[sloweste9x]

Hi guys, I recently sold my E92 and just picked up an E61, however I am having a boost leak that is driving me nuts that I can't seem to solve. The car is an automatic 08 with 60,000 miles, one owner who seemed to be an older woman.

The car ran very well on the OEM tune, but once I threw an MHD stage 1 map on the car it misfired and underboosted, however it only underboosts around 90mph in 3rd gear, not first or second.

I replaced the plugs, coils, and threw an RB pcv on the car as well as replaced every vacuum line, and the car kept underboosting while tuned. After this I put the car back to the stock tune, and it then started underboosting on the OEM tune as well. Yesterday when checking the codes I got two new ones:


2A87
3100


I cleaned the [exhaust] solenoid and even swapped it with the one on my father's wagon, to which the vanos code went away but the car did keep underboosting. I smoke tested the intake tract and found nothing, and am seriously wondering what the issue could be at this time. Whatever the issue is, it's extremely temperamental. Sometimes the car is a total freight train, other times it feels slow and lethargic, and might not even throw a code even though the car isn't pulling hard.

Any advice would be greatly appreciated.

Max

[Sgop335]

Few points,
Charge pipe leaking or broken?
Vacuum canisters? Measured vacuum?
Boost solenods...hmm

And the big one, turbos. Wg rattle? Any wg rod slop? My old turbos had such obvious slop and 30ff.

[sloweste9x]

The canisters seemed fine. My mechanic pumped a decent amount smoke into them and couldn't find a leak. I do not know the exact measurement of the vacuum however the shop conclusively said there are no leaks in the vacuum system. The boost solenoids could be going, however up until recently the car built boost very well, and the problem was only experienced during higher speed highway runs. The charge pipe seems like it's in great shape. I smoke tested it and removed it and visually inspected it. There is rattle, but it's not that bad, barely noticeable. My 335 had loud rattle and still held 20psi+ no problem. Rod slop is definitely something I should investigate.

[Chappers 71]

Check clamps from turbos to charge air manifold, mine we're loose this was misdiagnosed as needing new turbos, replaced clamps & all has been good since

[sloweste9x]

Originally Posted by Chappers 71

Check clamps from turbos to charge air manifold, mine we're loose this was misdiagnosed as needing new turbos, replaced clamps & all has been good since

They're pretty snug but I was thinking that as well initially.

[Chappers 71]

If there's any oily residue around the connection then there's a leak, if so clean area up, tighten or replace clamps

[YoungBlood]

sounds like a typical boost leak, the DME doesn't have enough time in 2nd gear to decide you're far enough under boost usually, but third and and "ding" half engine and 30ff. That was exactly what my car was doing when my intercooler o ring was blown

[sloweste9x]

Originally Posted by YoungBlood

sounds like a typical boost leak, the DME doesn't have enough time in 2nd gear to decide you're far enough under boost usually, but third and and "ding" half engine and 30ff. That was exactly what my car was doing when my intercooler o ring was blown

Appreciate the help. I actually have an extra gasket lying around that I might toss in, however I just have one. Was your hot side the one that went?

[YoungBlood]

Originally Posted by mb21111

Appreciate the help. I actually have an extra gasket lying around that I might toss in, however I just have one. Was your hot side the one that went?

it was, actually

[sloweste9x]

Well I replaced both intercooler gaskets, smoke tested the intake tract again and found no leaks, and the car is still underboosting. At this point it's safe to say the turbos aren't moving enough air. Maybe a clogged cat would present symptoms similar to this?

[mweisdorfer]

If you are still getting 2a87 after swapping the Vanos Solenoids and cleaning them, you should just bite the bullet and replace both. $200.00 sucks but it is what it is.

30ff is a tell tale sign the turbos are gone; it's not always the case, but a lot of times it is.

I agree with the other poster and check the wastegate & vacuum levels on the turbo regulators & vacuum canisters just to the left of the valve cover.

If those are bad, you've found your issue. If not, then I think you will be replacing your Turbos given the other items you have replaced and done and still a problem exists.

Your choices are OEM (Mitsubishi) or after mkt. Personally, I'd go After mkt.

You get better turbos for roughly the same money.

[mweisdorfer]

Originally Posted by mb21111

Well I replaced both intercooler gaskets, smoke tested the intake tract again and found no leaks, and the car is still underboosting. At this point it's safe to say the turbos aren't moving enough air. Maybe a clogged cat would present symptoms similar to this?

A clogged cat on a BMW is fairly rare.

[sloweste9x]

Update: The car was showing heavy boost oscillation tonight, with surging in and out of boost in higher gears. Tomorrow I'll try to bypass one of the solenoids and see if I can isolate one of them, or if not order two new ones as well as assess the wastegates.

[badblackcoupe]

Youre at that mileage where you need boost solenoids. I had the same problem as you, zero leaks, bubbles, hissing, no wastegate rattle nor smoking turbos but still underboosting. Sure enough it was the boost solenoids. i figured it out by buying a new one and routing the vacuum lines so that both wastegates were utilizing the new solenoid. it worked.

[sloweste9x]

Just replaced the solenoids only to find that the car is still under boosting, however now the code is 30FC, "Turbocharger, charge- air pressure too low: leak-tightness.". When I bypassed the solenoids and ran the wastegates fully shut the car was overboosting and making great power, however once I installed the new ones, the car felt sluggish and threw me the 30FC code, followed by a 30FF. At this point I'm thinking either the DVs or the wastegates. Does anyone have any other advice or tips?

[YoungBlood]

If you were over boosting, it's not the waste gates IMO. I think you've got a bad diverter or a boost leak you haven't found yet. Diverters are pretty easy to test, I'll link the thread

[sloweste9x]

Well I replaced the boost solenoids, replaced the vacuum lines, the pcv, and the charge pipe and installed an HKS BOV in case the oem DVs were faulty. The car is still underboosting. At this moment I'm starting to think outside the box. Clogged cat? Cracked intake manifold? The car has been smoke tested numerous times by different people and no leaks were found in the air tract. Beyond frustrated

[!LEFTCOAST!]

Originally Posted by mb21111

Well I replaced the boost solenoids, replaced the vacuum lines, the pcv, and the charge pipe and installed an HKS BOV in case the oem DVs were faulty. The car is still underboosting. At this moment I'm starting to think outside the box. Clogged cat? Cracked intake manifold? The car has been smoke tested numerous times by different people and no leaks were found in the air tract. Beyond frustrated

Awhile back I was chasing a 30FF that was being thrown only at WOT and was replacing parts as well. After a few months I still had the problem until one day I was organizing my garage and notice my stock chargepipe still had the o-ring so I uninstalled my chargepipe from the vehicle and saw no o-ring installed in the new chargepipe. installed the o-ring and 30FF was gone for good. Only brought it up because sometimes it's the smallest thing being overlooked. At least in my case.

[YoungBlood]

Smoke testing won't always find leaks, sometimes it takes a few psi to open a small one up

[sloweste9x]

So I replaced the charge pipe and dv valves with an aftermarket charge pipe and blow off valve, and the 30FF has decided to stay a while! The car after doing some hard pulls on the highway threw 30FF and after I cleared it the car threw 2A87 and 3100. I'm going to replace the VANOS solenoids and see if that's the culprit, however I have a feeling the issue is deeper than that. I do have a decent OFHG leak that needs to be addressed, and in rare cases some with significant oil leaks, especially OFHG leaks will have decreased oil pressure, and can damage the cam bearing ledges, leading to many different problems which can manifest themselves as underboost and less aggressive timing. I'll have to take some logs of the car and check more parameters, but my concerns of this being an air related issue are out the window. No leaks, no vacuum issues, and no wastegate/dv valve problems. Hopefully the vanos solenoid swap will do the trick but I am not confident.

[titan.n54]

Originally Posted by sloweste9x

Update: The car was showing heavy boost oscillation tonight, with surging in and out of boost in higher gears. Tomorrow I'll try to bypass one of the solenoids and see if I can isolate one of them, or if not order two new ones as well as assess the wastegates.

sorry for bump an old thread, but I'm currently stuck in the same scenario... did you find the cause of the error?