Oil in gas/water in cylinders 94 Volvo Penta 4.3

[Jason Boatman]

I have a 94 Genesis, Volvo Penta 4.3. I bought on consignment two years ago from a boat shop. Who, according to them had went through the boat and maintained regular maintenance. After going through this boat myself now, I can tell that was a lie, and needless to say the boat shop is now closed (and there's only one other shop open where I live) I may have not winterized it properly this last year, my first time working on them. When I pulled the plugs at the end of the year, no water came out, but it had sat for most of the season. I managed to get all the water out of the cooling system and filled it up with some of that boat antifreeze.

Took her out twice this year and she ran great, all day long, no issues. Then took her out this last weekend, and almost immediately ran into problems. Engine overheated and became hydro locked. I checked the oil right then and there and level was good.

Took her out of the water, and got the engine free, but wouldn't start. Checked the oil and it was quart over. Pulled the plugs and they were foul, and there was water in the cylinders, but not a ton (like I've seen in videos). Checked the oil and it was grey and smelled like gas (explains why we were over). There also may have been water in it, but it was hard to tell.

Changed the oil, running a quart or two through it to get the grey out, and changed the plugs. At the same time did compression test and was over 135 -150 on all cylinders. Engine fired right up, and ran great like always until we cut it off.

Pulled the water pump and the impeller was toast, but still intact for the most part, not a lot of rubber lost in the system (but still some, just at least not the whole impeller). Looks like we sucked up quite a bit of sand, as there was some sand stuck in the impeller and throughout the system. Pulled thermostat and it's badly corroded, not sure how it even worked prior. Pulled exhaust manifold and risers, also badly corroded. Pulled the intake manifold and found a little bit of rubber from the impeller sitting right inside the top of the engine. Which, I don't think that could have got through a crack.

I would like to go head and replace the pump, thermostat & housing, exhaust manifold & risers, but I'm hesitant to do that as I am worried that would be futile if we have a crack in the engine.

What is everyone's thoughts on this?

Tia

 

[itsathepete]

You say the oil was gray? Was it still transparent or was it milky looking (not white obviously? Milky oil is a sign of water intrustion. Since you now have a new impeller and thermostat run it on muffs in the driveway for a while and see if you get water in your oil. Assuming your engine is carbureted, oil smelling like gas can be from a leaking needle and seat or from float level too high. If it's fuel injected you have a leaking injector or some other reason causing it to run rich

 

[Jason Boatman]

You say the oil was gray? Was it still transparent or was it milky looking (not white obviously? Milky oil is a sign of water intrustion. Since you now have a new impeller and thermostat run it on muffs in the driveway for a while and see if you get water in your oil. Assuming your engine is carbureted, oil smelling like gas can be from a leaking needle and seat or from float level too high. If it's fuel injected you have a leaking injector or some other reason causing it to run rich

Yea, it was milky, and there was definitely some water in the cylinders. It is carbureted, I was thinking I could have flooded it when trying to get the engine to turn because it's an electric fuel pump and I had to hold the key down while the motor slowly turned before freeing itself When I pulled the intake manifold some water came out from a port that I don't think water was supposed to be in, and like I said I found some of the impeller rubber laying right in top of the inside of the engine. Engine doesn't seem to be running rich, runs nicely haven't had any problems other than this. I still have to get the new thermostat and impeller, which I'll either have to order it or drive a few hours. But I'm thinking I'll get those and slap it back together and see how it runs before getting new exhaust manifolds and risers. I've looked everywhere and I'm not seeing a crack in the block, and the head gaskets look good also. I saw a couple of these volvos get cracked intake manifolds, but I'm not seeing that either. If there is one, it's pretty hidden.

Thanks for the reply by the way!

 

[itsathepete]

A leaking intake manifold gasket could allow water into the engine and possibly an intake port, causing hydrolock. I would get a new impeller, thermostat and intake gasket and see what happens.

 

[Lou C]

Sounds like you had 2 separate problems contributing to the overheat & hydro lock: impeller & thermostat not maintained
Exhaust system not maintained
As far as evaluating possible damage that is difficult. IMO you can take the cyl heads to a machine shop to have them checked for cracks and check the deck surface of the block very carefully for cracks. In my experience with the Chevy V6 the cyl heads can crack from a bad overheat whereas the block usually doesn’t crack unless water wasn’t drained in winter. I’d have the heads checked, check the block carefully yourself. If the heads check out ok then just re use them but if not buy a pair of reman V6 heads. Then put it back together with Fel Pro marine head gaskets & new cyl head bolts. Replace the exhaust, you can use Barr Marine aftermarket instead of Volvo OE.
I did this same job myself on my old ‘88 4.3, total parts cost was about $750 for heads, gasket set & head bolts. Exhaust was about $725. So for about $1500 did a top end overhaul & exhaust replacement.

 

[Jason Boatman]

Sounds like you had 2 separate problems contributing to the overheat & hydro lock: impeller & thermostat not maintained
Exhaust system not maintained
As far as evaluating possible damage that is difficult. IMO you can take the cyl heads to a machine shop to have them checked for cracks and check the deck surface of the block very carefully for cracks. In my experience with the Chevy V6 the cyl heads can crack from a bad overheat whereas the block usually doesn’t crack unless water wasn’t drained in winter. I’d have the heads checked, check the block carefully yourself. If the heads check out ok then just re use them but if not buy a pair of reman V6 heads. Then put it back together with Fel Pro marine head gaskets & new cyl head bolts. Replace the exhaust, you can use Barr Marine aftermarket instead of Volvo OE.
I did this same job myself on my old ‘88 4.3, total parts cost was about $750 for heads, gasket set & head bolts. Exhaust was about $725. So for about $1500 did a top end overhaul & exhaust replacement.

I think I'm going to go ahead and put it back together with new parts i.e. impeller, intake gasket, and thermostat, minus the new exhaust system, hook it up to some muffs and see what we get. We got really good compression, but that doesn't always mean everything. If we still get water at least I haven't had done a lot of work or spent a lot of money. If we still get water I think I'll go your route for the final repair. Looks like I could be a out a few seasons, but that's ok I'm learning something new and I think I like working on these. I'll let you guys know how it turns out.

 

[Lou C]

better check first to see if that old system is leaking water back into the center exhaust passage....or else....can hydro lock again!
BTW, my engine ran find with cracked heads after a bad overheat, for almost 3 seasons, then the Hgs blew at the end of the season, had water in one cyl (not enough to hydro lock luckily) and I rebuilt it over the winter/spring with the new heads. Turned out well still running well 5 years later.

 

[Lou C]

got my cyl heads from a local machine shop, $275 each.
Fel Pro marine gasket set
ARP cyl head bolts for small block Chevrolet
the old ones will be real rusty from raw water cooling, I could not get the bolts out even with a long 1/2" drive ratchet, so used my 1/2" De Walt electric impact gun the all came out didn't break one bolt.
also a thread chaser to clean the threads in the block to get accurate torque when you install the new cyl heads.

 

[Jason Boatman]

better check first to see if that old system is leaking water back into the center exhaust passage....or else....can hydro lock again!
BTW, my engine ran find with cracked heads after a bad overheat, for almost 3 seasons, then the Hgs blew at the end of the season, had water in one cyl (not enough to hydro lock luckily) and I rebuilt it over the winter/spring with the new heads. Turned out well still running well 5 years later.

There was some water in the center exhaust port on disassembly. How would I go about checking the system for that leak?

 

[Lou C]

Yea, it was milky, and there was definitely some water in the cylinders. It is carbureted, I was thinking I could have flooded it when trying to get the engine to turn because it's an electric fuel pump and I had to hold the key down while the motor slowly turned before freeing itself When I pulled the intake manifold some water came out from a port that I don't think water was supposed to be in, and like I said I found some of the impeller rubber laying right in top of the inside of the engine. Engine doesn't seem to be running rich, runs nicely haven't had any problems other than this. I still have to get the new thermostat and impeller, which I'll either have to order it or drive a few hours. But I'm thinking I'll get those and slap it back together and see how it runs before getting new exhaust manifolds and risers. I've looked everywhere and I'm not seeing a crack in the block, and the head gaskets look good also. I saw a couple of these volvos get cracked intake manifolds, but I'm not seeing that either. If there is one, it's pretty hidden.

Thanks for the reply by the way!

There was some water in the center exhaust port on disassembly. How would I go about checking the system for that leak?

You take apart the manifold and elbow, and check the sealing surfaces for flatness after sanding them smooth with a sanding block. Use a straight edge and feeler gauges, there should be no more than .002" variation across them and no pits in the sealing surface. If there are pits the gasket won't seal and you will have water in a cyl & be back where you started. You can prop up the manifold level and fill the water passages with acetone (careful flammable) and see if it leaks down to the exhaust ports. If so it's junk. Post up pix of what they look like when you clean up the mating surfaces.
new looks like this:

 

[Jason Boatman]

You take apart the manifold and elbow, and check the sealing surfaces for flatness after sanding them smooth with a sanding block. Use a straight edge and feeler gauges, there should be no more than .002" variation across them and no pits in the sealing surface. If there are pits the gasket won't seal and you will have water in a cyl & be back where you started. You can prop up the manifold level and fill the water passages with acetone (careful flammable) and see if it leaks down to the exhaust ports. If so it's junk. Post up pix of what they look like when you clean up the mating surfaces.
new looks like this:

View attachment 364309

I took a couple of pictures of the different things. I forgot to mention there was rust in the engine just above the intake. As far as the exhaust goes, I don't think I will be able to reuse it and trust that it will seal. It looks like the last maintenance used anabond or something, and I can't seem to get that off the face. Plus there's some significant corrosion and wash in numerous spots. No telling if it goes all the way through to the ports or not in some spots. After thinking about it some more, I'm going to go ahead and buy all the replacement parts needed, probably with the addition of a new intake manifold, and see where we get, just in case. Also looks like I'll be having to order everything in online, can't find most of the parts within 350 miles of me in Wyoming, not even in Denver. If that don't work then we'll try the heads. If nothing else the whole engine will be overhauled by the time we're done.

 

[itsathepete]

I think it's worth trying to clean up those manifolds. Once you get whatever sealant was used off of them and sand them flat, you will be able to tell more. And I don't see any concerning rust in the engine. The rust around the top edge of the intake ports is just where the intake manifold doesn't cover and it's exposed. The rust on the balance shaft is likely due to some condensation and won't hurt anything. The shaft just spins in the lifter valley and isn't coated with oil. That's why it has some rust on it.

 

[Lou C]

Agreed those don’t have a lot of flaking rust you could use a belt sander to clean them up (carefully) no rotary tools though…

 

[Kepin]

Hi Jason, wondering, what the outcome of your issue is. I have a very similar problem with my VP 5.7 GL, water on spark plugs, grey/blackish smock, grey/blackish oil, and risen three inches on top of max level. The engine stalled at some point while idling. Everybody saying that its a crack in a block. What's your find? Thanks

 

[Jason Boatman]

I'm not 100% yet. I have replacement parts on order. Everything from new intake manifold, to exhaust and risers, and raw water pump of course. I haven't been able to find a crack in the block anywhere. There's two main reasons why you'd have a cracked block though. One, improper winterization, or two, severe overheating. My entire cooling system needs overhauled. I'm hoping to have it done in a few weeks and cost is about $1500.00. If I still wind up with water in the oil, then I'll replace the heads for about another $500.00. If that doesn't resolve the issue then I'll have to pull the engine and possibly try and find a new block . My opinion on my issue is that when my pump crapped out and my engine overheated, it caused some seapage through the exhaust manifold and intake manifold. Which would explain why I had water in my cylinders, also finding water in my center exhaust port and then finding impeller rubber in the top of my engine. But I guess we'll find out for sure in a few weeks. Fingers crossed. Also, you should get a compression test done. It's pretty simple. You can even buy the compression tester for all $30 bucks.

 

[Kepin]

I'm not 100% yet. I have replacement parts on order. Everything from new intake manifold, to exhaust and risers, and raw water pump of course. I haven't been able to find a crack in the block anywhere. There's two main reasons why you'd have a cracked block though. One, improper winterization, or two, severe overheating. My entire cooling system needs overhauled. I'm hoping to have it done in a few weeks and cost is about $1500.00. If I still wind up with water in the oil, then I'll replace the heads for about another $500.00. If that doesn't resolve the issue then I'll have to pull the engine and possibly try and find a new block . My opinion on my issue is that when my pump crapped out and my engine overheated, it caused some seapage through the exhaust manifold and intake manifold. Which would explain why I had water in my cylinders, also finding water in my center exhaust port and then finding impeller rubber in the top of my engine. But I guess we'll find out for sure in a few weeks. Fingers crossed. Also, you should get a compression test done. It's pretty simple. You can even buy the compression tester for all $30 bucks.

I gather information on how to conduct the cooling system pressurized test. Already have a compression test done, a dry compression test for all cylinders, and a wet compression test blowing fogging oil into the plug hole. The test shows 140 on two neighboring cylinders and 180-200 on the other 6. The wet test shows 190-200 on all cylinders, including two with lower numbers.
As for winterizing, I do it by myself for about a decade every winter. Drain the water from water plugs and detach the hoses, on top of this I run 4-5 gallons of antifreeze through the engine, but as overheating, I can't say much, I have this boat for the second season and the previous history is a "mystery" and unknown. What Ive noticed is one of the elbows, the starboard side runs much cooler than the port side. Im trying to find a good marine mechanic, who can take the boat for repair, as she seats in the marina and I don't have a trailer.