[danb21t]

Hi all,

I seem to have developed an issue with my 335d, between 1.5k rpm and 3.5/4k rpm there is pretty much no boost.

After doing some searching around there are a few things to check this weekend. I have a JBD tuning box which I am going to remove to rule out along with checking any boost/vacuum hoses.

Ideally I'd like to read any codes, which leads me onto which cable would be best to buy?

Cheers!
Dan

[danb21t]

I've removed the jbd and that has made no difference. Ive checked my red boost hose and that looks to be fine.

I have found that the air filter is pretty grotty so I went to get another and on the way to the auto factors I check the coolant temp in the hidden menu.
The temp never got above 79c and I blasted down and up a by pass.

Looking like I'll have to read some codes

[Steinegal]

It may not be totally applicable to a 335D, but my 320D died this week. Just pulled it off and the Variable Geometry vanes were completely stuck. Split the turbo and found a huge amount of soot that had built up inside the Vane control part. As the 335D comes with two turbos as far as I know, the smaller turbo working on the lower RPM range might have a similar problem. Is there any strange sounds from the turbos? My sounded like a cat in pain :P

[danb21t]

Hi Steinegal - No odd noises really, its all a bit odd.

I have installed INPA and associated softwares and am going to order a cable beginning of next week.

I will also check the coolant temperature on my way to and from work (25miles each way) on Monday.

[///M.aster]

Originally Posted by danb21t

Hi all,

I seem to have developed an issue with my 335d, between 1.5k rpm and 3.5/4k rpm there is pretty much no boost.

After doing some searching around there are a few things to check this weekend. I have a JBD tuning box which I am going to remove to rule out along with checking any boost/vacuum hoses.

Ideally I'd like to read any codes, which leads me onto which cable would be best to buy?

Cheers!
Dan

Hi Dan,
There are obviously a number of things that can influence this type of fault however a common cause is the EDPW valve (vacuum switch) at the rear of rocker cover. Sometimes if you're lucky this valve will be displaying other symptoms such as being excessivly noisy and or being very hot - too hot to touch in some cases.
From memory this valve controls the compressor bypass flap meaning the exhaust gases bypass the high pressure (small) turbo thus not generating boost.

I'm guessing that once you reach 3.5k it takes off like a scolded cat? Pretty sure you will have a boost pressure plausibility fault code but best to read them first before putting your hand in your pocket.

[danb21t]

Originally Posted by ///M.aster

Hi Dan,
There are obviously a number of things that can influence this type of fault however a common cause is the EDPW valve (vacuum switch) at the rear of rocker cover. Sometimes if you're lucky this valve will be displaying other symptoms such as being excessivly noisy and or being very hot - too hot to touch in some cases.
From memory this valve controls the compressor bypass flap meaning the exhaust gases bypass the high pressure (small) turbo thus not generating boost.

I'm guessing that once you reach 3.5k it takes off like a scolded cat? Pretty sure you will have a boost pressure plausibility fault code but best to read them first before putting your hand in your pocket.

Thank you for your reply!

Yes, sounds like you could be onto something there.
After some more reading this evening the solenoids that control the turbo actuators is a known weak point. I'm hoping this is the issue.

As you say, once I actually get boost it takes off like a spaceship.

[danb21t]

I had read that the car should be up to temperature by the time I had driven 9 miles.

Well my journey to work is 25mins, mix of A road by pass and a 15mile stint on the M4.

I saw a maximum temperature of 70c when stationary. On the motorway the temp sat at 64c.

Doesn't sound good for the thermostats eh!
Obviously this will mean that I never hit the conditions to trigger a DPF regen.

I have ordered a K/DCAN cable and will read the codes.

[danb21t]

Cable arrived today, going to have a look tomorrow after work...

Also how can I tell if I have the M57TU or M57TU2.
Car is on a 07 plate.

[danb21t]

Read some codes this evening using INPA, I haven't looked into it too far as I wanted to use DIS but my laptop is playing up so I couldn't get VMware installed.
I will reinstall and start a fresh and see what DIS has to say.

First look says that I have a DPF code, a lambda code and a couple of other unidentifiable codes.
Will probably clear all of the codes, try and force a regen and then see what codes return.

More to come!

[danb21t]

I have now checked the codes with DIS and can confirm that I have a boost issue. Looks like my pressure converters may be on the way out.

However after some reading this is quite a common issue and the initial suggest is to replace the vacuum hoses first.
After inspecting them the outter braiding is very perished.

So my first point of call is to replace the vac hoses with silicone replacements and then go from there.

[335DEE]

firstly , change both the main & EGR thermostat. That way if your DPF is still in reasonable condition you won't fuck it completely by not changing the stats, at the same time change the vac hoses if they have never been changed. Still no boost , then ..

Pressure controllers ...

Changeover actuator ( this badboy seizes up and doesn't reroute the charged air when it is supposed too).. ends up suffocating the car... Warning , mega expensive fix

Boost hose from intercooler to EGR valve. The boost hose splits on the underside of the top hose... But you would definitely know this was split by the amount of noise it would generate.

[danb21t]

335DEE, cheers for the reply - not a lot of input from people around here! Feel like I'm talking to myself.

Anyway, I'm going to keep this up to date as it may help others.

Indeed you are correct about the thermostats, I will look at replacing these.
When looking at DIS the back pressure readings were extremely good and the car believes there is another 100k+ km life left, the last regen was 16k ago! Must be in pretty good nick.

So the plan is to replace all of the vac hoses and get some new thermostats in.

I may even take some pictures for those DIY mechanics.

[335DEE]

Yeh , i'm afraid anything really technical on this forum just goes by the way. It's all about which spoiler which tyres and which spacers to use.

On the flipside a lot of your issues have been done to death on here which may also explain the lack of responses too.

Blimey on the 16k for last regen. When mine was in place it was going into regen every 200 miles !!

The vac hose is by far the biggest culprit for loss of boost. If you have the older style pressure controllers ( which you probably do) then they do fail.

Small boost leaks can be attributed to the seals on the red boost hose( no point in buying a new hose just 7 quid for the seals is good enough). You might as well change the breather assembly too while you are at it.

Not many have complained about the changeover actuator. A friend who is an indie has seen several. Mine included but have not seen much written about it. The part is about £600 and a good few hours to change over. Make that one your last resort !

[danb21t]

£600, ouch, definitely the last resort!

I'm fairly confident that the vac hoses/pressure converters will sort the issue.

Funny you say about the breather, I was just looking at other threads about these.

Had a poke about in the engine bay after work and noticed the rubber tube from the hard pipe on the breather looks a little oily, it would appear that the fitment can become warped so will check it out again in more detail.

For reference the existing vac hoses are 4mm ID and 7mm OD, looking on eBay the closest is 4mm ID and 8mm OD so should fit snug into the clips.
Will order up 3m and get it all replaced.

[335DEE]

Buy 2 colours, red and blue. Easy to identify which turbo they go too then

[danb21t]

Looking at some of the pics from peoples threads there appears to be three colours; blue, black and red.

[ssc330d]

Originally Posted by 335DEE

Blimey on the 16k for last regen. When mine was in place it was going into regen every 200 miles !!

I think from memory that the DIS readings are in metres not km! I.e. last regen was 1600m ago. I would double check.

[335DEE]

Who is to say that other manufacturers don't have the same issues. VAG use cheap plastic components where really metal should be used.(water pump, Cam belt guides and components) They even have issues where intake pipes collapse under boost on the compressor side. Grass isn't always greener!!

If you got an issue with the red hose, change the seals. They are like 7 quid each. No need to replace the whole thing

[danb21t]

Originally Posted by ssc330d

I think from memory that the DIS readings are in metres not km! I.e. last regen was 1600m ago. I would double check.

Interesting, I will definitely double check. Some units were definitely KM and anothers were M for sure.

I will report back!

Just ordered up a load of hoses.
4mm ID / 8mm OD.
4M of black
2M of red
1M of blue

[danb21t]

Well I had a fun weekend!

Started stripping the engine bay on Saturday and got a good look at what was required and needed replacing.

Sunday I went for it and got all of the hoses (except the one that goes down and underneath the turbo) replaced.

I took some pictures which I will upload later in the week along with a more detailed explanation of events.
It was a pretty easy job.... annnnddd the boost issue is now fixed.

I've also noticed that my o/s/f shock absorber is leaking so I am now looking at potential upgrades/replacements.

All in all pretty chuffed for a £16 repair.

[mistryn]

I can appreciate your concern for lack of technical responses but this has been discussed before (there have been a couple of threads started by myself as well)

With the lack of boost after 3.5k will be down to boost pressure/actuators/pressure converters/vac pipes/sensors

Very first thing I would do without even replacing anything is to scan the car for codes and see what the errors are to give you a good starting point.

In my experience I have experienced lack of boost before 3.5k, after that the big turbo would kick in and fly. I had my codes read (can’t remember off the top off my head) but indicated lack of boost - first thing I did was to replace all the vac hoses that I could see. In my case this did not make any difference, some of the vac hoses outer cotton braiding had perished but the rubber tube was ok/slightly hard.

Next thing led me onto checking the pressure converter/actuators to see if they are operating (335dee has put up a short video clip how to check). I replaced both PC with a new bracket and this solved my problem and car went like a rocket. However then it started to hesitate under 3.5k did some more research and found it to be the manifold absolute pressure sensor which was gunked up with oil - cleaned that out but ended up replacing it which sorted out the hesitancy issue.

If you have a DPF, consider looking at when it last regened and if it hasn’t then why hasn’t it - most common causes are the egr and main thermostat failing - BMW in there infinite wisdom of choosing not to fit a temp gauge doesn’t help matter - but this can be checked via hidden menu (again there is a guide on how to access this). If a DPF is blocked this will also causes power issues

I would always advise starting off with the cheapest parts and work your way up through elimination.

I do agree that BMW should use silicone hoses as they are less prone to heat considering how hot these engines get. But its not like these vac hoses are going every10k, mine were still good after 100k miles

Hope this helps

[danb21t]

Mistryn has hit every point of my troubleshooting technique.

Here are some pics to help others out should they be looking for info on this issue.

Firstly once the engine cover is off you can see the hoses on the left that do not look to clever.





There isn't much space down the left of the engine. However once parts are removed, airbox, airbox lid, and the scuttle panel there is much better access. Also removing the vacuum reservoir, without dropping the 10mm nut down into the depths of the engine.







Once all of this is out of the way you can get access to the two convertors and associated hoses.
I found the hoses to be very perished and easy to "break off" if pulled on. On a couple the help of a razor blade was needed.

Underneath the plastic inlet manifold is the vacuum supply manifold. This is a bit of a pain to get to, not enough access to get your whole hand under. Some gentle prying and persuasion got the job done.

Unfortunately I dropped a 6mm socket and it landed in the under tray, to retrieve it I have to have it off. Luckily I did as I also noticed that my o/s/f shock absorber is leaking - sounds like an excuse for coilovers.

Anyhow, to get good access to the red hose at the front of the engine I had the radiator fan out. Very easy to do, only two torx screws, one at the top and the other at the bottom.

I was running out of light at this point and had to get the car back together so no more pics.

The only hose that is unchanged is the blue hose that heads down past the turbos and then back up under them, absolutely impossible to get to. BMW are kind enough to put a join half way to the top half did get changed.

Picture of my engine by all finished and back together with hoses routed correctly.





The converts are interesting. I was expecting Pierberg however these are both Bosch.



Once I was finished I hooked her up to the laptop and ran a function test on the exhaust actuator and could see it moving, positive result.
Then cleared all of the codes and went for a drive. Woohoo boost was back.

Makes you realise how much of a tractor they are without boost, and how bloody fast they are with!

It is definitely a task that those handy with spanners can undertake, however I recommend having the whole day available as it can turn into a lengthy task if the under tray has to come off.