SOLVED! HPFP was the issue.
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Hi! This is my first thread because up till now I've found great advice on other's posts. As an overview, I've experienced waste gate rattle forever and have had issues reaching target boost, but lately a new problem arose with hard cold starts and very bad idle and decreased high fuel pressure, but if the engine is warm it seems ok. I'm thinking it may be clogged injectors due to turbo oil blow by. Here's a history of the car and and deeper explanation of everything going on with it. Please let me know if my thoughts sound reasonable, and give me input on what else I can do to diagnose this issue, thanks!!!
Google doc with everything below in an easy to read format: https://docs.google.com/document/d/103SE9PgHCzeMFDIvn96sBoFVAXGBD-raIXsiznXZr3U/edit?usp=sharing
2007 BMW 335i 6MT
Current Mileage: 103,000 miles
(See Appendix A for list of mods)
Logs:
Summary of Issues - Cold start up is very rough, RPM goes high (1,900) then low (600) and and then back up (1,300) upon a code 29F2 (High pressure pump / open loop set too high) being thrown with an engine malfunction screen. Radiator fans turn to max and idle remains at 800 RPM. Car runs very sluggish, but once warm if the car is turned off and back on it drives more normal, yet still has some performance loss (maybe due to bad turbos).
- Turbo wastegates rattle like a nonstop maraca band.
- Boost under target (code 30FF) typically when doing a 3rd gear WOT pull from 30-70 mph.
- Since 98,000 miles (5,000 miles ago), engine has gotten low on oil needing a liter of oil every 2,000 miles.
Engine Codes Thrown
** Look at the Google Doc to see more details in a pretty table **
- 29DC - Cylinder injection switch-off
- 29F2 - High pressure pump / open loop set too high
- 30FF - Boost under target - possible boost leak
- 29E0 - Fuel mixture control
- 29E1 - Fuel mixture control 2
- 3100 - Low boost mode engaged - CEL displayed
Diagnostics Performed- Logs. (don’t know how to come to a conclusion on anything though…)
- After rough start up with codes 29DC and 29F2, high fuel pressure is a constant 2 on JB4 when driving (2 converts to 300 psi). Though after the car warms up and is turned off and on, the high fuel pressure goes between 4-11 (600-1,650 psi) with regular driving, and between 8-14 (1,200-2,100 psi) when WOT.
- Low fuel pressure seems to always be around 65-75 psi, and most often remains at about 66.
- Removed all spark plugs. All of them were dry, and no oil on the threads and generally looked good.
- Emptied oil catch can - very little amount of oil (9,000 miles since install)
- Also see Appendix for recent maintenance performed.
- Edit (Sun 5/19): Last night I ran the car on the freeway for about 30 minutes at around 4,700 RPM (trying to burn off an unclog injectors - if that was part of the problem). This morning's cold start was normal and didn't have the same response as yesterday when the RPM went crazy and threw the codes. Fuel pressure was good too.
Possible Problems- HPFP or fuel injectors? Unsure if HPFP because pressure seems to hold after the car is warm. HPFP was replaced under warranty at least 3 yr ago with previous owner. Unsure if injectors because spark plugs look good with no wetness or oil.
- Turbos - Pretty sure they are the culprit of the boost issues. Would they be part of the rough cold start and idle? I wouldn’t think so. Also, I’m thinking maybe they have oil blow by which is causing the low oil every 2,000 miles. When I installed my charge pipe, the stock charge pipe and intercooler had a ton of oil in them. Could there be so much oil blow by that it causes the rough start and idle if there’s too much oil getting in the cylinder??? Randomly I’ll notice white smoke coming out the exhaust while driving (after the car is warm). But it seems random and I’ve not seen white smoke when idling and I’m looking at the exhaust, or even if I rev the engine. Excessive blow by may be clogging the injectors which would cause hard cold starts. Also heard (from this video https://www.youtube.com/watch?v=OQeFqAG9Iig) that bad crankcase ventilation could cause oil blow by. Maybe there’s an issue because my OCC had just a very small amount of oil in it after 9,000 miles. How would I check this?? Do I have a bad PCV valve and should it be upgraded?
My Proposed Solutions (what I’m leaning toward)- Replace PCV valve with upgraded one in hopes to reduce oil blow by.
- Replace turbos.
Appendix A - List of Performance Modifications- JB4 G5 (typically run on Map 5)
- DCI (BMW Dual Cone Performance Intake)
- VRSF Charge Pipe
- Tial BOV
- VRSF Catless Downpipes
- Corsa Exhaust (catless - full exhaust from downpipes back)
- BMS Oil Catch Can
- Fuel: Always premium. Never had e85.
Appendix B - Relevant Maintenance History
Most recent at top
- Oil + filter changed (Liqui Moly Molygen 5w-40) @ 100,741 mi
- Engine air filter washed and oiled (I did measure and use the correct amount of oil) @ 100,538 mi
- Cleaned VANOS solenoids @ 90,928 mi
- Installed silicone vacuum lines @ 88,500 mi
- Walnut blasting to remove intake carbon deposits @ 88,062 mi
- New Spark Plugs (NGK Laser Iridium 95770 gapped to 0.022 in) @ 88,062 mi