermosensor was actually broken. We spliced it back together and no more problems.
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