I know this is a long read, but I was hoping to give as much info as I could. Thanks to those who make it through!!

About 3 mornings ago as I was performing my pre-run checks, I noticed the coolant overflow reservoir on my STBD main engine (SN:46174828) was empty.  I checked the main reservoir and it was completely filled.  So I started looking for external leaks but could find no evidence of an external leak anywhere.

I turned to looking for internal leaks and checked the oil and transmission fluid but neither had any abnormal level or visual indication of contamination.  At this point I was thinking I probably had a heat exchanger leak and was slowly losing coolant to the seawater side via a tube/sheet leak.  So I refilled the overflow reservoir, warmed the engines then started our cruise at 1050rpm @ 7knots, our typical cruising speed.

Within 10 minutes, the STBD engine started producing thick white smoke from the exhaust – and a lot of it.  I went and verified the coolant overflow reservoir level and I could definitely see that the level had lowered.  Typically I see level go up an inch or so, but it had dropped about a quarter inch.  Given the lowering level and thick white smoke, the heat exchanger leak seemed less likely.  During all of this, temperatures were normal at the helm indications (165F) as well as temps taken locally on the engine with an IR gun.  I was comparing them to the PORT engine and both were as matched as they ever are (within a couple of degrees).

We continued to slowly make our way and I kept checking the overflow reservoir every 5-10 minutes and could definitely see a lowering trend, but nothing drastic.  The white smoke sometimes got a little less, and sometimes would get worse.  Finally, I saw the helm temperature start to rise pretty rapidly and I turned off the engine immediately as the temp was passing 200F, but it continued to rise to around 220F before stopping.  No alarms were ever received.

After putting the other engine in neutral, I went down and saw that there was still coolant in the overflow reservoir, but it was lowering pretty fast as it was being drawn into the main reservoir – and it was empty within just a few minutes.  I didn’t want to open/check the main reservoir at that point as everything was pretty hot.  We finished our trip on the PORT engine and once the STBD engine cooled I checked the main reservoir and it was completely empty.

My research of the symptoms seems to suggest a potential coolant to exhaust manifold leak and based on my research I thought I would go after the two most obvious locations first: the exhaust manifold cap gasket and then the turbo charger to exhaust manifold gasket.

I am attaching pics of the exhaust manifold cap after removal – before doing any cleaning other than wiping off the gasket.  You can see what looks to be a loose sealing surface on the gasket hanging down in the pic with my hand, but there was no evidence of external leakage from the cap so I am not sure if that tear was the result of removing the gasket or a potential failure mechanism. 

Also I definitely found what appears to be residual coolant in the exhaust manifold.  (I stuck a paper towel inside and it came back soaked with a yellowish liquid which is the color of the coolant I use (Valvoline Zerex G05).  It didn’t fill the manifold, just some traces of it that I was able to see.

I haven’t removed the turbo from the exhaust manifold yet.  I basically wanted to attack this one step at a time so I started with the cap gasket replacement (the easiest) to see if that works.  If not, I will proceed to the turbo to manifold gasket and replace it and see if that works.  If not, then I am guessing I will have to remove the manifold and have it inspected/tested.  And the final attempt would be a head gasket replacement if all else fails. Basically after each step, I'll pressure test the coolant system and see if it holds.

My questions so far that I would like help with are:

• Given my symptoms and indications, am I on the right track?

• Does my work progression (1. cap gasket, 2. turbo gasket, 3. manifold removal, 4. head gasket) seem reasonable?

• Is there anything specific I should be looking at to confirm the source of the leak or which component likely failed? Nothing jumps out at me on the manifold exhaust cap and gasket, but maybe the pics reveal something to more experienced eyes.

Thanks for reading and any feedback is greatly appreciated!

Kyle

Most here know the fibreglass around the AC discharge normally gets stained from the water running/trickling over it. I guess if the pressure is on the high side it may shoot out far enough that this is not an issue for some however on Midnight Sun this is not the case therefor each spring the resulting stain/discoloration is removed however it does require some really intense work to get the area back to new condition.

I have 3 AC outlets, the front is at the water line below the antifouling paint and the rear is under the swim platform once again just above the water line into the antifouling paint and both of these are not an issue. It is the central AC discharge located midship about a foot or so above the water line which is staining the white fibreglass.

Last year my wax guy mentioned some boaters have started to install transparent PPF (paint protection film) just around the affected area. Has anyone here done this and if so what is the outcome. Going to try it this spring after cleanup just before launch.

Are there any other solutions that you know of or have heard about?

Will post some pictures on this thread once PPF is installed unless someone can point me to a better solution.

Hi everyone,
I have a 2001 Carver 406 42' aft cabin with Cummins 330's operating in the Chesapeake Bay. She has been a great boat, and we have enjoyed her touring the bay. I have been able to back into most slips we have visited except, of course, mine. It is a 45' slip with full finger piers (which is nice), but it has no pylons on the ends. It is 16' wide for a 14' beam boat, so there is not a lot of room for error. Backing in, I am completely blind to where the finger piers are. As a result, I am paying $3,000 this year fix all the scars and scuffs I have made over the last 3 years. The biggest problem occurs if it is windy since the boat has so much windage or there is a current. It can make returning to the slip a bad end to a good day...
I have 2 questions for the forum:
I recently read about crossing the helm to move the boat sideways-if you want to slide it to stbd, turn the helm to port, reverse stbd engine, and put port engine forward. It seems to work for some, but comments from others are that it has not worked for them no matter the variations they try. The boat is scheduled to go in the water in a few weeks, so I will try, but I am curious if anyone has had experience with a 406/similar boat.
Depending on how option 1 goes, I am contemplating a stern thruster. I don't have a problem swinging the bow with the engines, but being able to move the stern to align to the slip would make docking a lot easier. There are several companies that make them, and I would appreciate any input on other's experience or knowledge.
Any and all comments appreciated.
Buck

I recently purchased a new electric toilet and I had to upgrade the circuit breaker and wiring for the installation. I have a 1999 406 aft cabin. Is there a "neutral bar" or gang connection for neutral wiring in the bow area of the boat? How about the stern? Thank you!!

For the nerd boaters out there..... have a happy, safe and productive Pi Day.......

Hi all!
I am wondering if anybody has any information on the specification of carver vessels in regards to buoyancy, center of gravity and metacentric height. Why would I have interest in this you may ask.... I would like to add a Quick MC2 Gyro stabilizer to the boat. With the helm station a dozen or more feet above the waterline, I get rocked around quite a bit up on top of my 430. Its exhausting. In order to size the stabilizer system, I need to know these technical specs. Of course I have looked on the internet for quite a while, but I haven't found any useful information. If anybody can offer any information or direction I would really appreciate it!

Hi all,

I have a 10kw Onan generator, model MDKWB Series E, and the alternator has seized - again!

It happened the first time back on 11/23/23 and I took it to Holt Generator Shop in Jacksonville,FL and they replaced all three bearings and all seemed good, until today. Seized again, but now I'm in Key West and there are NO alternator shops here. I've called seven shops and no one works on these things.

An OEM one looks like it is running $600+, which just seems ridiculous to me. So, two questions:

1. Has anyone replaced their alternator with a comparable aftermarket one - and been happy with it? The model number for my current alternator is 185-5431 and I'm looking for a like-for-like drop-in as I don't have the ability to change/alter mounting brackets/pulleys/etc.

2. Can anyone recommend someone in the Key West/Marathon areas that has the ability to work on these, including replacing the bearings?

I'm going to disassemble it when everything cools down and if I find out it is something else I'll post back. But for now, it definitely looks like a bearing issue.

Thanks in advance!!
Kyle

I bought an Odyssey 4D AGM 174AH. I was going to use it as a start battery for many 390 454’s, then use the 2 GC AGM as house, and an odyssey GRP 24 for the genset. the 4D was a steel at West Marine for $350.00! Had not her thought. What about getting a group 31 AGM for start, hook 2 4D Odyssey AGM as house (380 SH, versus 210 for GC) . I guess the question is where to place the genset grp 24. I was thinking of under the dinette where the A/C is. Does anyone think that would be an explosion hazard? I will use Battery trays as the box or this may fit between the stringers. https://www.fisheriessupply.com/dyno-ba ... /batbox-4d

I guess i am asking if putting the battery (genset) in the area with the water heater and A/C would be a danger?

I am planning on selling my 2008 41CPMY. I am going back to sailboats. I have enjoyed the boat, I purchased it in 2021 after my wife passed away. She wanted a Motor yacht as our next boat.
The brokers around here (Clearlake, TX) seem to be unable to come up with comps.
Can anybody give me an approximate value? It has the D6 Volvo 370, new Eisenglass, Bow and Stern thrusters replaced in 2022.
Thanks in advance.

Okay...long shot...there used to be a frequent commercial for some travel destination(s) in the Caribbean ... there was a brief picture of a Carver tied to a pier in the background....it appeared to be a 3607 or 3807...It revealed externally mounted louvers covering the forward trapezoid windows ....obviously fabricated from sheet metal and adjustable...no doubt it could be open or closed....I have searched every where for some mention of this "louver" style treatment addressing an easy/handy control of privacy vs. visibility and yet sun blockage always....considering its functionality with a bonus of good styling and looks for the yacht it should be in high demand....anyone have a clue of a source for this kind of 'aftermarket' front window treatment ??