When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hello All. I wanted to do a full scan on my car after doing the engine mounts and got some (probably unrelated) error messages. I did some research on the 0521 and it pointed to an issue with the intake flaps. There is a known issue on the M272 and M273 engines with a broken flap pivot thingy which I thought was going to be the problem on my car, but I popped the cover off and looked down in there (You can clearly see the arm from the actuator from the top of the engine) and it is not broken at all. I was wondering if anybody had any thoughts on this. No CEL and runs fine. Pics attached.
You could try clearing it and see if it comes back. Normally the engine runs a little rough either at high speed or low speed if it's broken. I think it has to run for a while before it actually sets a code. Check ebay for repair kits. There's also the rods in addition to the lever that breaks. If you search the old threads, you should just replace the intake instead of getting those repair parts unless you're going to sell the car soon. Eventually those flaps break off and can damage the engine even if you fix those parts. There's several youtube videos on how to replace the intake. Nothing too complicated but it looks like it'll take a while as there's lots to take apart. If you have the luxury of time, you could also send out the fuel injectors to have them cleaned. The price of the Pierbug intake seems to have gone up, I think somewhere in the $600 range now.
You could try clearing it and see if it comes back. Normally the engine runs a little rough either at high speed or low speed if it's broken. I think it has to run for a while before it actually sets a code. Check ebay for repair kits. There's also the rods in addition to the lever that breaks. If you search the old threads, you should just replace the intake instead of getting those repair parts unless you're going to sell the car soon. Eventually those flaps break off and can damage the engine even if you fix those parts. There's several youtube videos on how to replace the intake. Nothing too complicated but it looks like it'll take a while as there's lots to take apart. If you have the luxury of time, you could also send out the fuel injectors to have them cleaned. The price of the Pierbug intake seems to have gone up, I think somewhere in the $600 range now.
That's good advice. I didn't realize the flaps inside the manifold can break off. I would guess mine isn't to that point yet but I should probably plan on replacing the intake manifold at some point. It looks like a tedious job but MUCH easier than the engine mounts, and it doesn't look like I'd have to get under the car at all to do it.
There's a number of videos that show step by step. Irepaircars on YouTube does a good job explaining the process, especially little trick to keep new intake gaskets in place (uses old intake bolts as temporary alignment studs). Personally, I'd consider installing that metal link pivot on the new intake to replace the oem plastic pivot.
It's a real shame about the design components of these V6 intakes .
There's a number of videos that show step by step. Irepaircars on YouTube does a good job explaining the process, especially little trick to keep new intake gaskets in place (uses old intake bolts as temporary alignment studs). Personally, I'd consider installing that metal link pivot on the new intake to replace the oem plastic pivot.
It's a real shame about the design components of these V6 intakes .
I did some research on this in the W211 forum where the M272 has been around since 2006. Basically those flaps get coated as they age so it gets more and more difficult to move as the mileage goes up. Eventually something breaks, those rods or the pivots. But if you replace them with metal bits, then those flaps still get harder and harder to move until eventually they break off and they can end up in the engine causing additional damage. That's why it's probably fine for a short term fix if you're thinking of getting rid of the car soon, but if you plan to keep it for a while, you should just replace the manifold.
There's a number of videos that show step by step. Irepaircars on YouTube does a good job explaining the process, especially little trick to keep new intake gaskets in place (uses old intake bolts as temporary alignment studs). Personally, I'd consider installing that metal link pivot on the new intake to replace the oem plastic pivot.
It's a real shame about the design components of these V6 intakes .
irepaircars video is fantastic. I've watched it a couple times and written everything down and feel confident to tackle this job.
Originally Posted by cetialpha5
I did some research on this in the W211 forum where the M272 has been around since 2006. Basically those flaps get coated as they age so it gets more and more difficult to move as the mileage goes up. Eventually something breaks, those rods or the pivots. But if you replace them with metal bits, then those flaps still get harder and harder to move until eventually they break off and they can end up in the engine causing additional damage. That's why it's probably fine for a short term fix if you're thinking of getting rid of the car soon, but if you plan to keep it for a while, you should just replace the manifold.
Ultimately I will sell the car to a friend, so I will fix it right.
Does anybody have any thoughts on what exactly the 0521 means? Does that mean that one of the arms that moves the flaps has broken off, but everything else is connected? I also don't understand why there is no CEL for a problem like this.
irepaircars video is fantastic. I've watched it a couple times and written everything down and feel confident to tackle this job.
Ultimately I will sell the car to a friend, so I will fix it right.
Does anybody have any thoughts on what exactly the 0521 means? Does that mean that one of the arms that moves the flaps has broken off, but everything else is connected? I also don't understand why there is no CEL for a problem like this.
Try reading some of the old threads about the intake manifold in the w211 forum. Basically it takes a while before the system sets a CEL, I think it's so many times before it gets triggered which is why some report poor performance even though there's no CEL.
I did some research on this in the W211 forum where the M272 has been around since 2006. Basically those flaps get coated as they age so it gets more and more difficult to move as the mileage goes up. Eventually something breaks, those rods or the pivots. But if you replace them with metal bits, then those flaps still get harder and harder to move until eventually they break off and they can end up in the engine causing additional damage. That's why it's probably fine for a short term fix if you're thinking of getting rid of the car soon, but if you plan to keep it for a while, you should just replace the manifold.
Good info and that's a good point as well. Yes I'm aware that especially if the pcv system is not working that well, a heavier concentration of oil can be drawn into the intake and accumulate /bake on those flaps. I would replace the intake regardless but was thinking that installing the metal pivot may add more miles to the new intake. However, maybe MB purposely designed the actuator rods and pivot as plastic to snap before the flaps jam and break, causing a lot more damage. But I think it's a poor design overall - intakes generally last the life of the car. Yet on these engines they are a commonly known issue, almost like a maintenance item, which I think is ridiculous. I know all mfg have certain issues their vehicles are known for, MB is no exception it seems.
Good info and that's a good point as well. Yes I'm aware that especially if the pcv system is not working that well, a heavier concentration of oil can be drawn into the intake and accumulate /bake on those flaps. I would replace the intake regardless but was thinking that installing the metal pivot may add more miles to the new intake. However, maybe MB purposely designed the actuator rods and pivot as plastic to snap before the flaps jam and break, causing a lot more damage. But I think it's a poor design overall - intakes generally last the life of the car. Yet on these engines they are a commonly known issue, almost like a maintenance item, which I think is ridiculous. I know all mfg have certain issues their vehicles are known for, MB is no exception it seems.
The flaps are for tuning the intake runners. You can just have one length but it won't be tuned for high speed or low speed operation. Basically it's an attempt to get every last drop of performance out of the car. I don't know what they did with the M276, it's a 60 degree V6 instead of the 90 degree V6 in the M272.
You could say the same thing about the motor mounts, they lasted 200k on a different car brand although technically I think they were shot, just never noticed as they were just basic rubber mounts instead of liquid filled ones that MB likes to put in.
UPDATE: Even though I never got a CEL, the ball socket on the pivot arm was definitely broken off and the flaps were stuck about halfway open. There was a very noticeable difference in both low end torque and high RPM power. These things really do make a difference! Plus the 0521 is gone and has not returned.
Kudos for fixing it right before your friend got the car. I'm curious, you mentioned the flaps were stuck, do you think the cause of the pivot break was from the stuck flaps, or where they stuck because the pivot broke/jammed?
Also, sorry if I missed it but how many miles on the car?
Kudos for fixing it right before your friend got the car. I'm curious, you mentioned the flaps were stuck, do you think the cause of the pivot break was from the stuck flaps, or where they stuck because the pivot broke/jammed?
Also, sorry if I missed it but how many miles on the car?
OK, by "stuck" I meant that they were in a fixed position because the pivot lever broke. You could actually move the flap arms back and forth by hand fairly easily, but there was a good bit of gunk in there. Almost 212K miles now, and it was the original intake date stamped from 2010.
My friend and I have been talking about this and he said he's ready to buy when I am ready to sell, but he hopes I hold on to it for a while because he wants to pay off his credit card first, so I will be driving it for a while. Now with the new engine mounts and intake, it's back to fantastic shape again and is a true joy to drive.
So $425 before the coupon just for labor? I assume you bought the Pierburg or Mercedes part for them to install right? Otherwise $275 including the part is a steal. Did you get the Pierburg or the Mercedes part? I know some dealers will install parts you bring to them as long as they're Mercedes.
So $425 before the coupon just for labor? I assume you bought the Pierburg or Mercedes part for them to install right? Otherwise $275 including the part is a steal. Did you get the Pierburg or the Mercedes part? I know some dealers will install parts you bring to them as long as they're Mercedes.
Yes $425 for labor before coupon with my Pierburg manifold. I am not sure what their policy is but I think they require OEM because in the past they've not always replaced what I brought them.
I am very happy with the outcome. So many things that could have gone wrong that could have (and almost did) make a big, expensive mess if I had done it myself. $275 was a steal as it was.
11-24-2018, 06:59 PM
