2001 merc 225 EFI overheating a slow idle

[01Cougar]

I just installed a new water pump but I'm still over heating if I continue a slow idle for more than about 10 minutes. any thoughts??

 

[racerone]

Leaking head gaskets can cause overheating.

 

[faztbullet]

New to you engine?

 

[01Cougar]

New to you engine?

No, bought it new 23 years ago

 

[01Cougar]

Leaking head gaskets can cause overheating.

I guess that could make sense. A compression test could help to confirm. Thanks

 

[faztbullet]

Could be a bad/weak t-stat. Have you upgrade the t-stats. Here is link to TSB

https://shop.davecrawfordmarine.co.uk/catalog/media/F53DEL3EMF3GKY3SMF3WM33SMQXW2ZLENFQS6YTNMUXUOQKZIRBVQQSRI5HE6RCFJVBFCR2KJ5CUWVCTG5DUCNCBFZYGIZQ

 

[01Cougar]

Could be a bad/weak t-stat. Have you upgrade the t-stats. Here is link to TSB

https://shop.davecrawfordmarine.co.uk/catalog/media/F53DEL3EMF3GKY3SMF3WM33SMQXW2ZLENFQS6YTNMUXUOQKZIRBVQQSRI5HE6RCFJVBFCR2KJ5CUWVCTG5DUCNCBFZYGIZQ

Thanks for the info, Ill check it out