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2013 Ilmore heater hose connections

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  • 2013 Ilmore heater hose connections

    If you have a stock heater in your 2013 MC, would you mind snapping a few shots of your heater hose to engine connections? The 2013 5.7 L Ilmor has a 1" "sub manifold" under the main engine manifolds. Out of each side, on the bottom, is a hose which runs up toward the thermostat. Curious to know if the stock heaters are spliced into the passenger side hose, or if a "T" connector is used and the heater hoses run to both sides of the engine.

    Attached Files
    Last edited by kyfooter; 10-25-2015, 12:37 PM.

  • #2
    or is it this hose?
    Attached Files


    • #3
      I had a heck of a time finding my heater hoses. I have this plastic fitting that tees off. When I removed it and blew in the other suspected hose off the engine my assistant could hear bubbling at the heater. So, I figured that had to be it - right!? Anyway, I blew through it until no water came out and it took about 1/2 gallon of AF before it came out the other hose. Let you know after winter if I was right. Anyway, here is a pic of mine. I would go with the hose from second post.
      Last edited by Cyoder1; 10-04-2016, 11:09 PM.


      • #4
        Bump to see if anyone can take photos of their factory heater hookup to the engine. Looking to see exactly where the two heater hoses hook to the engine.



        • #5
          ...Nothing? Anyone else have a heater in their boat with an Ilmor engine? Anyone???


          • #6
            Can you get a pic of the that plastic tee with the other end in it. If the hose is clear I'm pretty sure it runs to your prop shaft and is used to cool the prop shaft seal.

            Making boomers great again!! Boomin'


            • #7
              Agreed...and if that is indeed a heater hose of the "T", then where does the other heater hose attach?

              On my 2003 with the Indmar engine, one hose hooked directly into the engine next to the thermostat, and the other hose hooked to the passenger side of the block, under the manifold. MC used a hose bib on the engine.

              Ilmor doesn't have as obvious of a least not obvious to me.


              • #8
                I have a 2012 Ilmore with a heater. I also struggled to figure out how the lines run. Since we brought the boat out of storage this spring the heater hasn't been producing much heat. I thought the problem might have been flow to the heat exchanger. Any help would be appreciated.

                Sent from my iPad using Tapatalk


                • #9
                  Maybe we shouldn't be looking at the first few years of the Ilmor engine, but perhaps 2014 and 2015 to model after?


                  • #10
                    I had a heater in my 2012. It didn't work well, and they installed a kit to improve performance. They moved the hot water supply to a hotter point on the engine and moved the return line to another spot that was supposed to increase flow through the heater core. Here are some pictures of where the original and new locations were. Even with the changes, it worked better, but still wasn't that hot. I didn't get the heater on my 2014 because of that. I took the pictures in case I put an aftermarket one in someday. I don't know if these changes are where the production locations are at now or not. If you are looking for the heater lines, they are the only two 1 inch soft rubber hoses running up the middle of the boat past the transmission. You can find them through the rear seat access point.
                    Attached Files


                    • #11

                      Very helpful. The new hookup seems to match where I have hooked up my heater. But if I'm interpreting your pictures correctly the new set-up isn't much better. I have lake temp water coming from the "new in" and darn hot water coming from the "new return." Heaters don't have a specific flow, nor a pump, so I'm wondering if the flow from the engine either isn't enough to cycle the hot water through, or there is yet another, better way to attach the heater hoses.


                      • #12
                        I have a 2013 and looking to improve mine as well. I have heard changing from a t connector to a y improves flow. Hope some can chime in on advise, hopefully pull mine out of storage this weekend or next and I can get pics where these connect up at. I do know th two lines that run toward the bow are the heater lines.


                        • #13
                          It still wasn't very warm air coming out compared to other boat heaters I've seen.

                          Sent from my SM-G930V using Tapatalk


                          • #14

                            Good info! When I winterized I located the supply line where your "old" supply is located (and capped). However, if you look at my pic in the thread I believe I have both the "old" and "new" return. Very strange.

                            My heater was marginal last year. I installed a new thermostat this Spring and when I ran the boat on the hose to leak check I wasn't getting any heat from the heater. Maybe when it's in the water and really run?

                            Anyway, appreciate the pics and the light you've shed on this mystery!



                            • #15
                              Is this an Ilmor engine design issue? Doesn't seem that anyone is happy with the heat produced when attached to an Ilmor.