thamomo007

I think that in your case resetting the error could work, because you have maybe reach the "software" end of the particles filters.

But before resetting this, you should do an exhaust back pressure test for testing "how your filter is clogged". it's pretty easy to do whith the dis software.

detune

Back to update the thread with my progress.

Quick Summary:

- Problem started with complete loss of power - No turbo boost
- All the usual DPF related errors plus 4530
- Cleaned and cleared the DPF but 4530 kept recurring and still no boost.
- Mechanic stripped and cleaned Mass Airflow (MAF), EGR, Intake manifold MAP(Intake Manifold Boost Pressure Sensor) was cleaned, then replaced. All the parts were gunked up with oil etc.
- Eventually gave in and mechanic stripped down the turbo. Turbo was destroyed! Looks like running with a blocked DPF had eventually screwed the turbo.
- So, turbo profesionally rebuilt and re-installed - For reference, making sure to change the oil breather in the rocker cover, clean and/or replace all oil feed pipes etc.
- Turbo back on and (almost)back to normal performance. Now my next problem - I have plenty of boost once I get over 2500 RPM, but very little if any below that. Very difficult to diagnose given it's a closed-loop system. The obvious culprits are:

1. Leaky hoses loosing boost pressure or vacuum
2. MAF(already cleaned)
3. MAP sensor - just replaced
4. Dump-valve/variable vanes in the turbo a problem in the re-conditioned turbo - the electronic actuator is moving freely on the car.
5. Blockage in the exhaust side - CAT/DPF/Boxes, causing too much back pressure and therefore limiting boost until the turbo eventually generates enough flow in the exhaust to force the issue???

Car driving well enough so that I can get by for a week or two(although it's like driving an old-fashioned petrol turbo - loads of turbo lag and constantly trying to keep the revs up!)

Anyone have any thoughts on the issue or how to go about debugging it? I know this is getting a bit off the DPF topic and I'll probably open another thread for it.

Thanks for the help so far and any input appreciated.

Colum

AI001

This is exactly the symptoms I have. Mine never had any turbo failure at all, its just lack of proper boost before 2500 rpms, it feels kinda sluggish before 2500 once u reach go past 2.5k woosh and u fly.

I did check my DIS and reads I have regen 24kms before and will have another one in 8kms (if I am reading it properly) is it suppose to happen this frequently? There are no error codes (the x you see before DDE is due to low battery and starting problem I had last week)

A few suggestions, in the DIS you can activate turbo actuator (with engine started) and it says to measure the "25 mm stroke of control rod", then I saw the turbo actuator moving in and out upon diagnosis request. A member on other forum had this low rev problem and it was sorted by adjusting the screws. I don't have much detail on this at the moment, will find and post later. Hold the urge to just change the actuator screws and they are quite sensitive and unless you know what you are doing and why you are doing don't do it for a trial, it can be messed up and will be very hard to restore back.

In the mean time please read this assuming urs is the same engine as mentioned in this.


btw. howz your car temperature, is it reaching 90ish?

detune

I'm still confused and looking for a solution.

My problem is this:

- I have paid out ?600 to have the turbo re-conditioned. It was done by a reputable specialist and my mechanic fitted it. the Re-conditioning company has given a computer printout showing the test on the turbo after re-conditioning. It is possible that there is still a problem with the turbo. Possibilities are I think:
- The turbo core they used is not correct - core had to be replaced as there was extensive damage.
- There is a problem with the variable vanes mechanism and the vanes are sticking thus not giving boost early
- Some other problem in the turbo wasn't correctly fixed.
- DPF - there is still a blockage in the DPF or somewhere on the exhaust side slowing the flow through the turbo and preventing boost at low revs
- Some other problem such as leaks in the input side, MAF, MAP Sensor.....
- Adjustment - Anyone know if there is any manual or electronic adjustment of the variable vane system? Thinking of a screw adjustment on the actuator arm. Right now, I can see the arm moving, but it could be moving too early or late????? Similarly, could the engine management system need to be adjusted.

I assume that the DIS could be of some help, but I've had some recent problems there that discourage me from playing.
I bought a usb OBD cable that came with the software. I got INPA working basically - reading errors and clearing them, but wouldn't seem to communicate with the rest of the engine management system. I put it on hold temporarily. Unfortunately, it looks like whatever I did, I screwed up the EWS->Key synchronisation! Car wouldn't start - just turn over. Tow truck to a BMW specialist and ?200 to sort that problem.

The mechanic who removed the turbo and replaced it only has a generic tester, so can't do the same testing as the DIS. The BMW specialist who reset the EWS won't agree to look at the turbo problem as he didn't do the original work! He was happy enough to take ?200 for the 20 minutes it would have taken him reprogram the EWS though!

An alternative is to take it to a main dealer although they may be sniffy about looking at a car where the turbo has been re-conditioned rather than replaced. So - HELP! this is getting really annoying.

I'd appreciate if anyone has had any serious turbo experience on where I go next..

Colum

Anzafin

Sorry I don't know much of turbos, but with a DIS you could check if there is a blockage in the exhaust system or not by running the test. In the test the DIS will measure the backpressure at idle, mid revs and high revs.

Also, I'm sorry if you already have done these little checks:
- Check the packpressure sensor + tubing (sensor #5, tube #7)
- Check the charged air temperature sensor (#10). You can read the live values with DIS and they should be around 40°C (mine showed 90-100°C and was obviously faulty because I could touch the hose with my hand)
- all vacuum tubing in the engine compartment

- Antti -

AI001

I know this is quite painful, you need to check few things to make sure there aren't any underlying issues. Let me explain my understanding of x35d bi-turbo engines.
On the exhaust air side air goes in the small turbo first and big turbo afterwards. on the fresh air side big turbo gets the air first and small afterwards. On idle/low rev smaller turbo is used fully and bigger one bypassed by means of canister shaped cup having a rod connected to actuator which you can see on the driver side of engine. As rev goes higher air distribution changes path and bigger turbo is engaged (actuator released down gradually as the rev goes up) now both the turbos are working togather but for very short rev range. On very high revs big turbo is fully engaged by the actuator control rod (all the way down as it was before starting the engine) and then small turbo is bypassed by means of bypass plate located in the center of engine controlled by again another vaccum controlled actuator. When pressure reaches too high then wastegate is opened which is controlled by actuator in the center middle underside of engine. You can monitor 2 actuators play when you rev the engine and see it will move as I described above. If its not then its easy to solve problem where you have either dead pressure convertor or disconnected or wrongly connected vaccum hoses.

When car is not started look at your engine bay on the turbo side you will see a turbo control flap which switches between large and small turbo, its kind of canister shaped cup having a rod connected to actuator. When engine isn't running actuator is at fully open position means small turbo is bypassed. You should be able to move it by your hand. Move it using whatever you can and see how much is the play, it should be able to lift up all the way to top leaving almost 5mm gap between the actuator and the turbo shield cover. Now start the engine, once started this actuator will be pulled to highest possible level which you just saw by doing it manually. Try to move it now manually (engine running) and if you can't move it any further then your control rod adjustment is right, but if there is even a slight play it means your small turbo is being bypassed slightly. Its effect will be significant though. You can adjust the screws to make actuator go all the way to the top, but if you do it too much then your large turbo will be slightly bypassed under heavy load condition.

There are other things to consider too as how hot your engines are running, did you check your coolent temperature, that will effect egr cleanup.

In my case I have checked all these things and still feel the lag so I have more to discover. Atleast done the easy bits first.

AI001

I will verify a few more bits before doubting condition of my turbos (smaller one in particular), where did you get turbo rebuilt? Are you based in the UK? What exactly is turbo reconditioning?

detune

Hi,

I'm based in Ireland and have a 520d, so only one miserly turbo for me.

These have a variable vane system for getting low-rev boost. This is activated by an electronic actuator rather than traditional vacuum system.
In my case, I can see the actuator move to the full extent when the engine starts and moves back and forth when revved.
I can't see any obvious adjustment screw that would adjust the amount of movement.

As to your question on Turbo re-conditioning, it depends on who you use. Turbos seem to go faulty most often when they are starved of oil. This causes bearings and seals to be damaged. A basic re-conditioning tends to involve replacing of seals and bearings. In my case, because there was significant damage to the turbo, the full "core" of the turbo is replaced. This includes the spindle with the two rotors on it and all seals and bearings. Basically, the only parts not replaced are the housing. What makes me suspicious is that there was no reference to the variable van mechanism having been replaced/repaired or checked.

I was hoping that the BMW Specialist I went to would be keen to put the car on the DIS and check temperature and pressure readings, but he only seems keen to rip me off for quick diagnostics.

I think I'll get back to the turbo guy and see has he any thoughts.


Colum

Liam

I have similar problems in my 535d. When I read the car in INPA, the car showed blocked dpf.

DPF replaced; no joy, further inspection showed a destroyed main turbo & blocked catalyst converter. Question of course is "what caused what"? A failing turbo does not show up in INPA, but is a mechanical problem; in the good old days, the symptoms would be a lot of black smoke coming out of the back, but now with the DPF & Catalyst converters, you notice nothing from the back.

In my logic, a failing turbo caused all the subsequent damage - in my case due to faulty earlier repair.

I would most definitely also have the catalyst checked; if your dpf was blocked due to a failing turbo, the catalyst will most likely be toast.

In my case, I hope my car will be fixed by this afternoon

Anzafin

That is a good point (the broken turbo causing the DPF blocking) that I've never thought! Thank you for sharing that.
I hope you get your car fixed soon.

- Antti -