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Discussion Starter · #1 · (Edited)
After a 300 mile road trip the other day I notice that my car had developed a very rough idle when I got home and pulled it into the garage (2003 330i w/ 88k). Next day it was still there - accompanied by the SES light. As this is not my first bad experience with this car, I immediately took it down to my independent BMW service shop to get it sorted out.

This morning the mechanic told me that it was a bad DISA Valve - easy enough to replace. Well I just went to pick the car up and he showed me the old DISA - and let me know that there was no Pin on the other end of it when he pulled it out. Said he spent a good amount of time fishing around with a magnetic but that the Pin seemed to have vanished - he is convinced it did not fall out when he was removing it (though I hope he is wrong). This is a one-man shop - nice guy - claims to be a 10 year BMW Master Technician... But he didn't have any advice on the missing pin other than a bewildered look / shoulder shrug.

So now I am left with a big "NOW WHAT?!". As far as I read online, this could be really bad. Should I find someone that will completely disassemble the engine to find this thing? Is there a chance that it has found a safe new home? Are there collection magnets in the Engine like I am told there are in the transmission that it could have end up on? Or am driving on borrowed time each time I use this car now?

I know nothing about the inner workings of these things (which is probably obvious at this point)... Any helpful advice would be appreciated!
 

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Discussion Starter · #3 ·
I am considering calling the mechanic back tomorrow and asking him:

1) To scour the floor to make sure the pin did not fall out after it was removed - though I would be surprised if he didn't already do that
2) and ask him how much it would cost to have him disassemble the intake manifold to try and find it

Also thinking of using an air compressor to blow out the engine block area to make sure the pin didn't fall down and get stuck in there somewhere.

Not sure what else I can do. I am very concerned about this. The last thing I need is another fried M54. The first one was (luckily) under warranty, but this would not be...

Could the pin potentially stay in the engine and somehow NOT become a problem?
 

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2016 340i xD 6-spd
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OP,

Many disas have broken and I know pins have been lost...and haven't heard of one 'disa pin' related failure.

I guess it's metal, from what I've read, and coz your mech used magnet to try to get it...but I also guess coz of that that it's not going to get sucked up into the engine. If it could, it would have already. It'd have to travel up and over quite a bit to get into the valve cover...and honestly, even then, I suspect our cams would just chew it up and spit it out like it was nothing. But, I don't think it's getting transported very far, nor anywhere near things that would be damaged by it.

When you do your CCV, which if you haven't, you will, take the extra time to remove the intake manifold, which many do anyway to make it easier, and look around then. Bet it will be lying there waiting for you somewhere, stuck firmly in some oily residue.

I don't think you should worry about it; but understand why you are. BTW, next time, come here, we'll probably tell you it's DISA, and you can replace yourself in 3 minutes with a T-40 bit. Two screws, one electrical plug.

I don't think your Indy did anything he shouldn't have either...don't think it would have fallen out just coz he removed the DISA...it was already gone and thus why you had the issue you did. Bet you heard a funny ticking sound, right?

Doug
 

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He thinks it's from the DISA, but he's not really sure about it.

But, you know what...this would be pretty easy.

Take the DISA off and go fishing with a magnet yourself...maybe rig it up on a flexible shaft (like from a desk lamp) and go wandering around.

It doesn't seem like it fell out when he removed it...again, you had symptoms before he removed it. It's a few minutes to get disa off at most (check and see if you need rtv or if it came with an 0-ring (earlier models did from what I hear...mine has o-ring)...anyway, a little fishing won't hurt...just don't strip the screw as many do coz they use a hex bit, not T-40 (which iirc is what disa takes).

Hook a wet/dry vac up to it maybe and suck. Also, the pin is round...so first place to look would be inside the disa 'hole' and to the right...to the back of the engine where it'd be pushed under acceleration...which I suspect is a stronger force than the vacuum sucking elsewhere.

Good luck!
 

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Discussion Starter · #7 ·
Thanks for the helpful advice. I really (REALLY) hope the pin has settle down into some thick gunk - or that it fell out unnoticed on the shop floor.

I left a VM with the mechanic - as this is sinking in, I really need him to cough up some advice on the situation. He told me that he fished around in all but the farthest areas of the intake manifold with a flexible magnet tool and didn't come up with anything. I would be willing to pay him to disassemble the intake manifold if that would find it - and not be too terribly expensive. If he isn't helpful, I think I might just try my hand with a magnet tool to try and find some peace of mind.

A couple other potential DISA Pin-related engine failures that I have found online:

(Search for DISA VALVE PIN - about 1/2 way down the page)
http://www.consumeraffairs.com/auto_warranty/us_fidelis_p3.html

and Post #7 here:
http://www.bimmerfest.com/forums/showthread.php?t=501440
 

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Ask the mechanic and see if he removed the intake manifold to try and find it. There are a few cavities in it and it could be sitting on one of them--maybe at the bottom of the intake manifold, and you will be lucky it did not land in one of the intake ports. :tsk:
 

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Discussion Starter · #9 ·
I dropped the car back off with my mechanic this morning. He had a disassembled intake manifold out to show me how it works and where the pin might be. He says the whole DISA valve was in pieces when he removed it, and this is the first time he has not been able to find the pin. It sits in a recessed pocket when the DISA is inserted so it is hard to imagine how it might get loose other than while removing the DISA. He also said it might have fallen out on the floor or somewhere else when he was removing it - but that we will never know.

He is going to use a tool (I think he said endoscope) to look around more thoroughly. He thinks that if it is there - it is likely in the bottom part of the manifold where the air comes in - and if there it will not likely ever get pushed up into the engine block. If he still can't find it after a more thorough search, he says he can disassemble the intake manifold to look for it, but he thinks that might be wasted money (about $400 in service fees). Says it is possible that it already got sucked through the engine without causing any issues.

I definitely feel better having him do a more thorough inspection. If he doesn't find anything I am on the fence over whether to have him disassemble the whole thing...
 

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Wow, dude. I feel your pain. Im wondering what I might do in such a situation.

When the weather warms, I plan to DIY the ICV, boots and DISA. Especially the DISA. Im just gonna install a brand new one.
 

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So, I asked my mechanic about your predicament...

He 'thought' the pin was plastic, but based on what I've read, he might be wrong...but confirm that...many here have fixed their disas (sort of) with jb weld, so would know better than I.

But, he also said that he thought if it got sucked up into the valve and cylinder, that it'd have been chewed up and spit out by now. Don't take that to the bank, but file it away under 'possible.'
 

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OP,

It'd have to travel up and over quite a bit to get into the valve cover...
It wouldn't have to travel over anything. It sits in the top of the intake manifold which angles down, so if it came out while it was still in there it would fall straight onto an intake valve if not in the motor, believe me you would know. It probably fell out onto the shop floor somewhere.

If its running ok now, honestly I wouldn't worry about it. Yes, they are metal.
 

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It wouldn't have to travel over anything. It sits in the top of the intake manifold which angles down, so if it came out while it was still in there it would fall straight onto an intake valve if not in the motor, believe me you would know. It probably fell out onto the shop floor somewhere.

If its running ok now, honestly I wouldn't worry about it. Yes, they are metal.
Oops! I'm going to have to cut apart an engine now to see what's going on!

Ciand, you know how long the pin is and whether there's any chance for cylinder to swallow it whole and spit it out the same without messing things up?

Also, OP, maybe if the mechanic didn't do anything requiring removal of the underskirt, that it dropped down there...or hiding in the oil that's in your waffle part beneath...you have a magnet on a stick to look there...presuming the metal the pin is made of is ferrous.
 

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Oops! I'm going to have to cut apart an engine now to see what's going on!

Ciand, you know how long the pin is and whether there's any chance for cylinder to swallow it whole and spit it out the same without messing things up?

Also, OP, maybe if the mechanic didn't do anything requiring removal of the underskirt, that it dropped down there...or hiding in the oil that's in your waffle part beneath...you have a magnet on a stick to look there...presuming the metal the pin is made of is ferrous.
its a pretty small pin, but could possibly cause some pretty bad damage.
 

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Discussion Starter · #15 ·
Just spent a while talking with the mechanic. He says he scoped the entire thing thoroughly - also took the plastic engine covers off, removed the catch pan, etc - no signs anywhere inside or out. Only explanation that is left - is that it must have fallen out when he was removing the DISA. I drove the car hard coming home - so far so good - have probably put 10+ spirited miles on it now - you would think if there was a loose pin in there I would have thrown into the engine by now. He showed me the intakes - and they are plenty wide enough to let that pin shoot straight up them. In fact I really don't see how a loose pin could possibly NOT get sucked into the engine, unless by some miracle it falls into the lower cavity (which would require tilting the car one way or the other - for gravity to do its thing)... There is no oil or other gunk in the manifold that and really no way you could really get the pin "stuck" - until it gets to a piston.

I definitely feel better - though I would have been much happier if the damn pin was found.
 

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Discussion Starter · #16 ·
The Pin is probably about 1.25" long... think a screw with no threading... It is definitely metal and definitely magnetic. He showed me other ones that he had removed from other cars
 

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I would guess that the pin is in there somewhere and yes, it will cause engine damage if it gets ingested into the combustion chamber. My logic is that is fell off while being operated which would have meant the engine was on and probably in a high-vacuum situation thus sucking the pin away. The only way to know would be to pull the intake manifold and inspect. I have heard of them hiding in precarious places in the manifold. It may stay there until the day the car is crushed in a junkyard, or it could become dislodged after hitting a pothole. It's a gamble.

Pull intake manifold = $400

New (used) valve train, plus install = $1200
 

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I know this isn't helpful to this post other than to let you know I have found the same problem to ask the original poster whatever happened (if you're still around) or others who have had the same problem.

The fear of worst is obvious, yet some of what is written here makes me feel
better a little bit. :)

What started it:

Rough idle in Drive and Reverse. All vacuum leaks fixed with various maintenance done over the last year for other issues which fixed a lot but not the rough idle. It purrs in Park and Neutral.

So, I knew it had to be the ICV and/or DISA.

Took out the the DISA and it was screwed upon test of workings and the pin was missing.

I cannot find it anywhere. I actually have read this can happen, so I was very careful when I removed it, so it didn't drop in the opening of the intake where the DISA sits or below outside.

I doubt this happened recently, because one would conclude the rough idle has been there for a bit so it's the DISA and the missing pin causing the flap on the DISA not work properly has got to be the cause of the rough idle (I'm also replacing the ICV valve while in there.)

So feedback would be great...from people like the original poster. Did the engine it screwed up later? Did it end up being a non-issue? Was there anyone else who knows for sure it's not in the engine compartment or on the floor?

Just wondering....
 

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Discussion Starter · #20 ·
I sold this car about 18 months ago. Never had an issue and as far as I know the buyer also never had an issue related to this missing pin. A very nerve racking mystery nonetheless. My best guess is that it got sucked through the engine and I was lucky nothing bad happened
 
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