Boost problem

[Jd.toit]

Hi
I have the same problem as most other on the boost issue
I have a 320d 2004 e46
when I bought the car 6 months ago there was no boost so I returned it to the garage they took it in and it was repaired. I found the printout of the fault code in the car and on it was boost sensor.
everything was fine but the car did not have much power but I did not know how much it should have. last week there was no boost again I did not want to take it in as they would charge me for the diagnostic so I first wanted to see if I could check the sensor. while searching I found all the other stuff to look at and came on the suction tubes that was broken now I replaced those pipes and the boost is there now but also only at 3000 RPM and not much but the power that was there was not that much to start with. how can I check the turbo if everything happens as it should and how do I get to it and all other suggestions is more than welcome

 

[///Shaun]

Best is diagnostics. It will help determine where the problem is. Remember a boost leak can do all sort of funnies along with faulty injectors and the likes.

 

[Jd.toit]

but will a diagnostic pick up if it is a boost leak or a faulty suction hose

 

[Jd.toit]

Does anybody know what the suction should be in the suction hoses to the turbo and is there any way to test them as there is suction in mine but I do not know if the pressure is enough

 

[Jd.toit]

is there supose to be oil in the intake and boost pipes as i understand in a diesel there will be some but how much. I took of the boost pipe on the intercooler and there was oil in it, lets say about 2 to 3 drops actualy fell on the floor so is that normal or should i be concerned

---

is there supose to be oil in the intake and boost pipes as i understand in a diesel there will be some but how much. I took of the boost pipe on the intercooler and there was oil in it, lets say about 2 to 3 drops actualy fell on the floor so is that normal or should i be concerned

 

[aBitDifferentX5]

I had the same problem when I bought my X5.

There are a couple of items you can check yourself if you have a bit of tecnical knowledge:

-Replace all cracked and broken vacuum hoses. These are most probably the cause. (this was my problem)

-The vacuum acumulator. This is a oval cylinder where the vacuum hose go into. This is a unit installed to prevent pulsating pressure shockwaves.

-boost pressure regulator. this is a small unit that bolts close to the tubo. there is vacuum hoses going into it, as well as electric wires. The unit is used by the ECU to regulate the boost pressure by opening and closing the waste gate. These units are normally difficult to get to, and can't really be tested, but relative cheap to replace (+- R1400). If you have done all the other checks, replace this unit. If this unit is faulty, the waste gate will be open prematurly.

There will always be oilyness in the boost pipes, but if there is insuffiecent boost, there will be more oil than normal.

When the turbo leaks oil on the shaft from the bearing / bushes to the compressor housing, there will be exesive oil in the pipes, but there will also be heavy smoke from the exhaust.

 

[Jd.toit]

Thank you for that feedback. I've replaced all the suction hoses so far and the car does not smoke alot either so then the turbo should be fine, thats a relief, the boost is better now but I'm still not sure if it is enough the boost kicks in on about 2800RPM is that about right. maybe everyting is fine now but I can't seem to wonder if it is not as powerfull as it should be

 

[aBitDifferentX5]

Thank you for that feedback. I've replaced all the suction hoses so far and the car does not smoke alot either so then the turbo should be fine, thats a relief, the boost is better now but I'm still not sure if it is enough the boost kicks in on about 2800RPM is that about right. maybe everyting is fine now but I can't seem to wonder if it is not as powerfull as it should be

No prop.

It's very difficult to diagnose problems without seeing and hearing the eninge, and I am not to clued up with the 3 series, but atleast maybe will give you an idea of something to check.

The boost accumulator that I spoke about, is also prone to crack and leak boost, so check that.

Earlier you asked how much suction there should be on the hoses... there must be reasnably a lot, when the engine is running, and you place your finger on it, you should feel a possitive suction.

When you rev the engine up, do you hear the turbo spool up and pipes expand with pressure? this is a good and easy way to find out of there is boost.

My engine starts boosting roughly at 1800 to 2000rpm, and full boost at about 2400 to 2500 rpm, so recon yours should also be in that area.

I also can't promise the turbo is 100%. if the impellers are worn, this may also cause lack or late boost. If the exhaust wheel is worn, it must have much more engine rpm to spool. If the compressor wheel is worn, it may need much higher turbo shaft rpm to make sufficient boost.

I will just start and go through the diy items and check all of them, before having to spend big bucks on a replacement turbo.

 

[Jd.toit]

Thank you once again
well first off, if the car is swiched of and about 2 min later I remove the suction pipe of the accumulator you can hear that there was still pressure in it (negative pressure) so that tells me that there is no more leaks in the suction system. I have not checked that the pipes expand if I rev it up but will check that tomorrow. I can defenetly hear the turbo spooling up if I drive it not loud but you can hear it if you open the window. to describe the power is if I'm in 6th gear and get a slight hill I should go back to 5th if I want to remain at the same speed and a steeper incline at some places I have to go to 4th so maybe that is how it is supposed to be but I doubt it. besides that now that I have changed all the suction it is back to how it was but i still think it should be better.

 

[aBitDifferentX5]

Like I said, I'm not really up to speed with the 3 series, but agree that this sounds a bit under powered.

Then I must agree, and suggest you take to have it plugged into a diagnostics reader.

There also the possibility that you have problem like airflow meter and fuel pressure. These issues will be identified with the diagnostics. If the ECU finds a reason to drop the boost pressure, it might even be doing "limp" mode and thus reducing the perfomance.

Best of luck

 

[Jd.toit]

I agree now that the pipes is fixed I think I will get a better reading from the diagnostics does anybody know of a good mechanic in Secunda area that can do it as I understand that BMW is expensive

 

[Andy1GP]

Bump! Any updates? I'm in desperate need of diagnostics and don't trust no dealer. I have a micky mouse laptop with software and cable, but don't think it's up to the task...

 

[Spy007]

-The vacuum acumulator. This is a oval cylinder where the vacuum hose go into. This is a unit installed to prevent pulsating pressure shockwaves.



Is this the small black round plastic 'geyser' looking thing.

reason I ask is that when gopher boosts there seems to be a "rattle"

 

[Jd.toit]

Problem solved
after I took it to BMW Secunda and they gave me a quote of
R51 568.99
I decided to go through everything I could
I had the Cat's removed and still no deference
So this weekend I removed the turbo and cleaned it
When I stripped the exhaust side I noticed that the vanes did not move with the ring that was supposed to open and close it (see attached image's)
I cleaned everything and reassembled it and now has boost all the way through so I just saved R51 568.99
:rollsmile:
I have a movie clip of the movement of the vanes if there is a way to attach it here if someone would like to see it

 

[Dippies]

:thumbs: Good for you Bud and Glad you got it Sorted those bloody agents :nonono:

 

[Hellas]

Well done JdT. I did exactly this about two weeks ago. Cleaned out the VNT mechanism since it was stuck, but the solid metal ring containing the blades were also cracked, pressing the blades down onto the turbo body, making it impossible for them to move.

I lightly sanded the bottom of the blades wit 600 and 800 grit paper and reassembled. Checked all the hoses and sensor connections and now I have a steam train on my hands again!

 

[[email protected]]

Hi
I have the same problem as most other on the boost issue
I have a 320d 2004 e46
when I bought the car 6 months ago there was no boost so I returned it to the garage they took it in and it was repaired. I found the printout of the fault code in the car and on it was boost sensor.
everything was fine but the car did not have much power but I did not know how much it should have. last week there was no boost again I did not want to take it in as they would charge me for the diagnostic so I first wanted to see if I could check the sensor. while searching I found all the other stuff to look at and came on the suction tubes that was broken now I replaced those pipes and the boost is there now but also only at 3000 RPM and not much but the power that was there was not that much to start with. how can I check the turbo if everything happens as it should and how do I get to it and all other suggestions is more than welcome