N54 30FF Low Boost Pressure/Wastegate Rattles Diagnosis Guide

[thetaobear]

Getting 30FF (low boost pressure)?

I am not a technician. This unfortunate event happened to me so I did a lot of research and ended up sending the car to the shop to get the turbos replaced...

I am not responsible for the accuracy of this post (I try my best) and the outcome. This will hopefully help those save some money on those ridiculous diagnostic fees, replacing random vacuums, etc. that some dealers love to do.



Here is a mini-guide

The more you proceed down the list, the more expensive the fix is.

JB4 logs are useful

************ 30FF
1. check your bottom to right side pipes: intercooler, chargepipe, BOVs, Diverter Valves
http://www.n54tech.com/forums/showthread.php?t=13114
SYMPTOMS:
- car may stall at idle
- shaky at start-up
- log shows unmet target (usually VERY low)
- 30FF pops up almost immediately after startup

If no leaks and problem persists, continue to (2)

************ 30FF AND Wastegate Rattle

2. check your vacuum tubes
- Fantastic Diagram:
http://www.e90post.com/forums/showthread.php?t=894084
- Replacement Hoses: 3.5mm
http://www.verociousmotorsports.com/...ld-by-the-Foot
SYMPTOMS:
- shaky at start-up
- wastegate rattles
- log shows unmet target (usually VERY low to a few PSIs)
- 30FF pops up almost after driving for a bit

If no leaks and problem persists, continue to (3)

3. replace your boost solenoids
- 2x (or 1- try to listen to leaks) Part #11747626350 - most updated as of this post
- diagnose and DIY
http://www.e90post.com/forums/showthread.php?t=507168
SYMPTOMS:
- shaky at start-up
- wastegate rattles
- log shows unmet target (usually VERY low to a few PSIs)
- noisy boost solenoids
- PWM and WGDC are messed up (very low)
- 30FF pops up almost after driving for a bit
- 30FE may also pop up

If problem persists, continue to (4) OR skip to step (5)

4. Adjust your actuators
http://www.e90post.com/forums/showthread.php?t=176269
SYMPTOMS:
- shaky at start-up
- wastegate rattles
- log shows unmet target (usually VERY low to a few PSIs)
- TICK TICK TICK noise upon start-up
- 30FF pops up almost after driving for a bit

If problem persists, continue to (5)

5. Replace your Turbos
I recommend
Vargas Turbos
RB Turbos

because these Rob (from RB) and Tony (from Vargas) have been SUPER helpful.

Thanks again to this community for the useful posts. Feel free to post comments, etc. to help others out!

[BRR]

Originally Posted by thetaobear

Towards the end of my track day, I got a 30FF engine malfunction light. I checked carefully and Google searched quite a bit,

Symptoms:
- ticking loud during start of the engine
- wastegate rattle after pushing the peddle and letting of the gas
- 30FF goes off usually 20 minutes into drive
- Logs, PSI are about 5 PSI lower than target

I checked the vaccuum tubes, intercooler, CP, and Diverter Valves that would cause wastegate rattles but I didn't find any leaks.

Is it time to take it into the shop? Or any other suggestions?

Thanks in advance!

Wastegate rattling is common in n54's and can be adjusted with jb4. Sounds to me like you are losing pressure somewhere. Make sure nothing came undone etc... You could have blown out an internal turbo part causing more rattling and severely effecting boost, which would require turbo replacement.

[thetaobear]

Originally Posted by NicholasLacouture

Wastegate rattling is common in n54's and can be adjusted with jb4. Sounds to me like you are losing pressure somewhere. Make sure nothing came undone etc... You could have blown out an internal turbo part causing more rattling and severely effecting boost, which would require turbo replacement.

Thanks!

I ended up changing the Turbos. The WG Actuators broke for the front turbo.

[BRR]

Originally Posted by thetaobear

Thanks!

I ended up changing the Turbos. The WG Actuators broke for the front turbo.

No problem. Did you replace with stock or aftermarket?

[thetaobear]

Originally Posted by NicholasLacouture

No problem. Did you replace with stock or aftermarket?

I decided to go with Dinan rebuilt (upgraded wastegates, etc.)

I wanted to go with upgraded but it is quite expensive.