Heads Up.....early Mercruiser 8.1's w/ aluminum manifolds

fwebster

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Oct 6, 2006
12,150
Middle Tennessee ; Panama City Beach, FL
Boat Info
1996 450DA
Engines
3116 Caterpillars
Here is yet another heads up for owners of early 8.1 liter Mercruiser engines with aluminum manifolds that are run in salt water. These are aluminum manifolds with tubular stainless steel risers. Both the riser and manifold are sea water cooled even if the boat has FWC.

We had hoped to see the need to check manifolds and risers decreased when the 350 and 454 cid Mercruiser engines were phased out, but that does not appear to be the case. I saw 3 different boats with 8.1's and aluminum manifold failures last week in Florida. The years affected seem to be about 2003-2005 or up to the time Mercruiser stopped using aluminum manifold castings. Failure can either be external where a hole corrodes thru to the outside or internal in which case the engine is lost usually due to internal corrosion and hydrolocking.

The recommendation is to remove and check both the risers and manifolds immediately if you have aluminum castings. If there are signs of corrosion, go to your dealer and ask them to contact Mercruiser for you and that you want the manifolds replaced with later cast iron ones.

This is apparently another one of Mercruiser's "super double secret recalls". They are not advertising the problem and have not contacted dealers with a recall notice, but they are repairing some affected boats at no cost to the owner if the owner handles the repair thru a dealer who goes to bat for the customer. In one case last week, Mercruiser paid for a haul out and replacement of the port engine on an '04 390DA, long out of warranty, so it is worth seeing your dealer if you have a suspect boat.
 
Frank,

Is there anyway to id these engines by serial number, or was this manifold used on all 8.1 liter engines? I don't have access to boat/engine (all buttoned up under shrinkwrap for the winter) so looking is not an easy option.

Thanks
Henry
 
Henry,

I am sure, at some level, there is a record of the serial numbers and what components were used on what engine. Due to the fact that Mercruiser has chosen to do a "double secret recall"......i.e., you figure out you have a problem and them pitch a fit and they might help you fix it...... they aren't publishing any useful information to help us track down which engines are affected. In other words, if the wheel does not squeak; Mercruiser isn't going to tell you it might nor will they give you any oil.

So the short answer is, I don't have any information to help you figure this out, short of telling you to go check your manifolds. With an '02, I can tell you that I wouldn't launch the boat again without knowing. If you do have aluminum manifolds, I'd put a full court press on your dealer to get Mercruiser to replace them. A little aggrivation next spring may save you a $10K engine/labor bill in the future.
 
Hi All,

I posted the question to MerCruiser and they replied thus

"Good Morning. It appears your product would have been built with aluminum
exhaust manifolds. We had a running change in 2004. I hope this information
is helpful."

So I guss I need to have mine done pronto..

cheers

Ozzie
 
Ozzie,

How did you contact them specifically?

Thanks
 
I went to their website under (contact us) I typed in my name etc and provided my engine serial numbers..

then posted the question in the field provided, which was "I am inquiring if my engine is fitted with an Aluminium manifold"



Ozzie
 
I went to their website under (contact us) I typed in my name etc and provided my engine serial numbers..

then posted the question in the field provided, which was "I am inquiring if my engine is fitted with an Aluminium manifold"



Ozzie

Thanks! I just contacted them by E-Mail.

John
 
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Aluminum. BOAFT. My Boaft is getting to be really expensive. I'm hoping that once I get through all of these 3 - 4 year replacements, it'll slow down a little bit. I'd like to get it all done so we can go boafting next summer without too much worrying.

Today, I found out that replacing all four manifolds would be $4,000, which means $5,000. Getting the glass work done that we want would be 5 - 6,000. Extending our current warranty 3 more years would be $5,000.

Boafting is really expensive. Insurance - approaching $5,000. Annual gas $5,000. You get the idea. The good news is that the payments are only that much every 4 months.

I think my daughter is going to boafting school - Dorm 5,000; Sorority 5,000; Living expenses 5,000.
 
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John,

You seem to have had some type of problem with your local Sea Ray dealer in the past, but their service manager has been able to get Mercruiser to pay for aluminum manifold replacements. Just last week, Mercruiser sent in a new engine for a 2003 390DA that had one manifold fail and fill up an engine with sea water. Mercruiser also replaced the manifolds on the other engine at the same time.

I wouldn't write a $5K check until I explored getting Mercruiser hooked up on this one.
 
Hopefully Merc comes to the plate for you guys and aggree to fix this. Now's the time of year to get it done.
Best of luck, it's frustrating to hear.

John, when your daughter's done with School then she'll want to get married......that may cut into your manifold fund, but like OI said hopefully Merc will help
 
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John,

You seem to have had some type of problem with your local Sea Ray dealer in the past, but their service manager has been able to get Mercruiser to pay for aluminum manifold replacements. Just last week, Mercruiser sent in a new engine for a 2003 390DA that had one manifold fail and fill up an engine with sea water. Mercruiser also replaced the manifolds on the other engine at the same time.

I wouldn't write a $5K check until I explored getting Mercruiser hooked up on this one.

Concur. Roland told me about Eric's boat, but made no promises.
 
Todd,

He has no idea about overhead yet..........his kids are still in the "cheap to operate" stage!

Are you kidding? I'm 1/2 way through college on one, past the gymnastics phase on both, both cars are paid for (so far) - I'm hoping it doesn't get too much worse, other than weddings.
 
just before it gets better, there will come a time when you just want to go bury your billfold and checkbook somewhere in a place your wife and kids can't find.
 
I hear ya, man. We've already provided our kids more than 10X the luxuries that were provided to me. Their lives are different. I mowed lawns to buy my first new Sunfish in 6th grade. I bought my first new motorcycle (Yamaha 80 Enduro) in 8th grade, was working 1/2 time in a restaurant at age 15, and bought my first new car at age 16 (Honda Accord) and paid it off in 10 months.

They are busy in after-school activities, gym, dance... They can't get themselves around by bike to go to a friend's house or work - the world is different. When I was a kid, our lives revolved around my parent's social lives. I rode my bike to most after-school activities. As an adult, our lives revolve around our children's schedules. Now they're both driving, but just recently. I hope my wife joins me at the dock at sunset more now that she's free from choeffering (sp?). Now I won't have to feel guilty about spending early evenings on the boat after work. If she's not there, it's her own decision!

As a matter of fact, I'm going to offer to cook for her one night on the boat at the dock next week. I'll put the ball in her court, so to speak.
 
Aluminum. BOAFT. My Boaft is getting to be really expensive. I'm hoping that once I get through all of these 3 - 4 year replacements, it'll slow down a little bit. I'd like to get it all done so we can go boafting next summer without too much worrying.

Today, I found out that replacing all four manifolds would be $4,000, which means $5,000. Getting the glass work done that we want would be 5 - 6,000. Extending our current warranty 3 more years would be $5,000.

Boafting is really expensive. Insurance - approaching $5,000. Annual gas $5,000. You get the idea. The good news is that the payments are only that much every 4 months.

I think my daughter is going to boafting school - Dorm 5,000; Sorority 5,000; Living expenses 5,000.

It's obvious that the suspense is killing you guys, so I tell you: Break Out Another FIVE Thousand = BOAFT
 
Frank,

Very interesting! I had an engine replaced two months ago because of a failed riser. The dealer checked the other engine and replaced the manifolds and riser on the good engine because they where corroding. I have a 2005 340 with 8.1. The dealer did not say anything about a recall. However, it was all taken care of under warranty.
 
It's obvious that the suspense is killing you guys, so I tell you: Break Out Another FIVE Thousand = BOAFT

John - Until I read your entire post, I thought you might be thinking of a word that rhymes with "trucking" ;-) It certainly would apply!

Frank - Why would Merc use an aluminum manifold when they have no idea where the boat will be operated? Weight? Co$t? I can hear the discussion in engineering...lets use the manifold for an annode.

Should non-saltwater applications be concerned?
 
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