Just Had a "HOLY S**t" moment - Need Advice (Mercruiser 470)

[natemoore]

Re: Just Had a "HOLY S**t" moment - Need Advice (Mercruiser 470)

NateMoore - thanks for the encouragement. I am willing to do what ever it takes to get this thing back going again, but my better half would have a few issues with another couple of grand being dumped into the boat. For me, it is worth it, but for her, not so much. I'll have to figure out a way of her not finding out.

I probably will end up pulling the head and changing the gasket at this point, but it looks like the exhaust manifold/elbow might be where this problem potentially gets solved. I'm looking at close to a grand for a new manifold/elbow set up, so maybe I'll try to get mine fixed at a machine shop.

By they way...nice plane in your picture. Did you fly them?

I RODE in them (naval flight officer) when I was in the Marine Corps. That's the EA-6B Prowler; electronic warfare bird.

You can get intake manifolds on ebay no problem. Exhaust manifolds are harder to come by. New ones are insanely priced. I bought a new aftermarket exhaust riser on some website that was reasonably priced and good quality. I'll dig it up tomorrow. Bite the bullet and use Quicksilver gaskets.

 

[solar7647]

Re: Just Had a "HOLY S**t" moment - Need Advice (Mercruiser 470)

I did not get the chance to get the manifold off yet. I wanted to but I am in "supposed" to be babysitting my sick 7 year old. Wife will be home soon and I don't want the 7 year old to rat me out. Tomorrow is my wedding anniversary, so it will be Thursday at the earliest. Weather permitting I'll knock it out then. I'll refer to my manual once I find it, but how hard is it to get off? Doesn't look like it should be too bad. I'll take off the manifold and elbow in one shot if i can. When I get it off, what should I be looking for in both the manifold and elbow?

You can get them both off by removing the bolts that go down the side of the manifold.Refer to the 3.7L rebuild link in my signiture, it will provide some guidence. It is the same engine just a newer model then yours.

when you get it of the first thing you need to look for is signs of water in the manifold and the exhust ports on the head....

If the manifold is the problem there will be in both. If there is no signs of water it isnt the issue.

If water is was is in the oil, there is only one way for it to get there. The water only goes through the engine at the rear right side of the riser (looking at the front of the engine so the intake is on the left and exhust on the right). So for it to get into the engine block it would need to drain over comming the thrust of the exhust leaving the engine, drain into the manifold, then down onto the head, get through the exhust valve and then you would have to have bad pistin ring for it to get into the oil. Or once it gets to the head it goes through the valve seal into the top of the head, mixes with oil and down through the oill system.

That is the only way for it to be water.....every other issue would mean that you have coolant leaking into the oil so if involves more trouble shooting.

possible other loacations the issue could be are:

1) There is a gasket between the riser and manifold that could be leaking coolant into the engine
2) The intake manifold gasket
3) The head gasket- intake side of the engine---if gasket goes and is leaking coolant into the cylinders and is draining into oil you need new piston rings too.
4) cam shaft oil seals
5) Cracked head
6) cracked Block


Even though your coolent level seems fine when you take the cap off dosnt mean that you not missing some. To be 100% sure drain the hole system, it should hold 11qrt so if your missing a signifcant amount one of the mentioned areas is the issue.

 

[natemoore]

Re: Just Had a "HOLY S**t" moment - Need Advice (Mercruiser 470)

When you start disassembling, take digital pictures of each and every step. Those will come in handy when you're putting it all back together.

Here's what my cylinders looked like. Notice the pitted areas where water entered the cylinders.

 

[djfam]

Re: Just Had a "HOLY S**t" moment - Need Advice (Mercruiser 470)

Solar....awe inspiring post on the rebuild. I am impressed. If I have to go that route, why dont I just send you my motor for a while? Just kidding.

Nate...I will be sure to take a lot of pictures because this process will test my limited mechanical capability to be sure.

I did some preliminary searching online today for manifold replacements. The story is not good. Apparently, the part is no longer made and no-one seems to carry it anymore. Some guys in Australia are making some and charging about $2k for them. That is out of the question. I guess I'll be scouring craigslist and ebay in the next few weeks to find one (If I need it). Mercruiser part number is 71527A17. Can I get a machine shop to do the repairs?

Thanks as always.

 

[nola mike]

Re: Just Had a "HOLY S**t" moment - Need Advice (Mercruiser 470)

Thanks for the responses...

The coolant levels and oil levels were both fine although i did not check them again after the fact and the coolant mix was correct (50/50). I'll do a compression test and check that. I dont think i have the tools to do a pressure test on the cooling system, so i"ll need to schedule a visit to the dealer for that. If it is just a head gasket - i know that is not an easy job but is it one i can do on my own? Any special tools required?

I'll keep you updated.

you can borrow a pressure tester from autozone, etc. whoops, someone beat me to it. and if you had AF in the block, it isn't cracked. did you drain the seawater section? if you left water in there, that might account for a cracked riser...

 

[solar7647]

Re: Just Had a "HOLY S**t" moment - Need Advice (Mercruiser 470)

Solar....awe inspiring post on the rebuild. I am impressed. If I have to go that route, why dont I just send you my motor for a while? Just kidding.

Nate...I will be sure to take a lot of pictures because this process will test my limited mechanical capability to be sure.

I did some preliminary searching online today for manifold replacements. The story is not good. Apparently, the part is no longer made and no-one seems to carry it anymore. Some guys in Australia are making some and charging about $2k for them. That is out of the question. I guess I'll be scouring craigslist and ebay in the next few weeks to find one (If I need it). Mercruiser part number is 71527A17. Can I get a machine shop to do the repairs?

Thanks as always.

2K is crazy!!! I got my hole new long block that I did that rebuild on for $1899 and it came with all the gaskets, new oil pump and a 18 mounth warrenty!!

I found a cheaper one! Still not cheap though! But new!
http://bpi.ebasicpower.com/c/MER37EXHA/3.7L+Exhaust+System+for+Mercruiser

Hears a link to a bunch of 3.7L parts on ebay there is a super cheap one if you go down the list!
http://shop.ebay.com/?_from=R40&_trksid=p3907.m570.l1313&_nkw=3.7L+mercruiser&_sacat=See-All-Categories

Dont get to far a head of yourself though!!! This issue could just be a gasket.....You need to start ripping that thing down!!

When you search for parts search 3.7L mercruiser and 470 Mercruiser.

They are the same engine for the most part the only differances will mainly be intake and extras..such as power steering cooler, oil cooler and so on.

 

[natemoore]

Re: Just Had a "HOLY S**t" moment - Need Advice (Mercruiser 470)

Let's see pictures of of your exhaust manifold before you worry too much. I imagine #4 cylinder will show a lot of pitting, like mine, but will be okay. The important thing is to pressure test it. I did this using an old inner tube, some hose clamps, and a piece of melamine. More on that when you get that far.