2010 Prius, 238K I cleaned my EGR cooler a few thousand miles ago. (car was running rough at startup, actually I put in a used one from a 2014 so I could clean it before the day of the swap) I installed an oil catch can too. The engine still sounds a little rough at startup, just for a few seconds, sometimes just a split second. So I decided that I had not cleaned the intake manifold well enough. I pulled it off today and found milky water in the bottom of the intake, just past the throttle body. The oil catch can was FILLED with the milky water. It seemed mostly like water, not oil (thin and watery). The hose connected to the PCV valve (going to the oil catch can) did have milky liquid, but I'm not clear if that just happened because I let the oil catch can overflow. There is NO milky sludge on the dipstick or milky color on the oil fill cap. My coolant reservoir level does not seem to be moving down, but it could be moving just a tad and I'm not noticing... Do you think I have a head gasket leak? Please help! See images.
Does it ever sound like the video below? How much oil does it burn? Have you done a borescope inspection of the cylinders? If it rattles severely and has a steam cleaned cylinder then yes its a hg.
No, I think you're not maintaining your OCC which is just as bad as no OCC installed. It's normal to have more blow by at that mileage. I bet if you maintain OCC so it doesn't get half full - the start up shake will go away. Your rings may even seal better which will lead to less blow by. Burning oil gums up the rings. moto g power ?
Thanks for the reply! It never rattled that long but that is what it did before I cleaned the EGR cooler/pipes. Does not use much oil, maybe 1 quart every 4000 miles. I have not borescoped the cylinders. Do you suggest that as the next step?. What does a "steam cleaned" cylinder look like? Any suggestions of which borescope to get?
Actually I took the oil catch can out of the equation today. I thought maybe that was part of the problem. Do you think I need to put it back?
Also, I thought the oil catch can caught oil. Are you saying it is okay to have that milky liquid in there? When I did the EGR cooler there was some oil in the intake manifold, but no milky liquid.
My spring harvest from oil catch can is maybe 50% water. Due to high humidity through winter. Settling out in a jar the water layer is pretty much clear though, not milky. I actually have 2 cans in series, and the second surprisingly catches the most, and mostly water.
I second Mendel. The milky fluid in the OCC is perfectly normal for this time of year. Every winter I have to empty it at least once per gas fill-up. For me it's mostly water in winter. This fluid is better outside your engine because it can lead to hydrolock which causes failed head gaskets. moto g power ?
I was concerned that somehow the oil catch can was not pressure sealed and somehow collecting water but after hearing you guys I think it might be normal. I'll reconnect it and keep an eye on the levels. Mine has a steel wool piece inside but I cannot see the purpose. Any clue if that is needed? @rjparker I will get a camera and try to borescope my cylinders soon. Thanks for the advice on that.
The steel wool is for increasing surface area for the hot oil vapor to condense to the liquid state. As mentioned, it's normal for the OCC to catch mostly water in cold climates. Here in Hawaii, it catches pretty much pure oil. Posted via the PriusChat mobile app.
Ok, much of the blowby gases that end up in the crankcase is exhaust- which has a lot of water vapor. Normally this goes though the PCV system and back through the combustion chamber again to go out the tailpipe. If you have high gas flow (lots of blowby), that flow will carry more oil droplets with into the intake manifold. When you put in an OCC, the PCV flow goes that to separate some of that oil from the gases. In warm climates the water stays a vapor and continues back into the engine. In winter it's a different story. The OCC is outside the engine and isn't directly heated. So water vapor goes into the cold OCC and condenses into a liquid. So yes, more "spooge" is normal in winter. That said, I would keep a close eye on oil and coolant levels and condition. I wouldn't expect the OCC spooge to be that uniformly mixed if it was just oil and water. But oil, water, and coolant + agitation = " coffe with cream" colored stuff. My usual technique for possible H/G problem is to get a pressure tester (a hand pump that fits in place of the radiator fill cap) and pressurize the cooling system to 13-15 psi- whatever the cap is rated for. Leave the system under pressure overnight. The next day, remove the spark plugs and inspect the cylinders with a boroscope - videoscope for ANY coolant. Even a few drops is a fail. Posted via the PriusChat mobile app.
How much vacuum would be too much? Any at all? Have you all had luck with the blue liquid "block testing" kit?
Update: I cleaned by intake manifold and put the oil catch can back on. Checked today after a few days driving and there was a little water in there, not much. And it was not mixed with oil so that is good. Sounds normal according to your input. Also, I got a borescope and looked into the cylinders. It's pretty carbon-cruddy in there (photos attached) so that may be contributing to some of the roughness at startup. I was also wanting to see if there was coolant in the cylinder (let it sit for a few days before checking with borescope) It appears to be free of coolant. Lastly I did the chemical "block tester" with the blue liquid. It stayed blue so that means no exhaust gases in my coolant so I think my head gasket is okay! My last step is to use valve cleaning spray at the air intake. Any suggestions welcome. Thanks for your help everyone.