Mercruiser 470 exhaust manifold cracked

[jabfd]

Re: Mercruiser 470 exhaust manifold cracked

do you mean 220 degrees . your right about how a/f can get into oil but someone told me that it could go down the exhaust into the cylinder and into the oil .that seems a long way to go ! so when i checked the riser and found a hole letting raw water into the manifold i thought maybe he's right . found those leaks i stated before and now hopefully the 2 pound drop in 35min was just the tool . oil still looks clean .what do you think ? does your engine run good now ?how hard was it to replace head gasket ?

 

[Live-liner]

Re: Mercruiser 470 exhaust manifold cracked

Yes, I meant 220, sorry I'm typing fast cause I'm at work. Head gasket was not difficult, just have to make sure it's not warped from the overheat, and follow instructions as per manual.
I am taking the boat for a sea trial Saturday, hopefully all is well. For the record, I never ended up with water in my oil. I changed head gasket because at that point, it was the right thing to do. If I had time, I would have brought the head to a shop and had refreshened. I fish in the OTW Striper Cup and want to salvage the remaining season. I will take the head off and have it gone through this winter.

 

[jabfd]

Re: Mercruiser 470 exhaust manifold cracked

Yes, I meant 220, sorry I'm typing fast cause I'm at work. Head gasket was not difficult, just have to make sure it's not warped from the overheat, and follow instructions as per manual.
I am taking the boat for a sea trial Saturday, hopefully all is well. For the record, I never ended up with water in my oil. I changed head gasket because at that point, it was the right thing to do. If I had time, I would have brought the head to a shop and had refreshened. I fish in the OTW Striper Cup and want to salvage the remaining season. I will take the head off and have it gone through this winter.

sounds like a plan iam hoping i can make this work untill the winter i dont want to lose out on boating ! Tomorrow i will be taken it out and see if the oil stays clean i hope . going out to potter's cove hoperfully i make it there back is another story lol.

 

[wake2013]

Re: Mercruiser 470 exhaust manifold cracked

Hello - I am currently having the same symptoms as you are describing. I found a large piece of my riser missing which was allowing A/F to leak from the reservoir into the exhaust chamber in the riser/manifold. I am going to replace riser/gasket. Did you ever end up having to change your head gasket or did the riser gasket do the trick? My oil had the consistency of a milkshake. Thanks.

 

[jabfd]

Re: Mercruiser 470 exhaust manifold cracked

Hello - I am currently having the same symptoms as you are describing. I found a large piece of my riser missing which was allowing A/F to leak from the reservoir into the exhaust chamber in the riser/manifold. I am going to replace riser/gasket. Did you ever end up having to change your head gasket or did the riser gasket do the trick? My oil had the consistency of a milkshake. Thanks.

I pressure tested the engine when I had my exhaust manifold off and it held so I replaced my exhaust manifold with the newer aluminum and problem was fixed which exhaust manifold do you have?

 

[wake2013]

Re: Mercruiser 470 exhaust manifold cracked

I have the cast iron manifold. It does not appear it has any defects, however the riser is definitely leaking coolant from the reservoir. I just picked up a new riser. When your manifold/riser leaked did you have a milky consistency oil? Thanks.

 

[jabfd]

Re: Mercruiser 470 exhaust manifold cracked

I have the cast iron manifold. It does not appear it has any defects, however the riser is definitely leaking coolant from the reservoir. I just picked up a new riser. When your manifold/riser leaked did you have a milky consistency oil? Thanks.

Yes i did .I don't know where your from but I have a riser for cast ion manifold used three months I upgraded to aluminum

Make sure the surface is clean and not pitted I had that problem with mine and could never get it to seal well . so I purchase the aluminum version good luck

 

[wake2013]

Re: Mercruiser 470 exhaust manifold cracked

That is encouraging news. I am hopeful it is just the riser and not a head gasket or the exhaust manifold. I live in Olympia, WA, otherwise that would have been great to buy it off you. Where did you end up getting your aluminum manifold/riser from and approximately how much were they? Thanks.

 

[jabfd]

Re: Mercruiser 470 exhaust manifold cracked

That is encouraging news. I am hopeful it is just the riser and not a head gasket or the exhaust manifold. I live in Olympia, WA, otherwise that would have been great to buy it off you. Where did you end up getting your aluminum manifold/riser from and approximately how much were they? Thanks.

I got mind from a local shop used for $200 with the riser I would pressure test the coolant system before you put the boat in water if the pressure drops start to isolate the exhaust manifold and test just that . Then you can do the engine and heat exchanger that way you know what is wrong

 

[wake2013]

Re: Mercruiser 470 exhaust manifold cracked

Good idea. How would I go about doing a pressure test with the riser off? Is there a way to "plug" the coolant jacket that is on the manifold? Thanks for your help!

 

[jabfd]

Re: Mercruiser 470 exhaust manifold cracked

Good idea. How would I go about doing a pressure test with the riser off? Is there a way to "plug" the coolant jacket that is on the manifold? Thanks for your help!

I tried to make a cover out of plexsi glass but failed I took my manifold off and put the riser back on that way I could look in the exhaust ports to see where the leak was coming from I found it was by the gasket . You can get the pressure tester from autozone or any other parts store you have to cap all four connection and then pump it up .

Also then you can cap one line on the engine and put the adapter made to go from one size of radiator cap to the smaller size I used this to connect the tool to the other line and then pumped it up .

I used PVC end cap from 1inch line and stuck it in the hoses and tighten the clamps and it worked good

 

[wake2013]

Re: Mercruiser 470 exhaust manifold cracked

Put on the new riser... Oil looks better, however still a little cloudy. Just got pressure tester and the system is holding 13-14 psi... Fixed??? Does it maybe just take a few "flushes" to get rid of the old oil?