Diamond

So that is the call I get today-I opted to have my spark plugs changed and somehow the tech saw that the butterfly valve on DISA 2 was completely off, laying in the intake, with 1pin beside it and 1 pin missing.

They are scoping and looking for the other pin.

I guess the obviosu concern-what would happen to a cylinder or engine if a metal pin was sucked into a cylinder-I assume it would do something bad no?

And how liable is a dealer when 3 weeks ago they found a DISA code thrown-but reset the computer and did not find this problem.

They also did a cylinder head replacement for lifter problem 2 months ago and clearly would have taken off the intake manifold-and again not seen this.

If indeed it is in the engine-is this something I should be getting a new engine for-or what is reasonable to expect-car is still under initialy warranty

turboawd

any metal object that falls into the combustion chamber, is going to cause big damage. if they dont find it, stick a small camera into the cylinder to inspect for damage.

Diamond

But would I notice this or is this over time? I would think any foreign object in there would be bad-but then again a small pin-i guess it could be feasible

turboawd

what kind of pin?
how big?
was it hardened metal?

even a small pin, can scratch the cylinder wall.

Diamond

For anyone who cares-this post I have about the 3 stage air intake-my one valve was broken and today got my car back-The entire engine was scoped, I saw the pictures they took with the camara and the little tiny pin, holding my valve in place was nowhere to be found-must have gone out with the old cylinder head-all the cylinders are perfectly clean, no pieces in them, no scratches or anything.

The cylinder head was brand new including the valve train.

Ended up getting my Actuator (comes with two of them) replaced 700 bucks for parts only-would have been 1200 not under warranty with work.

Anyway for anyone who cares-the 530 n52 is the only engine of the bunch that came with a 3 stage intake-pretty rare-2 stage is common and 1 stage is the norm.

Different length runners leading up to the intake manifold for the air to travel depending on the RPM-basically my low RPM plenum (air track) with the valve was broken and permenantly open-and was the source of my LONG sought out cabin vibration and DISA fault.

Low RPM-both valvles closed-forcing air to go through lowest air flow path
mid-one valvle open-causing pulse wave in mid range to maximize air into cylinders
high-both open-maximizeing air into all cylinders

I often rev my car hard and long and am guessing this was the cause-also when they did the Lifter bleed which included holding the rpms at 3500 (mid) the valvle was pushed too hard and too long at the same rpm and am guessing is what caused it.

The shop foreman had never seen such a thing as a broken DISA valve in his 26 years of working on bimmers-boy am I lucky!

turboawd

i thought these valves were known for coming loose on the diesels. others have removed them.

530inOK

My limited knowledge of these motors is based on what I learn on this forum and research. I had no idea a DISA valve even existed, much less what it does.
I do understand the importance of intake runner length and tuning at different RPMs. It does makes sense to block off parts of the intake to increase air velocity at lower RPMs.
These valves must be on the underside of the intake out of view.
Thanks for the update and info. Glad you got it squared away!

Diamond

bingo, nice bottom picture-you are right they are out of site-the runners/plenum is underneath the intake manifold so you dont see it-and really have no way of knowing if they are working or not unless you get a fault thrown and CEL on-the 528s/328s use a single stage and obviously run fine-you would over time probably not notice the loss of 30hp over months as they stopped working-I notice a big difference in low end torque now that mine is fixed since the one that broke was the one supposed to be working in the low end-

I also had spark plugs changed so that probably helped-anyway-everything I learned have been from these boards and the internet-good reads

530inOK

Did you get the head changed under warranty? Maybe it was you that mentioned that BMW is now installing updated lifters instead of complete heads. I noticed the "ticking" noise last winter but haven't
heard it since.
I've got 68k miles on my car and haven't had any real issues yet (fingers crossed). I do want to change the plugs and get a good look at the coolant hoses and reservoir.
With all the work you've done on your car you should be good to go for awhile.

Diamond

Yes was me-unfortunately with all the models on this forum not too many have the n52 engine so not as much info as the 3 series boards but yes I had my head replaced.

I would say if you have that many miles to just leave things alone

I had 30 some thousand and at that time a new cylinder head and drive train-considering it has all the vanos, camshafts, lifters, valves- etc etc-was a good deal since the block and pistons arent usually a problem.

So had that replaced- 7500 USD

Now have had the intake off and my cylinders inspected, pistons inspected and all is well-so my hope with a brand new cylinder head, clean block cylinders and pistons and recently inspected air intake with new actuators and new spark plugs and ignition coils (asked dealer while he was in there why not-did it for free due to the hassle), engine reprogrammed-I can say it has not ran this well since I drove it off the lot-and I would hope my engine problems are over.

Have also had my entire step shifter apparatus changed and gearbox inspected, have had all engine and tranny mounts replaced, have had all bolts and frame/suspension inspected for 6 hours and tightened, lubed, adjusted, had an alignment.

Probably 13k in warranty work and 1k in prevenetive stuff-early oil changes, spark plugs-on a car with 42k miles-

I hope since I decided to buy this lease out right before all this happened-that it will last awhile!

Oh good point with the swirl flaps-however these are a bit different-being the location and point of them-but the swirl flaps on diesels are on each air intake so six of them. These are on the runners before the actual intake and there are two of them-but I geuss similar principle.

These seem to have a lot different effect though than the swirl flaps since these are diverting air in different directions based on RPM's so removal is not optimal considering this piece and the ECU tune is what gives it the 30 more hp than the "detuned " version.

I agree any butterfly valvle opening and closing that much seems like trouble to me.

Also this is a rare problem-on the diesels since it is turboed-it was mainly the dirty exhaust slugde build up on the flaps plus their poor construction that seemed to be the reason for breakage-on NA engines clearly we dont have the exhaust sludge and these are a much newer part-and hopefully designed a bit better-in my case apparently not!