Possible Boost Leak?

ekendall1 · **Posted:** Tue Mar 22, 2016 11:13 am

As the title states I believe I may have a small boost leak. I recently purchases a bluetooth OBDII scanner/monitor and I am only seeing approximately 17.5-18 peak psi on full throttle. I have seen in other threads that say people are seeing 21-22psi under full load. Would someone be able to confirm that my suspicions are correct and give me some guidance as to how to hunt down the leak?

flash7210 · **Posted:** Tue Mar 22, 2016 1:06 pm

18 psi is not horrible, but it could be better.
Kinda need some more info though...

Do you have a 05 or 06 CRD?
Have you cleaned the MAP sensor?
Have you checked your boost hoses for holes/tears?
Are the clamps for your boost hoses tight?
Do you hear air rushing out at full throttle?
Is your EGR still active?
Have you installed the Weeks intake elbow kit?
Any codes?

Other things to check...

1a. Check turbo inlet hose for tears.
1b. While the inlet hose is off, stick your fingers inside the turbo and try to wiggle the shaft. There should only be a tiny amount of movement.
2. Behind the air filter box are two vacuum solenoids, a big one and a small one. With the engine running, is the big one buzzing loudly? If so, it should be replaced and replace the little air filter that is connected to it.
3a. There is a vacuum line that goes to an actuator on top of the turbo. While running at idle, pull the vacuum line off the turbo. Do you feel strong vacuum at that line? If so, vacuum system should be good.
3b. Reconnect that vacuum line to the turbo. Now, look down between the turbo and engine (engine still running). You should see a rod connecting the vacuum actuator to a lever on the turbo. Pull off that vacuum line again and watch that rod drop. Reconnect the vacuum line and watch that rod pull up. Does it look like lever is getting full movement? If not, the vanes in the turbo are stuck and need to be cleaned.

ekendall1 · **Posted:** Tue Mar 22, 2016 1:21 pm

- 05 CRD
- Band new MAP sensor (replaced less than 1000 miles ago)
- Visual check of the hoses, however, I may try spraying them down with some soapy water to do a more thorough check
- Clamps are tight (first thing I checked)
- No air rushing noise (only turbo and engine heard at full throttle) What would the air rushing noise be an indication of?
- EGR disabled (GDE Eco Tune)
- Weeks kit not installed but on my list of things to buy
- No codes

I will check all of 1-3 mentioned and get back with my results.

WWDiesel · **Posted:** Tue Mar 22, 2016 1:43 pm

All the afore mentioned items are good to check!
Add these checks:
CAC (intercooler) for any cracks or leaks at tank to cooling fins corners, some have found leaks in these areas and repair it with JB weld, epoxy or similar cold weld sealer. Even though EGR is disabled by computer, the valve itself can still leak some boost back into the exhaust if is not fully closing. Only sure way to eliminate is to cap or blank off EGR tube till you get the Weeks kit installed. :wink:

Good luck....

Possible Boost Leak?

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