I believe it is virtually impossible for the pin to drop into the inlet whilst car is in operation. It simply cannot move back enough in its housing to drop out. However as I understand it the pin can drop out if you are not careful whilst removing the DISA for inspection or whilst putting it back in after inspection and its is then that the engine can be destroyed.
DISA Valve Replace or Rebuild? What's the consensus? ANSWERS
- Thread starter StudioWizard
- Start date
So maybe the article I read was scare tactic or something.... Here's a link to the article:
https://bmwtuning.co/m54-engine-problems/
I'm curious what you all think.
https://bmwtuning.co/m54-engine-problems/
I'm curious what you all think.
I also just emailed the writers of the article to ask if they have any first account experience of a DISA unit failing and causing major engine damage from a dislodged pin or other debris from the unit. I'll keep you posted.
That's actually a good, well-written, accurate and truthful article.StudioWizard said:
Most M54 engine owners, including myself have experienced most of, if not all of those issues.
Where they indicate that 'debris can get into the engine, and that's not good', well, of course that's a plausible claim, but it's still anecdotal and doesn't offer any evidence. So I wouldn't regard it as scare tactics necessarily. It may have been better to elaborate on the risk of damage occurring should the DISA fail as it can fail in more ways than one. It can also fail without damaging the engine of course.
Agreed.
I read the article, then started researching on Google/YouTube (uh. oh.). And of course, I found videos that talked about how a filed DISA unit can "grenade" your engine. Here's the one I watched:
https://www.youtube.com/watch?v=ZNYUhWk6WUc
He seems reasonable... but the fact is that his engine did not suffer catastrophic engine damage.
I read the article, then started researching on Google/YouTube (uh. oh.). And of course, I found videos that talked about how a filed DISA unit can "grenade" your engine. Here's the one I watched:
https://www.youtube.com/watch?v=ZNYUhWk6WUc
He seems reasonable... but the fact is that his engine did not suffer catastrophic engine damage.
Here's one of the comments from that video:
"@TheDemockery
8 years ago
If the DISA valve fully fails, parts of it will get sucked into the engine, which may cause significant damage. At the least, the head will have to be removed to repair the engine. I know this from first hand experience."
So there's some "firsthand" experience via YouTube comments for whatever that's worth.... maybe not much. haha I found lots of other articles and comments where people claimed their engine was badly damaged due to DISA failure. Somebody on Amazon posted a review for a cheap aftermarket DISA unit that failed soon after installation and said that this cheap unit caused him $4000 worth of engine damage.
"@TheDemockery
8 years ago
If the DISA valve fully fails, parts of it will get sucked into the engine, which may cause significant damage. At the least, the head will have to be removed to repair the engine. I know this from first hand experience."
So there's some "firsthand" experience via YouTube comments for whatever that's worth.... maybe not much. haha I found lots of other articles and comments where people claimed their engine was badly damaged due to DISA failure. Somebody on Amazon posted a review for a cheap aftermarket DISA unit that failed soon after installation and said that this cheap unit caused him $4000 worth of engine damage.
StudioWizard said:
Good choice. The aftermarket ones are no better. the OEM is very expensive. I ended up rebuilding my original 20 year old DISA and all is well. Better fuel economy and no more hesitation at lower RPM's.
Posted what it looks like after 260,000+ KM's > https://z4-forum.com/forum/viewtopic.php?t=141384
My advice is, if your current DISA's diaphram is good, just rebuild it with the aluminium kit. you can test the diaphram by setting the car key to pos2, then block the vacuum hole tightly with your finger, then unplug the disa power connector. If the bell crank arm, moves slightly, then youre good. once you remove your finger, the arm should move all the way back to its homing position. Bear in mind, a working bell crank arm does not mean your flap works. if you look at my thread, for the past year i believed my DISA was good when in reality, the flap was just spinning freely.
Hi all, as far as I'm aware the DISA on the N52 engine can't be rebuilt using the X8R kits, so what options for replacement DISA's do us facelift owners have?
I don't want to buy an aftermarket version which is going to be problematic- is OEM BMW the only thing available in that case?
I don't want to buy an aftermarket version which is going to be problematic- is OEM BMW the only thing available in that case?
Did you contact the guys over at X8R? They're very responsive. They'll probably know.
UPDATE:
Today, I "upgraded" my DISA unit. TLDR: A big nightmare and possibly ruined a perfectly good DISA unit.
I took the unit out and examined it. It's an OEM part and I had to tug a bit to remove it. All the parts appeared to be working perfectly. I considered just putting it back in and moving on. Ah, what the heck? I have the X8R kit right in front of me. Might as well upgrade, right?
I went to the X8R website... no instructions - all broken links. Went to YT and found their instructions on my own.
Step 1: Remove the pin. Looks super easy on the video, but that pin did NOT want to come out. I spent over an hour trying to pry it out as shown in the instructions, then ultimately was able to get it out with pliers. I can't see how that thing was ever going to fall off into my engine. Oh well...
Step 2: Remove the rotating arm inside the unit. Again, looks super easy on the video. I spent well over 2 hours trying to pull that thing out. You know what? I never was able to pull it out. I had to DRILL it out and even then, the main piece remained inside the original flap. I don't think this unit was ever going to fail... seriously. I nearly gave up, but finally I decided I have to continue.... no turning back now since I don't have a working unit. I did FINALLY get all the old parts out, but with some slight damage to some rubber trim (see below).
Step 3: Put it back together with the new parts and remove the old O ring and put on the new one. Should be easy, right?? Nope. Mine doesn't have an O ring. It has some kind of glued on seal and it wasn't budging either. That took another HOUR to scrape off cleanly. At least putting on the new O ring was super easy.
I was just about to put it back in the engine when I noticed that some of the orange rubber edge trim was peeling. So, peel it off or just leave it alone? I'm sure with all the tugging and wrangling I did, I must have rubbed on accidentally. I don't think it was already like that. (See picture below). I thought about super glueing it, but seemed like a bad idea.... plus with all the oil/grease it probably wouldn't have held. I just left it... for now pending any suggestions you all might have.
Anyway, in the end, it seems like the DISA unit in my 2005 2.5i came from the BMW plant ROCK SOLID. I don't know how old the unit is. It could be original from 2005. Maybe it was replaced once? Or if it's more recent, maybe BMW is designing them better now. Either way, my unit was super solid - I probably should have just left it alone and/or only replaced the O ring.
So, should I be concerned about this? Any suggestions?
Today, I "upgraded" my DISA unit. TLDR: A big nightmare and possibly ruined a perfectly good DISA unit.
I took the unit out and examined it. It's an OEM part and I had to tug a bit to remove it. All the parts appeared to be working perfectly. I considered just putting it back in and moving on. Ah, what the heck? I have the X8R kit right in front of me. Might as well upgrade, right?
I went to the X8R website... no instructions - all broken links. Went to YT and found their instructions on my own.
Step 1: Remove the pin. Looks super easy on the video, but that pin did NOT want to come out. I spent over an hour trying to pry it out as shown in the instructions, then ultimately was able to get it out with pliers. I can't see how that thing was ever going to fall off into my engine. Oh well...
Step 2: Remove the rotating arm inside the unit. Again, looks super easy on the video. I spent well over 2 hours trying to pull that thing out. You know what? I never was able to pull it out. I had to DRILL it out and even then, the main piece remained inside the original flap. I don't think this unit was ever going to fail... seriously. I nearly gave up, but finally I decided I have to continue.... no turning back now since I don't have a working unit. I did FINALLY get all the old parts out, but with some slight damage to some rubber trim (see below).
Step 3: Put it back together with the new parts and remove the old O ring and put on the new one. Should be easy, right?? Nope. Mine doesn't have an O ring. It has some kind of glued on seal and it wasn't budging either. That took another HOUR to scrape off cleanly. At least putting on the new O ring was super easy.
I was just about to put it back in the engine when I noticed that some of the orange rubber edge trim was peeling. So, peel it off or just leave it alone? I'm sure with all the tugging and wrangling I did, I must have rubbed on accidentally. I don't think it was already like that. (See picture below). I thought about super glueing it, but seemed like a bad idea.... plus with all the oil/grease it probably wouldn't have held. I just left it... for now pending any suggestions you all might have.
Anyway, in the end, it seems like the DISA unit in my 2005 2.5i came from the BMW plant ROCK SOLID. I don't know how old the unit is. It could be original from 2005. Maybe it was replaced once? Or if it's more recent, maybe BMW is designing them better now. Either way, my unit was super solid - I probably should have just left it alone and/or only replaced the O ring.
So, should I be concerned about this? Any suggestions?
Attachments
UPDATE: X8R finally got back to me regarding the loose rubber lining. They suggested using super glue to re-attach it. I did it and so far seems to be fine. I'll pull the unit out in a month or so to check up on it. I'm sure how critical the rubber lining really is....
Little thread revival
I am thinking of doing my DISA valves. BMW prices are quite frankly even more ludicrous than the usual ludicrous prices for BMW stuff. Did anyone contact X8R? Or anyone got advice on how to service/replace without spending a small fortune on two little plastic flaps worth about twenty quid from BMW.
I am thinking of doing my DISA valves. BMW prices are quite frankly even more ludicrous than the usual ludicrous prices for BMW stuff. Did anyone contact X8R? Or anyone got advice on how to service/replace without spending a small fortune on two little plastic flaps worth about twenty quid from BMW.
If you read the above messages in this thread, you'll see that I actually installed the kit from X8R. My mechanic told me I didn't need to update my DISA unit and that he'd never seen a bad DISA unit nor heard of one causing catastrophic engine damage. I decided to try it anyway and my DISA unit was in perfect condition. It was a nightmare to replace the flat and pin, but it was successful. Will it make a difference. I doubt it.... I've come to completely trust my mechanic as everything he's told me about my Z4 has been spot on.
So, you can do the "upgrade" if you want. It will guarantee that the pin and flap will never malfunction, but it's likely the original OEM part will never fail/malfunction either. My Z4 has 160,000+ miles on it and I'm pretty sure the DISA unit is the original. When I took it out, it was in perfect condition and rock solid.
I'd recommend taking your unit out and inspecting it. If it looks like it's in perfect condition, don't try to "upgrade" it.
My .02
So, you can do the "upgrade" if you want. It will guarantee that the pin and flap will never malfunction, but it's likely the original OEM part will never fail/malfunction either. My Z4 has 160,000+ miles on it and I'm pretty sure the DISA unit is the original. When I took it out, it was in perfect condition and rock solid.
I'd recommend taking your unit out and inspecting it. If it looks like it's in perfect condition, don't try to "upgrade" it.
My .02
StudioWizard said:
I find this odd. They are bound to malfunction at some point, so rebuilding this specific component is crucial as a preventive maintenance step. The pin falling into the cylinder is indeed impossible if you look at the way the disa sits.
Here's the state of mine when i decided to pull it out and rebuild it as just a preventive measure
Wow! That looks horrible. However, it didn't cause catastrophic engine damage even considering the bad state your DISA unit was in, right? That's what my mechanic was telling me - that he'd never seen or even heard of engine damage caused by a bad DISA unit. I would think if DISA units were commonly failing and then causing fatal engine damage, BMW might be getting hit with lawsuits. There might be an example or two out there about this, but it sounds like it's not a common thing.
In your situation, it's worth upgrading your DISA unit vs buying a new one as long as the rest of the unit is working correctly. There are two tests that I'm aware of to check the operation of the DISA unit. You can do this once you've upgraded your unit.
1. With the DISA unit removed, rotate the flap in the closed position and put your finger on the little intake hole on the side. When you release your finger, the flap should rotate back to the resting position. This means the vacuum is working.
2. With the DISA unit removed, but still connected to the electrical connector, turn the ignition into the accessory position. The flap should immediately close. When you turn the ignition off, after a few seconds, the flap will go back to the resting position. Here's a video demonstrating this test: https://www.youtube.com/watch?v=so6xLmg1zno&t=69s
Post pictures of your updated unit if you can. Also, be careful with the rubber lining around the arch. It's really easy to rub on it and make it peel. I had to glue a portion of mine back with super glue.
In your situation, it's worth upgrading your DISA unit vs buying a new one as long as the rest of the unit is working correctly. There are two tests that I'm aware of to check the operation of the DISA unit. You can do this once you've upgraded your unit.
1. With the DISA unit removed, rotate the flap in the closed position and put your finger on the little intake hole on the side. When you release your finger, the flap should rotate back to the resting position. This means the vacuum is working.
2. With the DISA unit removed, but still connected to the electrical connector, turn the ignition into the accessory position. The flap should immediately close. When you turn the ignition off, after a few seconds, the flap will go back to the resting position. Here's a video demonstrating this test: https://www.youtube.com/watch?v=so6xLmg1zno&t=69s
Post pictures of your updated unit if you can. Also, be careful with the rubber lining around the arch. It's really easy to rub on it and make it peel. I had to glue a portion of mine back with super glue.
StudioWizard said:
Was a task i already tackled 4 months ago, nevertheless here's the picture of it post rebuild.
always thought mine was fine because i kept doing the vacuum test you mentioned with it still attached and it sounded good. but in the end, the flap was just free spinning on its own axis
Beautiful work!! That's very satisfying!
