2006 mercruiser MAG MPI standard cooling engine life expectancy question

[Marc2]

Hello All,

I have heard a couple of times that 10 years is the life expectancy of standard cooling mercruiser engines.

I have just changed manifolds and elbows with no signs of water intrusion.

I know I have the option to install heat exchanger but am at the 7 year mark and wonder if damage is already done and might be time to move on.

Any thoughts on standard cooling mercruiser engines greatly appreciated.

Thanks
Marcos

 

[Dshow]

Re: 2006 mercruiser MAG MPI standard cooling engine life expectancy question

How hard you use the engine, how well you maintain the engine, and where you use the engine (salt or fresh) are more of a factor than the model year...

 

[Marc2]

Re: 2006 mercruiser MAG MPI standard cooling engine life expectancy question

How hard you use the engine, how well you maintain the engine, and where you use the engine (salt or fresh) are more of a factor than the model year...

Yes.. Salt water. Very light use. Engines have 500 hrs.

 

[tpenfield]

Re: 2006 mercruiser MAG MPI standard cooling engine life expectancy question

Hello All,

I have heard a couple of times that 10 years is the life expectancy of standard cooling mercruiser engines.

I have just changed manifolds and elbows with no signs of water intrusion.

I know I have the option to install heat exchanger but am at the 7 year mark and wonder if damage is already done and might be time to move on.

Any thoughts on standard cooling mercruiser engines greatly appreciated.

Thanks
Marcos

Don't believe everything that you hear (or read) . . . you will find that most I/O engines will go 20 years or so with salt water use. Then you will start to have rust-through issues, etc. Manifolds/risers will need to be replaced maybe 3 times during those 20 years.

Converting to a closed cooling system after 7 years of salt water use may help, it is hard to say, but it certainly cannot hurt. If I were me, I'd run salt-away through the engine and maybe let it sit there for a while, prior to converting to the closed cooling system.

Bottom line is. . . at 7 years and 500 hours, there is still plenty of life left in the engine - salt or no salt.

 

[04fxdwgi]

Re: 2006 mercruiser MAG MPI standard cooling engine life expectancy question

Hello All,

I have heard a couple of times that 10 years is the life expectancy of standard cooling mercruiser engines.

I have just changed manifolds and elbows with no signs of water intrusion.

I know I have the option to install heat exchanger but am at the 7 year mark and wonder if damage is already done and might be time to move on.

Any thoughts on standard cooling mercruiser engines greatly appreciated.

Thanks
Marcos

It all depends on how well maintained it is. I wouldn't buy a poorly mainteained boat w/ 200 hours on it. But a very well maintained one with well over 500 hours on it is a deffinate candidate for purchase.

Mine is almost 22 years old w/ 1305 hours on it. Combo of salt and fresh water, raw water cooled. Engine and drive are origional and everything runs like new. Probably spend more time / $$$ than most, but she shows, with people stating they can't believe her age and she has never left me stranded (but I do have towing insurance anyway).....

Just make sure you stay on top of the maintenance and keep a close eye on the mainifolds and thermostat housing areas for corrosion / rust, using only high quality replacement parts and keep everything flushed after a salt water run.

After it's been in salt for a while, Closed Cooling Conversion generally is not recommended, since the salt and corrosion is already in there now (and always will be) and raises havoc with antifreeze. But I have seen some do it quite successfully after flushing with salt away, but who knows. I was going to do mine, but decided to do it if and when the engine needs to be replaced, then I'll start out fresh with no worries. BUT, if I got my hands on good used 454 5" heat exchanger for the cheap, I may be tempted to try it on this engine, anyway.

 

[achris]

Re: 2006 mercruiser MAG MPI standard cooling engine life expectancy question

General recommendation is if you are going to closed cool a saltwater engine, you have the first 12 months or 100 hours... After that, the internals are corroded enough to cause problems with the heat exchanger blocking up all the time.... At 7 years... don't even think about it....

Chris........

 

[Marc2]

Re: 2006 mercruiser MAG MPI standard cooling engine life expectancy question

General recommendation is if you are going to closed cool a saltwater engine, you have the first 12 months or 100 hours... After that, the internals are corroded enough to cause problems with the heat exchanger blocking up all the time.... At 7 years... don't even think about it....

Chris........

That was my main concern....is it past that time where changing is not worth it.

My biggest question is this....the engine is well maintained but has not been fresh water flushed in a consistent basis. I would say less than more. Engines are at 200 hours. Used very lightly and never abused. However, I know that when corrosion starts it does not stop. Soooooo. Is it better to move on or can I count on a good amount of years. Like I mentioned, I just changed manifolds and elbows. I am more concerned about internal corrosion.
Thank you so much for input.
Marc

 

[achris]

Re: 2006 mercruiser MAG MPI standard cooling engine life expectancy question

I would keep using it. I have worked on many inboard engines in moored boats that are seawater cooled and NEVER get flushed. Seen plenty with 20 years +... And still going strong. Worse case, all you do is get a truck 350 and swap your marine bits onto it (and I really can't see that happening anytime soon). And in that case (if you wanted to) put fresh-water cooling on then...

Chris.......