Philster
Captain
- Joined
- Sep 15, 2009
- Messages
- 3,344
I have either a cracked head (or corroded with a hole) or blown head gasket.
After a manifold/riser/elbow/gaskets job, I had the misfortune of seeing salt water coming out of the starboard side exhaust gasket (engine meets exhaust manifold). These new pieces/installation supposedly check out fine. Apparently, they happen to go in place withing weeks of either my head or head gasket going.
Item in discussion in my 1996 502c.i./8.2 liter Mercruiser EFI/MP with 333 hours on it, which has new manis/risers/elbows/gaskets.
Along with the salt water squeezing out the exhaust port (as mentioned above), I experienced an incredible amount of 'blow by'. Not just a little out the blow-by tube, but so much that the NEW oil went to a brown chocolate milk, the blow by tube sprayed a two-foot wide swath of blow-by onto my hatch AND the dipstick was raised and oozed chocolate milk into my bilge and all over said engine. That's a lot of combustion by-product getting into my crankcase to cause all that! Engine ran fine. That's the kicker.
MY DILEMMA: I don't want to have anyone dive into a head gasket repair, or dive into replacing a head, when the engine could be shot. The blow-by says one of two things:
1. "Sorry, bud, but the salt water has corroded the engine (eaten away at the internals, such as rings/pistons/walls/etc) and this is causing so much combustion by-products to get into the crankcase that blow-by is out of control, and compression is shot"
or
2. "Hey, Compression might be okay, and the blow-by might just have been a result of the water entering the cylinder, there-by increasing pressure through the roof and forcing large am'ts of combustion by-products past the ring and into the crankcase, plus the water/salt out the exhaust port (seen as visible water/salt on the exhaust manifold gasket where it meets the engine)." Now why this wouldn't go out the exhaust is beyond me.
I would think that nothing should happen repair-wise w/out a compression check. However, if I have a blown head gasket AND corrosion from salt water entering my engine... I have a dilemma as how to interpret a compression check.
Blown head gasket will lower compression in some cylinder(s). I'd expect to see some lower number(s).
If I replace the head gasket, I could still wind up with bad numbers if salt water got into those cylinders and the biggest loss of compression is from corrosion. So, I drop money on a repair that can't repair the corrosion.
I need some expert advice on how to proceed. I am afraid repairing the leak source might still leave me with an engine that has lost compression. The blow-by is incredible... but some say that could be because there was water in the cylinder jacking up the pressure... so of course there'd be blow-by.
Help. :redface:
After a manifold/riser/elbow/gaskets job, I had the misfortune of seeing salt water coming out of the starboard side exhaust gasket (engine meets exhaust manifold). These new pieces/installation supposedly check out fine. Apparently, they happen to go in place withing weeks of either my head or head gasket going.
Item in discussion in my 1996 502c.i./8.2 liter Mercruiser EFI/MP with 333 hours on it, which has new manis/risers/elbows/gaskets.
Along with the salt water squeezing out the exhaust port (as mentioned above), I experienced an incredible amount of 'blow by'. Not just a little out the blow-by tube, but so much that the NEW oil went to a brown chocolate milk, the blow by tube sprayed a two-foot wide swath of blow-by onto my hatch AND the dipstick was raised and oozed chocolate milk into my bilge and all over said engine. That's a lot of combustion by-product getting into my crankcase to cause all that! Engine ran fine. That's the kicker.
MY DILEMMA: I don't want to have anyone dive into a head gasket repair, or dive into replacing a head, when the engine could be shot. The blow-by says one of two things:
1. "Sorry, bud, but the salt water has corroded the engine (eaten away at the internals, such as rings/pistons/walls/etc) and this is causing so much combustion by-products to get into the crankcase that blow-by is out of control, and compression is shot"
or
2. "Hey, Compression might be okay, and the blow-by might just have been a result of the water entering the cylinder, there-by increasing pressure through the roof and forcing large am'ts of combustion by-products past the ring and into the crankcase, plus the water/salt out the exhaust port (seen as visible water/salt on the exhaust manifold gasket where it meets the engine)." Now why this wouldn't go out the exhaust is beyond me.
I would think that nothing should happen repair-wise w/out a compression check. However, if I have a blown head gasket AND corrosion from salt water entering my engine... I have a dilemma as how to interpret a compression check.
Blown head gasket will lower compression in some cylinder(s). I'd expect to see some lower number(s).
If I replace the head gasket, I could still wind up with bad numbers if salt water got into those cylinders and the biggest loss of compression is from corrosion. So, I drop money on a repair that can't repair the corrosion.
I need some expert advice on how to proceed. I am afraid repairing the leak source might still leave me with an engine that has lost compression. The blow-by is incredible... but some say that could be because there was water in the cylinder jacking up the pressure... so of course there'd be blow-by.
Help. :redface:
