No.
Contaminated fogging oil could, though...
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| fogging oil and rings sticking?? https://www.smwebhead.com/phpBB3/viewtopic.php?f=11&t=13666 |
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| Author: | Oldsmoduck [ Tue Dec 16, 2014 6:15 pm ] |
| Post subject: | fogging oil and rings sticking?? |
So im dealing with 2 low hour engines. 7.4 Gi's they have not been run for 4 years. both fired up. starboard engine runs good. port engine had a dead miss and low compression in several cylinders.. Does fogging oil (which its super thick and sticky) have a tendency to stick the rings?? We started these engines in 35ish degree weather so that could be exacerbated due to cold weather.. i know it sounds like im trying to confirm my theory, but i want to ask others who may have possibly had the same experience??? A boroscope inspection showed a decent amount of carbon buildup too... Dry 1 - 170 2 - 115 3 - 142 4 - 110 5 - 170 6 - 170 7 - 150 8 - 180 Wet (with PB blaster) 1 - 170 2 - 160 3 - 160 4 - 150 5 - 170 6 - 170 7 - 150 8 - 180 Thanks, Duck |
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| Author: | alex8q4 [ Tue Dec 16, 2014 6:41 pm ] |
| Post subject: | Re: fogging oil and rings sticking?? |
I am not a mechanic but I suspect your test was flawed. 180 is high and there is a rather significant variance in all readings. I dont know your back ground. Have you completed much testing in the past? Was this a salt water engine and how was it treated before put away for 4 years? |
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| Author: | deafwish [ Tue Dec 16, 2014 6:50 pm ] |
| Post subject: | Re: fogging oil and rings sticking?? |
No. Contaminated fogging oil could, though...
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| Author: | LouC [ Tue Dec 16, 2014 10:48 pm ] |
| Post subject: | Re: fogging oil and rings sticking?? |
Normally fogging oil would not cause ring sticking, actually its used to prevent that. But if the engines were not run in 4 years, and it was stored in a damp climate, you could possibly have sticky valves or rings if it was not fogged enough. Was your compression test done with the engines warmed up and the throttles wide open? If not then some of your lower results may not be valid. I'd want to make sure the test was valid before I did repairs. If you go over to the Merc I/O form on iboats forums a user by the name of tpenfield did a great report on compression testing and the results of decarbonizing his engine. He has a pair of Merc 7.4s. I'd take a look at his results and see if you want to try that first, then re-test and see what you get. The miss suggests a sticking or stuck valve or one not seating. That could be a rusted valve stem, or un even carbon build up. http://forums.iboats.com/forum/engine-r ... 7-4-lx-mpi |
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| Author: | Oldsmoduck [ Wed Dec 17, 2014 8:51 am ] |
| Post subject: | Re: fogging oil and rings sticking?? |
LouC wrote: Normally fogging oil would not cause ring sticking, actually its used to prevent that. But if the engines were not run in 4 years, and it was stored in a damp climate, you could possibly have sticky valves or rings if it was not fogged enough. Was your compression test done with the engines warmed up and the throttles wide open? If not then some of your lower results may not be valid. I'd want to make sure the test was valid before I did repairs. If you go over to the Merc I/O form on iboats forums a user by the name of tpenfield did a great report on compression testing and the results of decarbonizing his engine. He has a pair of Merc 7.4s. I'd take a look at his results and see if you want to try that first, then re-test and see what you get. The miss suggests a sticking or stuck valve or one not seating. That could be a rusted valve stem, or un even carbon build up. http://forums.iboats.com/forum/engine-r ... 7-4-lx-mpi Hey lou, engine was cold, throttle cracked open. i was just trying to isolate a dead miss/hole. i could hear several cylinders down on compression while cranking and wanted to see if it was a burnt valve or rings not sealing with a wet/dry test.. i'll get them warm and decarbon and see what i get then.. here is some of the other stuff i build in my spare time for friends and paying customers. 1000hp - 565BBC  mild 12:1 406 - 650hp 
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| Author: | alex8q4 [ Wed Dec 17, 2014 12:33 pm ] |
| Post subject: | Re: fogging oil and rings sticking?? |
So I guess you are relatively confident that you possess the knowledge to compete a proper compression test. 
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| Author: | Decision [ Sun Dec 21, 2014 12:10 pm ] |
| Post subject: | Re: fogging oil and rings sticking?? |
alex8q4 wrote: So I guess you are relatively confident that you possess the knowledge to compete a proper compression test. Yep, I'd guess he is relatively confident in compression testing. Nice looking engines BTW. |
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| Author: | acguy [ Sun Dec 21, 2014 12:36 pm ] |
| Post subject: | Re: fogging oil and rings sticking?? |
Why not do a leak down test to isolate where your issue lies. |
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| Author: | TX H210SS [ Mon Dec 22, 2014 11:45 pm ] |
| Post subject: | Re: fogging oil and rings sticking?? |
Maybe a dumb question...and off topic but it is winter. Do all Chevy blocks have the drain plug. I thought it was a marine feature but see the same plug on that bad boy motor. As to your compression test results....over my head:). |
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| Author: | LouC [ Tue Dec 23, 2014 12:00 am ] |
| Post subject: | Re: fogging oil and rings sticking?? |
Yes they do and most others do as well. Sometimes there is just a bolt there with sealer. The reason for it is to be able to drain all of the coolant when changing it. In practice they are often frozen in place so all you can do is remove the lower rad hose and jack up the rear of the vehicle. |
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| Author: | Paul I. [ Tue Dec 23, 2014 9:34 am ] |
| Post subject: | Re: fogging oil and rings sticking?? |
If it was me, I would use Marvel Mystery Oil in each cylinder. Let it sit for 5 min, start the engine and do this 2 or 3 times. In other words, let the oil work itself in. The rings may be a little rusted and need to work themselves loose. After that, the engine may have to be pulled. You could take the heads off and look and turn it over by hand just to see. But just taking the heads off, you can't replace the rings. Someone mentioned if the boat was used in salt water. Salt water has nothing to do with this, under normal conditions. The engine has been seating for 4 years, even if it was fogged well. It’s still a long time. |
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| Author: | alex8q4 [ Tue Dec 23, 2014 7:03 pm ] |
| Post subject: | Re: fogging oil and rings sticking?? |
Paul I. wrote: Someone mentioned if the boat was used in salt water. Salt water has nothing to do with this, under normal conditions. The engine has been seating for 4 years, even if it was fogged well. It’s still a long time. If a healthy engine was fogged well, 4 years is not a long time. Key term is healthy. Knowing if this was a salt water engine or not it would be a good start in determining whether or not it was healthy, would it not? We have an '86 Liberator with original raisers and manifolds. I would consider the engine to be healthy. Obviously, if this was a salt water boat I could not have made the same statement. Any who... I wonder how the OP made out? |
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| Author: | LouC [ Tue Dec 23, 2014 9:15 pm ] |
| Post subject: | Re: fogging oil and rings sticking?? |
It all depends on maintenance... If the mainfolds and risers were done on schedule then yes it could be fine. My '88 is on its 3rdset since I've had it (2002), never had any water in the engine. Always fogged as well. Salt water is not a death sentence you have to have a basic understanding of adjusting your maintenance to fit the environment you are in. If you're a real good mechanic you can even keep your trailer brakes and lights working lol... |
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| Author: | Paul I. [ Fri Dec 26, 2014 12:35 pm ] |
| Post subject: | Re: fogging oil and rings sticking?? |
Could not have said it better! "Salt water is not a death sentence you have to have a basic understanding of adjusting your maintenance to fit the environment you are in." As Lou knows, there are many salt water boats that are over 30 to 40 plus years old were the 2 of us are. |
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| Author: | alex8q4 [ Fri Dec 26, 2014 8:13 pm ] |
| Post subject: | Re: fogging oil and rings sticking?? |
Yep, nothing wrong with what Lue had to say at all. So I guess you are also saying you now understand how salt water vs fresh water could play a role in premature valve or ring failure.
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