Is it a boost leak or just a bad boost solenoid?

[ianc]

Thanks for threads Dack, will watch as time allows (when my daughter quits bugging me).

Have ordered a vac tester and will check them out,

ianc

[tjswarbrick]

No boost again twice this week:
Drove 600 miles at highway speeds over 2 days last weekend. Ran like a charm. Got home about 5pm. Garaged.

8pm, needed to take a trip to the hospital. Door locks acting up, stumble at startup, no boost. 15 minute drive.
Post hospital, door locks still weird (driver won't unlock, mostly), but boost was back.
Door lock has gotten progressively better throughout the week, but Tuesday afternoon I had to open passenger door and hit the dash button to unlock driver.

This morning, stumble at startup. Cold idle didn't last long, and as it came down it overshot the target and nearly stalled. No boost.

Throughout, it hasn't thrown a code, flashed a light, or advised me to be concerned.

Not overly concerned about door lock at this point - just noticed that the issue somewhat coincides.

My BMW-Only indy who's worked on Bimmers for 20 years and has a 435i has no idea what's going on, but said I might want to replace my "boost valve" and if that doesn't work take it to the dealer for vacuum check!

Does that sound like my best course of action? I left a VM for a dealer service advisor.

[WedgePerformance]

Originally Posted by tjswarbrick

No boost again twice this week:
Drove 600 miles at highway speeds over 2 days last weekend. Ran like a charm. Got home about 5pm. Garaged.

8pm, needed to take a trip to the hospital. Door locks acting up, stumble at startup, no boost. 15 minute drive.
Post hospital, door locks still weird (driver won't unlock, mostly), but boost was back.
Door lock has gotten progressively better throughout the week, but Tuesday afternoon I had to open passenger door and hit the dash button to unlock driver.

This morning, stumble at startup. Cold idle didn't last long, and as it came down it overshot the target and nearly stalled. No boost.

Throughout, it hasn't thrown a code, flashed a light, or advised me to be concerned.

Not overly concerned about door lock at this point - just noticed that the issue somewhat coincides.

My BMW-Only indy who's worked on Bimmers for 20 years and has a 435i has no idea what's going on, but said I might want to replace my "boost valve" and if that doesn't work take it to the dealer for vacuum check!

Does that sound like my best course of action? I left a VM for a dealer service advisor.

I know this might sound a bit off, but put a voltage tester on your car and see what voltage is doing. I've seen failing voltage regulators cause all kinds of strange issues. Might just need a new alternator.

[Dackelone]

tjswarbrick

Sounds like something electric rather than a failing mechanical solenoid.

Q). Did you ever have the battery cable recall done? I would also check your battery terminals to see if they are tight and clean of corrosion.

[tjswarbrick]

Thanks guys.
I got a Northstar AGM battery last summer. Had charging system programmed to match, but haven't looked at it since then.
Will check in to that.

Not sure about battery cable - I bought the car used at about 45k mi. But when I spoke to BMW Customer Service all that was outstanding is the airbag.

[tjswarbrick]

Getting worse - happens pretty much every day now, but not all day. Just one drive cycle, or trip (start-up to shut-down.)
Last night instead of stumbling, idle just wavered and throttle took a couple seconds to respond the first time.
Battery, terminals, and cables are spotless and tight.

Dealer never followed through on my inquiry.
Made an appointment with a local respected repair/tune facility (can I name names?)
From description, they also suspect electrical gremlins. (Not the AMC kind.)
Joys. But better than HPFP, Injectors, Turbo, or a host of other potential failures...

[Dackelone]

Originally Posted by tjswarbrick

Getting worse - happens pretty much every day now, but not all day. Just one drive cycle, or trip (start-up to shut-down.)
Last night instead of stumbling, idle just wavered and throttle took a couple seconds to respond the first time.
Battery, terminals, and cables are spotless and tight.

Dealer never followed through on my inquiry.
Made an appointment with a local respected repair/tune facility (can I name names?)
From description, they also suspect electrical gremlins. (Not the AMC kind.)
Joys. But better than HPFP, Injectors, Turbo, or a host of other potential failures...

Getting worse is a good thing... bc now your shop can observe whats going on and hopefully diagnose it and FIX it!

Yes, you can name your shop here on the forum(just don't go making ads for them all over the forums).

Dackel

[Bimmer TV]

Just replaced both of mine this weekend. Between adjusting the wastegates and replacing these and my vacuum lines, holy moly!

[ianc]

I tested mine last weekend, and when subjecting both to vacuum, one leaked down extremely slowly, and the other almost imperceptibly, so I think I'm probably ok. As long as the vac pump can overcome whatever leakdown the solenoids have and the wastegates hold vac, there shouldn't be a problem... I guess the next step would have been to apply vacuum to the lines running to the wastegates, but I lazed out. Maybe next time...

ianc

[tjswarbrick]

Originally Posted by Dackelone

Getting worse is a good thing... bc now your shop can observe whats going on and hopefully diagnose it and FIX it!

Yes, you can name your shop here on the forum(just don't go making ads for them all over the forums).

Dackel

Even though it never gave me a warning indicator, when they scoped it they found 10 instances of Cold Start Fuel Pressure Too Low.
So it looks like I have one of those N55's with HPFP issues. They're keeping it overnight to try to confirm issue at cold start. Joy.
But it's not the boost solenoid.

[Dackelone]

Originally Posted by tjswarbrick

Even though it never gave me a warning indicator, when they scoped it they found 10 instances of Cold Start Fuel Pressure Too Low.
So it looks like I have one of those N55's with HPFP issues. They're keeping it overnight to try to confirm issue at cold start. Joy.
But it's not the boost solenoid.

Any updates ? Keep us informed.

[tjswarbrick]

Their tech said my car has the dread "long cranking." I had no idea. Fires up as readily as my wife's Pathfinder or F-i-L's ES350, every time. Also registered some cold-start misfires.

They kept the car an extra day to confirm Cold Start Low Pressure on their watch. I told them that twice this year I gunned it quickly before shutdown, and when I fired it up next time it did the no-boost thing. Not sure if they tried that, but the next time they fired it up they got the error. Replaced HPFP.
They wanted to keep it Friday to confirm the repair, but I'm sure how they could be sure since it took them a few days to diagnose the problem to begin with. They're not open over the weekend, and I really need a car this afternoon and tomorrow AM.

All I've done so far is drive it home 15 miles from the shop Thursday night. Started before I even got my finger off the button, so, I guess I need to realign my expectations there.
Delayed-reaction tach didn't register anything amiss, but I thought I felt a couple misses during cold start. Drove fine. Boost didn't feel appreciably stronger than normal, and the first time I got into the boost I felt a hint of lag - which is very out of character for my baby.
But the next couple times (in the name of science, of course) it felt just fine. Took the girls camping in the Nissan this weekend, and drove FiL to church in his Lexus this AM.
So I'll be taking her out for real a little later today.

Also had a leaky oil-level sensor, dropping oil on the harness. Probably just the o-ring. I had the OFH replaced a couple months ago elsewhere - seems he just reused the sensor. Laziness? They charged a few bucks for the part, but considered the labor "included."

[jessreds]

Hello, someone knows, if that piece is disconnected and the car is started, it circulates like 30 miles, after I realize that being the turbo does not work well I feel that it does not push, thanks for the support

[maltocaro]

Just changed my boost solenoid and vacum lines and it has made a hell of a difference! Boost on target and pullong hard

[Yavarm3]

Good info here hope this resolves my problem, Thank you.

[Aeleane]

Originally Posted by WedgePerformance

In the past month I have been testing pump / meth on my Pure Stage 2 car and started to notice my boost taping off. I was running a map that should have been pushing 21 psi without issue, but I was only hitting 18. Two week later 13 psi. Normally if you had a boost leak and you were dropping almost 10 psi you would hear the leak. I didn't hear anything other than my turbo spooling and logs showing 90% wgdc and only 11 psi to show for it on a Pure Stage 2 turbo.

Last weekend I checked my clamps and all was good so today I bought a new boost solenoid. Install took 20 min because I removed the intake inlet so I had room to work. I still dropped the F'n bottom nut trying to install the solenoid. Murphy's law...

Good news... It was the solenoid and my car is boosting harder than it has ever boosted. Actually need to turn things down a bit. So before you go pulling your car apart looking for a boost leak, do yourself a favor and spend the $ to buy a new boost solenoid. It's a simple fix...

i have a 330D e93 which gave me a loud pop and no more pull i’ve just had the boost pipe from the intercooler to manifold replaced as there was an air leak from the plastic part of that. it seems to have improved but it is still not pulling anywhere near as hard as it did before the loud pop. no codes no lights no smoke.could this solenoid be an issue is there away to test it?