Modern Vespa

So my 2006 Granturismo 200 L is leaking coolant into the oil but no oil has migrated into the cooling lines. It is exiting directly underneath the center stand, ive taken off the water pump impeller, seals are in good shape and spins as it should. Oil dipstick removed reveals foamy mixed oil and coolant, Ive flushed the coolant lines and started fresh only to have this happen immediately. Im wondering if someone could tell me a specific gasket, seal, or fail based off of the symptoms ive stated, no oil in coolant but coolant in oil sump. I only ran it roughly a mile total in diagnosing this, no signs of damage or change in the way it rides. Im just glad i checked the oil when i saw the first couple drops of mix.

head gasket failure is most likely, so I'd start there.

Thanks greasy125, but what gasket is it directly under the center stand that's leaking, half crank case gasket? Is that a commen weak point with head gasket failure?

I ask cause Im ordering a gasket set, rings, & such so i wanted to get them in one shoot.

it's likely leaking from the head and running down the case to under the center stand.

clean it all off and run it, that way you'll be able to assess.

there's a lot of things right in that area that can leak oil, but not coolant.

I cleaned it and ran again, the half crank case gasket is where it is coming from. Head is dry all the way down. Oil is foamy, its the mix leaking from that gasket not just coolant i apologize. I just dont know what caused this in the first place. Pump Impeller is working, fan is working no overheating, so if i replace the head gasket base gasket and half crank case gasket, crank case bearings, all piston rings and seals in motor i still dont know what caused the initial failure. Any thought what parts i should check while it is torn down. Thanks in advance greasy125. [img][/img]

disregard the water pump, it's not part of the equation of why there is coolant contamination in your oil. the water pump on GT200 is entirely separate from the crankcase.

the contamination and mixing is more than likely due to a failed head gasket, that is the most common type of failure, followed by a base gasket and then a cracked head or barrel-- rare but does happen.

crank case bearings are not replaceable, they're pressed in babbit type. depending on the mileage, your rings are probably fine along with the barrel.

if it is in fact leaking from the case gasket that was just like coincidence and collateral damage-- but I would give a hairy eyeball to the sump plug, oil filter and oil pressure sensor. leaking from the case is fairly rare occurrence unless the case has been some how damaged or compromised in some way.

but yeah, looks like you're in for a removal and tear down at this point.

Well that's good news to me, thanks again for expert advice, it is greatly appreciated. Im excited to dive into the rebuild & I'll take some photos along the way. Gaskets will be here on thursday so ill have her buttoned up and running by monday afternoon.

Good luck with the project. Hopefully relatively straight forward.

I have to say, having been on this forum for a bit, it seems like we have a record number of engines apart at once....though I'm pretty sure it has to do with it being personal for me, and gitder and my snail's pace.....

Greasy125, turns out the cylinder jug was cracked on the base side. Also there is some odd modifications to the case, specifically where the bottom timing chain slide goes into the case. Just left of the slide but south of the piston is this pinhole in the case, im wonder how ït got there, and if it could be allowing coolant into the case with the oil. Head gasket was bad

ohh... somebody was in there with chicanery! see the orange gasket sealant? that's not supposed to be there!

more pics please!