Coolant tank leaking on nautique 200 6.0 L

[NEO]

Has anyone had an issue with the closed coolant system on the 200s with the coolant tank forming spider cracks and cracking at the seam of the tank & leaking?

[Horton]

happened to a buddy of mine. boat smelled so bad. I thought @rico had a seriously terrible case of halitosis. unbearably stinky.

[rico]

I thought @horton had a bad burrito…

 

In our friend’s case, it was the heater leaking. Once heater was bypassed, no more leak and no more smell

[NEO]

Seems like a poor place to put the plastic overflow tank, right next to the exhaust manifold. Looks like the heat from the manifold is compromising the plastic. I bet the tank was made in China.

[jayski]

Had that issue with tank, replaced under warranty, Ski N Sport in Tyler TX was awesome as always!!

[Horton]

@rico that would have had to been one amazing bad burrito

[unksskis]

@NEO Can you post pictures?

[NEO]

 

[unksskis]

Thanks!

[NEO]

Have a replacement tank coming under warranty.

[gerjon2005]

I have had the exact same issue on my 2020 N 200, TWICE now.  I am on my 3rd coolant reservoir.  Nautique in Orlando told me to contact PCM.  My dealer wants it in for servicing, but that is weeks out each time and not worth it for a 60 dollar part I can swap myself.  This time I am going to try and put some thick washers under the mounts to raise it up a quarter inch or so to try and prevent any contact with the manifold which seems to be causing the small crack to form from slight vibrations against the hot manifold.  Not a huge deal in the grand scheme of things but annoying to have to deal with,  I don't want to have to do this every 2 years.

[unksskis]

@gerjon2005 are you purging your system? Sounds like there’s air and it’s getting hot. 

[Bufootin]

Had a similar issue with the coolant tank on my 22’ Response.  Coolant level was low due to a slow drip at a hose clamp connection so I suspect it was due to heated air expansion.  New tank for $30, tighten hose clamps and filled coolant to proper level.  No more issues.

[gerjon2005]

I can add some coolant, but is isn’t massively low, maybe just slightly below the “cold fill marker” on the side of the tank.  

On 7/6/2023 at 6:32 PM, Bufootin said:

Had a similar issue with the coolant tank on my 22’ Response.  Coolant level was low due to a slow drip at a hose clamp connection so I suspect it was due to heated air expansion.  New tank for $30, tighten hose clamps and filled coolant to proper level.  No more issues.

 

[gerjon2005]

On 7/6/2023 at 5:39 AM, unksskis said:

@gerjon2005 are you purging your system? Sounds like there’s air and it’s getting hot. 

Can you shed light on the “purging” process… thanks 

[unksskis]

PCM OM

page 36-37.  Basically take the hose from the heat exchanger, open valve, and bleed the system while filling the coolant reservoir until all air is removed.  It is helpful to have the reservoir end elevated, like on a boat ramp if possible.  @Jody_Seal may have some additional comments. 

[Jody_Seal]

what model 6 liter ? cat or non cat? if it is  a cat engine there are 1/8" ? vent plugs on the very top of the exhaust manifolds to bleed off air out of the coolant system. non cat is a bit more time consuming and requires elevating bow of boat and run on hose a couple heat cycles squeezing hoses and allowing air to rise up through the reservoir.

[GMC]

@gerjon2005 Before you shim that tank higher, check for contact between the cap and the top of the motor box.  I've seen four 200s with this system and they all leak coolant.  It drove me crazy trying to find leaks at connections/heaters/etc without success.  Someone recently noticed on one boat that the cap contacts the top of the motor box and shimmed the new one down.  I looked at another boat this weekend while changing the oil and I see all three things:  coolant in the bilge, a cracked reservoir right at the seam, and a witness mark of the cap in the foam on top/inside of the motor box.  I'm thinking that contact would be the cause of the cracking/leaks not necessarily the manifold temperature.  

Edited July 14, 2023 by GMC

[gerjon2005]

On 7/14/2023 at 9:36 AM, GMC said:

@gerjon2005 Before you shim that tank higher, check for contact between the cap and the top of the motor box.  I've seen four 200s with this system and they all leak coolant.  It drove me crazy trying to find leaks at connections/heaters/etc without success.  Someone recently noticed on one boat that the cap contacts the top of the motor box and shimmed the new one down.  I looked at another boat this weekend while changing the oil and I see all three things:  coolant in the bilge, a cracked reservoir right at the seam, and a witness mark of the cap in the foam on top/inside of the motor box.  I'm thinking that contact would be the cause of the cracking/leaks not necessarily the manifold temperature.  

The issue is that the tank when hot expands and then the seam of the tank rubs / vibrates / etc against the exhaust manifold and then a crash forms….  If I could figure out how to insert a photo other than using the URL I would  share one. 

 

[gerjon2005]

40 minutes ago, gerjon2005 said:

The issue is that the tank when hot expands and then the seam of the tank rubs / vibrates / etc against the exhaust manifold and then a crash forms….  If I could figure out how to insert a photo other than using the URL I would  share one. 

 

There is approx 11/16 inch clearance between the top of the cap and the inside of the engine hood,  so if i shimmed it up 3/8 of an inch it would still clear without coming in contact with the underside of the hood…. but good idea to check beforehand…

[GMC]

Cool, just didn't want to see anyone create one problem trying to fix another.  Meanwhile I looked at ours today and it is also contacting that boss on the exhaust manifold and it seems to be sawing into the seam on the bottle.  The crack is on the other side but a replacement bottle is in order along with some relocation shims to keep it in a good place.

Edited July 16, 2023 by GMC

[gerjon2005]

17 hours ago, GMC said:

Cool, just didn't want to see anyone create one problem trying to fix another.  Meanwhile I looked at ours today and it is also contacting that boss on the exhaust manifold and it seems to be sawing into the seam on the bottle.  The crack is on the other side but a replacement bottle is in order along with some relocation shims to keep it in a good place.

What year and hours  is your 200?   Is this the first one you have done?

[GMC]

This one is a 2021 with about 265 hours.  It would be the first bottle replacement I've personally done.  Someone else recently did the 2020 (550ish hours) at my other club.  

Edited July 17, 2023 by GMC

[Jtim3032]

This has happened a lot on 200s in the UK. We have just taken delivery of a new 200 and we noticed that our dealer had carved a circular recess into the underside of the engine hood to give the filler cap a little more room. If this is not done, apparently there can be contact between cap and foam insulation which in turn creates pressure on the hot coolant tank which eventually cracks, usually at a seam. The problem does not seem to happen to the same engine in a wakeboard boat that has a different engine hood.

[gerjon2005]

I really wish I could just get a straight answer out of PCM.   My dealer told me today that their explanation was that they had a bunch of bad reservoirs that they shipped in 2020, that had “weak” plastic that would develop cracks, but they didn’t really have a suggestion to address the fact that the replacement they sent last summer did the same thing other than it could have been from the bad batch made in 2020.   Trying to get the dealer to see if PCM will send what they know is a most recently made version.  I’ll keep you posted…

[gerjon2005]

PCM told my dealer that they had a bunch of bad bottles in 2020-2021 and that when I bought by replacement degas bottle it was likely still from that bad batch… Supposedly they are sending a no charge replacement or “good will” replacement to my dealer… it’s been a week and I’m still waiting i’ll keep you posted as to it’s arrival.  I’m still gonna shim it up an 3/16ths of an inch to prevent it from contacting the manifold when hot.