Valve seal replacement on 4.3

[dlowdog9]

I have my rockers off and puttinng compressed air into the cylinder #1, but the air is leaking out of the exhaust port (manifolds are off). Cylinder #3 is eating air, but not coming out of the exhaust port. I dont want to risk sending a valve down into the cylinder. Am i missing something?? Or is the leaking normal while doing a head on seal job?

 

[Scott Danforth]

If you have the rockers off and the valve is not sealing..... Time to pull the heads

 

[dlowdog9]

That's what im thinking. Going to put it all back together and do compression test. Boat has always ran fine, just a bit of smoke at start

 

[stresspoint]

I have my rockers off and puttinng compressed air into the cylinder #1, but the air is leaking out of the exhaust port (manifolds are off). Cylinder #3 is eating air, but not coming out of the exhaust port. I dont want to risk sending a valve down into the cylinder. Am i missing something?? Or is the leaking normal while doing a head on seal job?

thinking you may also have a ring problem as well as needing a valve job.

 

[Scott06]

That's what im thinking. Going to put it all back together and do compression test. Boat has always ran fine, just a bit of smoke at start

do a leak down test if you can. Have had older engines that had good compression but also had a lot of blow by ... doesn't tell the full story if you are diagnosing. Either way of you get air leaking out valves into exhaust need to pull the head

 

[dlowdog9]

do a leak down test if you can. Have had older engines that had good compression but also had a lot of blow by ... doesn't tell the full story if you are diagnosing. Either way of you get air leaking out valves into exhaust need to pull the head

Yeah, i am going to do one. Ill put it all back together this next weekend and run some tests before i pull the heads. Thanks for the responce!

 

[Bondo]

Yeah, i am going to do one. Ill put it all back together this next weekend and run some tests before i pull the heads. Thanks for the responce!

Ayuh,..... Just run each piston up to Tdc, compression, 'n pressurize through the spark plug hole,.....
That'll tell ya whether you have a rings problem,or burnt valves,.....

No need to put all the rockers back on for such a test,.....
Matter of fact, you just need to move each piston to Tdc, as it'll be in compression anyways, without the rockers,....

 

[dlowdog9]

Pulled the heads off. What do yall think? Ill be headed to a machine shop tomorrow to see about valve job. The leaking valve is in the first picture, closest to me.

 

[Bondo]

Ayuh,..... I guess you didn't pressurize the cylinders to see exactly where it was leakin',..??......

What do the piston tops, cylinders look like,..??

What I see on the heads are,.... Too much rust on all the cylinders,....
Pic 1, top, possible detonation piston bits on the lower side of the spark plug boss,....
Center, Ditto, just to the left of the intake valve,....
Lower, Ditto, to the left of the intake valve, 'n possibly on the top of the plug boss,....
Pic 2, Ditto in the top, 'n center,.... bottom, the intake valve looks to clean,....

 

[dlowdog9]

Ayuh,..... I guess you didn't pressurize the cylinders to see exactly where it was leakin',..??......

What do the piston tops, cylinders look like,..??

What I see on the heads are,.... Too much rust on all the cylinders,....
Pic 1, top, possible detonation piston bits on the lower side of the spark plug boss,....
Center, Ditto, just to the left of the intake valve,....
Lower, Ditto, to the left of the intake valve, 'n possibly on the top of the plug boss,....
Pic 2, Ditto in the top, 'n center,.... bottom, the intake valve looks to clean,....

I didnt run anymore tests. I knew the heads had to come off either way. Here are the pistons and cylinders. Thanks for the responses!

 

[Lou C]

This looks like a reman engine due to the .020 stamp on the pistons indicating that it was bored .020 but what's more concerning to me is the flecks of something in #2 cyl (front cyl on the starboard side) of something (aluminum?) and 2 scratch marks on the cyl wall. Also what's the flaky looking stuff on the top of #4 piston (center one), carbon or aluminum? I'd want to clean off the pistons well to verify what's going on. Mine had carbon build up on them as expected since when I took the heads off (2017) it was 29 years old but no alu pits or flakes.
What did the spark plugs look like?

 

[dlowdog9]

This looks like a reman engine due to the .020 stamp on the pistons indicating that it was bored .020 but what's more concerning to me is the flecks of something in #2 cyl (front cyl on the starboard side) of something (aluminum?) and 2 scratch marks on the cyl wall. Also what's the flaky looking stuff on the top of #4 piston (center one), carbon or aluminum? I'd want to clean off the pistons well to verify what's going on. Mine had carbon build up on them as expected since when I took the heads off (2017) it was 29 years old but no alu pits or flakes.
What did the spark plugs look like?

Wow, i didnt even notice the 20 over. I was in a hurry to get the heads off before the sun went down. Ill take a closer look at everything you mentioned next time im out there. The boat had 74 hrs on the tach when i bought about 5 years ago. 2004 Sea Ray 185. Very clean boat. Now im super curious about its history. Has always ran really well other then some smoke on initial startup. Here is a picture of one of the plugs. They all looked identical.

 

[dubs283]

Pics show history of water ingestion coming most likely from the exhaust. Could be cracked heads but to be so widespread suggests failing exhaust manifold, riser or gaskets

 

[Lou C]

The plugs don't look lean, from what we can see, also if it's a 2004 Sea Ray then it should be a Merc rigged 4.3 and by then, it should have had the dry joint manifolds & elbows so I wouldn't expect water leaking back into the cyls to be that likely at all, unless either one rusted out. Fresh water use?
However, being a votec engine, water intrusion could have happened from the intake manifold, leaks from these were common till they upgraded the intake gaskets. That USUALLY puts water in the cam valley though not so much the cyls like a manifold/elbow leak.
Even though I suspect it is a reman because of the .020 stamp, I see the OE GM style head gaskets, same ones I took out of my engine after they started leaking. When you peeled the gaskets off were they split anywhere near a water passage? That's what I found with mine, had water in 2 cyls and in the oil. I used Fel/Pro head gaskets and replaced the head bolts with APR head bolts, and a set of reman heads.
When you put it back together I like those Fel/Pro marine head gaskets and take a good look at your cyl head bolts, mine were really rusty after so many years in salt water so I replaced them, also make sure to really clean the cyl head bolt holes out well so you get accurate torque readings when you re-install the heads. I used a thread chaser on mine and they also need sealer on the threads like Permatex Aviation or Evinrude gasket sealer. Did mine 5 years ago still no leaks, or water in the oil.

The other thing I noticed is that there is a big difference in the appearance of the piston tops for the port vs starboard side, your starboard side looks almost steam cleaned but the port side looks more like the typical carbon build up. Maybe there was a water leak on the starboard side? What did your motor oil look like, any mayo under the valve covers?

 

[dlowdog9]

The plugs don't look lean, from what we can see, also if it's a 2004 Sea Ray then it should be a Merc rigged 4.3 and by then, it should have had the dry joint manifolds & elbows so I wouldn't expect water leaking back into the cyls to be that likely at all, unless either one rusted out. Fresh water use?
However, being a votec engine, water intrusion could have happened from the intake manifold, leaks from these were common till they upgraded the intake gaskets. That USUALLY puts water in the cam valley though not so much the cyls like a manifold/elbow leak.
Even though I suspect it is a reman because of the .020 stamp, I see the OE GM style head gaskets, same ones I took out of my engine after they started leaking. When you peeled the gaskets off were they split anywhere near a water passage? That's what I found with mine, had water in 2 cyls and in the oil. I used Fel/Pro head gaskets and replaced the head bolts with APR head bolts, and a set of reman heads.
When you put it back together I like those Fel/Pro marine head gaskets and take a good look at your cyl head bolts, mine were really rusty after so many years in salt water so I replaced them, also make sure to really clean the cyl head bolt holes out well so you get accurate torque readings when you re-install the heads. I used a thread chaser on mine and they also need sealer on the threads like Permatex Aviation or Evinrude gasket sealer. Did mine 5 years ago still no leaks, or water in the oil.

The other thing I noticed is that there is a big difference in the appearance of the piston tops for the port vs starboard side, your starboard side looks almost steam cleaned but the port side looks more like the typical carbon build up. Maybe there was a water leak on the starboard side? What did your motor oil look like, any mayo under the valve covers?

Ill have to get back to you on the gaskets. I didnt look really close at them yet, but have them. I have a full Felpro gasket set already and new Felpro head bolts on the way. The oil under the covers looked fine. Oil changes have always looked good.
I do have new dry joint gaskets between the manifold and elbow. The manifolds and risers look great, no rust on any of them. As far as i know, its always been a fresh water boat. I have to believe this boat sat for alot of its life with water in the motor. I just dont know. Thanks alot for the in-depth responses. It really helps and has me thinking!

 

[dlowdog9]

@Lou C
Here is a picture of the intake manifold gaskets after i pulled it off.

 

[Scott Danforth]

I would acetone test the exhaust manifolds. Looks like water in the cylinders

 

[Lou C]

I’m not seeing a clear sign of a leak with the intake so I’d carefully check the exhaust manifolds esp on the side where the piston tops looked steam cleaned.

 

[dlowdog9]

I’m not seeing a clear sign of a leak with the intake so I’d carefully check the exhaust manifolds esp on the side where the piston tops looked steam cleaned.

Will do! Thank you for your help!

 

[dubs283]

Post a picture of the exhaust ports on both heads and exhaust manifolds. You definitely have water intrusion to the combustion chamber from somewhere, almost every time it's from leaking exhaust

Other pictures don't give definitive proof of water intrusion but can really only see intake ports in provided photos, need to see exhaust ports on heads and manifolds