Jump to content

Welcome to TheMalibuCrew!

As a guest, you are welcome to poke around and view the majority of the content that we have to offer, but in order to post, search, contact members, and get full use out of the website you will need to Register for an Account. It's free and it's easy, so don't hesitate to join the TheMalibuCrew Family today!

2015 Indmar GM LS3 Winterize - Confirming process. Vee-Drain?? Accessing Exchanger drain plug/anode??

Recommended Posts

I'm DIY winterizing on new to me 2015 23LSV with Indmar GM LS3 engine - half-system

Thanks to the Mega-Manuals collections for Indmar LS2/LS3 Winterize 3 page instructions. The Indmar 3 pager seems to differ/conflict with chapter 7 on winter layup in the Indmar Operator's Manual.

Aside from those 2 docs, I've searched/read at least 15 posts here an elsewhere on LS3 winterization.  After multiple reviews, I think I'm ready to to go, but looking for final check before I dive in. 

1) Have I understood the process correctly? (confirming with my pics below)

2) Do I drain the Vee-drain per the operator's manual? Or is that not needed, per the 3 page winterize doc? 

3) What's best way to get a wrench on the drain plug/anode on the heat exchanger? (it's below storage floor level and bow side of the forward clamp) It don't see a get good angle.  Can I remove the bolt on the end of the exchanger as an alternative? (the one holding the circular plate on the end, may be dumb question) I have Permatex anti-seize on hand, will that work on sacrificial anode before reinstalling the plug or is it something else?

I added Stabil and did oil change ahead already/ahead of draining water and will clean/dry overall boat afterward.

1- Drain Transmission/oil cooler (starboard side)



2- Remove/drain hose from inlet side of raw water pump. (starboard side) Looks like mine has an easier to reach elbow hose connector.  (note: I think the Operator Manual says to remove/drain both hoses to impeller, the 3 pager just says remove the lower hose)


3-Remove impeller, coat with Vaseline and store. (I don't plan to do that now - plan to replace the impeller in Spring)

4-Remove drain plug/anode from raw water portion of heat exchanger. (port side, plug is bow side of front clamp, lower than pnp storage floor)

See question #3 above on how do I get a wrench on it ???  Can I remove bolt holding cap on the front of the exchanger as alternative?? (and miss on reviewing the anode wear?/)


5- Test and fill Sierra engine anti-freeze as needed.

6- Test engine anti-freeze with litmus paper, if turns red/pink coolant has acid and must be replaced. 

??- Remove/ Drain Indmar-Vee drain plug. This is shown in Indmar Operator's Manual (but not in Indmar Winterize 3 pager)  Does this need to be done? 


I understand there's no need to drain heater as it's on the "closed side" on my half-cooled system.  


THANKS for any updates, corrections or pro tips!  What else am I missing?



Edited by TOAST
trying to delete 2 duplicate pics at end of post
  • Thanks 2
Link to post

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...