[335i E92]

Anyone know much about these on our 335i's??

Spoke to Rob at DMS today and will be taking my car down to southhampton so he can diagnose my reoccurring fault.

He thinks the reason my car runs great after the adaptations have been reset but then within a few hundred miles starts to drop of a little in performance is that I may have a boost issue that the ecu picks up on and subsquently alters the boost.

The reason the adaptations make the car feel stronger inicially is that it takes the ECU a little time to pick the leak or what ever it is then backing things off.

Anyway he's advised that I replace the boost control valves or solanionds (not sure what there called) before I make the trip down to eliminate them as a cause.

Anyone know much about these or how much they cost, think our cars have 2 of them.

[Yahoo]

Diverter valves?

[doughboy]

wastegate actuators?

[335i E92]

Originally Posted by Yahoo

Diverter valves?

It's good but it's not quite right!!

I asked rob if he meant the diverter valves and he said no they are different!!

Next guess??

[335i E92]

Originally Posted by doughboy

wastegate actuators?

No, I but apparently they control the boost to the wastegates I think to decide when they open ant close. My car has had new actuators fitted a few months ago

[335i E92]

Ha ha... What are we all doing on here on a Friday night??

We should be in the pub, were did it all go wrong!!

[Yahoo]

LOL

[335i E92]

Had the car on a dyno this morning and my suspisions have been confirmed.

Peak bhp: 343 @ 4rpm
peak torque: 423

I'll try to post the graph up on Monday!!

The the graph shows the power peak at 4rpm @ 343 and then completeley flat line to 6.5rpm.

As I said when the adaptations were first reset the car wad stronger much higher up the rev range and after a few days dropped of. The dyno has relayed exactly what I wad feeling in the car.

Still not fault codes but the car is definatley raining in the power for some reason. Given it's strong tourqe output I don't think this is a boost leak. More lke a sensor is faulty but not enough to throw a code??

Anyway I'm down 30 bhp and needs some suggestions??

Cheers!!!

[pjs]

There is something called a Vanos Solenoid, no idea what it does, but mine had a new one last december when they were busy guessing what to try next.

[335i E92]

Originally Posted by pjs

There is something called a Vanos Solenoid, no idea what it does, but mine had a new one last december when they were busy guessing what to try next.

Funny you should suggest that as have been Reading up on what they do and it's high on my list of maybe's!! One of the main reasons I suspect this is that the engine was sooo much smoother imeedaitley after the adaptations were reset n then when the power started to drop off a few days later the engine also didn't sound as sweet.

I belive the vanos solanoid controls the timing somehow

anyone agree with this. Anyone know how much it is to change the vanos solanoid?

Cheers!!

[doughboy]

Originally Posted by 335i E92

No, I but apparently they control the boost to the wastegates I think to decide when they open ant close. My car has had new actuators fitted a few months ago

the actuators move the wastegates, thus the actuators are the primary means of controlling the boost level.

the diverter or dump valves just release excess boost on a closing throttle.

maybe you should check again with rob?

[335i E92]

OMG...

I'll forgive you all for starting to think I'm bonkers!!!

However, following the dyno run yesterday my car is now going Stupidly quick and I mean quick. Quicker than it's ever been before infact so bloody quick that it kept up with a Lamborghini Murciélago, I'm absutley astounded at it's pace!!!

Don't know what the hell is going on but the dyno run must have cleared something out like a blocked fuel filter or somthin??

It's also Purring like a kitten and I'm SUPPER chuffed, just got out of the car with a mahoosive smile on my face!!

Hopfully this is it for me know and I can't start enjoying the car again.b

[335i E92]

Obviously meant now & can, posting from my iPhone.

[E92Fan]

Originally Posted by doughboy

the actuators move the wastegates, thus the actuators are the primary means of controlling the boost level.

the diverter or dump valves just release excess boost on a closing throttle.

maybe you should check again with rob?

And what makes the actuators move? Vacuum pressure, controlled by a boost solenoid


Boost solenoid - This is the tiny device that controls the vacuum pressure to the wastegate actuator. If the solenoid fails, the car (via the ECU) cannot generate the correct vacuum pressure to close the wastegate, so therefore the wastegate remains open and you lose boost pressure.

There are two boost solenoids on the car, one for each turbo. They are a bitch to get to as they are behind the wastegate assembly so not so easy to replace. Cost is quite cheap - can't remember the exact cost but £40 for both seems to ring a bell.

[335i E92]

Sorry, it was a gallardo not a murcielago!!!

Thanks for the info Tony, although hopfully I won't be needing any new parts now the car has made a miraculous revovery.

[doughboy]

Originally Posted by E92Fan

And what makes the actuators move? Vacuum pressure, controlled by a boost solenoid

Correct again Herr Tony.

In my naivety I thought things would have moved on since my last turbo adventure on a 94 Sapphire Cossy.

The cheap little plastic boost solenoid seemed a crude method, even then, of controlling the vacuum level.

I didn't for one minute think our N54 would still use such a thing!!

[N54B30A]

Vanos solenoids?