Prius 2011, caramel like syrup in the intake, causing cylinder 2 miss fire, rest of cylinders are ok, 200K miles, any suggestion?
How does it taste? Sweet like honey? jk/ that's just oil. Are you losing any coolant? When was the last time you changed the spark plugs?
"causing cylinder 2 miss fire" How'd you come to that conclusion? More likely a plug, coil, or dirty injector.
For as long as there have been Prii, there have been posts about the gloop in the intake. Because of the Atkinson-like engine cycle achieved by delaying intake valve closure, there is always some cylinder charge being pushed back into the intake manifold. There's always a puddle of gloop there, whether the car is misfiring or not. Some owners get obsessive about it and clean the gloop out, and then there is gloop there again. Beyond that lies the whole oil-catch-can thing.
Having installed an oil catch can (two now, in series), I'd speculate at the least the PCV circuit is responsible for 60~70 percent of the goop. Plus, the spit-back from the intake ports looks like straight oil, while the PCV goop is a real olio, sort of toxic mayonnaise, some of it. @Rick4112 how many miles on it? If over 100K it's time for EGR cleaning*. MIght be overdue if you're getting misfire; a leak-down test can diagnose head gasket condition. * Info in my signature.
I didn't have a toasted bread to taste it. Looks like oil, but the color I assume comes from the coolant is loosing. The Oil chamber oil looks clean (free of coolant). I have replaced injectors, spark plugs and swap coil from cylinder 2. and symptom remains
Ah geez, just realized you noted the miles in your initial post. 200k miles is way past the usual EGR cleaning time, it's very likely near totally blocked, both the EGR components, and the EGR passages in the intake. I would get a leak-down test ASAP.
You should remove the intake manifold and do a cleaning. You will probably find that clogged with Carbon as well. Since you are experiencing a misfire on cylinder #2, there is a chance you may already have a blown head gasket. Which is quite common on these turd generation cars with 200k miles. You may want to do a leak down test of all the cylinders before spending time doing EGR and Intake manifold cleaning (don't really want to waste time if head gasket is blown)
There’s an EGR link in my signature; if you click on that you’ll find info, plus links to @NutzAboutBolts video on Exhaust Gas Recirculation cleaning. Theres also a thread pinned at top of 3rd gen maintenance forum, a lot of his videos linked.
Let me add to this: Your intake manifold has four large input ports. Of course these aren’t clogged. But beneath each port on the plastic manifold, there is a small, pipe-cleaner sized port. THESE are the buggers that get clogged with goop from the EGR (exhaust gas recirculation). You’ve already pulled the intake manifold so take a look at those four small ports and run a pipe cleaner thru them. As for your photos: That orangish color doesn’t look good. Have you been losing engine coolant? What’s the engine oil look like? Take off the oil cap and look, and if you can’t tell, drain a little oil and look. (Dipstick won’t tell you).