Volvo Penta 3.0 GS Keeps Blowing Head Gasket

[gator fan josh]

Boat information:
2000 Four Winns 170 Horizon
3.0 Volvo Penta GS
Volvo penta SX-M outdrive.

I bought this boat last October knowing that the head gasket was blown. I finally figured out the cause of the blown gasket was the raw water pump housing tubes had separated from the housing allowing the pump to suck air instead of water and cavitate the pump. his caused the engine to overheat and blow the head gasket between cylinders 2 and 3. I changed the head gasket Memorial day weekend and everything checked out fine. All cylinders had around 150 PSI of compression and the engine ran smooth on muffs with water temperature and oil pressure looking good after several minutes of idling and revving the engine. We took the boat out and cruised around for a while taking it easy, then I accelerated to get on plane and as soon as it did the head gasket blew out on the side of the block right next to the intake/exhaust manifold. The temperature wasn't above normal operating range. I pulled the engine apart again and figured the head was warped; I checked it before replacing the gasket but wasn't confidant in the straight edge I used. I was optimistic that since the head gasket blew out in a different location than it had originally that it was just an installation issue. Last week I took the head to a very reputable machine shop locally and they resurfaced the head and replaced one valve seat as they said it was cracked. I installed a new head gasket and was much more meticulous this time. I even checked the calibration of my torque wrench at work to ensure that the head bolts were properly tightened. I thoroughly cleaned the mating surface and checked the block with a different straight edge and it was flat. I got the new gasket in and everything was good again. I took the boat out today and waited longer before i tried to get on plane. This time I was able to run on plane for approximately 20 seconds before the gasket blew out in the exact same style as last time. I haven't pulled the intake/exhaust manifold off yet to see if it was the exact same location as I was pretty discouraged after the gasket blew out for the second time in 7 days. I have replaced the thermostat housing gasket and manifold gasket.

Does anyone have any input as to what could cause the head gasket to blow out like this? I'm not sure if the gasket blowing out in this way is a symptom of something I am not aware of. I have done some searching and haven't been able to find much information. A few posts referenced timing which I haven't checked I just don't know how likely it is for this to cause the issue.

Another post i saw recommended that water entering the exhaust in the riser could enter the cylinder and cause excessive cylinder pressure and cause the gasket to blow. This seems slightly more likely than the ignition timing suggestion, I didn't replace the riser gasket since it seemed like it was in good shape and the integrity of the all metal gasket also seemed good. I just don't want to tear the whole engine apart again and replace the head gasket and riser gasket for the same issue to happen again.

Sorry for the long post just trying to provide as many details as I can. While I am no boat mechanic I am a Engineer with competent wrenching skills and can provide any more details if needed.

Thanks

 

[matt167]

Re: Volvo Penta 3.0 GS Keeps Blowing Head Gasket

The deck itself could be warped.. If that's the case you gotta pull it out so it can be decked. Not sure if the 3.0L is zero decked or not but I don't think it is so it should be good for machining... Risers can also become an issue but I think if they were an issue, you would have found it by now.

 

[tpenfield]

Re: Volvo Penta 3.0 GS Keeps Blowing Head Gasket

I'm thinking that something has to be seriously wrong for a head gasket to go bad in minutes/hours rather than years/decades.

Seeing that you have checked everything 'flatness-wise' perhaps, if you install another head gasket, you do a cylinder leak test rather than a compression test. Also, do a cooling system pressure test.

These additional tests may point the way to the underlying issue.

 

[aerobat]

Re: Volvo Penta 3.0 GS Keeps Blowing Head Gasket

i cannot say for sure what your problem is but probably nor ignition neither exhaust riser. yes, a too agressive ignition timing can blew a gasket but that is more a question of contious use and not blowing it immediately on first burst of throttle. severe leaking manifold would probably hydrolock your engine and you would have more trouble than a headgasket "only"

i would take the head to a shop and let plane it, i strongly believe you will be fine then.

you use OEM marine gaskets ?

 

[Glastron3.0GLP-C]

Re: Volvo Penta 3.0 GS Keeps Blowing Head Gasket

I did a lot of research on the blowing head gasket because I have a blown head gasket too. The most common cause of this type of head gasket failure is detonation. I think you need to examine the blown head gaskets or send them to a reputable machine shop. The head gasket were blown by either overheating or detonation. A head gasket that failed because of overheating will be crushed and measurably thinner in the damaged area when checked with a micrometer. A gasket that has failed due to detonation or preignition will usually have cracked armor around the combustion chamber which leads to burn-through. Another posibility might be that the head is over-milled resulting in a high compressing ratio and pressure blowing the head gasket immediatelly. I think this can be easily measured by the machine shop.

 

[gator fan josh]

Re: Volvo Penta 3.0 GS Keeps Blowing Head Gasket

Thanks for the replies.
Matt: The more I think about it the more I think that it is a warped deck also. For me pulling the engine out to take to a machine shop would be a pretty big undertaking as this is the first time I have ever worked on the internals of an engine. I have had the head off twice now and I think I could do it, its just a big project and I do not have a cherry picker to pull the motor so I would have to buy/rent one. Just want to make sure that is the absolute only thing that could be causing this.

enfield: Wouldn't a compression test dissolve most things a leak test checks? if the compressions reaches 150 PSI in each cylinder doesn't that mean that the rings and valves are sealed on the compressions stroke? Also with the gasket blowing out on the edge wouldn't that suggest elevated cylinder pressure? and if a the rings or valves we leaking wouldn't it keep the pressure from reaching that high. What would a cooling system pressure test show? When the engine is running the hoses are pretty firm. What would make cooling pressure higher than normal and what would be considered normal?

Aerobat: I had the head panned last week at a machine shop that builds very reputable racing engines so I am pretty sure that it is not that. I have used Sierra head gaskets both times.

All: in recalling the events from yesterday: I was cruising at around 3000 rpm not on plane, I then gave the boat a little more throttle and got on plane around 3200 rpm. Do you think the internal pressures in the motor is much higher on plane at 3200 rpm vs 3000 rpm not on plane with a lot more drag on the hull.

I will post some pictures of the gaskets tomorrow. The original one that blew looked to be in much better shape than the one that blew last week. In hindsight I did not spend alot of time cleaning the deck when I replaced the original gasket because it came off in one solid piece. When I replaced the second head gasket it left alot more residue and looked like the gasket was much more broken down than the original gasket? While the engine may have been run for an hour max on the replacement gasket it looked like it had been on the engine for a long time.

Thanks again for the replies.

 

[gator fan josh]

Re: Volvo Penta 3.0 GS Keeps Blowing Head Gasket

Glasron: what are the other signs of detonation and what can be done to resolve it? I am confidant that the latest gasket blowing is not due to overheating. If when i measured compression with a gauge and it read 150 psi how much could the pressure raise once the engine was under a load? What makes me curious is that it does not blow when accelerating to get on plane when you think the load would be the greatest and instead blows once it is on plane and gliding across the water pretty smoothly when you would think the load on the engine is lower than when accelerating.

Thanks for the reply.

 

[Glastron3.0GLP-C]

Re: Volvo Penta 3.0 GS Keeps Blowing Head Gasket

If it is detonation it is very likely than the timing is way off or the gas is old or spark plugs are wrong.

 

[gator fan josh]

Re: Volvo Penta 3.0 GS Keeps Blowing Head Gasket

I can check the timing with my light but I dont believe it is way off as it seems to run fine without any knocking or hesitation. The gas was in the boat when I bought it in October it has about 3/4 of a tank and I added sta-bil in OCT. The plugs are champion replacements I got a few weeks ago. Should I try NGK instead? It seems kind of a long shot that 18 gallons of old gas and 8 dollars in plugs have cause me so much trouble. What are the other signs of detonation? (eg. excess carbon on valves or excessive engine knock)

Thanks

 

[gator fan josh]

Re: Volvo Penta 3.0 GS Keeps Blowing Head Gasket

Here are some pictures of the gasket that blew last weekend.

 

[matt167]

Re: Volvo Penta 3.0 GS Keeps Blowing Head Gasket

Looks like the fire ring blew out.. I can't tell as it has been a long time since I've seen a 3.0L with the head off and don't know which way is which, but is it the #3 cylinder or the #2 cylinder. All blown gaskets look simmilar?... From my experience the front cylinders run the hottest on inline engines and the rear cylinders run the coldest but that is with carb motors so it may be different if you have EFI..

Check your deck with a straight edge especially around that cylinder. Hopefully it's within tolerances.

 

[gator fan josh]

Re: Volvo Penta 3.0 GS Keeps Blowing Head Gasket

That is the number 3 cylinder. This engine has a carb, I guess I am going to have to break down and take it to a mechanic because I have had the engine apart twice and checked the deck both times. I will post what the mechanic says.

Cheers

 

[tpenfield]

Re: Volvo Penta 3.0 GS Keeps Blowing Head Gasket

I assume that your flatness checks have focused on that particular area where the gasket blew out ?

Almost looks like there is a void or something on the deck or the cylinder head in that one area . . . Hopefully the engine shop will be able to figure it out.

 

[gator fan josh]

Re: Volvo Penta 3.0 GS Keeps Blowing Head Gasket

Got some information back from the mechanic. I took it to a reputable shop here on Lake Cumberland that works on boats from all over the world. He said that I had done everything right and that they checked the block and it was flat and that the inside of the engine was in good shape. They checked the manifold and said it was good also. They are installing a new head gasket and putting it back together. I am also having them install a water separator in my fuel line and changing the oil. He said it could be a timing issue so he is going to check it once the engine is back together. He is the third person to tell me this so hopefully that will yield some results.

Seems like everyone has done their due diligence and still have not found a definitive answer as to why the gasket blew almost instantly. If it happens again after it is out of the shop i will be out of ideas. I still have a hard time believing that timing could result in catastrophic failure of a head gasket, I guess its possible. The only other thing I can think of is the head bolts being stretched from being torqued down too much. I was going to have them replace them but my father has been the one dealing with the shop since I work two hours away. Does anyone have experience with head bolts stretching and not providing adequate clamping force between the head and block?

I will post again once the shop check the timing.

Cheers

 

[dypcdiver]

Re: Volvo Penta 3.0 GS Keeps Blowing Head Gasket

You could be in the correct area i.e. head bolts, I once had an automotive engine that someone had put a load of grease in the tapped holes and the bolts just hydrauliced out at the correct torque. Ran the engine on the starter to get oil pressure and I could hear it hissing from the head gasket, worth mentioning to the mechanic.

 

[Grub54891]

Re: Volvo Penta 3.0 GS Keeps Blowing Head Gasket

I prefer to use oem gaskets on my work.,aftermarket stuff may not be the same quality. Hope ya stop having troyble with it. Looks like ya are headed in the right direction!
Grub

 

[tpenfield]

Re: Volvo Penta 3.0 GS Keeps Blowing Head Gasket

If you re-used the head bolts, then that may be the cause of the repeated failures. They could have stretched upon re-torquing or backed out if there was not thread lock on them.

 

[500dollar744ti]

Re: Volvo Penta 3.0 GS Keeps Blowing Head Gasket

You could be in the correct area i.e. head bolts, I once had an automotive engine that someone had put a load of grease in the tapped holes and the bolts just hydrauliced out at the correct torque. Ran the engine on the starter to get oil pressure and I could hear it hissing from the head gasket, worth mentioning to the mechanic.

I have also had this happen, it's worth looking into. It caused my head gasket to blow within minutes of starting the engine. It was the first time I had encountered that but I made sure it didn't happen again.

 

[gator fan josh]

Re: Volvo Penta 3.0 GS Keeps Blowing Head Gasket

If i replace the bolts, would I also have to replace the headgasket again once the bolts are loosened? It just makes me wonder since they said I had done everything right and didnt give me a definite cause of the gasket blowing. I am supposed to hear back from them today, I will update afterwards.

Thanks,

 

[Glastron3.0GLP-C]

Re: Volvo Penta 3.0 GS Keeps Blowing Head Gasket

If there are a couple of stretched bolts they can be measured by the shop. By the way how much did the shop quote for the head gasket replacement?