GDI engine sticking valves?

You should just lease like all the dealers want you to. They really have your own best interest at heart.

 

Yep DI is great until its not. The smart car mfgs are gonna be switching to dual injection systems (with port injection) to prevent the intake and exhaust valve gunk up.

 

Reason I picked up the car, my friends lease is up soon on his car.
Found this for a song and knew it needed some attention...
But shoite, I didn't expect this much lol.

 

I'm looking past the throttle plate gizmo and there seems to be a pool of oil in behind it.

Should I remove the manifold and delve deeper?

 

When you pulled the spark plugs...what did it tell you about the cars burn pattern in those cylinders? Did the plugs look like they need replacing?

 

Oil in intake is a bad sign...I would head over to the equus forum to see what others have seen with this engine.

 

Pulled the manifold and #8 valves are the cleanest, almost whitish/grey color, with absolutely no oil deposits.
All the rest are caked in crud.
Under the sound deadening foam between the banks, discovered a nest and a dead mouse....could be a small rat.
I'll inspect the wiring for damage.

The pooling of oil in the manifold wasn't as severe as I thought I was seeing. T'was very hard to see clearly past the throttle plate.
The MAP sensor on the back of the manifold has a film of clean oil (not sure if that's normal)

I've no clue how to read plugs but 5 of them were clearly damp with fuel. I've marked/numbered them and the coils also.
#8's center & ground electrode is brown..ish, the rest are black with "soot" NGK LKR7DIX-11S

#8 coil is a Duralast C1667, the rest are OEM Denso 27300-3F100.

Wish I'd have become an auto mechanic when I moved here at 17. I became a pseudo taco/burrito mechanic at Taco Bell instead...dope
I enjoy the crap outta this

 

Water/methanol injection

got a snow performance system on my 4.2 CFSA. But then, it’s also aftermarket blown…

those are notorious for carbon buildup.

friend just did the walnut blast on his 957 cayenne S

 

Had your friend done the walnut treatment before?
I'm trying to figure out what's needed and also weighing the consequences of screwing it up.

Set of plugs and coils ordered and I'll remove/clean or replace the injectors.

 

First time he did it. He borrowed my HF blaster bottle, made some spray wands, got my shop vac and bought an adapter.
Thing looked like new afterwards and drives great (90kmiles)

 

With your description it sounds like several problems.
A junk non standard coil, gunked up valves due to lack of maintenance (cleaning at right intervals) and possible injectors that are gunked. I'd chunk those plugs for a new set after running injection cleaner through the car. If it will run...

The walnut clean would be the fastest way to solve your gunked valves for sure. It may take 2 CRC intake cleanings in a row to do any good. Wow...you are having fun

 

Gets some MAF sensor cleaner as well. Oil on that thing will cause all kinds of running issues.

 

"having fun" yup.
Picked up an inexpensive borescope and first place I tried using it, was up my nose
I've ordered a new sensor.

Phil...the HF blaster, is that the red one, about $150?

 

I seriously doubt any of this is valve related. More likely maf/map, ignition or clogged pcv

 

New MAF sensor probably not needed...just visually check and some spray cleaner.

 

Will the CRC cleaning process clog up the catalytic converter at all?

 

Not normally, the can will say if it's safe for cats

 

Easy test is to unplug it while running. If it runs the same it's bad.

 

The 5.0 motors don't utilize a MAF but have a MAP sensor on the back of the manifold.
I believe the 4.6L previous generation motors use a MAF.

My sensor was/is soaked with oil.

Any idea why one cylinders valves are free of oil/crud....hasn't been firing for over 100k miles or more?

 

The ECU will throw the MAF sensor P code if its covered in oil/dirt as well.

Starting to think this car was not cared for prior to OP purchased it at 165k

Here is my MAF and intake on my Genesis