Oil Leak from the Turbo/Exhaust

Went to go take my bike out this morning and noticed a puddle of oil beneath my like and a leak between my exhaust and turbo. I know it's not much to go on, but is this a gascket that got blown? Or what exactly? Any thoughts are appreciated.



For better clarification, I circled the area I photographed.

Thanks!

 

A much clearer look at the spot.

 

I'm not familiar with turbo on this bike but I have 15+ yrs experience with heavy truck turbo diesels. The gasket circled seals exhaust gasses only. I would guess that either the turbo is going bad or engine is pushing oil out exhaust(more likely turbo). Be carful with this issue, I can't count on one hand that amount of times I've seen a turbo fail and take a engine with it or cause a fire. Most if not all turbo's don't have a oil seal like a engine, It's more like a piston ring on the turbo shaft. A normal rubber seal cant take the high RPM and heat/pressure. That being said sometimes a exhaust or intake leak will cause oil to seep around seal ring because of pressure differences. Hope this unfortunate info helps you. Sorry for the bad news.

 

This is some major bad news if you're right. I just had the Turbo unit replaced back in February which is even more disappointing.

On another note, I should be fine to disassemble that leaking part by removing those bolts?

 

Pardon the side track - I know nothing about turbos (car, truck, motorcycle).
I always ass-u-med they were an intake 'boost' - this is clearly on the exhaust side of the engine.
What does it do and how?
Ass-u-ming again - the exhaust gasses go in and the turbo some how increase the velocity of 'escape' which pulls the exhaust out of the engine faster . . . .? ? ? ?

 

Pretty much. It's where the exhaust pipes dump into the turbo, and there is oil seeping from it. I know nothing about turbos either, but as far as I know there shouldn't be oil coming out of that end.

 

Glad you asked. The turbo has a intake side and a exhaust side. Inside each housing is a fan or turbine. As the exhaust gas leaves engine it spins exhaust fan which is coupled to intake fan by a shaft. The intake fan spins and starts to build pressure in the intake manifold(boost). Now there is ALOT of theory and math involved with size of the turbines. Which all boils down to how fast the turbo "spools up" and starts making boost and how much boost pressure it makes. I've attached a pic for your viewing pleasure. Yes, you should be able to remove the exhaust pipe from turbo and determine where oil is coming from. Either upstream or down stream of turbo. Was this turbo rebuilt or good used one? Most of the time turbo's can be rebuilt as long as the turbine or housing isn't damaged. It's pricy thought.

 

Thanks for the explanation.

It was one of the rebuilt units from XJ4ever.com. I am just amazed that it let go after only a handful of rides. (If that is indeed the issue.) I tried removing the bolts but they are on so tight and it's an odd angle, so I couldn't get anywhere.

 

I have a little experience with Turbos and it may not be the turbo make sure all breather hoses are clear excess pressure can cause oil to be sucked into the turbo. Fixed a car that used 4 quarts of oil every 5 thousand miles by cleaning hoses and breather system so start with the free and simple then go to the more expensive

 

m'kay - but what is the theory of enhanced performance?
Quicker air exchange = cooler air = better combustion?

 

Stuff more fuel and air into the combustion chamber and get a bigger boom. It's the equivalent of increasing displacement without needing to increase displacement.

 

I have a Turbo in my garage waiting for some exploratory surgery. There was excess oil in the turbo (exhaust) smoking out the neighborhood, that is what the previous owner told me.
I've read a bit about what can cause this. The 1st place to look is the check valve located at the bottom of the motor in the oil line feeding the turbo. When this fails excess oil continues to pool in the turbo unit when the bike is sitting. If working properly it shuts the gravity feed of oil off when parked.

 

I've had a bunch of turbo cars. Turbos have an oil jacket to keep those bearings cool and moving nicely. There are oil seals to keep the oil where it needs to be (and out of the turbine and compressor housings). I would not expect to need to shut off the oil flow to the bearings. What I suspect if you're blowing oil is that either it's hitting the engine internally (and you'd be burning it), or it's leaking in the turbo, in which case, it might not burn, but would certainly smoke a lot!

 

it's pressurizing the intake air. It's not speeding up the exhaust air, in fact the pressure of the exhaust air is what's driving the shaft that powers the intake compressor.

Instead of being just atmospheric pressure (actually a bit less, as it's drawn into the engine via vacuum), the turbo forces more air through the carbs and into the combustion chamber.

What's fun with turbos is the way it spools up. You crank open the throttle, bike draws air, booms it, forces it out the exhaust. Exhaust pressure spins the turbo, which adds even more air. Bigger boom, more exhaust pressure, more spinning, more intake pressure.

As Metalliccurent (who knows way more than me, I'm just a dumb guy who likes zoom) said, a lot goes into determining just how much pressure your engine can handle, how quickly it can build that pressure, etc.

There's lots of fun videos on YouTube where people push the boost pressure up beyond what the engine can handle. It ranges from disappointing to really, really dramatic, depending on what fails first.

 

The seals in the turbo are like piston rings and will leak oil, they have to or they'd seize. Yamaha mounted the turbo below the motor and without that check valve the oil will continue to run into the turbo when parked.
I'm not saying that's the problem but it's the 1st place to look for sure, it is a known problem area. The inlet flange to the turbo is obviously leaking also so it will need to be redone with a new gasket.

 

That's interesting. Not used to a turbo mounted so low.

 

Yes.

Yes, again.


While a clogged/non-performing oil supply valve (front of crankcase, just off the side of the oil filter housing) is the main cause of an oil leak such as yours, there is also a pair of copper crush washers used at the turbocharger itself, for the oil supply pipe, and a paper gasket for the oil supply return pipe.

And although possible, it is doubtful that the burned exhaust collector output-to-turbo input gasket, shown in your photo, is the source of the OIL leak (although, if it very OILY at that leak point......on the collector itself.....then that is also a possible issue).


Our rebuilt turbo units carry a warranty, so if the internal piston ring seal has failed, of course it will be repaired for you. However, when that seal fails, normally it blows oil out of the exhaust (while running) like nobody's business......

 

Thanks for all the responses! And I am glad to hear about the warranty in case of a worst case scenario.

So, I'll start off addressing the issue mention by chacal: a clogged/non-performing oil supply valve.

Would this be the piece I am looking at to replace on the front of the bike? http://www.ebay.com/itm/Yamaha-Seca...ash=item46629c2777:g:ZZYAAOSwBOtY~OVH&vxp=mtr

 

Yes, but you won't need to replace it, you need to remove it and carefully clean it up/out..............there is a small fine mesh screen in there (called the "strainer" as well as a spring-loaded ball (that's the "check-valve" function) in there, and you want to be sure that is not seized due to junk/gunk/residue/demons of any sort.

 

Alright. So I'm going to drain my oil and attempt to clean out the relief valve. Anyone have recommendations for motor oil to use? I noticed that the Seca Turbo service manual states Yamalube 4 cycle sae 20w40 type se motor oil but I am only pulling up marine outboard and a transmission oil on amazon. Even a search on shop yamaha comes up with the marine oil. Any help is appreciated.