Offroad Trailblazers and Envoys

Yellow Foamy Looking Oil In Intake Resonator

Something not working right?

by wet13827 » Tue Feb 04, 2020 1:13 am

Was changing my spark plugs today and noticed a ton of nasty yellow baby poop looking foamy oil in the intake resonator. I had just changed the oil about 2000 miles ago, and the oil looked good at that time, but I went to check the oil level and it didn’t even show on the dip stick. I immediately started panicking because I have no idea how long it has been low on oil and making this foam. I immediately thought maybe it’s a head gasket, but the oil in the engine looks fine, just low. I only had to add a half quart or so for it to show back up on the dipstick so that made me feel better.

The engine only has 115k miles, the thermostat is fine, the spark plugs looked very corroded but are now new. The only other thing I can think of is this random lean condition code I keep getting, it only happens when I’m idling in traffic for a little bit, and when I clear it it goes away for weeks or months at a time. Engine coolant looks fine and is staying full. So I don’t think it’s a head gasket, if it is, it’s a very minor leak. This weekend I’m going to change the oil with some sea foam and check for vacuum leaks.
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by DirtyBacon04 » Tue Feb 04, 2020 2:05 am

Out of curiosity, what oil do you use?
And not to insult your intelligence, but confirming that after your oil and filter drain, you put in 7 quarts of oil, correct? (assuming 4.2 I6 engine).
Doing some quick reading here, i've read that oil in the intake can be a result of failed PCV, vacuum leak, overfilled with oil, excessive time at high RPM, or worst case scenario is failing piston rings.
Hopefully one of the smarter fellas will chime in soon and make me look dumb, as they usually do.
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