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Discussion Starter · #1 ·
Hey Guys, been lurking for a while but finally decided to post.

My 2012 Renegade 600 ETEC is burning an insane amount of oil. When I stop it looks like the machine is on fire.

I picked up the machine used, it was low on oil and ran fine. No oil light or anything, it was probably 1/4 full. I finally topped up the oil and at the same time I checked my PTO bearing so I tilted the sled on it's side for a while. I probably left it that way for a week or more. The next time I used it, it started smoking like crazy. I just drove it like that for a while and eventually the smoking started to get better but I started having problems when I tried to put it in reverse, the engine would just cut out. I'm assuming the plugs are fouled at this point.

I've been reading the forum and my worst fear would be the inner seals on the crank that isolate the oil bath for the pump. I haven't vacuum or pressure tested anything yet .. mainly because I don't know what line to test. From what I've read, it's a line on the back of the oil tank and you can access it after removing the air box.
I also read that if these seals were gone it would only suck oil until it gets below that line but my oil level now is back to 1/4 of a tank so well below what I think it would be if that was the problem. I took a pick of my oil tank so can someone confirm if this is the right line to test?



If this doesn't seem to be the problem, the other potential cause I've read are the check valves but would that cause the tank to almost completely drain and then stop at 1/4 of a tank? It just seems weird that it was at the same level when I bought the machine and after topping up the tank it again dropped to 1/4 of a tank.

Thanks
 

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Welcome to DooTalk!

That is indeed the line to center oil cavity for the coolant pump shaft. Like you said, if it drops below that level then the oil is seeping somewhere else. If it isn't leaving a large puddle of oil under the electric oil pump or anywhere else outside of the engine, then it must be making its ways into the crankcase through the check valves. If this is the case then I can't see how the engine would start let alone idle. That crazy amount of oil fouls the plugs almost instantly, and a high risk of a hydrolock. So before starting the reed valves and boot assembly needs to be removed to siphon the oil using a brake-bleeder pump like Mityvac. I have both, one to bleed brakes, and a Mityva vacuum/pressure pump with all the test caps to do my testing on sleds.
 

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Discussion Starter · #3 ·
Thanks Daag, I guess in the grand scheme of things this is probably good news lol. Seeing how the oil level is well below that feed line is it safe to assume the seals are ok so probably no need to even pressure test?

The idling problem I had was from last year so I don't have a full tank of oil down in my crackcase. I did try starting it recently (which I probably shouldn't have done) and it does turn over but won't catch. I'll take your advice and pump out my crankcase and replace the plugs.

Any thoughts on why it seems to stabilize at 1/4 tank? I had my oil cap on tight and I did see other posts about pressure building in the tank and overcoming the check valves. Maybe at 1/4 tank the pressure stabilizes against the check valves. Maybe I'll add some more oil and see if it still drains with a loose cap.
 

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Exactly what I am thinking, seals are ok, and one of the oil check valves is faulty and equalizing at 1/4 tank. If you find excess oil in one of the crank chamber, then the tuned pipe also needs to be checked and drained.

For draining the excess oil from the crank chambers, keep in mind that a 2S does need a certain amount of oil pooling in the crank chambers for the crank webs to turn into an oil mist and lubricate all of the components.

For the need to pressure test the center seals, probably not. And even if you did, then an explanation would be needed for the high chance of a false negative, meaning the test passes but it still leaks. Slow oil leaks make for a confusing experience as the oil under a pressure tends to seal the leak. In those case the best way is like you said, fill the tank and observe, then compare with pinching the oil line. In any case, like you, I do not believe this is a concern.
 

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For the pressure in the oil tank that overcomes the check valves, it takes only ~2 psi or so to open the valves. I could measure the change in pressure of the air in the oil tank by heating it up, or by letting it cool outdoors with the cap open, then closing the cap and bringing it inside. I have the test cap, pressure/vacuum gauge, and some hose pinchers for the test, but I think it would be easier to estimate the pressure change with some physics. I did do the psi test for this post to see when they open. It may even be in the Shop Manual.
 

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Discussion Starter · #6 ·
Awesome, thanks for the research. I couldn't find the pressure for when the check valves open in the shop manual but I seem to recall someone saying it was around 5psi on another post ... but I don't know if that was from a real test like yours or just listed specs somewhere.

I just added an inch of oil and marked the levels before and after. I'll let it sit for a few days with the cap loosened and see what happens. There may not be much pressure building up in the fall/winter anyway compared to summer but this should at least tell us if one of the check valves is stuck open.
 

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Check valves are really hard to measure. Most devices don’t have a gauge that is accurate at that low a pressure. My mityvac starts at 3psi, the extreme edge of the range. When I installed my ski doo factory rebuilt engine, I checked the nozzles and they opened right at the 3psi mark. But there has to be some error in that reading.
 

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Discussion Starter · #8 ·
I'm on my second day now and the oil level is still the same with the cap loosened. It looks like my check values going to the crank are fine.
They may be a little weak because I've read posts where a full oil bottle would force oil out the vent tube rather than down to the crank when it gets warm. Looks like I'll just have to keep an eye on it. I'll fill my tank 3/4 full and let it sit a while longer with the cap loose.

I might tighten it and put a light on it for a few days to see if that little heat causes enough pressure for it to overcome the check valves and drain more into my crank. Just to prove to myself that this was the cause.

On another related topic, I guess it's pretty important to keep my oil tank level above the line feeding that center cavity otherwise a small leak could result in that cavity running dry and no way of noticing it. I think I'll try to suction oil into the cavity from the oil line now and see how much it takes.

When I suction the oil from my crank chambers, you mentioned not to remove too much. What's the easiest way to know the correct amount to leave if I'm suctioning from the reed ports?
 

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I like where you are going with this. From your questions you have obviously given it some though. How much is needed is maybe 10-20cc? The volume is something that is seen upon teardown. The more teardowns the more you see. My only intention was to caution against worrying to siphoning every drop. For a new build I add 10-20cc to each crank chamber. For an engine that is assembled, I have no way to measure so I guesstimate.

Before siphoning any oil, I use a flexible magnet that I curve to reach the bottom of the crank chamber between the crank webs. Since I cannot see the actual position of the magnet tip, this is somewhat a blind measurement. I am only looking for a rough idea of the oil level to compare both sides. I can post a picture of this tool, but it looks the same as the one that I picked-up from a google image. The one I have next to me has a 1/4 inch diameter which fits nicely between the crankwebs, but whatever works. The hose used to siphon the oil will do just fine as long as it is used to check the level before siphoning.

When I suspect an oil flood, I am only looking for a rough idea to know what I am getting into by comparing both crank chambers. On a side note, rough measurements are the most useful. I imagine that you have learned this as well. I mention it so that you know I am not a stickler for how much oil is in there unless there is none or far too much. That is the reason I often use the baseball analogy of being in the ball park or the left field.

All these kind of tests are enjoyable until a strict measurement is needed like piston and ring clearances, and even then an error on the safe side takes all those worries away. If a half of thou cost 1000-2000 miles on longevity, I don't really care. But I start caring when a used engine does not hold adequate compression. I think the light aircraft world with TBO have it better than us with sleds, however, we can make up for it with simpler diagnoses.
 

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For the oil tank level, I haven't bothered to look at the inside to see the intake drops any lower. On previous Ski-Doo tech for at least the Gen1 REV, this line was roughly at 3/4 tank.

The idea goes like this. It siphons the oil that it needs out of the oil tank, and expels the excess through the same line. Like any oil cavity or tank, this is related to pressure. What creates pressure is either oil that seeps through the center seals or the heat that generated in the cavity. I expect there is an obvious reason for BRP to move this line towards the top of the oil tank, but it is an unknown to me. It is one additional question that I have for BRP, which now you know how I come up with these questions.
 

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Check valves are really hard to measure. Most devices don’t have a gauge that is accurate at that low a pressure. My mityvac starts at 3psi, the extreme edge of the range. When I installed my ski doo factory rebuilt engine, I checked the nozzles and they opened right at the 3psi mark. But there has to be some error in that reading.
I think that we are among the few that have seen false positive test results in testing oil chambers with a vacuum/pressure pump. I still remember working the courage to ask you if you had seen this in any manual, and you had! That was many years ago and I remain grateful. Imagine the same type of question, but with what grease BRP uses for the mag side on later E-TECs. That is another second questions I have for BRP. It has taken years to understand that shop manuals are only as good as who contributes and cares to make updates.

For the accuracy of the Mityvac which we both own, the needle on my gauge is a little off of zero. The first two psi are not graded and perhaps for the lack of accuracy that you mentioned. However, I was able to guesstimate ~2 psi. Your reply did have me take another measurement with a low psi vacuum/pressure gauge that I had to T between the pump and oil check valve. The result was no psi lol The added connections for such a low reading only helped to raise the risk of leaks and inaccuracy. I did find another rubber fitting that went over the tinny fitting of the oil check valve, and obviously deleted the T. I came to the same ~2 psi. Unfortunately this is not a new check valve, and not even an E-TEC, so take it for what it is worth.

I do need to thank you for helping me find my lost dial indicator, extension, and T that were resting in a box dedicated for for these sort of tests and never thought to check. I was seriously looking for them.
 

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NL_Dirt, I hope that you have fun doing this stuff. There are few that want to get into this level of work, and I honestly don't know why as it is the easiest and most rewarding. I figure that over 90% of things that need to be checked on a two stroke sled engine is easier than working on a skid, yet in most cases the skid is favored to work on. Replacing an idler wheel bearing is difficult! A compression test that everyone seems to feel is easy, to me this is at highest degree of complexity, although properly alignling the clutches may be more or less.
 

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Daag- accuracy of most gauges diminishes as you approach the extremes of the range. That is why the reading of 3psi, may have some inherent accuracy flaws.
But your use of a secondary gauge shows it to be spot on.

Using air to test this cavity does present some challenges to the usual spec of holding pressure. Unlike the rest of the engine filled with air, this cavity contains oil. Oil is a larger molecule than air contains. So it doesn’t get past the seals as easily. My initial test of the engine in the frame showed it held pressure, even though it filled my crankcase with oil if it sat for a period of time.
But when I removed the engine and drained the cavity, the leak down test failed readily.
 

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Discussion Starter · #14 ·
NL_Dirt, I hope that you have fun doing this stuff. There are few that want to get into this level of work, and I honestly don't know why as it is the easiest and most rewarding. I figure that over 90% of things that need to be checked on a two stroke sled engine is easier than working on a skid, yet in most cases the skid is favored to work on. Replacing an idler wheel bearing is difficult! A compression test that everyone seems to feel is easy, to me this is at highest degree of complexity, although properly alignling the clutches may be more or less.
I do enjoy this type of stuff ... I was even considering rebuilding the engine if I confirmed it was shot because .. why not lol. My biggest limitation right now is where I'm doing it. I only have a 10x16 shed that's half full of other stuff and has crappy lighting.

I'd like to know if the engine is shot so I can start hunting around for a new sled before snow comes around. I do have an old 2000 grand touring 600 that I used as my backup last year but after getting comfortable with the new machines the old grand touring feels way too low. Even though I have to give credit to her considering she still runs after all these years.

So I just tried to vacuum test the line to my center cavity (I only have a vacuum pump) and I couldn't create or hold any vacuum at all. I'm hoping it was just the barbed connector I used wasn't sealing but I did smear some grease around the line to help seal it.

Anyway, I decided to tear into my reed boots to see how much oil was inside the crank cavity. I managed to get all the bolts out (the one behind the support bracket for the secondary clutch was a pain) but now that bracket is preventing me from getting the boot off. The flange is just hanging up on it ... I guess I need to take that support off or just loosen everything up but that's what I'm looking up now.

BTW, thanks for all the feedback. Having a forum like this is the only reason I'd consider even doing what I'm doing now let alone tearing the engine down lol.
 

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Xcrsp440, I fully agree, but the use of my secondary gauge did not work for the reason that you explained with the difficulty of approaching the low range. It was only with the Mityvac on its own that I could take the measurement. I repeated the measurement with two different fitting and got the same results.
 

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NL_Dirt, will it hold a vacuum if you block the hose with a finger? I have three different types of tests that I use whenever necessary. The vacuum and pressure from the tube requires a pump that does both vacuum and pressure, and the other is by pressurizing the engine. Yet it doesn't always give me the answers that I want lol

The reed boot and valves are two separate units, so they do come apart.
 

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Discussion Starter · #18 ·
Well I managed to get my right side reed out ... but looks like my boot is cracked :(.

What should I look for to see what damage this could have caused?

I still couldn't separate the reed from the boot that I got out. Seems to be corroded together even though I think I can see a separation line. The reed valve also has some bubbling on the body. Not sure if this is heat related or they all get like that.



Anyway, I looked into the crank cavity on the right side and couldn't see any oil. I'll dip something down tomorrow to see if there's anything out of sight.
 

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Discussion Starter · #19 ·
NL_Dirt, will it hold a vacuum if you block the hose with a finger? I have three different types of tests that I use whenever necessary. The vacuum and pressure from the tube requires a pump that does both vacuum and pressure, and the other is by pressurizing the engine. Yet it doesn't always give me the answers that I want lol

The reed boot and valves are two separate units, so they do come apart.
If I block the hose including the barbed end that's just connected to the pump it did hold a vacuum before I connected it.

I blew into the hose and I thought I could hear air but couldn't locate it. I'll spray some soapy water on the line and around the fittings and pray to god it's just a leak there lol. I can also try to connect the pump directly to the oil line and see if that helps.

I have a compressor that I could use and just set the regulator as low as I can. Would 15 - 20 psi be too much pressure to force into that cavity? At least if I can force air continually they I think that would make it easier to find the source of the leak.
 

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The boots are bad enough to be replaced. Is the tear through and through?
~$300 USD for oem, or $310 USD for V-force (V3127R-873A-2).

Which part is bubbly, the face with the numbers stamped?

The corrosion seen on the mating surface is the reason that I use Dow 111.
 
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