Crankcase breather spewing oil

[DeLewis]

I have just returned from a 1500km trip of mostly highway riding at speeds averaging around 100-110km/h. I noted a significant amount of oil emitting from the crankcase breather during the trip, but not enough to consider it a major concern. However, I have since checked the oil level and found that I had to add 700ml(!) to bring it up to the level of the last oil change (about 1600km ago). Clearly something's not right. Yes, I made sure the engine was at operating temperature before adding more oil.

The exhaust shows no sign of burning oil as verified by my riding companion. My fear is that I am getting serious blowby occurring. The engine only has 26k kms on the clock and has not ingested any significant amount of dust as far as I know (always had the PodMod).

My two thoughts are it is straight forward compression ring wear (although I don't see how such a young engine would wear so quickly) OR it is glazing on the bore due to changing the oil too frequently (every 3500-4000km) or not riding it hard enough (that seems unlikely). Buggered if I know!

I suppose a compression test would be an obvious place to start.

 

[hasenpfeffer]

This sounds familiar, but I can't remember...

Maybe try making sure the breather hose that attaches to the bottom right of the crankcase is not swelled shut? The original hose is known to degrade and close up, possibly affecting proper breathing. Cheap and easy to try replacing the hose anyway.

 

[mag00]

What is your breather setup? Did you run one of the filters in the inlet? Is that clean?

If that filter clogs, that will create some pressure in the crankcase, which could cause oil to push past the rings, instead of wiping off.

When folks were doing the paper filter in the housing to vent, I did the video showing pressure and explaining that dirt would not go into the engine. Also warned that the filter would need to be changed out regular. I run my vent in the same spot as stock, which uses a real coarse element that will still breath when oily.

If the filter clogs, it will not create huge pressure, but maybe enough to push the oil after continued low pressure. I would check that first if that is the setup you are running.

 

[Mark_H]

This same problem was suffered by another owner and in previous posts it was eventually traced to pinch blockage of the Upper Breather Hose that connects from Cylinder head to the top of the oil tank.
The guy had taken off the airbox to do mods and had pinched the hose when replacing it.

Clearing the hose relieved the problem, it is important you check and do it asap to avoid blowing the Crankshaft seals if you have not already done so.

 

[DeLewis]

Thanks for the all the feedback and advice. I have checked and confirmed that the crankcase breather and cylinder head breather are both clear and seem to be operating.

In addition, I have run the engine without the crankcase breather tube attached and place my finger over the breather nipple and there seems only a small amount of air movement even when I run the engine up to 5-6000rpm. I am somewhat reassured by this result as I would expect a lot more air being pushed out of the breather nipple if there was significant blowby.

The vast majority of my riding is at low and medium speeds up to about 70km/hr as a commuter and I have not noticed much if any oil ejected from the breather under these conditions. It seems to be caused by sustained speeds / rpm which brings about the oil loss issue.

I will get the engine compression tested tomorrow and see what that shows.

 

[DeLewis]

Since last checking in, I spoke to the local BMW mechanic about getting a compression test done. He informed me that it's a bit tricky with the 650 singles as the auto decompression lever/valve(?) has to be disabled to avoid false low readings, and that requires the valve cover to be removed!

Instead, I removed the plugs and got the bore scope in to have a look around. Around the edge of the piston face is distinctive oil glazing - which according to my research is evidence of oil leaking past the seals. Added to that the bore looks too shiny - glazed bore.

These two conditions explain the oil being pushed out the crankcase breather at sustained high speeds/revs and the continued consumption of oil at low speed commuting. Strangely, given how much oil is being lost it doesn't blow any discernible smoke and plugs look ok (although the gap on one had opened way out).

I have now turned to the task of getting the piston rings replaced and the bore honed. The KTM-parts website advised to call them for price on the rings. In response to my email enquiry I was told that Husqvarna was no longer supplying piston rings!! What happened to the mandated requirement to provide parts for 7 years, etc??

I contacted my local husqvarna dealer here who took the order and assured me that Husqvarna was indeed required to provide ongoing support and parts. We shall see.

I also compared the part numbers to the BMW part numbers on the BMW OEM parts website (thanks duibchek!). Only the base gasket was a match. The rings and head gasket were completely different part numbers.

So how did the bore glaze up? The local BMW mechanic (who I trust) suggested what I had already suspected - I was too gentle during the running in of the engine. It's only done 27k km and otherwise runs perfectly. But the vast majority of the riding is low speed commuting and I obviously did not ride it hard enough in the first few thousand kms to properly bed the rings in. Guess I've learnt a lesson - don't treat your ride to kind!!

 

[LED]

...I contacted my local husqvarna dealer here who took the order and assured me that Husqvarna was indeed required to provide ongoing support and parts. We shall see.
... So how did the bore glaze up? The local BMW mechanic (who I trust) suggested what I had already suspected - I was too gentle during the running in of the engine. It's only done 27k km and otherwise runs perfectly. But the vast majority of the riding is low speed commuting and I obviously did not ride it hard enough in the first few thousand kms to properly bed the rings in. Guess I've learnt a lesson - don't treat your ride to kind!!

When I had my gearbox repair requiring the case to be split at around 25000km I took the opportunity to put new rings in since everything was apart. This was around Christmas 2015 with local Husqvarna dealer. Not sure on the best approach to bed the new rings in I ended up doing a fair bit of googling. The method I ended up following was to use a range of rpms but nothing too extreme, avoiding constant steady rpm, and to do a reasonable amount of engine braking (decompression). Tried to follow this for the first few hundred km. So far all good.

 

[duibhceK]

The method I ended up following was to use a range of rpms but nothing too extreme, avoiding constant steady rpm, and to do a reasonable amount of engine braking (decompression). Tried to follow this for the first few hundred km. So far all good.

That's indeed the best strategy for optimal long term performance. But I would be really surprised if a gentle run-in alone could cause glazing so bad the engine starts consuming that amount of oil. You'd have to ride like an old lady in an electrical wheelchair.

So how did the bore glaze up? The local BMW mechanic (who I trust) suggested what I had already suspected - I was too gentle during the running in of the engine. It's only done 27k km and otherwise runs perfectly. But the vast majority of the riding is low speed commuting and I obviously did not ride it hard enough in the first few thousand kms to properly bed the rings in. Guess I've learnt a lesson - don't treat your ride to kind!!

Glazing is caused mainly by long low temperature operation in the engine. Even at light loads the TR650 engine still runs pretty hot. If there is indeed significant glazing i'd be looking for other causes. Where modifications made to the cooling system? Or to the fuelling, did the engine run (very) rich?

For a decompression test you'd indeed have to take into account the automatic decompression lever in the inlet cam shaft. It is a rather simple spring operated extension on the end of the shaft. But to get at it you do indeed have to remove the cam cover.

Got any pics of the piston head and cylinder wall from the scope?

 

[mag00]

So how did the bore glaze up? The local BMW mechanic (who I trust) suggested what I had already suspected - I was too gentle during the running in of the engine. It's only done 27k km and otherwise runs perfectly. But the vast majority of the riding is low speed commuting and I obviously did not ride it hard enough in the first few thousand kms to properly bed the rings in. Guess I've learnt a lesson - don't treat your ride to kind!!

Your bore cam should have a snapshot feature, can you get one and post it?

Did you have the Pod Mod done?

What oil filter are you running?

 

[DeLewis]

Here are some pics from the borescope:



And here are the plugs:



I'm pretty sure I didn't ride it very gently from new and generally ride it pretty hard.

I was first using Castrol Edge 5W-40 for the first few oil changes - that had the friction modifiers which obviously is not compatible with a wet clutch. Swapped to Motul 5100 10W-40 but more recently have been using Penrite fully synth (I'll have to check the bottle for actual type/weight. Yes Podmod was done when the engine was very young and it's never been dusted - always been very careful.

 

[mag00]

I wouldn't be too gung ho about pulling it apart yet. Here are some pics of my engine inside. Very similar in ways. Notice it is shiney from one angle then in the other pick you can see good cross hatching.


I have some carbon build too, not as bad as you, not as many miles either. My Strada with 19k miles looks similar.

You could soak the bore with something like seafoam, and run regular oil for awhile and see if it helps.

I use the Castrol synth blend from walmart. Clutch works great.

Your rings could be gummed up. Also the left plug looks funky.

You say you have the pod mod, where and how is your breather? That is what is suspect from the start. The stock breather is a real coarse material, and will breath fine when wet with oil vapor residue, the paper elements in the breather inlet are very restrictive. We are talking a very low pressure from the start, so any restriction is significant to the crank case pressure.

 

[duibhceK]

For reference, this is what my piston looked like after 35000km:

A bit of carbon build-up, but looking pretty good.
About 5000km later, it looked like the image below. Not extremely bad, but a very big difference for such a small increase in mileage.

 

[DeLewis]

Mag00 I wondered about Seafoam - I may try prior to tearing it down to see if it makes a difference.

The crankcase breather is routed into a small plastic bottle with a pretty course foam inside and a hole drilled at the end of the bottle. Do you think that even a small amount of back pressure may be enough to force oil past the rings? Wouldn't have through it would make any difference.

As for plug - yes not sure how the gap should have changed so much but I have occasional pinging which may have caused it to open.

DuibhceK any insight as to why the condition of the combustion chamber changed so much in 5000km?

I'm a bit baffled by how mine ended up in the current state when I have a very similar setup to many other TRs - Podmod, AFXIED (originally set to 8 now 6 out of concern for possible carbon buildup), slip on pipes. I guess small differences compound and cause other issues.

 

[duibhceK]

DuibhceK any insight as to why the condition of the combustion chamber changed so much in 5000km?

I'm not entirely sure. After the rebuild on the crank shaft in Tehran, it was clear that the engine wasn't back to 100%. The valves were rather noisy and the bike was lacking in top end power. On a long steep hill on the motorway the bike would not accelerate above 100km/h. That was one of the reasons I decided to do another rebuild in Bulgaria with a complete bottom end swap. And of course the metal particles that were still coming out during the oil change in Tbilisi (it later turned out these were just remnants from before that weren't flushed out completely).
My guess it was due to a combination of the wrong thickness head and foot gasket and incorrect gaps on the spark plugs.

 

[mag00]

Mag00 I wondered about Seafoam - I may try prior to tearing it down to see if it makes a difference.

The crankcase breather is routed into a small plastic bottle with a pretty course foam inside and a hole drilled at the end of the bottle. Do you think that even a small amount of back pressure may be enough to force oil past the rings? Wouldn't have through it would make any difference.

As for plug - yes not sure how the gap should have changed so much but I have occasional pinging which may have caused it to open.

DuibhceK any insight as to why the condition of the combustion chamber changed so much in 5000km?

I'm a bit baffled by how mine ended up in the current state when I have a very similar setup to many other TRs - Podmod, AFXIED (originally set to 8 now 6 out of concern for possible carbon buildup), slip on pipes. I guess small differences compound and cause other issues.

Don't know that it would make a difference soaking them either. The breather might. Just put it stock and keep an eye on the oil level.

The pinging is of greater concern to me. Take this with a grain of salt, but you would be the 3rd TR650 with ping and afxied. I would never run that gadget. Also, depending on your exhaust, you may not have enough back pressure.

 

[Nick780]

I've had two incidents of burping up a surprising amount of oil from the breather. Both times were during maintained highway (~120 km/h) speeds for a few hours. Each time the oil level was correct (possibly low since I burn oil as well, but not past min. on dipstick) and I can't see how anything would be intermittently pinched or blocked. I'm at 20,000 km.

 

[PaulC]

Don't know that it would make a difference soaking them either. The breather might. Just put it stock and keep an eye on the oil level.

The pinging is of greater concern to me. Take this with a grain of salt, but you would be the 3rd TR650 with ping and afxied. I would never run that gadget. Also, depending on your exhaust, you may not have enough back pressure.

Agree with putting things back to stock, and try again.
My experience with spoofers is that (and the afxied is a type of spoofer) these help with avoiding pinging.
On the flip side, DeLewis mentions running the afxied on setting 8. Is it possible that the new and maybe old catalytic converters have suffered damaged through to much carbon build up?
Causing too much exhaust back pressure. This would explain oil getting past the rings and also up the breather.

just my 2 cents worth

 

[DeLewis]

I hear what you say re the AFXIED and I know that it may well have contributed to the current state of the engine through carbon buildup. On the other hand, the stock bike suffered an unacceptable amount of pinging which was until recently eliminated by the AFXIED. Now I think its starting to ping frequently - although it's sometimes hard to be sure it's not some other vibration-related rattle - which is possibly caused by the carbon deposits on the piston. I recently experimented with running without the AFXIED and it soon reverted to the dangerous stumbling and stalling which doesn't mix well with my city commuting.

In relation to the exhausts, they are just open pipes (Screaming Demons) with a sports baffle - no cats. While I'm waiting for the piston rings to arrive (if they arrive I will try to source some Seafoam to clean some of the carbon out.

 

[mag00]

Seems you guys down under are the ones with pinging. It must be your ecu software version coupled with bad gas.

Run octane boost and see if the ping abates. I strongly recommend that when you go in and do rings, that you install a thicker head gasket to help out on the bad gas situation. Cometic makes one to the thickness you want, and for about the same price as the stock one. http://www.cometic.com/p-35446-custom-gaskets.html They have the jigs for the BMW 650 singles.

 

[PaulC]

I don't think we have bad fuels just more choices.

I personally would go the other way and do a squish clearance test and try to bring it into spec using the two gaskets. (without resorting to machining)

The main thing is to determine the cause.