overheating turbo Nytro

[MotleyOne]

I have an 08 FX MTX with an Imulpse Turbo kit with a VE tunnel. I removed the front and rear heat exchangers and went with the 4 pass rear cooler. My sled is over heating after about 10 minutes playing around. If I keep the boost low under 8 lbs or so it will not overheat. If I go over that for a couple runs it overheats. My first thought was that the head is lifting under the added boost. I did an exhaust gas leak test and it came out negative. I looked over the coolant lines and did notice a slight amount of coolant coming up from the right running board to the aluminum tubing for the VE Tunnel kit. It does not ooze out of there but you can see a tiny tiny amount of coolant around the rubber hose that connects the aluminum tube to the running board. I even tapped an M6 bolt into the very back of the 4 pass cooler just to make sure the system was bled properly then lifted the front end up 4 feet to make sure all air pockets came out. My queston is about my theory. Where that tiny amount of coolant is coming out could air be pulled in under high boost horse power and when that air hits the motor it instantly turns to steam and causes the overheating. I run a digital temp gauge on my sled and under normal operating and up to 8 lbs or so the temp rests between 150-170. Once I boost it up to 15 and it overheats the temp goes up as high as 230. I am at my wits end, I have been playing with this for 2 weeks. Any help is appreciated.

 

[Len Todd]

I am not a "turbo jock." But, here are some things to think about/check.

If you are forcing air into the cooling system, then you should be able to detect it, if you later bleed it off.

Is the Thermostat working correctly. Or, maybe it needs to come right out?

You might want to post down in the turbo forum. Or call the vendor that sold you the turbo and ask them.

I would call the tunnel vendor too. Maybe they did not understand the conditions that you were asking their product to handle.

If you are running up to 230 degrees F, then maybe you need more heat exchanger contact area. Can you easily add an exchanger and see what happens?

Could the coolant pump NOT be functioning?

No tight bends in the Coolant lines?

Are you using a 50/50 mix of coolant and water?

Are you using Water Wetter?

Are the snow conditions right to ensure the heat exchangers are making contact with the snow.

These may not help you much. But, these are the things I would be looking at.

 

[MotleyOne]

Thanks for all the tips Len. I double checked every connection today then bled the entire system and filled it up. Took it out and at 14-16 lbs of boost it overheated. This time it was a more forceful back pressure spewing collant all over the front out of the resevoir. It must be a head gasket with that type of force. I am replacing it Friday.

thanks again.

Kevin

 

[Len Todd]

Was there air in the cooling system, when you bled it?

Good luck. Let us know if you found the smoking gun.