Ilmor 5.7 Temperature Problems

[Justin D.]

Over Memorial Weekend I took my new X-15 to Lake Powell. When idling out of the marina my engine temperature started to climb up to 190-200 degrees. I quickly got the boat up to cruising speed and the temperature fell back down to 160. After another 5 minutes of cruising the engine temperature fell down to 120-130 degrees. So I took the boat down to an idle only to have the engine heat up to 190-200 again. I had no alarm when my engine temperature hit 200 and I noticed no performance issues with the engine. Any thoughts?

[ricford]

Check the strainer for blockage. Check impeller, even "new" ones can go bad if it's been sitting for a while. Check for water leaks around the engine.

[Justin D.]

Would a bad impeller explain the engine temp dropping to 120 at cruising speeds as well? Im thinking it could just be a faulty thermostat?

[JimmyDean]

I had the same exact problem. It was an airlock in the filter basket. The dealer bypassed the basket and it seems to be working fine.

[Justin D.]

Is bypassing the strainer something i can do by myself? Or do I have to take it in to a Mastercraft dealership

[JimmyDean]

I think so. I had a friend do it and he used the shorter hose when he bypassed the strainer.

[JimmyDean]

I would still talk to the dealer. I have gotten mixed messages regarding this problem.

[Justin D.]

Ill talk to my dealer about it. My boat is stored 6 hours away from the nearest Mastercraft Dealership so I really want to avoid hauling it all the way over there!

[X25 ED]

Originally Posted by Justin D.

Over Memorial Weekend I took my new X-15 to Lake Powell. When idling out of the marina my engine temperature started to climb up to 190-200 degrees. I quickly got the boat up to cruising speed and the temperature fell back down to 160. After another 5 minutes of cruising the engine temperature fell down to 120-130 degrees. So I took the boat down to an idle only to have the engine heat up to 190-200 again. I had no alarm when my engine temperature hit 200 and I noticed no performance issues with the engine. Any thoughts?

I assume you have a 2102 model? Then check the circulation pump, mine was broken and is replaced 2 weeks ago
good luck

[Justin D.]

Did you replace the pump yourself or did you have your dealer do it?