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!

340 Monsoon not reaching temperature


Recommended Posts

My 2007 VLX has not been reaching the 160 degree temp that it has always run at.  I installed a new thermostat, no change.  Tested the thermostat to make sure it was opening and reinstalled, no change.  I swapped out the temperature sensor, unplugged the batteries and plugged back in, no change.  The engine hovers right around 100 degrees and doesn't vary much.  I shut the engine down and the temp rises to 110, as soon as I turn the engine back on, it goes back to 100 degrees.  I also have verified this temp with an infrared gauge.  

I'm beyond frustrated at this point, but starting to think that maybe the engine isn't hitting on all cylinders?  When I try and get up to speed, the engine bogs down, like it's flooded.  

Any tips from folks that have seen this problem before would be greatly appreciated. 

Link to comment

I took the upper cap off of the thermostat housing and there is definitely corrosion. I wouldn’t think there would be enough to allow water to bypass the thermostat, but I have no experience with it. A friend of mine mentioned a second water pump interior to the engine. Does anyone know if these break often? And if they do, would that allow water to bypass the thermostat? 

Thanks everyone 

Link to comment

Read my post on "Monsoon 350 'conditional' overheating.

If you have Cat exhausts, and your boat was re-plumbed per Indmar recommendations, sounds like you have similar issues to mine running at 130'.

 

Link to comment

I found the resolution.  With some really solid help by Indmar and Inboard Online, the issue was the thermostat housing.  The old one was corroded to the point where water was making its way around the thermostat, thus not letting the engine get to temp.  Boat is running great again!

Link to comment

Join the conversation

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

Guest
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...