Crank seals leaking? Read this before you give up.

[68ragtop]

I thought I would share something with you guys that I found very interesting. Last spring I picked up a 1999 Challenger with the twin 800’s. The boat had been sitting for two seasons after the previous owner brought it out of storage in the spring of 2013 only to find that the starboard engine was seized up. Thinking it was the starter, he brought the boat into his service center only to have them inform him that the engine was hydro locked with injection oil. They told him the news of bad crank seals & gave him an estimate of $2800 to replace the engine. So he towed the boat back home unrepaired and it sat there until I purchased it & brought it home this past spring.

After removing several mouse nests & one dead squirrel, I got the boat cleaned up. I started to go through the vitals on the engines to figure out what was what. I did in fact find the starboard engine locked and full of oil, Just as I was told it was. The oil in the engine was a bright blue color that matched the oil that was in the tank. I contacted the previous owner and he informed me that the oil he was running Pennzoil synthetic injection oil. (possibly the cheapest synthetic injection oil on the market) I drained the tank and replaced it with XPS II, then Siphoned out all the oil form the engine as best I could. I went through the carburetors on both engines, & they were both soon up running. The now running starboard side smoked enough to fumigate the whole neighborhood as any oil submersed engine would I suppose. It was rather comical & I’m thankful no one called the fire department. ☺ After a few days of tweaking & more cleaning, I took the boat out on the water to test it. It was running & performing very well and just needed a few minor carb adjustments. Now that I knew there were no other major internal issues, I decided to dig deeper into the oil seals. I Pressure tested the RV case, and found it only lost about a pound over one day. It seemed like if it leaked, it was probably rather slow. I then looked at the injection check valves. No problems there, Both of them held just under 2 pounds of pressure with zero loss in 24 hours.

So, it was definitely looking like crank seals were the culprit. I decided to flush out the RV case. What I did was hook up a vacuum pump to the RV oil return line to the tank. What came out was rather dark & dirty looking. It was obviously a mixture of several different types of oils over the years and ironically none of it was really blue like the clear oil that managed to get past the seals and into the case. Once the oil was coming out in that reddish-brown XPS II color I decided to start up the engine and siphon some more while idling on the hose. The oil came out a smidge dirty again but it was looking good. After wasting about 1 quart of injection oil, everything was flushed out and I hooked the return line back to the tank. Now all I could do is have some fun with the boat and see what would happen. We brought it up North for the Fourth of July weekend and ran it all weekend long. The boat ran fantastic & we had fun tubing & skiing. When the holiday was over, days turned into weeks, and weeks turned in the months and sadly the boat did not get run again until I brought it home to winterize it just 3 weeks ago. Rather then attempt to just start the engines I decided to remove the airbox off the Starboard engine and take a look in the case with my borescope. To my surprise there were only small, normal sized oil puddles in the bottom of each side as if it was only run just yesterday! I was amazed. I fired up the engine and it hardly smoked at all. I fired up the portside engine & that one smoked quite a bit, But nothing too alarming.

While its just a strong hunch at this point, I’m starting to believe that RV oil maintenance may be somewhat critical in these engines. Especially the ones that have seen endless types of who knows what oils from how many past owners, & possibly even moisture contamination? When I was done, I left the drained out case oil in a clear measuring cup. After a few days some of the oils seemed to start separating to the bottom. Possibly moisture? Not sure, but it wasn't what you want in your RV case. If you think about it, that oil never gets moved, recirculated or anything. It just sits in there. It just might be possible that some of these leaky seals, might be due in part to all the “crap” that is trapped on the other side of them. So before you stick a fork in your crank seal leaker, I would suggest at least checking the injection check valves, then flushing out the RV case with a good quality oil & see if anything changes. Its easy enough to & sure worth a try.

I may get some flack for this idea & Maybe I got lucky, but I never pulled a bolt out of the engine & it only cost me a quart of oil & some time to fix. I don't think its going to cure an engine thats filling up with oil in one week, but for sure worth a try on the the seasonal slow leakers.

I’ll confirm in my finding spring, But so far Im feeling pretty good about it.

 

[Strizzo]

interesting. if i still had my 95 gtx i'd try this out. it had sat for a long time and then started smoking really heavy at idle, but no more than normal when running, so i figured the high vacuum at idle was pulling oil past the seals but the thing still ran great so i didn't worry about it.

 

[howie099]

Well it had the wrong oil in so maybe TCW3 oil seeps through the seals easier than the proper sea-doo oil does. RV cavity held up in the pressure test so there is really no other way the engine can fill unless when you pressure tested it you moved a seal a little bit, but either way if it never fills again money saved and you gain a good deal on a boat.

 

[JCJ256]

Very interesting... and especially so because after having one of my twins go through virtually the same thing shortly after I bought them, I installed a shut-off valve for extended periods of rest. Figuring that if the seals were really that terrible I would likely go through a ton of oil while running, I resigned to the fact that I was going to have a rebuild in my near future. Well, I was right about using a tone of oil... for the first quart or so. Then amazingly, it just seemed to stop. In fact, this particular ski has always seemed to burn more oil than the other one, until now. It seems that now it uses a little LESS than the other. Hmmm. Curious, considering the crank seals were leaking profusely a short while ago. So actually, IMO you may be on to something.

 

[68ragtop]

When I brought the boat back home to winterize & check things, I truly thought it was going to be full of oil again. Maybe not to the level that it was when I bought it, but maybe enough to lock it up, or at least smoke out the neighbor hood again. After all, I didn't change any parts or find the smoking gun. When I removed the air box & shoved my borescope into the case, I expected it to be fairly well submersed & to my surprise it was not. The funny thing is, the Port side engine did smoke quite a bit when I started it. & that one was not the problem. The "leaker" engine didn't smoke at all. Just the typical 2-stroke start up amount. ITs as if it went to a junk engine, to being in better shape than the "good" engine. IT was, & still is a head scratcher.

As far as the oil, I would agree that it might have had to do with the cheap & definetly wrong oil that was put in it. Maybe not so much that oil, as much as all the other oils combined over the years. One would think that if the seal was really leaking it would flush itself out, but that was not the case at all. I wish I would have saved a picture of the oil I removed & how it settled into layers as if it they were not compatible / mixable oils. I am suspecting having the correct oil, in fresh clean condition & filling the entire RV case is important. Who knows, maybe contaminated oil is what takes out the RV gears in some of these machines too?

I did not flush out the case on the other engine. I know it leaks some but not enough to cause trouble. yet....
I will flush that side out this coming spring, however I am not sure the boat will have the chance to sit for 4 months to see what effect that will have on its leaking rate.

The other thing that I know can cause oil trouble with these engines is the injection check valves. These oil pumps do not have any check valves in them, the check valve is in the nozzle. Mine held 2psi of pressure & thats enough to keep oil flowing so I called them good. But, Its also a possibility that one of those valves was stuck allowing it to drip day & after day. So hard to say when the problem is gone.

One thing I did do when I put the boat away for this winter was clamp the oil line supplying the pumps. Just incase those where the issue. This spring I will pull things apart & see how much oil is in the bottom of each engine before ever turning them over. At that time, I plan to flush out the other engine & I am also going to replace all of the injection nozzles proactively to remove that from the equation.

Also, looking at all my steps backwards, I wish I would have removed the RV cover before doing anything at all to this engine to check & see if the injection valves were dripping oil. This is a pretty easy test & I missed the chance to do it. Big goof on my part

 

[Mekanix]

I wonder if maybe installing an inline pump to the rv cavity would help.
Just to mix or purge it every now and then.

Now the only thing i can think of against that would be one experience where a striped rotary gear sent debris up to the oil tank which indicates a flow of fluid from the rv cavity to the tank.

 

[kbizz]

Hey there - interested to hear about any updates you may have on this. I have almost the exact same issue with a 96 Seadoo GTI jetski I picked up. I planned on draining, cleaning and refilling as you did and clamping the oil line during extended storage. Reading this make me feel better about spending the time on it!

 

[Minnetonka4me]

Great thread and a good reminder that there is nothing making the oil pump it just sits stagnant. Let me add my 2 cents to an already good post.

My theory is that these tanks build up pressure and sometimes they are going to leak. Major barometer changes, major temperature changes, etc.

Add to that long term storage...sitting for a year or more along with all the climate fluctuations and you have oil in the motor.

I always tell someone running into this is to get the oil out, get it running and go take it out. Then let it sit two weeks and see how bad it is. Typically it doesnt leak.

 

[68ragtop]

Well, Finally got to take a look. After the winter storage the seal/s did leak quite a bit in the starboard engine. This is interesting because It didn't leak a drop after more than three months of storage last summer. The one thing that is different was the storage temperature. It gets into the single digits & below here in the winter & just maybe the cold temps are causing the seals to shrink just enough to leak. I pressure tested both engines & found the same result as last year. both engines hold pressure for 24 hours with little loss. Strange for sure.

I never really though about the tank pressures. I am not sure there is a vent on these boat oil tanks, but there almost must be some sort of check valve or something? I'll have too take a peek at that. But, Only one of the two engines is being effected, so something is going on.

 

[mikidymac]

The oil tanks have a check valve that lets air in as the level drops but not out so oil doesn't spill out. As Nick said the temperature fluctuations could cause a little pressure to build in the oil tank and if the seals are just a little weak they might seep some oil.