Boost Solenoid broken? (50%boost)

[NLduffyNL]

Hi

i'm still busy with my boost problems, im creating a new topic for that, because i know my turbo's aint broken. (the topic where i asked the question later)

Im making 0,5boost instead of 1.0bar
What happened? i replaced standard vac hoses for silicone ones.

But this proberly aint the problem, because exactly 1 year ago i had the same problem, after about 2 months with 0,5bar boost and some days with 1.0bar boost the problem solved itself and end of may the problems stopped and i could run my full boost. Till this week.
I changed my vac. hoses and after that i got only 50% of my regular boost.

What i did for a little moment is disconnected the vac.hoses of the wastegates, just to make sure this wasnt the problem. Boost went over 1,5bar so im pretty sure there's nothing wrong there

How can i check if my boost selenoid is broken?

[NLduffyNL]

i started to research a bit further.
I losened my hose from the inlet that go's to the wastegates.
Get my compressor and gave it 1.0bar
Result: Only the actuator in the back reacts.

2.0bar: Both actuators are reacting.

0,5bar: Only the back actuator reacts.

What im hearing is a little bit of air sqweeking at the back actuator. (As far as i can feel and inspect is there no leak at the hose) So i think its coming from the actuator.
But should that really be the possible?
And is it possible that this is causing my problem?

[gallvr4]

What boost controller you useing???

[NLduffyNL]

None, its mapped in the ecu.

[NLduffyNL]

Is there someone who wants to help me and check out at how many bar or psi theire wastegate(s) open?
I assume it supposed to be the same value, but mine is defenatly diffrent.

Today ive checked again, at the front turbo the actuator is opening a a higher pressure then the back (I checked it at the actuators)
The whole boost-system (all those hoses and connections) are 100% pressureleak free.

[Davezj]

You may want stop what you are doing before damage something for good.
The factory fitted wastegates are rated at 14psi (1bar) and the workshop manual specifies that you do not pressurise them over this point. Otherwise you can damage them.
If you want to over pressurise them that is up to you.
The wastegate actuator should be fully extended (wastegate open) at 1 bar directly applied to the back of the actuator.
How people run higher boot levels above this value is through the use of a boost controller. This artificially raises the presure on one side of the controller with respect to the other. So the wastegates do not see the high side of the controller.

So if you front turbo wastgate actuator is not moving at 1 bar then it points to a broken wastegate. Probably a perforated diaphragm inside the actuator. Replacement probably required.
Weather the damage to the actuator is due to normal wear and tear, or due to you over pressurising it, who knows.
The actualatrs will have some degree of resistance to damage and will probably be ok up to about 20ish psi, but I don't really know, this is just a guess. But you can be sure that if you go slightly over the specified 1bar the actuator will not imeadiatly fail, it will be ok.
But you are running it at twice the specified pressure and are probably damaging them perminently.

And finally what are you using to regulate the pressure to the wastegate actuator?
If it is just the regulator that is on the compressor, then you are probably putting a much higher pressure on the actuaries than you think. The regulators that come fitted to compressors are generally in the range of 0-8ish bar on a very small gauge. Making the setting of the pressure a bit hit or miss. To be sure of the pressure you are applying to the actuators you should be useing a secondary regulator which has a range of say 0-2bar so you can set the pressure .
You set the compressor regulator to 2bar and then the second one to step it down further.

Well this is what I do and I have never had any problems.

[NLduffyNL]

Thanks for the info and reaction Dave,

I wasnt using the gauge on the compressor, but i had a little bit more detailed, that went to 5bar instead of 13bar, its accure on 0,2bar.

So i tried again how the actuators react with directly pressure:
Back actuator at 0,4bar just seeing that it feels air, like a vibe maybe a few millimeters out, nothing more
Back actuator at 0,6bar it moves a bit cant say for sure if its fully opened
Back actuator at 0,8bar i think its fully opened.
Back actuator at 1bar is defenatly open.

Front actuator at 0,4 no reaction
Front actuator at 0,6 no reaction (have to say its harder to see)
Front actuator at 0,8 i see a bit of movement but defenatly not open
Front actuator at 1bar its moving but still not fully opened i think
Front actuator at 1,2bar i think it went open.

If the front actuator is perforated or something like that, i think i should hear an air leak right?
If the front actuator is opening at higher pressure then the back actuator, shouldn't that mean that im making more boost instead of less?

I do hear a bit of air leak at the back one, so that would make more sense?

If i dont hear anything today or tomorrow before i got back from work, im going to remove the back actuator, and inspect it better and give it a better test.
What options do i have when my actuator is failing on me?
Where can i get new ones? (Couldn't find them on ebay) Or do there exist repair kits?

[Nick Mann]

I can't say for sure what is going on with your wastegate actuators, as I don't have any experience of testing them. However I recently couldn't get over 0.5 bar either. (Occaisonal brief spikes to 0.7 bar, but only on cold mornings before the engine bay had got very warm did the boost stay above 0.5 bar for any length of time. I posted a thread and my eventual findings:
http://www.clubvr4.com/forum/showthr...-issues-anyone
In summary, my solenoid wasn't working.

[NLduffyNL]

Hi Nick,
I read your topic,
Im not quite sure its my boost selenoid.

went for a testdrive again, this time i disconnected the boost selenoid and the result was exactly the same, no diffrence.

So i think its quite sure 1 actuator is broken/failing right?

[Davezj]

If the front actuator is opening at higher pressure then the back actuator, shouldn't that mean that im making more boost instead of less?

i would have thought this would be the case, the wastegate opens to reduce the boost. so if it is sticking shut then more boost should be made.
I still think you could have damaged one or both of your wastegates by puting 2 bar directly on the back of the wastegates. so you must bear this in mind when try to diagnose your issue.
wastegates are replacable but, i doubt many people would be inclined to sell them without the turbo still attached. as they really come as a pair. wastegate and turbo nicely rusted together.

hope you get it sorted soon, you sound quite frustrated by this issue.

[Davezj]

here is a recap on you situation, let me know if i am right.
you are saying the following.

1. you replaced the front turbo due to low boost.
2. boost is only reaching 0.5bar
3. disconnet the boost pressure from the wastgates and you get fulluncontrolled boost which rising to 1.5bar
4. front wastgate operates slighly different from rear wastegate by opening at a higher pressure. you checked this by applying 2 bar pressure directly to the back of the wastegates.
5. disconnecting the factory boost solenoid from the boost line completely the wastegate side and the boost pressure side to the big plastic elbow that connects to the throttle body (both pipes) and leaving it open to atmosphere still makes the boost pressure 0.5bar.

some of these statements seem to contradict eachother but let me know if this is correct with respect to what i have written and you have experienced.

[NLduffyNL]

Yea your right David, i am a bit frustrated Next week there's an event where i want to go to with my car

1. No i didnt replace a turbo
2. Yes, go's around 0,5/0,6bar
3. Correct
4. i checked this by sending in diffrent pressure values (first started low, stopped when the wastegate opened)
5. I putted the boostselenoid out of control by blocking the hose that leads to it. Leaving the hose on the elbow/pressure side going to the wastegates.

I think but im not defenatly sure about it: When i blocked the bleedhose i was making 1.5bar (stopped right away and re-opened it)

[Davezj]

well from what you have described above i think this is what is going on.

from point 3 and point 5 it can be seen that this is the correct opperation for the wastegates in these configuration.
point 3 wastegate open to atmophere maximum boost is reached 1.5bar
point 5 wastegate regulate the boost to the minimum pressure about 0.5bar because you are connecting the generated boost directly to the wastegates with no boost control.

so i would agree with nicks comments above that it points to the factory boost solenoid is not working correctly.
get a replacement or borrow one to see if it makes any difference or get a manual boost controller to quickly check that the boost can be raised and lowered by the MBC and if so then all is well.

[NLduffyNL]

Well im back at home again.
I went to a friend of mine wich has an mbc.

I let closed the hose that go's to the boostselenoid and i connected the mbc to the system.

Now its acting quite normal. It peaks to 1.2 go's back to 1.1 and slowly going to 1.0-0.90bar

So it has to be the boostselenoid thats broken.

I think i'll give camskill a call tomorrow if they got one and how long it will take to get to the netherlands. Hope i can get one within a week.

Thanks for the help so far.
When i fitted my new boost selenoid i'll will confirm if the problem is solved or not.

[NLduffyNL]

Btw, does someone have the MR number of the boost selenoid so i could try and order it at the dealer here in the Netherlands (might be quickker)

Cheers Mark

[NLduffyNL]

MR212636
is correct?

[Davezj]

Put up a Want To Buy (WTB) thread on here in the correct forum of course.
And someone will probably get back to you with one very quickly.

My factory boost solenoid part number is MR212636 (checked via ASA).
same as you have post ed up

[NLduffyNL]

To bad, borrowed a boost solenoid today, without results.

Im thinking that one of the actuators is broken, cant think of anything else.

[NLduffyNL]

how big is the chance that i got a failing ecu? Because today i changed the actuators. But still the same problem. Today ive changed both actuators without a difference. Someone any more ideas? still

[Davezj]

how big is the chance that i got a failing ecu? Because today i changed the actuators. But still the same problem. Today ive changed both actuators without a difference. Someone any more ideas? still

Thought you got it working with an MBC.