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Hey guys, I have been really struggling with a couple issues on my car since a rebuild. The place I got the rebuild done has essentially told me to figure it out on my own. I have a series of questions and I would really appreciate if anyone could guide me through it.
The car drives fine (idle seems a bit rough) but at around 4000 rpm I get a P164B (Oil pressure switch malfunction: Upper limit reached) code along with an EPC and "Do not exceed engine speed 4000 rpm". I am not sure if the next code is because of this or a code on its own, but I also get a P0014 (B Camshaft Position Bank 1: Timing over advanced or system performance). This code however does not trigger any CEL, and the fault remains there only for a couple minutes and comes back some time later, again only for a few minutes. The P164B also only remains red in OBDEleven for a couple minutes and returns to green (But EPC stays active until code is cleared). I have not been able to figure out if the codes are only triggered at operating temperature or any temperature.
Things that have been checked: 1. Oil is correct type 2. Oil level is correct. 3. Replaced Oil Pressure Switch 4. Replaced intake cam adjuster gear. 5. Oil Pressure Switch wiring seems OK 6. New oil filter (Not OEM but same part number)
I then decided to look at the specified vs actual cam adjustment values (while the P0014 code was active) and saw this: Exhaust gear adjustment
It's obvious there's something wrong there with the values being so far off. I started monitoring that and saw that even when the code is not active, the actual fluctuates a lot more (particularly on idle, and more with the AC on).
In that post, he has similar issues and replaces a N428 Oil Pressure Regulating Valve. After seeing this I felt joy as I thought I had finally potentially found a good fix, but I can't seem to find a similar valve for this 2.5L CEPA, not sure if it even has one. A valve like that stuck open would explain both the "upper limit reached" for the oil pressure and the exhaust cam adjustment being so off.
Question 1: Do these engines have a N428 Oil Pressure Regulating Valve or anything similar? I can't seem to find anything online.
I decided to also take a look at the inlet adjustment values and noticed this: The specified and actual values for the inlet are more or less very close together, but what felt off here was the range (this is also when the P0014 code was active)
Question 2: Is it normal for this adjustment to be outside of the "range" in the description?
I have been really suffering for months with this and would really appreciate any help that I could get.
06-14-2023 | 02:59 PM
MK2 8J TTRS Faults
