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I'm mostly through the initial teardown of an 06 JCW I just picked up locally. The car is ridiculously clean for 140k Wisconsin miles, and was supposedly only dealer serviced.
Unfortunately the quality of service seems to be pretty lackluster.
Supercharger clamps hanging loose because of broken hardware, self tapping sheet metal screws run into nutserts holding the bumper on, missing safety crash hardware, etc, etc, etc. Those items were annoying but mostly easily resolvable. Last night really had me scratching my head and I need some help from the hive mind:
The car was low on coolant when purchased, but had a cracked reservoir. When I got under the car I noticed some blue sludge on the front of the motor which I had assumed was a coolant leak from the water pump outlet. The car is running the dark blue mini coolant.
When I first got under this car I assumed this was a coolant leak from the water pump outlet o-ring.
The previous owner said that the supercharger had been replaced last year, and the cleanliness of the SC supported that. I hadn't planned on cracking it open; but then I elected to not be dumb and check the oil levels while I had it out. The blue/grey oil that came out surprised the hell out of me. It definitely stinks like supercharger oil, but I've never seen anything this color before. Never seen SC oil like this (Snout end)
The water pump gearcase looks the same. There's a bit of sludge built up on the sidewalls that you can see in this picture. Water pump end is the same
I removed some of the sludge with my finger and compared it to what I found on the outside of the supercharger case (what I thought was coolant) and it looks to be identical. However the oil level looks pretty good in the PTO end. Does anyone have any theories as to what's going on here? Did mini change the factory oil in 05/06? Did the previous SC leak out all of its oil and the dealer didn't clean it up? Am I getting coolant into the SC somehow (osmosis?)? I plan on draining the oil and replacing with standard AC Delco GM supercharger oil that I've used many times before. What is on my finger is from my inside the water pump gear case
I have no idea, other than to say that at one point there was an exterior paint color very similar to that, but I haven't seen it in a while. I'm curious to hear what the experts will say once they chime in...
That is the weirdest looking supercharger oil. Is it viscous like a gear oil? I know you mentioned smells like gear oil so perhaps it's what the rebuilder is used to using on their rebuilds.
When my kid and I replaced his supercharger and water pump in 2018, the root cause was a failed water pump that seized and caused the coolant to flush out the oil in the PTO reservoir because coolant was somehow was forced past the water pump seals at the PTO interface. There were traces of gear fluid in the coolant and I was suspecting head gasket failure, but the oil was clear and not the typical choco-shake consistency.
I'm wondering if the blue coolant mixed with the clear supercharger (Delco) to produce what you are seeing?? For reference, the kid's car had about 234K miles on a presumably original supercharger. I believe the S/C is still good despite it getting pummeled by the failed water pump and I suspect yours is also good, but I would take a hard look at that water pump.
That is the weirdest looking supercharger oil. Is it viscous like a gear oil?
It's been a while since I've drained a well driven SC, but I have the impression its a bit thinner than normal, but not significantly so. I would expect it to be watery if there was enough coolant to turn the oil blue.
Originally Posted by Zsm
When my kid and I replaced his supercharger and water pump in 2018, the root cause was a failed water pump that seized and caused the coolant to flush out the oil in the PTO reservoir because coolant was somehow was forced past the water pump seals at the PTO interface. There were traces of gear fluid in the coolant and I was suspecting head gasket failure, but the oil was clear and not the typical choco-shake consistency.
That was sorta my "I guess its plausible" thought too. However looking at both the water pump and SC PTO interface, I don't see any evidence of seepage, unless it's all evaporated by this point; but I would still expect some trace residue similar to what is on the oil pan and SC casing. It looks like there might have been a little weeping from the water pump weep hole, but I'm not completely convinced. The water pump doesn't spin freely. It rotates, but with a constant amount of smooth friction. I have a new water pump on the way.
Originally Posted by Zsm
I'm wondering if the blue coolant mixed with the clear supercharger (Delco) to produce what you are seeing?? For reference, the kid's car had about 234K miles on a presumably original supercharger. I believe the S/C is still good despite it getting pummeled by the failed water pump and I suspect yours is also good, but I would take a hard look at that water pump.
It makes sense on the PTO end...but how would blue oil make its way to the snout reservoir? The SC gears still look great (practically new) with the exception of an odd amount of wear/scoring on the non-functional surface of the smaller gear. See below:
I spent a while on google image search looking for blue supercharger oil, and didn't see any direct results, but found a potential culprit:
Hmm. Whatever is causing the blue color is rising to the surface and is less dense than the rest of the fluid. I'll let it sit a bit more and check the consistency and compare to the color of OEM mini coolant.
Even if it matches it doesn't explain how it got there. I drained the SC and I'm currently leak testing it with fresh oil.
