MR V

I have a 5241, 10kw purchased back in May 2007. It has 348 hours on it.  Regular maintenance every year and synthetic 5w30 oil.  Also I have checked and adjusted the valves twice since new.  I am located in the U.P. of Michigan.  Trout Lake, MI.  It runs on propane.

Last winter we had an ice storm December 31, 2019 and were on generator power for 4 days.  (we are in FL for the winters)  The only thing running at the home is a high efficiency gas furnace, security cameras and internet.  When returned in the spring, it was down 1.5 quarts of oil and it only holds 1.7 quarts.  I added oil and then changed the oil and filter a few weeks later along with the spark plugs and air cleaner.  The oil was a little dark color (like maple syrup), but not black that you find in car oil.  The spark plug nearest the front panel was corroded and the back one was normal.  Last week I did a load test on it while three of us took showers using the well pump and electric hot water heater.  After about 10 minutes of running there was blue smoke coming from the exhaust.  I checked the oil and it was down just a little from the full mark. 

I suspect it is something with the front cylinder burning the oil.   My question is what could be the problem?  Rings, bad piston, valve seals or something else?

I did pull both valve covers off, as a general inspections and found some metallic color pieces in the front valve cover, but they were not metal.  They were soft and about the size of #5 or #7 pencil lead.

The generator is model #5241, Serial #4798689.  The engine is model #OG4446 (GT-530), serial #8109098

I called our nearest servicing dealer in Sault Saint Marie, MI to have them check it out, I gave them all the above information and never received a call back.

I am looking for suggestions as what the problem may be.  I am willing to do the repair myself.   I also would like to get my hands on a service or repair manual for the GT-530 engine.

Thanks

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Birken Vogt
It bears some investigation to find out what is wrong.

But just saying, a 2007 that is an oil burner is getting pretty long in the tooth anyway with the other parts, and I would be considering a total replacement instead.

And for the record, an air cooled needs to have the oil checked at least every 24 hours of run time.  They tend to burn or leak a little bit and the hours rack up fast.
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Peddler
What has the oil consumption been since the change?  You need to determine if your blue smoke is coming from a leak or through the rings or valves.  I would not replace a generator for this problem but you need more investigation to the cause.
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MR V
The oil is just off the full mark, 1/8 inch down, since the oil change change 6 weeks ago. It has only been running for its weekly excerices, once for 15 min under load.
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78buckshot
I'm only suggesting this based on the last engine I found that was smoking and fouling the plug. It happened to be the single cylinder 8kw. I completely tore the engine down and found no other problems other than the head gasket, I knew right away when I turned the head bolts to loosen them that it was a good possibility that the oil problem was only due to loose head bolts and a failed head gasket. I put all new gaskets and seals in it along with new piston rings but I'm pretty confident it was the head gasket, owner has reported back with only good results.
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Ehenry
Pull a compression test on it.
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MR V
Thank you.  I was planning to do one this weekend.  What is a good pressure I should see?
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78buckshot
The diagnostic manual does not give specs for compression, they do recommend a cylinder leak-down test but you may not have the tools for that. Do the compression test and compare the readings between the two cylinders, normal engine should be within 25% of each other. My bet is a bad head gasket on the #2(front) cylinder, with your description of the soft metallic material in the rocker area that matches exactly what I found in the 8kw in my prior post.
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MR V
Thank you.
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78buckshot
I'm at our Hubbard Lake(Alpena area)get-a-way this week but I didn't plan a trip across "Da Bridge". You can get the parts from Ziller, I would be worried about the gasket material plugging the inlet screen at the oil pump, on the single cylinder engine the screen can be pulled out of the filter adapter without disassembling the engine, I'll try to bring up the engine break-down and let you know if it's the same on the 10kw twin.
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78buckshot
The oil pick-up screen appears to be a separate component from the oil pump however it looks like the engine would have to be split in order to access the screen. I think I would replace the gasket, change the oil and filter and check the oil pressure with a known accurate gauge threaded into the port where the pressure switch resides.
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MR V
Thank you. What oil pressure should looking for?
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78buckshot
I normally see 35 psi. or a little more, let it run enough to get the oil hot to see if it will keep a steady reading. The oil pressure switch is closed with no pressure, as the engine starts and builds pressure the switch will open, if you remove the switch and leave the wires disconnected the engine will continue to run without alarming, just make sure the temporary gauge shows some pressure before you run it very much.
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MR V
Ok. Good information.
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Ehenry
I dont know the compression spec for your engine but I'd say a healthy compression would be 100+ psi with no more than a 10% difference between the two cylinders.
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MR V
I was able to do some testing this weekend. The front cylinder was around 165 psi and the rear was 140. So I pulled both heads and found the rear head gasket was leaking. Picture below.

So I am going to order some new head gaskets or maybe both head assemblies if they are still available. Both are very carboned up both on the head/valves and on the valve stems inside the ports?

What is the torque value and sequence for the heads?
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78buckshot
The heads and valves look like they would clean up easily, you can disassemble them by hand, replace the intake stem seal, gaskets, and adjust the valve lash. I think the torque for the head bolts is 22 ft.lbs., just criss-cross on the sequence.
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Ehenry
Mr V,  How did this repair turn out for you?
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MR V
Thank you for the reminder.  I ordered both new complete head assemblies and put them on.  Did a load test and no blue smoke.  I still need to do another compression test, but I am sure the blown head gasket was the problem.  I will report back after I do a compression test.  Just need to barrow the compression tester again, or buy one. 

I did notice the corners of my valve covers have some cracks on them that are visible after tightening them down, they are not leaking.  Not sure what that is from.  Maybe I over tightened them.  I did order two new ones.

Thank you to everyone who replied with their input.  It was very much appreciated.
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