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Head gasket?

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Dean

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Dec 13, 2024
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Houma, La.
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I have a 2016 c650 sport Valencia orange with about 18000 miles.
Last time I road the scoot I noticed a change in the sound and decrease on power. When I parked I noticed it dumped some oil and coolant. I was thinking I may have blown a head gasket . It still starts right up but I have kept it parked since this took place. Any help would be great.
Thanks!
 
Good evening,

Do water and oil escape from the same place on your engine? And in what quantity?

Most of the time, a cylinder head gasket rupture occurs not towards the outside but towards the inside of the engine, as this is where the gasket undergoes the greatest stress.

The result is abnormal exhaust smoke (by abnormal, I mean that it doesn't come from the moisture in the muffler of a cold engine).

In this case, bluish smoke will indicate that the engine is burning oil (so it's not necessarily a head gasket, but rather a problem such as piston segmentation or valve wear), but white smoke will indicate that it's sucking in coolant (and therefore most likely a problem with the head gasket).
 
I agree, both oil and coolant spilling, as well as reduced power, are rare symptoms and to me sound like something rather serious. I hope you find out what the problem is and let us know. Mine is exactly the same year, color and miles! In fact there's anothet one just like it with a blown engine on LA Craigslist right now ...
 
I haven't taken enough plastics off the bike to see where the oil and water came from. Also I didn't notice any smoke coming from the bike. Would it be a good idea to drain oil and put new oil and filter and top off the coolant and run the scoot. I could also check compression.
 
Hello,

You can try what you say, but it's not a good idea to drive with fluid leaks.

The scooter's cooling system is very simple. Most of the components are located at the front, between the radiator and the engine.

You should check the following components for leaks:
- the radiator
- water pump
- hoses
- water/oil heat exchanger (located behind the oil filter)
- cylinder outlet line (located between the oil filter and the cylinder head exhaust outlets).
 
Something that caught my attention in Kiss4u's post is this: "water/oil heat exchanger (located behind the oil filter)"
If this thing broke internally, or in some other way, that could explain your symptoms, of seeing both coolant and oil leaking. Although I would still worry about the decrease in power you mention, unless that is the ECU forcing the bike into 'limp mode' if it senses loss of oil pressure or what have you.
Also, have you checked the oil and the coolant yet, to see whether there is any 'mixing'? (coolant in the oil, which causes 'milkiness' or sludge, or oil in the coolant reservoir/radiator)?
 
Cleaned the scoot yesterday, put on center stand and tried to see where things were leaking. Checked oil and topped off . Oil looked good.. topped off coolant to fill level in jug and at top cap. Ran on center stand in garage. Red warning light started blinking after a couple minutes so I turned off engine. Did this a couple times. New oil puddle under bike size of small pancake.
I noticed that the filter by the cvt was saturated with oil. It was late so I stopped working on it. I will continue to inspect it to get more info to report when I get up in the morning.
And btw I really appreciate everyone's input on helping me figure this problem out. Hopefully it's not major repair but I'm not too optimistic.
 
I Suggest you get the Motoscan app and a bluetooth obd2 dongle, and check the fault codes that must be there given the red triangle warning light. That will point you in the direction of the problem, most likely.
 
Hello,

Could you be more precise about the “CVT filter” ?

Is it the filter in the plastic cover of the CVT (in front of the transmission cover) or is it the filter in the drawer (located between the crankcase and the seat)?

If you're talking about the CVT cover filter, which I think you are, then your leak probably comes from the primary shaft seal. This is a large spinnaker seal behind the variator that provides a seal between the lower engine and transmission oil sumps.

The good news is that it's very inexpensive to change (the seal costs less than $30).
The other good news is that there's no adjacent water circuit, so the oil and water leaks aren't related (maybe you don't even have a water leak).
 
Thanks for the replies. I appreciate the help.
I took the side panels off to get a better look. Bad news. I see s hole and crack in the engine. I will send pics. I started the bike to allow me to see where oil was spitting from.
So what do I do now? Jb weld.? This sucks!
 

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Your motorcycle has been involved in an accident. Your crankcase cracks are located exactly at the frame/engine connections.

These connections are integralted with the drive unit (cylinders/crankshaft housing).

This is very important and complex mechanical work. Replacing the complete engine could be simpler and more economical.
 
Maybe the damage was caused by the timing chain issue, as you report it 'bent tings up in there'. Maybe there was initially only a hairline crack that got progressively worse. I would not trust JB weld but it could possibly be welded by a professional welder - likely aluminum / alloy.
Either way, I agree with Kiss4u, getting a replacement engine may be the most economical course of action at this point. That, or selling on Ebay as a parts bike.
I don't know how many of our scooters make it to 50K miles, but it seems many are failing miserably long before that marker.
 
I've owned a 318i a 328i, a 528i, a 530 and this scooter and I have had trouble with all of them. Can't say I will be shopping for another bmw anytime soon.
 
Dean, any update on the oil leak/crack issue?

I bought a Coleman UT400 that the guy said smoked a bit, didn't move very well, and leaked a bit of oil. But it was a great price, so I bought it. By the time we pushed and got it inside my enclosed trailer, the trailer was full of smoke and it would not even pull itself a little.

I learned a LOT on this thing. First, it has a motor mounted internal clutch system, similar to the C650's, but it's inside the motor and is a WET clutch in engine oil. After getting it up on my 2-post car lift, I found the oil leak... It had a hole in the bottom of the engine case about half an inch in diameter. It had been "repaired" with JB Weld, but very poorly. I hit the patch with a screwdriver and it fell off the case. Hard to tell what caused the hole, as it's above a 6" wide cross plate and no way to get HIT by anything external. Should I have tore the motor out to split the case, YES! But I didn't... :(

The hole drained the oil, the low oil burnt up the wet clutch and finally, the lack of engine oil burned up the piston and cylinder. Found all three issues in one whack! I bought an extended burring tool and ground the aluminum around the hole to get it clean and rough it up a bit. Used JB Weld again, but did it very well and it's still working great three years later. Put in a new wet clutch and cylinder/piston combo, and all is good now!

I know it's a TON of work to take the engine assembly out, but that's probably, in your case, the only good way to fix the crack. Someone on the BMW C650 Facebook forum has a complete spare motor assembly. Not sure if you're on the Facebook C650 forum/group there, but take a look. Might be an option for you.

Good luck with your oil/coolant leak.

Dan
 
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