Rebuild problem

[tlaw]

Hi, I have just finished rebuilding my 1993 5.7 mercruiser New rings, gaskets, valves had the heads tested. New OSCO manifolds and risers. Started it up and it ran fine shut it off and went to start it again. Starter sounded funny so I pulled the plugs and found about a cup of water in #8 cylinder, 6,4,and 2 had some wetness. Tried changing the riser to manifold gasket started it and found a cup of water in # 2 cylinder 4, 6, and 8 were damp. Also my exhaust flaps are making a clicking noise. I don't know if that is related. How can I test the new risers and manifolds ?Also how would I know if it is my intake manifold? I am going to do a leak down test in the morning but I understand that will only tell me if it is a headgasket, cracked head or valve seal problem. Please help. Thank you

[seapuppy]

wow....did you rebuild it yourself???...if your getting water in the cylinders then it has to be one of either manifolds..ie exhaust or intake....hard to check from a forum.....there is a fitting you can get to pressurize the coolant system if you have fresh water cooling....if it's raw water cooling then the only place you can get water is from the intake or the exhaust....with that said...you have to make sure that everything seals properly and that the bolts are torqued properly...and I mean every bolt.......has to be torqued properly....to the right settings...etc....
and as for the flapper valves ...they will click if they are running dry...so..check them to see if they are burnt from no water being pumped to the exhaust....check to make sure you have the water hoses connected properly also..if they are reversed they could pump water in the wrong direction....


SP

[pascavone]

i made a wood block and bolted it down to each mainfold then uses an air compressor in the raw water inlet to pressure test them.

over 40 psi is fine.

you should:
1. run the engine with out the raw water for a min to dry it out.
2. dry all plugs both sides.
3. connect on raw water side at a time, run boat.
4. check to see which side plugs are getting wet.
5. do the same to the other side.
6. the riser is holding a quart of water over the engine, so when you shut the engine off, the valves are open and no exhaust gas is blowing the drippping water, so it runs down the cylenders and into the intake mainfolds.
7. if you have fresh water cooled, then you could see anitfreeze if it was a head gaskets.

[tlaw]

Originally Posted by seapuppy

wow....did you rebuild it yourself???...if your getting water in the cylinders then it has to be one of either manifolds..ie exhaust or intake....hard to check from a forum.....there is a fitting you can get to pressurize the coolant system if you have fresh water cooling....if it's raw water cooling then the only place you can get water is from the intake or the exhaust....with that said...you have to make sure that everything seals properly and that the bolts are torqued properly...and I mean every bolt.......has to be torqued properly....to the right settings...etc....
and as for the flapper valves ...they will click if they are running dry...so..check them to see if they are burnt from no water being pumped to the exhaust....check to make sure you have the water hoses connected properly also..if they are reversed they could pump water in the wrong direction....


SP

Is there a way to know if it is the intake manifold? I have water in the oil as well. It is only one side of the motor that the plugs are getting wet. It is a sea water cooled engine. The engine was built by an auto mechanic. The block and heads were done at a machine shop. When he was building it the intake was put on and had to come back off the two center bolt holes had to be drilled out a little to fit properly. I suspect that he may have reused the gasket. Thanks for any advice that you could lend

[seapuppy]

you can't reuse the gaskets....it very well could be the intake manifold IF..the blocks were machined too much and will throw the angle off where the intake meets to the heads....or...if he mistorqued the sequence for the intake manifold.....
water in the oil is typical of the water hoses reversed....or an exhaust leak.....so....the next step is to find a MARINE mechanic...and have him help you out...2nd would be to get water out of the oil...I've used some stuff called "engine mechanic" or "Gunk"..pour it into the crank case..turn your water supply on...run for about 5 -10 min and then drain....but get the water problem fixed first....

one note..never ever run an engine without water supply to the leg....you will burn the flappers, boots, and impellers up.....don't ask how I know....


SP

[tlaw]

Originally Posted by seapuppy

you can't reuse the gaskets....it very well could be the intake manifold IF..the blocks were machined too much and will throw the angle off where the intake meets to the heads....or...if he mistorqued the sequence for the intake manifold.....
water in the oil is typical of the water hoses reversed....or an exhaust leak.....so....the next step is to find a MARINE mechanic...and have him help you out...2nd would be to get water out of the oil...I've used some stuff called "engine mechanic" or "Gunk"..pour it into the crank case..turn your water supply on...run for about 5 -10 min and then drain....but get the water problem fixed first....

one note..never ever run an engine without water supply to the leg....you will burn the flappers, boots, and impellers up.....don't ask how I know....


SP

Here is an update. Today we did a leakdown test on all the cylinders. They all tested ok. When I cranked the engine alot of water came out of 2, 4, 6, 8 so more water got into the cylinders overnight. That would usually indicate a riser or exhaust manifold, Right?

[ss3964spd]

Rule of thumb: Water in the oil, especially if it's a lot, usually means the intake is leaking water into the crank case. Water in the cylinders usually means risers/elbows/exhaust manifolds.

Each cylinder head has 2 water passage ports - one on each head. The intake manifold, however, only has one water passage cross over and it is located at the front. Regardless, either end can leak if not properly sealed, but they generally won't leak into a cylinder. If they do, they will only leak into a cylinder adjacent to the water ports on each end. On a Chevy engine those would be cylinders 1,2,7,8.

Water can leak past the rings and get into the crank case, but usually not much, which is why it's important to quantify how much water is in the crank case.

Since the problem is confined to the even side my guess is the exhaust system on that side. As a quick test I think you could loosen the exhaust manifold to cylinder head bolts - but don't remove them, and slide the mainfolds away from the heads a little bit, but leave the entire rest of the exhaust system hooked up. Then hook the hose up to the muffs and turn the hose on to pressurize the block and exhaust with water. See if any is coming out of the exhaust manifolds where you disconnected them from the heads.

Dan

[tlaw]

Originally Posted by ss3964spd

Rule of thumb: Water in the oil, especially if it's a lot, usually means the intake is leaking water into the crank case. Water in the cylinders usually means risers/elbows/exhaust manifolds.

Each cylinder head has 2 water passage ports - one on each head. The intake manifold, however, only has one water passage cross over and it is located at the front. Regardless, either end can leak if not properly sealed, but they generally won't leak into a cylinder. If they do, they will only leak into a cylinder adjacent to the water ports on each end. On a Chevy engine those would be cylinders 1,2,7,8.

Water can leak past the rings and get into the crank case, but usually not much, which is why it's important to quantify how much water is in the crank case.

Since the problem is confined to the even side my guess is the exhaust system on that side. As a quick test I think you could loosen the exhaust manifold to cylinder head bolts - but don't remove them, and slide the mainfolds away from the heads a little bit, but leave the entire rest of the exhaust system hooked up. Then hook the hose up to the muffs and turn the hose on to pressurize the block and exhaust with water. See if any is coming out of the exhaust manifolds where you disconnected them from the heads.

Dan

I have about a gallon of water in my oil. When we cranked it over most of the water came out of 8 but 2,4,and 6 was spitting water out as well.

[tlaw]

Originally Posted by tlaw

I have about a gallon of water in my oil. When we cranked it over most of the water came out of 8 but 2,4,and 6 was spitting water out as well.

Also we pulled that manifold yesterday and water came out of the ports. The riser was empty. Will muffs pressurize the system or does it have to be running?

[ss3964spd]

A gallon of water in the crank case is a lot, and I think much more than would leak past the rings, but the fact that 2,4 and 6 were also wet still suggests the exhaust mainfolds.

You might actually have two problems; intake manifold and exhaust.

Like SP said above if the machining on the block deck, head to deck surface, and/or head to manifold surface wasn't done correctly it could easily result in a intake leak. Basically, if the block deck and head surfaces get cut it effectively widens the distance between the heads (and you mentioned they had to enlarge the intake manifold bolt holes). Remember that the intake seats against the heads AND the end rails of the block. If the heads are now farther apart the intake may be dropping too low and resting on the end rails. At this point I think you'll need to pull the manifold, remove all the gaskets, then lay the manifold back on without any gaskets and center it.. Then check the gap between the manifold and heads. If you can slip an intake gasket between without resistance that's at least one of your problems. You could also place new intake gaskets on the heads, don't use any sealer yet, then drop the intake on and see what the end rail gap looks like.

You shouldn't need to start the engine to get water flowing through the exhaust.

Dan

[tlaw]

Originally Posted by ss3964spd

A gallon of water in the crank case is a lot, and I think much more than would leak past the rings, but the fact that 2,4 and 6 were also wet still suggests the exhaust mainfolds.

You might actually have two problems; intake manifold and exhaust.

Like SP said above if the machining on the block deck, head to deck surface, and/or head to manifold surface wasn't done correctly it could easily result in a intake leak. Basically, if the block deck and head surfaces get cut it effectively widens the distance between the heads (and you mentioned they had to enlarge the intake manifold bolt holes). Remember that the intake seats against the heads AND the end rails of the block. If the heads are now farther apart the intake may be dropping too low and resting on the end rails. At this point I think you'll need to pull the manifold, remove all the gaskets, then lay the manifold back on without any gaskets and center it.. Then check the gap between the manifold and heads. If you can slip an intake gasket between without resistance that's at least one of your problems. You could also place new intake gaskets on the heads, don't use any sealer yet, then drop the intake on and see what the end rail gap looks like.

You shouldn't need to start the engine to get water flowing through the exhaust.

Dan

Just pulled the intake manifold and the gasket had slipped. Will post results when I get it back on. Thanks to you and seapuppy for all you guys help.

[ss3964spd]

What type of intake gaskets are you using?

I always put a thin coat of RTV type sealer on both sides of the gaskets. Helps keep them in place and seal small imperfections on the head and intake sealing surfaces.

Dan