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!

Impeller replace or not after overheating


Recommended Posts

So last weekend is out cruising fast across the lake when I got an overheat code. The engine temp was at 180 I backed off the throttle immediately and the temp came down fast.  It was at the end of the day so I just took it slow back to the ramp with no other overheating issues. At the ramp I checked the fresh water intake and it was clean.  The next day I inspected the sea strainer and it was 1/4-1/3% full of sand.  So I'm pretty sure that was the cause of the overheating.  So my question to you guys should I replace the impeller or not?  A little background is I'm going on a weeks long vacation Saturday.  I've already ordered a new impeller just in-case but I'm not sure if I should replace it before I leave or just see how the boat performs first or just take the cover off and inspect it.  Replacement/inspection seems pretty straight forward but I'd hate to screw something up and not have a boat for the trip. FYI M6di 55hours

Thanks

 

Link to comment

If it were me I'd just go stick the boat in the lake today and make sure it is working right.  I'd do the same thing if I replaced the impeller - since I don't want to find out if a new impeller has a problem when I am on vacation either.

  • Like 3
Link to comment

Before changing the impeller, I think I would check to see if you have any rubber pieces in the top of your heat exchanger (follow the horizontal hose starboard of the impeller pump) by removing that side of the hose and looking down. If so, definitely replace the impeller. If not, I might just keep an impeller and some tools in the boat.

My impeller exploded on the lake a few weeks ago and swapping it on the lake wasn't bad assuming you have a spare and the appropriate tools. I had 56 hours on the motor with original impeller. 

Edited by G Spot
Link to comment

I just replaced my impeller on 22vlx. Impeller is under the muffler with no visual access. I was able to remove impeller cover, gasket and impeller by feel. To replace the impeller was easy. To line up the gasket and cover was a no go. So I used threaded rod, I think it was 8/32 threaded about an inch long in each of the 4 bolt holes so that I could feel the gasket being positioned in the correct location. Then I slid the cover over the rods. Then one at a time I unthreaded a rod and replace the brass bolts. This way I ensured the gasket was in the correct location.  I keep the old impeller, rods and gasket in the boat tool box for emergency.

Link to comment

Being that it is an M6 (and there have been FAR too many stories of the M5/M6 impellers toasting rather early in life, even the newer version) i'd go ahead and replace it before your trip just so you don't have to worry about it.  Keep the old one as a spare if it looks okay. It may have been the sand in your filter but it also might be that you have a vane or two that are already melted.

Link to comment

The impeller in our M6 went out after the fireworks Saturday night. Had to be towed back to the dock. About 42 hours on the motor. Will be getting a spare and checking the sea strainer every trip from here on out. 

Link to comment

Just FIY, the most recent recommend maintenance schedule for the M5 and M6 from Malibu suggests impeller replacement every 50 hours or annually, whichever comes first, just like engine oil and filter changes.

Link to comment
On 7/7/2020 at 5:14 PM, AxleGrease99 said:

The impeller in our M6 went out after the fireworks Saturday night. Had to be towed back to the dock. About 42 hours on the motor. Will be getting a spare and checking the sea strainer every trip from here on out. 

Were you idling while waiting/watching the fireworks?  Idling seems to be what does it (fails to prime.)

Link to comment
9 minutes ago, gregtay said:

Were you idling while waiting/watching the fireworks?  Idling seems to be what does it (fails to prime.)

Maybe idled for 2 minutes while pulling in anchor lines. Then started a slow cruise back to the dock. 800-900 RPMs. Started getting hot about 2 minutes into the cruise. Killed it and opened all engine compartments. 

Link to comment
13 minutes ago, AxleGrease99 said:

Maybe idled for 2 minutes while pulling in anchor lines. Then started a slow cruise back to the dock. 800-900 RPMs. Started getting hot about 2 minutes into the cruise. Killed it and opened all engine compartments. 

Unfortunately it seems it doesn't take much.  Until Malibu can figure out a "fix" i'd suggest the following:

1) always have a spare on the boat (and I hear inventory is low for some dealers since they are flying off the shelves)

2) IF you need to idle for a bit after starting the boat (marina, etc) pop it in neutral and rev the motor a few times to ensure the pump primes.  Once water is flowing idle should be fine.

Link to comment
1 minute ago, gregtay said:

Unfortunately it seems it doesn't take much.  Until Malibu can figure out a "fix" i'd suggest the following:

1) always have a spare on the boat (and I hear inventory is low for some dealers since they are flying off the shelves)

2) IF you need to idle for a bit after starting the boat (marina, etc) pop it in neutral and rev the motor a few times to ensure the pump primes.  Once water is flowing idle should be fine.

Great suggestions. 
 

Thankfully we had been tied up watching fireworks with my dealer. He jumped on board right away when it got hot. By the time we finished breakfast the next morning (on a Sunday) he had personally came over to swap the impeller out. 
 

Anyone looking to purchase a BU in northern Wi should definitely contact Ryden Marine. 
 

Side note: there was a ton of boat traffic this past weekend which was stirring up the lake pretty good. I’m sure it was a combination of both the known issues and dirty water. 

Link to comment
10 hours ago, gregtay said:

Unfortunately it seems it doesn't take much.  Until Malibu can figure out a "fix" i'd suggest the following:

1) always have a spare on the boat (and I hear inventory is low for some dealers since they are flying off the shelves)

2) IF you need to idle for a bit after starting the boat (marina, etc) pop it in neutral and rev the motor a few times to ensure the pump primes.  Once water is flowing idle should be fine.

Number 2 goes a LONG way.

Link to comment

Okay I got the old impeller out and its missing 3 fins so where do I clean the debris out from like @G Spot  instructed.  1 Hose?, Heatsink looking thing? or Canister?

Once I find the right place any tip on how to get it out?

Thanks, Crew

IMG_20200710_162335046.jpg

IMG_20200710_162327478_HDR.jpg

IMG_20200710_162320903.jpg

Link to comment
48 minutes ago, dcarl said:

Okay I got the old impeller out and its missing 3 fins so where do I clean the debris out from like @G Spot  instructed.  1 Hose?, Heatsink looking thing? or Canister?

Once I find the right place any tip on how to get it out?

Thanks, Crew

 

 

IMG_20200710_162320903.jpg

Ok I figured it out its this guy right here, there's a honeycomb grate below it I got 2 of 3 fins. Then ran it on a fake lake and got the other one.

  • Like 2
Link to comment
52 minutes ago, Steve B. said:

Great job on not taking a chance !  Very well just saved you big time !

Steve B.

Thanks @Steve B. crossing figures it lasts through the week of vacation if not I'll post a pic of me on a pontoon that says rent me on the side:(

 

Link to comment
2 hours ago, dcarl said:

For all you M6 & M5 owners this is the best impeller puller... for sale you only have to pay for shipping and handling.

puller.jpg

Nice job finding the pieces and catching it before it got worse. 
 

If that’s the free paint can openers from HD, I use them as well. Lol

Link to comment
5 hours ago, dcarl said:

Okay I got the old impeller out and its missing 3 fins so where do I clean the debris out from like @G Spot  instructed.  1 Hose?, Heatsink looking thing? or Canister?

Once I find the right place any tip on how to get it out?

Thanks, Crew

IMG_20200710_162335046.jpg

IMG_20200710_162327478_HDR.jpg

IMG_20200710_162320903.jpg

That first pic of the canister is your oil filter. Glad you didn’t look there first. 

Link to comment

All appears to be working but now I can't remember what the normal operating temperature is.  I searched here and goggled but couldn't find anything M6 specific.  Its running between 160-172.  I thought when it threw to overheating error it was only 180 or so. 

 

Link to comment
1 hour ago, dcarl said:

All appears to be working but now I can't remember what the normal operating temperature is.  I searched here and goggled but couldn't find anything M6 specific.  Its running between 160-172.  I thought when it threw to overheating error it was only 180 or so. 

 

My M6 typically operates between 168-172 once up to temperature. I don’t believe it threw the overheat code until 190-200. 

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...