Temp issues with 15 Viper

[Mooney 2]

I am having issues with the cooling system on my 2015 SR Viper . It has 2600 miles, I bought it used with 1700 miles. In the 900 miles I have put on I have been dealing with overheating issues on almost Every ride. So far here is what I have found. On the first ride it got warm enough to flash the light and cut fuel down after about a 10 mile ditch run about 60mph stopped for 1 minute and temp climbed from 170 to 220 in that minute. Got up to speed and it cooled and stayed cool as long as I was moving. When I got home I checked the level in the over flow and it was full right to the plug. Took rad cap off and system was down . Topped it up and sucked out overflow to proper cold level. Next ride got hot again , couldnt stop for anything or it would get hot instantly. Got home same deal coolant pushed out of system into over flow. Checked thermostate (fine) changed temp sensor and blead system by running with cap off. Next ride 3°C was fine all 120 miles never an issue. Next ride -10°C made it 15 miles and temp climbs at a stop for road crossing and quickly goes into limp mode. Get home and system is low again and over flow is full. Tunnel rad is hardly warm, front rad is cool, hoses water pump etc no warmer than 125°F on infered gun ( sled temp gauge reading 225). Temp sensor reading 225 On infered gun. I then noticed that someone has trimmed the heat shield to access the temp sensor which has now exposed it to the exhaust muffler (stock). Built a shield to add to the factory one to get it back to factory form. Filled system blead again put new rad cap on just in case ( spring seemed a little weak) . Ran 220 miles yesterday with no temp issues. Noticed when I got in the shop this morning the overflow is full again. So I'm sure the system will be low again and if I don' do anything it will run hot again next ride. So my question is are these systems supposed to suck coolant back in from the overflow or Not? Secondly what is the problem. I switched brands so I could put the tools away and I have about worn out the threads on the screws taking the hood on and off. Thanks for any help. Very frustrated!

 

[super1c]

Sounds like problem comes up when stopped. Is you fan comming on when getting hot?

 

[Mooney 2]

Yes fan comes on. After filling system and getting air out the sled will sit and idle in my shop for half an hour or more without over heating. It warms up to 195 fan comes on and it cools to 185. Then slowly back to 195 fan comes on and back to 185. And on and on. Runs down the trail at 165-172 all day. I believe my high temp issue was the temp sensor being heated from the exhaust and lack of heat shield. I' not sure why it has filled the overflow again? And why doesn' it suck it back into the system after cooling ?

 

[Yamasledder]

Yes fan comes on. After filling system and getting air out the sled will sit and idle in my shop for half an hour or more without over heating. It warms up to 195 fan comes on and it cools to 185. Then slowly back to 195 fan comes on and back to 185. And on and on. Runs down the trail at 165-172 all day. I believe my high temp issue was the temp sensor being heated from the exhaust and lack of heat shield. I' not sure why it has filled the overflow again? And why doesn' it suck it back into the system after cooling ?

That really sounds like a faulty coolant cap. Coolant under pressure from heat should overcome the spring in the cap and go into the recovery tank. When the engine cools a check valve should open allowing the coolant to flow easily back into the main cooling system. It sounds like the check valve isn't releasing allowing coolant to flow freely back into the cooling system which actually comes under a slight vacuum as the system cools.

 

[Mooney 2]

I Just put a new cap on for this ride. 16lb cap just like factory. Didn't seem to make a difference.

 

[cannondale27]

Have you looked for bubbles or oil when running with Rad cap removed? Was this sled previously a turbo?

 

[Mooney 2]

Have you looked for bubbles or oil when running with Rad cap removed? Was this sled previously a turbo?

Yes coolant and oil are fine no contamination. No bubbles either when cap is off. You can see the coolant moving but no bubbles. Not sure if it had a turbo, no obvious signs and I don' think so but don't know for sure.

 

[cannondale27]

Yes coolant and oil are fine no contamination. No bubbles either when cap is off. You can see the coolant moving but no bubbles. Not sure if it had a turbo, no obvious signs and I don' think so but don't know for sure.

I think you maybe you should look at the over flow tube. Its hanging in bottom of sled. If it is kinked or plugged a vacuum would form in tank and coolant wont go back into the rest of system once cool enough to.

 

[Mooney 2]

I think you maybe you should look at the over flow tube. Its hanging in bottom of sled. If it is kinked or plugged a vacuum would form in tank and coolant wont go back into the rest of system once cool enough to.

I checked that. And checked the part that the tube goes to in the top of the tank. Seems to flow air through no problem. I' not sure how that valve in the top of the tank is supposed to do but it seems to allow air to flow through either direction when blowing into either side.

 

[viper strike]

Could be a faulty temp sensor.
Have you checked coolant temp with a thermometer or temp gun.
Just to see if dash temp accurate.
Maybe little dielectric grease on plugs would help I've seen corrosion issues on a few sled myself. Green wires and terminals.

 

[Mooney 2]

Could be a faulty temp sensor.
Have you checked coolant temp with a thermometer or temp gun.
Just to see if dash temp accurate.
Maybe little dielectric grease on plugs would help I've seen corrosion issues on a few sled myself. Green wires and terminals.

Yes changed temp sensor. Entire system was cool and the temp sensor was hot from the lack of heat shield and getting heated externally by the muffler. That part is corrected . I need to figure out now why it fills the overflow with out ever overheating. And why it doesn't suck back into the system when it cools from operating temp.

 

[viper strike]

Is the cap seated properly the rubber one on the overflow tank sounds like you might have a pinched breather or tube somewhere.
I would just change that crappy 50\50 mix with some evans water less coolant.
Wont expand and contract due to pressure or steam. Because their is no water in it.

 

[viper strike]

Is the cap seated properly the rubber one on the overflow tank sounds like you might have a pinched breather or tube somewhere.
I would just change that crappy 50\50 mix with some evans water less coolant.
Wont expand and contract due to pressure or steam. Because their is no water in it.

Do you have any leaks anywhere else sounds like the coolant system isn't breathing properly.

 

[Mooney 2]

Do you have any leaks anywhere else sounds like the coolant system isn't breathing properly.

Doesn' seem to. If I suck out coolant from overflow it fills the system back up and the bottle level is back to cold fill line. It doesn' seem to be loosing any fluid just pumping it to the tank.

 

[viper strike]

Right but if you have a small leak above the bottle height it might not have the right vacuum to put it back in the system and you would only see a small leak while its running.