Plastic Block Drain Plugs

[muc]

Scott, I think that the problems you’re describing with this one engine are probably caused by using the engine in an application that it wasn’t designed for rather than flawed engineering. It sounds like this engine should have had freshwater cooling and maybe a seawater strainer? I feel that it’s very unfair to bad mouth a system like the single point drain system because some people choose to use it in a application it wasn’t designed for. I think it’s a fact that any product used in the wrong application and/or not properly maintained will have issues.

I think a lot of this comes down to price. I read on this forum that some people think Volvo products are to expensive. This thread started with the plastic drain plugs. For a few years I winterized more Volvo’s with plastic drain plugs then I did MerCruiser engines with plastic drain plugs. Volvo plugs cost 3 times more than the MerCruiser plugs, but there were some years I didn’t replace any Volvo plugs but would replace more than 10 MerCruiser plugs.

“You usually don’t get quality you didn’t pay for”

 

[muc]

a closed-cooled re-man 6.2 is $3k more than a raw water cooled

that is for a $680 heat exchanger, a $100 bracket, and a few hoses.

Merc wont honor the warranty if you buy a raw-water cooled motor and add a heat exchanger (even though its the exact same HX)

and it has a 5 week lead time.

per the broker now listing the boat, the added expense of the HX would not have translated into that much more money. the big thing is the "new engine and 3-year warranty"

Yes freshwater cooling can be expensive, one of the MerCruiser kits is $3676.00 just for the kit -- labor would be extra.

Not sure where your're getting a heat exchanger for $680. Some models of the 6.2 use a heat exchanger that's over $2000. Every freshwater conversion I've done required a different thermostat housing and almost all of the 6.2 MPI engine require a new ECM as part of the job.

MerCruiser will honor the warranty! I've installed more than a few freshwater kits on engines that are going to saltwater and it has NO effect on the warranty.

I think any good boat broker will explain to sellers that anything added to a boat won't increase it's value as much as the cost to add that thing. But it can increase the number of possible buyers.

 

[Scott Danforth]

Muc I used to design the mercruiser, VP, Ilmor, Indmar, PMC HX's, including the 7 marine units. I am still an active customer

the 6.2 unit is a 6-pass, 5 x 15-3/8 bundle with 223 tubes

BTW, Merc pays much less than I do. yet, they charge $2k for something they only pay about $450 for

according to the Merc rep down here in FL, they would not honor the warranty. so to get the boat back on the water in a timely manor, it went without HX cooling. Now its getting sold.

 

[muc]

Scott, Maybe you could answer a question about heat exchangers? I once had to replace a 6.2 MCM HX that the customer had damaged while they were replacing batteries. Our parts guy quoted and ordered the wrong P/N. The one he ordered was for a 6.2 just for the wrong serial number and didn’t fit. If I remember right it was $1200. The correct HX was like $2100.
They both looked pretty much the same, only real difference that I saw was the hose connections were in different places. Do you think there was any real difference like the number of passes the water made or the number of tubes in the more expensive one. Or was it just “what the market will bear”? Because the amount of heat that has to removed should have been the same. Are some HX that much more work to make that justify’s the price?

i understand that they need to make a profit, but sometimes they seem to get carried away.

As as far as warranty, I do understand why they don’t want to warranty a product they didn’t make a profit on.

P.S. The customer didn’t want to pay the difference so the Marina ate it. Unlike some of the places I worked, where they just would have told the customer “so sorry so sad”.

 

[Pzilly]

Run far from these plastic drain plugs! I just installed a new Mercruiser (383 Mag Stroker) last March. During a recent trip offshore, I noticed my bilge pumps were turning on excessively. Sure enough, I discovered that the top portion of the plug going into the Gen III cool fuel unit severed off for no apparent reason whatsoever and water was shooting through the hallowed portion of the piece broken off in the unit into the engine compartment. When I tried to remove the broken piece still in the unit after the trip, it kept disintegrating on me to a point I ended up damaging the threads. I was able to screw in a spare plastic plug that came with the motor as a temporary fix, but not easily (I still need to clean up the threads with a tap).

Some of you may have not of had any issues with these. But there is NO reason why one of these should have failed on me! I really think making these out of plastic was really lame.

How old where yours? They are plastic for a reason, metal to metal can seize, especially stainless, same reason I no long put metal valve stemmcaps on my vehicles, had to buy two new 60 dollar tpms because of seizing. If your using metal I highly suggest anti seize. I change the blue plugs out every year or two since they are cheap.

 

[Lou C]

Metal can seize....but if you winterize your engine once a year...and remove the metal plugs...and put either gasket sealer or marine grease on the threads, they will never seize! And never break off in the engine and cause you grief!
As far as those aluminum TPMS stems and caps, I know Chrysler changed the caps to plastic to prevent that problem, then changed the whole thing to a rubber stem. On mine what I did was just put a light coating of dielectric grease on the threads of the stem and no seizing.

 

[achris]

Most dealers actively advocate AGAINST closed cooling. "Adds complexity" is the common cry. I had CC on my previous engine (4.3LX) and the selling dealer did his level best to talk me out of it. Due to the expense I opted for raw water on the MPI. And again, it was the selling dealer (different dealer to the 4.3LX) who argued against it. Regrettably, I listened. :facepalm:...

As I won't be buying a new Mercruiser ever again (due to them using their own in-house built engines, and me then being open to the Australian consumer rip-off system that operates here), when the current 4.3 turns up it's toes, I'll be getting a remanned base engine and transferring all the fruit over. That engine WILL get CC (along with new exhaust manifolds)....

Chris.....

 

[PremierPOWER]

Here is proof of failed plastic plugs on a 2018.

Also, FWIW, I would not use the SS plugs on a cast iron block. You don't want to have those two metals contacting each other or you'll see galvanic corrosion.