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!

Sign in to follow this  
Troy

Need Help finding leak in cooling system

Recommended Posts

Troy

Although no one may be able to positively identify my leak, I am hoping to get pointed in the right direction. I was out the other day just to run the boat and I heard a belt chirping, I opened the hatch to see that water was being sprayed all over the place, the underside ov the hatch was soaked and dripping and there was water all over the air intake cover and sidewalls.

I was by myself on an empty lake so I tried to run the boat about 15 mph while looking at the engine to find the source, I definately had water leaking into the bilge, but no spraying. I did not feel comfortable trying to run at speed while back at the engine, so I gave up and idled back to the dock. Had enough water leaking to need to use the bilge, but not enough that the bilge pump could not keep up.

At the dock, I left it running and dug around the engine compartment to try and locate. while the boat was idleing at the dock, absolutely no water was leaking, so it was only leaking under load.

History: Malibu VLX, last time out was about 6 weeks ago, at that time, the thermostat stuck and we heated up to about 20-5 for less than 5 minutes. Fixed the thermostat, replaced the gaskets, replaced the impeller and gasket and ran in driveway in neutral for 30 minutes with no leaks or overheating. While out on the water with this leak, the boat ran perfect and never got above 160 degrees. So it seems I have a leak that gets worse the faster the boat is going and is spraying up towards the top ot the engine when under load. The boat has been drained and kept above freezing, so I am ruling out cracked block from cold temps (unless it could have cracked when it overheated)

I am hoping to get out soon with another so I can observe at speed, but anyone that knows or wants to guess what I am looking for (it might be obvious, but just in case) I am all ears.

Thanks for any tips.

Troy

Share this post


Link to post
electricjohn

Loose coupling on the exhaust manifold crossover hose?

Share this post


Link to post
NorCaliBu

My guess would be the engine circulation pump that is mounted on the front of the engine (the front of the engine in a V-drive faces the back of the boat :Doh: )

At idle the circulation pump doesn't move much water (very little pressure is created) but the story changes as RPM's increase. Get in there with a flashlight and look for a water trail (calcium deposits left behind as the water dries). Usually pretty easy to see on a black block. Good luck.

Share this post


Link to post
Troy

Thanks guys, I'll check those. The water circulation pump seems to match the symptons. I'll look for deposits or any drips now that the engine and compartment are dried out.

Share this post


Link to post
99response

I would check that new thermostat gasket first, maybe the new one did not seal 100%.

Share this post


Link to post
tvano

my money is on a leaking impeller cover.

be overly cautious in snugging it because those bolts are brass (soft) and the torque spec is in INCH pounds (not ft. lbs.).

good luck w it.

Share this post


Link to post
BlastRlxi

Wasn't there a problem a while back about one of the hoses failing? I think it was the large "J" shaped hose that was splitting. This could be another possible source of the leak.

Share this post


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.

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.

Sign in to follow this  

×
×
  • Create New...