2007 GTX Wake 155 High Oil Consumption

[BUGGA]

I am burning oil as t a high rate. 1/3 a quart per hour. Want to check my logic with those of you that know more about these engines. I am saying valve seals and here is why:
1. Compression is 145, 150, 145.
2. Compression with oil added is 155, 160, 155. I read a post where someone wanted their compression numbers not to go up. Don't understand that. If the compression stays the same after oil addition in the cylinder then that tells you it is going through the rings (correct?)
3. I get blue smoke at start up but it clears up after the engine is warm and stays clean as long as it is warm. After a cold start up it gives me blue smoke until warm. However, I can smell nursing oil when I am running the ski from time to time, just can't see it.
4.theee are no leaks in the hull.
5. PCV valve passed the test.
6. Spark plugs on #1 and #3 cylinders show oil is burning there.
7. Got the ski used and engine says it has 120 hrs but not sure I believe it based on the age of the machine.

While I'm thinking it is valve seals, the one thing I find difficult to believe is that valve seals would be responsible for such high oil consumption. The compression test tells me that I don't have a ring issue. If it did, I would expect to see blue smoke all of the time correct?

What are your thoughts?

 

[Digdog]

It could be the V ring on the oil separator is hard or worn , check for oil before and after the supercharger in the hoses and in the crankcase vent line , it could be the supercharger oil seal if it only shows after the supercharger. If its the valve seals it will not be in any of the intake system, if it's compression rings or the V ring it will be because it's venting excessively and being burned and it would be entering from the vent tube just before the super charger. Not sure where you found a PVC valve? You must have been looking at the oil separator/tip over switch.

 

[BUGGA]

It could be the V ring on the oil separator is hard or worn , check for oil before and after the supercharger in the hoses and in the crankcase vent line , it could be the supercharger oil seal if it only shows after the supercharger. If its the valve seals it will not be in any of the intake system, if it's compression rings or the V ring it will be because it's venting excessively and being burned and it would be entering from the vent tube just before the super charger. Not sure where you found a PVC valve? You must have been looking at the oil separator/tip over switch.

Thanks for the reply. This model does not have a super charger because it is a 155 how version and N/A. Yes you are correct that I called the tip over switch a PCV valve. It appears to work the same way.

Is the V ring the main seal on the oil separator/tip over switch coming from the engine? If it is, I don't understand how that seal could be contributing to oil consumption. I would think it would leak out and into the hull.

On this model the tip over switch is vented directly into the throttle body intake. There is a film of oil in the line to the intake but I would say that's normal because there has to be some oil from blow-by and windage that makes its way to the oil separator.

 

[Digdog]

Yes the V ring can cause high oil consumption, if it's non supercharged then yes the valve seals could also contribute.

 

[BUGGA]

Thanks for the information! I got a hold of the service manual but I don't see a spec for compression. Does anyone know what the lower spec is for a 155 NA 1503 engine?

Also I have read on the forum that the compression on the SC engines is lower. I have one of those too. Is the head different or clearances different to get a lower compression? I can't seem to find this information.

 

[ski-d00]

pistons are different which allows more volume in combustion chamber so lower compression
a better test is to do a leak down test instead of a compression test

 

[BUGGA]

I am going to do the leak down to try and figuyre out where the problem is.....but I am going to change the valve seals and the v-ring first.

 

[sktn77a]

You'll have a real hard time getting meaningful information on "normal"/"good" compression values. I've tried many times from Sea-Doo, dealers and online sources. And when someone does offer up a number, it's usually an n-of-1 (and they are all over the place)! This forum is a good resource to discuss your leakdown test numbers as is the green hulk.

 

[BUGGA]

Ok everyone-Here's the situation. I did a leak down check. I have bad exhaust valves. Rings don't appear to be an issue. However, when running out on the water, I am losing/burning oil out of the exhaust at a rate of 1qt per hour. The plugs look great. Where could this oil be coming from? I replaced the V-ring and associated O-Ring on the oil separator valve as a low cost ruling out. I can't figure out where the oil is coming from. Could valve seals let that much oil out? I don't think so because the oil burn is constant. bad exhaust valves don't explain the oil consumption. The two may not be related, but I am learning about these engines.

 

[Digdog]

In the troubleshooting page I posted it says valve seals are a possible problem with high oil consumption, blue smoke at start up is also an indicator of the same problem. You could have worn out oil rings and not compression rings, there is also an oil seal in the supercharger , maybe it's that? Just out of curiosity what oil are you using?

 

[BUGGA]

In the troubleshooting page I posted it says valve seals are a possible problem with high oil consumption, blue smoke at start up is also an indicator of the same problem. You could have worn out oil rings and not compression rings, there is also an oil seal in the supercharger , maybe it's that? Just out of curiosity what oil are you using?

I am using BRP semi-synthetic 15W-40. I took the ski out and while I can't see the oil burning, I can smell it when I chase my wake going Inna circle. What is amazing to me is that I put new plugs in and they look really good. I expected to see oil on them.

From my experience, normally the valve seals would not contribute to that level of oil consumption. But these engines are different. #3 cylinder has bad exhaust valves. I'm off the chart on the leak down test table in the service manual.

Maybe the valve guides are leaking? Or cracked head? The compression ring usually sits highest on the piston correct? So you think it could be an oil ring on the piston?

 

[BUGGA]

I saw online that SBT charges $495 for a rebuilt head if you give them yours. Anyone ever use their heads or engines?

 

[BUGGA]

Digdog, this 155 Hp is naturally aspirated and has no supercharger