P0302, Full Compression, Dirty Plugs, Rough Idle

Alrighty. Plugs are regapped. Codes still persist. The P0302 code is still active and pending, but there is also P2088 code. I was reading about it, you guys are right, definitely not the sensors. So, what is the most likely culprit of P2088?

The oil control valve came up as a common problem, as well as a problem with the wiring of the connection to the sensor.

I did retime the engine myself during the rebuild, but that should have sent other codes relating to timing if that was the issue. Same with a problem with the battery or charging circuit. So, it seems like there is either a problem with the wiring or the oil control valve. Is that a reasonable assumption ?
 
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P2088 is the oil control valve for the VVT, on top of the valve cover, passenger side. First check to make sure it's plugged in and there are no broken/exposed wires. Once you verify it's not a simple case of it not being plugged in, then you can move on to diagnosing the OCV itself:

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^ What he said. I was in the middle of typing that. One time I had the connector plugged in but not completely until it was fully seated and I was throwing cam faults.
 
PlutoMs3 said:
I did retime the engine myself during the rebuild, but that should have sent other codes relating to timing if that was the issue. Same with a problem with the battery or charging circuit. So, it seems like there is either a problem with the wiring or the oil control valve. Is that a reasonable assumption ?
Click to expand...

If you end up diagnosing the OCV to the point of pulling it and inspecting the spool valve, you might as well recheck timing at the point just to be sure it's still all good since you already have the tools and it will be simple with the valve cover already off for the OCV removal. Edit: Forgot about the HPFP lol. Maybe not so easy to fully check timing, but could at least check with the TDC pin against the crank, the pulley bolt and make sure both cams are pointed at each other and the exhaust cam flat is where it should be.

You did get the crank bolt torqued to spec when you did the timing chain, right? 75 ft lbs then an additional 90 degrees? And used all new friction washers?
 
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Yes, crank bolt and all other bolts torqued to spec from the online manual. I believe new friction washers came with the gasket set from edge auto sport. If they did come in that set, they were replaced. If not, they were reused.


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I had my mechanic (professional Subaru guy) do that section of the rebuild. I will have to talk to him to verify about the friction washers.


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I just ran a multimeter test for ohms on the OCV, and it came back as 10... that’s higher than the manual states. What does that mean ?


Update: solanoid did not move or change to the “wide open” position when connected to positive power. I replaced the solanoid, and put the valve cover back on. The car is still throwing the P0302 code, and I’m not sure if it’s throwing the P2088 because the mobile mechanic had the code reader that saw that one, mine does not see it. However, none of the symptoms have changed. It still exhibits:

Trouble starting
Running shitty at low rpms and idle
Misfiring cylinder 2
Very shaky and clunky under load, clearly running on 3 cylinders.

I’m stuck. Not sure what else to try here. I guess it could be timed wrong? But why would that have caused a sudden failure because of high boost on a cold engine?
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Here is a photo of my engine with the valve cover off, and the old solanoid out front.
 
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If your timing was off then all cylinders would be misfiring.

What needs to be done is a cylinder leak down test on all the cylinders. This will tell you if you have a burned valve/seat, bent valve, bad rings etc.

Have you checked spark on cylinder 2 with an inline spark tester? Maybe also try swapping injectors between cylinders and see if it moves.

Check all the pins and terminals in connectors. If a terminal got spread open or a pin bent then it can lead to problems.

Last thing is never ever boost hard on a cold engine. The metals havent fully expanded and neither have the rings. The sudden increase in stress internally coupled with the added heat of boost/combustion can lead to damage. I wont even go WOT until the car is at least 3/4 warmed up.

Your "professional" mechanic guy, is he any good? Did he bend a valve while setting timing? Did you ask if he used the timing tools for these engines etc? Did you get the head resurfaced when you blew the head gasket or did you just put a new gasket on? Why did you not replace the head studs?

Always check the deck surface of the block and head when dealing with head gasket failure.
 
I know not to boost on a cold engine, I was just being reckless
:(

Yes, I sent the head to the machine shop to get 2 valves replaced and the head resurfaced. Reused head studs because they appeared to be in condition and I did not have any money to spare. My mechanic tried to convince me to get them replaced, I just couldn’t afford it after all of the other stuff we had to do.

Mechanic is a Subaru guy that specializes in head gaskets and engine rebuilds. Also rebuilds transmissions. He mostly works on STI’s, both stock and modified.

I haven’t checked the spark on cylinder 2, I can do that myself before I take it in for a leak down and inspection.

I will be running a leak down test ASAP. I was under the impression if all cylinders had compression it couldn’t be the rings or valves. Injector seals were replaced during the rebuild. I will have the injectors and seals inspected at the same time as the leak down, hopefully early next week.


I was instructed to buy the timing tool, but couldn’t spend any more money again. We had 4 people timing the car, so I was very confident it it’s stability. Especially because it ran perfect for so many months.
 
L337TurboZ said if the timing was off then all cylinders would be misfiring. Also, wouldn’t it have shown signs of incorrect timing long before a cold boost pull 6 months later ? But yes, next time there will be far fewer things I will be willing to cheap out on.


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If timing slips anywhere, even a little, shit won't be very good. At the crank your timing could be too advanced or retarded without you knowing, at the cams you could potentially slowly burn valves under WOT, etc.
 
As I said before do a cylinder leak down test, check your spark and try a coil swap with another cylinder. Just cause there is spark doesnt mean it is strong enough to properly light the mixture.
 
Well… cyl 2 has no compression. Not sure why my compression test did not register that but whatever. Car needs an entire new head, one of the valves burnt just like last time. Valves are caked in carbon and crud. Just wanted to give you guys an ending lol. Car is getting a brand new top end including camshafts. No blowby from the rings, no grooving in the cylinder walls so we are keeping the bottom end.


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