Water in Cyl Merc 140 am I on track?

[marlboro180]

-1983 4 Winns 180 w/ Mercruiser in-line 4 serial #6319412 with 881 hrs on it. mr/Alpa
Bought it used last year, inland freshwater boat. Not sure of prior owners maintenance habits, but seems in reasonable condition overall. I run the boat on a river in WI.

Compression test:
Cyl 1- 135, cyl 2 135, cyl 3 142 and the winner is...cyl 4 at 145!
Oh, did I mention the water shooting out of cylinder 4 at the top of each stroke??? - I still had the muffs on at well less than full house pressure.

I put the plugs back in, ran it back up to 130 degrees ( new 140 t-stat)and it seemed just as before, I guess I was just in denial of a serious problem like a cracked / warped head and was hoping to wake up from a dream. Took the plugs out , shot quite a bit of that wonderful PB Blaster into the cylinders and there she has been sitting while I have been reading all I can.

Being more familiar with sealed cooling systems and having read many, many posts on water in engines/ cylinders/ heads I'm not sure where to start.
I have to ask if I would be right in investigating the intake manifold mating surface and gasket before condemning the head or block?


Any advice would be greatly appreciated as to how to proceed.

 

[Fishermark]

Re: Water in Cyl Merc 140 am I on track?

Should I be looking for anything other signs of " tracing"?

Pull the riser and see what it looks like.

 

[fossill]

Re: Water in Cyl Merc 140 am I on track?

This should help you out:

http://www.boatfix.com/merc/Bullet/01/01_13.pdf

 

[marlboro180]

Re: Water in Cyl Merc 140 am I on track?

Thanks for the link to water intrusion. Hope to get to it this weekend.

Brian

 

[marlboro180]

Re: Water in Cyl Merc 140 am I on track?

Thanks fishermark. Pulled the exhaust riser and it looked fine except for the half burned flapper.... Decided to look further and this is what I found:

Pulled manifold off and there was a chunk of gasket missing/ heavily damaged between cyl 2 and 3 exhaust ports and part of cyl 4 exhaust looked pretty bad too. Checked for flatness on the mating surfaces( head and manifold), seems to be within tolerance per Clymer book.

Decided to go further and take the head off and see what's in there- Turns out the metal part of the head gasket was installed improperly- it had a kink in the gasket between 2 and 3. Obvious signs of exhaust crossover between the two cylinders. (black soot/ carbon) Checked head for flatness and was relieved to find it was good. Whew!

There is an area of repair/ sealant just below the head / block mating surface above the " freeze" plugs that seem to have been weeping water . Wish that had been disclosed to me when I bought it last year, as well as the 1988 stamp in the head ( it is an 82/83 GM inline 4 motor) Live and learn...

Due to the wear in the bores, I think I am now going to just put this thing back together , JB Weld? the weeping area closed and hope for the best while I look for another motor.

Any tips out there for sealing a block? I've seen a few...

Any tips on re-assembling the head? (besides not messing up the gasket )

Sealant or no on the manifold gasket? I couldn't tell from mine as it was so bad....

My lesson learned thus far is to ask a lot more question buying used and poke around a LOT more......Caveat Emptor!

 

[Fishermark]

Re: Water in Cyl Merc 140 am I on track?

A couple of thoughts...

1. So did you decide where the water is coming in at? You mention a bad head gasket between 2 & 3 with signs of exhaust gas between the two. But your water problem was on #4. So where is the water coming from? You need to make sure that problem is solved before putting it back together.

2. On the freeze plugs, or core plugs, are they seeping water from around them? If you replace them be sure to use brass plugs and put a coat of sealer on them - Aviation sealant works well.

3. Same thing on the head bolts. They go into the water jacket, I like to put a coat of aviation sealant on them with a light coat of oil at the head so you do not get a false torque reading.

4. No sealant on the manifold gasket. Be sure to get a quality OEM black graphite type of gasket for the riser, not one of the aftermarket green paper gaskets.

Good luck! Be sure to post your results.

 

[marlboro180]

Re: Water in Cyl Merc 140 am I on track?

A couple of thoughts...

1. So did you decide where the water is coming in at? You mention a bad head gasket between 2 & 3 with signs of exhaust gas between the two. But your water problem was on #4. So where is the water coming from? You need to make sure that problem is solved before putting it back together.

---Yeah , seems like a couple things going on here. Surely a bad head gasket seal between 2 and 3, and on futher close inspection also found a bit of moisture ( water) in cyl. #2 and 3 exhaust manifold passages as well as
# 4. The manifold gasket was in such terrible shape that when I took it apart it was hard to tell if there was crossover to the intake side. I will keep looking and am bringing the parts to a mechanic to see if his more experienced eye might find something I am surely missing.
Would the bad exhaust flapper valve have anything to do with it?


2. On the freeze plugs, or core plugs, are they seeping water from around them?

---My description was not good, sorry. It is the area above the freeze plugs near the top of the block in the water jacket that appears to be weeping through the block, not around the freeze plugs.


3. Same thing on the head bolts. They go into the water jacket, I like to put a coat of aviation sealant on them with a light coat of oil at the head so you do not get a false torque reading.

-- Roger that.

4. No sealant on the manifold gasket. Be sure to get a quality OEM black graphite type of gasket for the riser, not one of the aftermarket green paper gaskets.

--- I'm picking up parts today and the gasket is supposed to be what you've recommended.

Good luck! Be sure to post your results.

Thanks for the well wishes! I'll post update later!

 

[Fishermark]

Re: Water in Cyl Merc 140 am I on track?

My description was not good, sorry. It is the area above the freeze plugs near the top of the block in the water jacket that appears to be weeping through the block, not around the freeze plugs.

The only thing that can cause weeping "through" the block is a crack - freeze damage. OR perhaps corrosion all the way through. (Not likely). If you have a crack that is leaking OUTSIDE the block, then the chances are good that you have a crack leaking INSIDE the block - into the oil.

Not to beat a dead horse here.... but you really need to identify the source of the water leakage before spending much money. It sounds like you block may be "toast" - if it is leaking internally, it is not something you are going to want to spend money on.

 

[marlboro180]

Re: Water in Cyl Merc 140 am I on track?

Fishrmark,

Just got back from the shop and got the related parts to re- assemble.

While I was cleaning up the ehaust ports ( decorbonizing) I hit a spot way inside the manifold and under the carbon buildup was a crack in the wall between the wet jacket and exhaust side. Viola?
Well, besides the block weeping...

 

[Fishermark]

Re: Water in Cyl Merc 140 am I on track?

The crack in the manifold would certainly allow water in the engine. I would still look closer at the block however - especially with "the water shooting out of cylinder 4 at the top of each stroke." Perhaps someone else will chime in with their experience....