06 900 overheating issues

[deanross]

I did a search but nothing came up. So I'll ask away. Last spring my 06 900 started getting hot (about 170) on and off throughout the day even when there was enough soft snow to get up under the tunnel.
I put a new thermostat in it last summer, but that didn't help. I went out yesterday in 4" of new powder and it kept getting hot. Would go up around 180 then cool down, sometimes to 129, then back up. Jumped all around between the two all day. Any ideas. I don't really want to pull the engine to check the water pump fins . But looking at the shop manuel I'm also concerned it might be the oil water pump shaft wore out. Whats your guys take?

Thanks,
Dean

 

[chunkysoup]

Make sure you have all the air bled out of the system.

 

[Z-Man]

It sure sounds like the thermostat is not working right. If you rode it all day the air should be out. erratic and unpredictable temps while in powder almost always means thermostat is bad. Mine just did exactly what you are describing and the thermostat was in two pieces when I pulled it out. I would pull it and check just to be sure. Won't lose much antifreeze if you just pull the bolts. Also check or just replace your coolant bottle cap.

 

[Shum]

When I bought my 900 it has similar issues... It would run cool then hot for no real reason. Looking into the system I found 2 issues.

First, the prior owner had removed the front radiator, but had not eliminated the hoses for that missing radiator so there was basically still a hot water loop inside the hood. Being a shorter less resistant loop the flow will choose that loop over the through the running boards loop.

Second, while I was in there I found a restrictor (hunk of aluminum with a smaller hole in it) that was in the cooling system (not sure where it is supposed to be). He had this restrictor in the hose that comes out of the motor. That hose had been stretched there allowing the restrictor to move arond and get sideways in the tube. I assume this restrictor should have gone down where the radiator was removed, but I'm not sure I just got rid of it.

Not sure if this applies to you, but that is what I found wrong with mine, my temps have been great since.

 

[deanross]

I was thinking air at first also. But I've checked for that a couple of times. But thanks, Thanks for the other reply's. I'll check to see if any of them apply.

 

[deanross]

Well I bled the coolant again and took it out Monday. Still has problems. When it was hot I grabbed the hose that goes to the thermostat housing and it didn't have any pressure on it at all. Also I couldn't feel or hear any anti freeze moving in the hose. I replaced the coolant cap and let it warm up here at home but still no pressure on the hose.
So any idea if that hose is supposed to feel hard like it has pressure and should I feel and hear anti freeze moving through it?

Thanks,
Dean

 

[Z-Man]

Hose will get hot once it reaches 123 degrees and thermostat opens. Might try removing the thermostat all together and take a short ride and see if it over heats.

 

[Shum]

Open the bleed screw right there on the top of the motor while it is warmed up and running, if water dribbles out then there is no pressure. It should have a pretty steady (like a squirt gun) stream coming out of the bleed hole when it is running and thermostat is open (over 120 I believe)... Don't let the hot water burn you on its way out of there... If there is not a hard stream try the same test without the thermostat, if it starts squirting then you have a bad thermostat that is not opening, if there is still no stream you have a blockage(not likely) or a bad pump.

 

[deanross]

Thanks, I have a couple more things to try it sounds like. I'll let you know if I find anything.

Dean

 

[deanross]

I took a longer look at it tonight and found out that when the front radiator delete was done they left the front hose from the tank attached to a tee that went to the thermostat and down to the rear. I took out the tee and will cap the hose that comes out the front of the tank. It looked possible that some of the coolant could bypass the rear radiator loop. Hopefully this will help circulate all the coolant through the radiator.

Dean