oil pump

[rossi]

Not normally one for superstition but we had a nightmare on Friday (13th). 2 miles from home I glanced down to see the oil light flash on. Pushing the bike home a neighbour stopped to give me a lift. I hooked the trailer up to the landrover and went to start it - battery flat. After 30 minutes on charge I got it started to find the pipe to the silencer had rusted through. I retrieved the bike and went to work thinking that would be it but my wife came home with her car door handle in her handbag. Arghhhh.

I got to work on the bike today and it is not looking good, although it could have been much worse had I not seen the light come on or taken a chance that it was an electrical issue. Unfortunately I have no oil pressure to the engine. Judging by the fact that the oil tank is also full to the brim, my best guess is the engine oil pump has failed leaving the engine without oil and allowing the scavenger pump to pump all the oil to the tank. Having checked the manual this shouldn't be too major a job as the oil pumps are accessed behind the clutch. It could well be the plastic drive gear has failed as this would seem to be a weak point; if so they will all be replaced. Not having a clutch holding tool, and being up to my eyes in it with other stuff, I am going to hand it to the local dealer this time. I guess my shock is going to have to keep on squeaking for a few more months.

 

[JohnnyBoxer]

Any pics of the broken/rusted pipe?

Sorry to hear of that trouble, keep us all posted

 

[rossi]

Any pics of the broken/rusted pipe?

Sorry to hear of that trouble, keep us all posted

You want to see pics of my landy? The oil pump might be more interesting; I'll need to ask for the broken parts back so I can post some pics.

 

[Timpo]

Did i read somewhere about an oil pump drive gear issue with higher mileage BMW/Rotax engines? I could be wrong though chaps.....

 

[JohnnyBoxer]

You want to see pics of my landy? The oil pump might be more interesting; I'll need to ask for the broken parts back so I can post some pics.

Sorry got confused with which vehicle, sorry to hear of your woe

Anyone have similar on AdvRider?

 

[JohnnyBoxer]

Did i read somewhere about an oil pump drive gear issue with higher mileage BMW/Rotax engines? I could be wrong though chaps.....

I thought it was the plastic water pump drive impeller on high mile bikes, not the oil pump ????

 

[Timpo]

I thought it was the plastic water pump drive impeller on high mile bikes, not the oil pump ????

Yes JB, you could be right.....

 

[rossi]

Oil pump drive gears are plastic but it is the water pump failure I am aware of. 33k miles isn't low miles but these engines normally go much furthes. I'll keep you posted.

 

[Timpo]

I'll keep you posted.

Yes mate, do that. I'm very curious to hear what the reason for the failure is.

 

[rossi]

Update

There are 2 oil pumps, each driven by a plastic gear (8) from behind the clutch. There is an additional idler gear to drive one of the pumps. Each gear slides over its shaft, slotting over a pin going through the shaft (9) and held in place by a circlip. 1 pump scavenges oil from the bottom of the engine to the tank. The other supplies the engine.

As I suspected the plastic gear to the upper pump (engine supply) has failed. The problem is to understand the cause of the failure. The oil pump shaft was also very tight however the mechanic was unable to confirm the cause - there was no blueing or scoring which would have suggested the shaft seizing and overheating due to lack of lubrication. Not surprising since it runs in engine oil and I am pretty meticulous about oil changes. There was some bruising to the metal on the oil pump cover (7), probably caused by the pin which would have been able to slide out of its hole once the gear had failed. This in turn could have caused the tightness on the oil pump shaft as the cover is thin metal and could be pushed out of shape. Alternatively the oil pump may have been tight for another reason which caused the gear to fail. Basically the cause of the failure is unknown.

The end result will be a complete new oil pump. Around £100 in parts and new filter, oil etc plus around a couple of hours labour. Hopefully the few seconds that the engine was running while I came to a stop, and later when testing the pressure switch, has not resulted in damage elsewhere in the engine but only time will tell.

The good news for everyone else - the plastic gears are not a new part and have been used in all varients of this engine since 1993. This is the first such failure the dealer has seen. They also checked the BMW parts database to see how often the plastic gears were ordered. The result - 0.07 gears ordered per year, approximately 1 gear every 14 years. Not sure whether this was UK only or international but, either way, not something to be worrying about.

 

[Timpo]

Thanks for the feedback Rossi....
I take it you have opened the pumps and looked at the rotas?
Also, I'm not telling you how to suck eggs, but ensure you clean the oil galleries out prior to assembling the new pumps on the engine crankcase assembly. There could be some debris that may of caused the seizure.....
The part order history is promising, at 1 gear in 14 years, I'll live with that.....
Best of luck and if you find any more issues, please post the details here.

Timpo.

 

[rossi]

Thanks for the feedback Rossi....
I take it you have opened the pumps and looked at the rotas?
Also, I'm not telling you how to suck eggs, but ensure you clean the oil galleries out prior to assembling the new pumps on the engine crankcase assembly. There could be some debris that may of caused the seizure.....
The part order history is promising, at 1 gear in 14 years, I'll live with that.....
Best of luck and if you find any more issues, please post the details here.

Timpo.

Since I didn't have access to a clutch tool and have 2 cars and job application to sort this week I have left it with the dealer this time. They seem to have been pretty thorough so far. Thanks for the suggestions though.

 

[rossi]

Bike is now returned. The good news is the engine sounds sweet and Oceans have done a thorough job. They removed the rocker cover as well to check the cams - all fine there. Even better was the fact that the total bill was only £250. I know how long they spent on the job and that is a VERY good deal. Thanks guys

I have the broken parts and the pump shaft is definitely turning a little rough in the cover pump cover. However it appears that this has been caused by a few scratches on the shaft caused during the failure or subsequent disassembly. Not the cause of the problem. The pump rotor was not turning freely inside the outer part due to debris, what appears to be black plastic, rammed into the end of one of the points on the outer rotor. After removing the debris the rotors turned smoothly. Now what has most likely caused the problem; there are a couple of dimples on the lobes of the inner rotor, and matching ones in a point of the outer rotor. No idea what has caused the dimples but I doubt it was the plastic as there is no damage in the point where the plastic debris was lodged. With the pump parts being steel it is most likely a piece of metal debris that has passed through the pump. This in turn has damaged the gear which has then failed.

No sign of metal debris when I changed the oil over Christmas. Fresh oil and filter have been fitted with the pump but I am inclined to give it a couple of weeks to flush round the engine and change again, just in case there is anything else washing round in there.

Give me a while and I will get some pics up.

 

[rossi]