Frozen air bypass valve

[74Nitro]

Could someone have overfilled the oil tank and now its puking it out?

I hope that engine wasn't woofed before you bought it and now it has a bunch of blow-by blowing oil into the intake.

I'd second that, it's easy to overfill these by accident.

 

[rock doc]

Early indications are a bad head gasket. Should know more my end of day tomorrow. This could get expensive! Dealer claims I somehow did this is 70 miles by letting the intercooler fill with snow. Absolutely false but very hard to prove. Conditions were perfect and we were trail riding. I kept a close eye for ice on the intercooler and snow that would block airflow. Sled had 4700kms on it.

 

[KnappAttack]

They plug with snow all the time, you can't prevent it and honestly it doesn't hurt anything, It actually helps cool the charge better than air most of the time as long as there is not a big ice chunk in front of it stopping the fresh snow from hitting it. They are SNOWMOBILES that do run in the snow.

You did not hurt this sled unless you ran it out of coolant and ran it hot. It had to have been traded in injured prior to you taking ownership would be my guess if its a head gasket. Stock sleds just don't lift the head, it takes a big tune some real deto to lift the head on the 998.

 

[rock doc]

They plug with snow all the time, you can't prevent it and honestly it doesn't hurt anything, It actually helps cool the charge better than air most of the time as long as there is not a big ice chunk in front of it stopping the fresh snow from hitting it. They are SNOWMOBILES that do run in the snow.

You did not hurt this sled unless you ran it out of coolant and ran it hot. It had to have been traded in injured prior to you taking ownership would be my guess if its a head gasket. Stock sleds just don't lift the head, it takes a big tune some real deto to lift the head on the 998.

Thanks for the info. I thought these motors were pretty bullet proof. Wish this guy would work with me.

 

[rock doc]

Making some progress now. Mechanic completed compression test and reports it is fine. Had a closer look at the oil and indicates it looks like there is condensation but not coolant (he will investigate further - he has a dye test for coolant). It is pretty dirty though. The odd thing is the oil reservoir is now overfull and it was on the low side when I dropped it off. Could the ROV or Air Bypass Valve have caused this? I have not added any oil, but it was marginally above the full line when cold at the time I picked it up from the dealer.

The mechanic is digging into it now. Very happy to have someone working on it that knows turbos very well.

 

[rock doc]

We cleaned it up and changed the oil. Took it for a 15min test ride and no luck. Noticed there was some leakage around the Air Bypass valve again, which seems odd.

Called the original owner that the dealer took the sled in on trade from. Seemed like good people. They were surprised to hear of the problems I am having. Apparently no history of overheating or any major issues. They seemed to think it was unlikely to be anything serious.

As for the findings of the test ride Oil seems to have some moisture in it and foamed up. Definitely air in the cooling system. Assuming it is a head gasket at this point.

 

[WinderFab]

How did you determine the oil was foamed up?

 

[rock doc]

The level in the tank goes up initially but settles back down if allowed to sit enough.

 

[WinderFab]

When you start your sled the oil goes up in the sight tube? Then goes back down while it’s still running or after you shut off the sled?

 

[rock doc]

The oil level seems to very a lot, I am assuming it is foaming up.

 

[WinderFab]

Obviously something is wrong around the air bypass valve, have the mechanic figure that out.
Even though the roll over valve shoots oil/condensation back into the air intake it shouldn’t be coming out around the air bypass and by your pics you have excess amount inside the charge tubes, something not normal there.
Intake track should be cleaned.

Just a thought but I would remove the roll over valve hose that goes into the intake, seal the fitting that the hose was connected to and run the sled and see if anything is coming out of that hose. I had quite a bit of oily water in my air box with only 800 km on sled but nothing like yours.

Roll over valve or the bypass valve will not effect oil level.

Did the coolant level change on your last test ride?

 

[rock doc]

Yes. The coolant level was way down. I am losing coolant somewhere with no obvious leaks.

 

[WinderFab]

I feel your pain on this bud, definitely sucks..

From what you are saying it sounds like the head gasket, coolant is going into the oil which raises the oil level in the tank then dumping it up into the roll over hose that explain the mess in the intake tubes.

 

[rock doc]

I feel your pain on this bud, definitely sucks..

From what you are saying it sounds like the head gasket, coolant is going into the oil which raises the oil level in the tank then dumping it up into the roll over hose that explain the mess in the intake tubes.

Yes - I still don't understand how this could happen. The sled has not been used hard or abused. Hopefully it is just the gasket. I did not think these motor were known for problem like this.

 

[Turboflash]

Rock doc, et all - if you're coolant level goes down when you run the sled, and your oil level goes up, the coolant is going into the oil sump. I have first-hand knowledge of this problem. I know of only 2 sleds that had this problem. One was my 20