Fixing DISA for $1- BMW M54 P0171 & P0174

but you'll notice any time anybody mentions any problems with this engine eighty percent of the time they'll say something about ccv and that's because that is the biggest weakness of the m54 is that ccv system so welcome back to another video here this one is again on my 525i and i recently got a check engine light which gave me these two engine codes these codes correspond to a lien condition on bank one which is cylinders one two and three and bank two which is cylinders four five and six these codes can be caused by many different things and this intro here is actually um being filmed well after i've solved this issue um i was not happy with the way that i originally filmed it so you know this is your uh your warning that this video will kind of be happening in some choppy segments but that's okay because um this video is not about the solution it's about the process to get to the solution because the solution is within these four here guess which one it is you were correct it was the diesel o-ring so with these codes what i did is i looked at the fuel trims and i was at a positive 10 that is quite high if i remember correctly anything plus or minus 2 or so is considered either normal or acceptable ten percent to me is quite unacceptable and if the dme which is the um german word for the german acronym for an ecu if it detects a 20 fuel trim positive or negative for more than a few seconds it will throw an engine code for both of these well whichever one it thinks is suitable in this case i got both and that's actually a good thing for troubleshooting so the first thing that i did was check for vacuum leaks uh vacuum leaks that mainly would affect both banks you know so every single cylinder would be affected so the first part of this video is going to be me disassembling the intake system and looking at every pretty much every possible place where there could be air leaking in to the vacuum system or you know the vacuum side which is um after the throttle body or even before it with the intake boot so basically anything that is unmetered by the mass airflow sensor is considered a vacuum leak i didn't find anything suspicious there the next thing i looked at was the intake air temperature sensor which is um in the middle at the it's at the top of the intake manifold in the middle between cylinders three and four and i checked that o-ring and it needs to be replaced but i don't think that's where the leak is coming from the next thing i did was check the diesel o-ring and uh for those of you who don't know there is no such thing as a diesel o-ring because it doesn't have one the ceiling elements on the diesel valve are all molded into the to the part there's nothing removable or serviceable but what you can do is remove um remove the o-ring around the circle boss from which it seals and replace it with an actual o-ring so if you're looking for the answer you can just skip to the time stamp for that i put all the time stamps in the description for this video and then the last thing that it could be um is the fuel filter regulator i'm not doing any of that in this video i have a separate video for that that i will be posting probably after this video comes out uh so you can see how that's replaced uh it's it's actually pretty easy and if you don't know when yours was replaced last it's a 60 part so i think it should be um it should definitely be part of your regular maintenance every 50 to 75 000 miles i think uh that should be replaced i guess that is one more thing i should uh mention is my fuel trims were initially at uh 10 thereabouts i went on a 600 mile road trip and then they went down actually sorry only after 300 miles of that 600 mile road trip they were already down to six percent and when i returned they're down to three percent and this is positive and that means the engine has to add fuel so um i haven't checked it since i saw the three percent so it could still be going down and these are in the long term so i should clarify these are long term as long as i can see this going down and 3 percent is beginning to be at the far end of the acceptable range if it can get down into the one or two percent range even if it's positive well i guess even if it's negative i will consider this the solution to the problem officially but so far the long terms have been coming down over the last few hundred miles and i will continue to monitor to save some time i as you noticed i did put a picture in picture of a time lapse up here for disassembling the intake system so right now i'm going to switch to the footage i took a couple weeks ago um before i knew what the solution to the problem was mind you that uh i did not know that until i did the diesel o-ring segment and the intake air temp so this was filmed on one on one day these two were filmed on another day and this i actually just did today so i didn't know what the solution was until i got here so i don't hold you up anymore let's just go into uh checking for vacuum leaks and you can see where all the potential vacuum leaks are um in the m54 engine uh and trust me there's a lot of them and i'll catch you on the flip side here's a look inside the engine bay now you can see in here that is looking really scummy it smells really bad so this so the unit that sits here is called diesel it uh it's a four letter acronym that stands for something in german so i'll show you what it is over here this is a diesel unit it's vacuum operated so there's a little hole down here for testing it you twist it a certain way but it's worth it this is the idle control valve this is the old style it's uh it's electromechanical there's a a pin out here and these can stick so if you have a rough idle or if the car doesn't want to idle properly at all make sure this is clean and free to move like that this is the lower intake boot inspect it for any cracks inside the this uh accordion pleading here they always crack it'll crack anywhere there's a sharp line but you know these are still nice and soft and pliable i don't think there's gonna be any issue here uh this is the intake box uh this is the mass airflow sensor this could also be the problem that i'm experiencing is if this thing is dirty or if it is malfunctioning but i've cleaned this several times in the past when i was experiencing similar issues that i was able to solve and this never did anything so i think that's clean um this tends to crack right in here and then getting this seal correct is also important making sure this seal down here is correct and then again inspect all these accordion style pleats make sure there's no crack in there again this is nice and soft i don't think my issue is here uh there's one other place and that would be right in here where the mass airflow sensor connects to the intake box uh you can take off these clips and that'll come out but you've also got to remove this lower box i've taken this all apart before it's a little bit of a pain actually it's not the most fun thing to do so now if you look right here that's the throttle body right down there that's that's one of the bolts this is the actuator section right there and if you look carefully here you'll see the ccv and you can see this one is the foam covered cold weather version and then there's a drain hose that goes down into the oil pan right there it's actually it's that one right there that goes down into the very dirty oil pan and that is nice and tight so i don't think that's my problem uh i really don't think the problem here is a vacuum leak be very very careful when you lift this up because it will crack if you're not very very gentle with it oh i didn't like that come on there we go okay now this thing is still tied down because there's a hose right here that leads down to the ccv look at that nasty it's running all over the place and that is what's going to be going through these straight into and there's some in there too and that goes straight into the engine yay all right the system doesn't look clogged but you'll notice any time anybody mentions any problems with this engine 80 percent of the time they'll say something about ccv and that's because that is the biggest weakness of the m54 is that ccv system and that's also why the n52 engine is such a significant uh it's such a significant improvement over the m54 in a lot of ways the n52 has weaknesses that this engine does not have and they're more mechanical but bmw really solved a lot of those those problems with the ccv system and they again they adopted other problems but it does the n52 doesn't have this the n52 also has a much much more simplified intake system that this engine just you can see if you've seen my videos on the z4 with the n52 engine you'll notice that like it has half the amount of wires and hoses and just things running around the intake side of the engine this it's more like a subaru honestly and subarus are just man they machine gun it with all of those all the vacuum lines just everywhere throughout the engine and it's pretty much all for the sake of emissions so i don't really know where to go from here how much one about that is all caked full of that sludgy nastiness let's take a look this is about as close of a view as you're gonna get and this is also why these engines have such problems in the cold and cold weather yeah it's got some and it is actually pretty bad it doesn't look so bad right here but if you look down in further it's it's a lot worse but it's not forming on the oil cap yet which it'll do when it gets colder that always happens but you can see the problems i'm talking about you can see why catch cans are such a good idea on these engines it's oh man it it's just very frustrating dealing with this stuff if you can't hear from the tone of my voice it's it's really annoying so the problem i had last year actually stems from this ccv system uh i had been running to work my work was only maybe barely 10 minutes away from where i lived and even though at least once or twice a week i would go for a longer highway drive to get the engine up to full temp and try and boil off all the moisture in the engine and have it get sucked through into the intake it just wasn't enough and eventually the cc vis the ccv system completely clogged up sorry the ccv system completely clogged up and i got oil in every single cylinder i pulled out all the plugs like all of a sudden the car started smoking as if it had blown a head gasket it was bad it was just a huge trail quarter mile back from where i had driven that's how big this uh the smoke of uh the trail of the smoke was and i pulled up spark plugs there was oil sitting in every single cylinder so it had sucked what happened is it sucked oil up probably from the oil pan right through the ccv system in through these it was a mess and all i had to do really was take a vacuum and uh and some compressed air and just let the car sit in a heated shop overnight and that cured it and it just had to burn off all the oil which uh doesn't do any favors to the cats so here i have the intake air temperature sensor this comes out of the top of the intake manifold right between cylinders three and four i'll show you a couple quick images of that and where it's placed right now and what i want to do is replace this o-ring here if it'll focus replace this o-ring and then i also used some mass airflow sensor cleaner to clean off the sensing unit here um i may or may not have an o-ring that fits in my kit but at the very least i'm going to take it off try and refresh it the best i can and hopefully i'll i'm able to replace it so i believe this is an eight millimeter by three millimeter o-ring actually i will get you the dimensions or i'll put the dimensions on screen somewhere and then you'll know what this is um it's listed as an eight millimeter by three millimeter but i don't i think the eight millimeter is talking about eight millimeter id then three millimeter wall thickness okay unfortunately i could not find anything in my o-ring set that would fit this properly i did try staggering two different sized o-rings an eighth inch um i'll show you the ones i chose here add an eighth inch and a sixteenth inch o-ring maybe it's three thirty seconds but a larger and a smaller o-ring that would kind of make up the difference but the problem is the id is not big enough or i should say it's not small enough even though the od works just fine so i don't have o-rings with a thick enough wall they aren't quite three millimeters so they don't fill up the space quite correctly so all i did is i'm going to be reusing the original i flipped it around and originally this o-ring was pinched a little bit you can see that right here so i hope that doesn't give me any trouble with flipping it around and then i did add it just a little bit of silicone grease just a light coat um this might be a little bit too much but so long as uh you don't get anything from this flange forward you should be fine something i don't know is how sensitive this temperature sensor is i don't know if it's as sensitive as a mass airflow sensor or if it's a little more robust than that something tells me it's a little bit more robust but i would not chance it so be very careful with this so now to install this make sure you have the tab this push tab at the roughly two o'clock position and slide it in this way another thing to be very careful of when you're taking this out as best as you can clean out everything around this area because odds are dust and dirt will pack into these recesses in the sensor and that's going to fall directly down into the intake the better you can clean it the less you'll have fall in there but i guarantee you something's going to fall in and you're just going to have to deal with it and then make sure you clean out all the grit from the walls in there and then you simply slide it back in this fit does not give me any sort of confidence um and i tested the fit with the other two o-rings and it was about the same so the ceiling surface is down in another counter bore it's not in this larger bore obviously and then just put the sensor connector back on and that's all there is to it not uh not a likely leak on this engine but i figure if i'm having potential vacuum leak problems i want to go over every single possible point where it could be failing something i did the other day is i replaced this upper vacuum hose this is actually not for a vacuum exactly this is a fresh air source that goes and matches up with one of the brake booster lines here and then it goes it ends up back underneath behind the throttle body somewhere um i don't think anything on this line further back is leaking because they are um there they have those permanent uh hose clamps the crimp style and those are all very secure so i still would doubt that those are a problem um something else i will be doing is replacing an o-ring in here and i'll show you that uh shortly because i think this this diesel valve is leaking around its periphery but it also might have some sort of leak internally that would allow vacuum into the manifold i'm just i don't know how these are even constructed so i can't say for sure if that is even possible but it's not uh it's not impossible anything anything can go wrong with the vacuum system on these engines that's for sure so in this part the diesel valve this is where i think a lot of my problems lie in terms of vacuum uh as you can see i removed this portion of the molded in ceiling element i think it's some sort of silicone it feels like silicone to me and it comes off in strings and bits and then you just have to keep picking at the little pieces that are left i think i have it clean enough for what i need the hardest part to get at is in this section right here because this really gets in your way so one thing that i recommend is get yourself on one of these jewelers or you know ultra fine flat blade screwdrivers and push it up against the top push it up against this way and then press your finger and it together pinch them together and then carefully roll it around and you can see you'll scrape stuff off that front edge and then you can push it down into there and then you can continue scraping if you hear a gritty sound then that is definitely because you are starting to cut into this glass-filled plastic other tools that i recommend are a slightly larger flat blade screwdriver and then a sharp pick this sharp o-ring pick was really good to get in behind here when it when the whole thing was intact i went behind here at about that angle and then just went around and was able to peel it off and i was able to do that on the other side and it tears more than anything and that's why there's so many so much stuff left so i'm going to wipe this up and then i'm going to install some o-rings so i'll be right back so here i have my o-rings [Applause] i ordered two sizes this is a 57 by 2.5 so it's a 62 millimeter outside diameter o-ring this is the one that i ordered because of my own measurements and then this one here is a an sae number 139 and this is what the internet told me to buy this one is smaller this one is slightly bigger but you can see they're very very close so i'm going to try the one that i measured first and see how that fits and i'd say that is the appropriate and perfect fit and you can see how the the top profile of the o-ring there is proud of the flange so i'm going to remove this very gently i do have two of these metric ones but i would really rather not wreck them if i don't have to obviously and because they're brand new they're very easy to put on and take off so here is the one the internet told me to use and there's an awesome thread in a forum i'll i'll link it in the description that goes into this particular o-ring and other o-rings for the m54 now that once it's a little bit more proud which i kind of like but it is a tighter squeeze so i will try both but you know what i'm going to try the one that i measured first it seems to give more space in the o-ring groove and would might be less likely to pinch and i don't know i these are both viton these are the slightly more expensive chemical resistant viton o-rings so these aren't just the oil-resistant these are the it's the good stuff let's go try that over at the car i added some grease to both the o-ring and the ceiling bore it's a bit tight but i think i'm going to attempt to screw it down and see if it will pull in uh i just really don't want to pinch the o-ring because that's going to cause more problems than having left it original it's also possible that if it takes too much force to draw this in that it may crack some of these plastic components it actually looks like it's drawing in quite nicely so i think i've got a good seal here i keep going for the wrong spot because i've got the cover off from the lever arm for this little piston in here for the vanos unit let's see if i can actuate that i don't think i can i know i can there we go so the other thing i was going to say well i think this unit might be faulty is i don't necessarily think that there there's a bad seal in here but i think it's either caked full of carbon from inside the manifold or something maybe some of these vacuum ports are clogged up that it just doesn't really want to actuate properly but is that going to cause a vacuum leak no so if the vacuum leak is being caused by here then there is a bad seal um it just doesn't actuate smoothly but it doesn't seem like it's leaking at all that's why i'm going to call this part 50 condition so hopefully this o-ring is going to help a little bit i think my 171 and 174 engine code problems are kind of a combination of a bunch of little leaks and possibly still a fuel filter regulator which i won't be getting in until next week so my verdict on the o-rings i would personally go with these ones the 75 millimeter id by 2.5 millimeter cross section i think these ones um are gonna fit a lot better than these ones because this was already pretty tight to get in that bore and these ones would have been even tighter because there was less space in the o-ring groove in terms of width and these are a slightly taller profile so i think these are the ticket right here um i got these ones i got both of these off mcmaster both these packs together two metric and the 10 imperial were like 13 bucks so not too bad to have some extra o-rings in stock i have a road trip coming up here uh actually tomorrow and it's about i don't know 300 miles one way so it'll be about 600 miles round trip and i'm running on an engine that i would consider to be in 95 running order um only because of those weird fuel trim problems i generally would call 95 pretty good but you know i don't like running my vehicles anywhere below 100 so hopefully made it all the way back here in one piece as you can see the uh the diesel unit that i have is kind of on its last legs they're spendy i think it's for the factory one it's 300 to get the factory diesel valve the aftermarket ones are like 160 i think i haven't looked at prices recently but it's in that ballpark so it's it's not something you just want to chuck apart at the car and hope it's right because it's getting to be on the unreasonable side for um just throwing parts of the problem hopefully you found some of that information helpful maybe it'll scratch your brain a little bit if you're having these problems it gives you a few more ideas of where to look if you haven't checked some of these places already and then you know coming out later probably next week i'll have the video on the uh the fuel filter regulator because that can also contribute to this problem because if it's not if this is clogged if the regulator isn't giving you the proper pressure or if the fuel filter is clogged in any way you're also going to be starving the engine of fuel which the engine will compensate compensate for by adding extra fuel so i think that's all i'm gonna have for today this is already like a 30 minute video um and not many people like to sit through things like that unfortunately i'd say take your time don't rush through life well with that see ya

Channel: Casey Schmidt

Views: 39,542

Keywords: Casey Schmidt, BMW, M54, car service, maintenance, P0171, P0174, DTC code, troubleshooting, removal, installation, E36, E39, E46, E85, 325i, 330i, 525i, 530i, 2.5i, 3.0i, Z4, o-ring, replacement, detailed video, how to, diy, working on BMW, budget maintenance, easy car repair, upper intake boot, lower intake boot, idle air control valve, CCV, solving vacuum leaks

Id: 8VPazxqe2Xk

Length: 30min 11sec (1811 seconds)

Published: Sat Nov 21 2020