Eccentric Shaft Sensor Seal Replacement

rapodac · 11-05-2018, 02:53 PM

So I've been been driving around with what I thought was a VCG leak and have been procrastinating the gasket replacement. Yesterday my car ran real rough, especially at idle, and displayed SES on the cluster. I pulled codes and found 29CE (Cyl 2 misfire) and 2D06 (MAF sensor). Popped the hood and noticed oil around the fill cap. Cleaned the oil and tightened the cap. I proceeded to pull the engine cover and swapped cylinder 1 and 2 coils to further investigate the coil code. The problem went away and hasn't come back (yet). I assume it was vacuum related due to improper closure of the oil fill cap. I opened it the day prior and looked around just for good measure. Must not have closed it well.

While I had the engine cover off I noticed fresh oil around the eccentric shaft sensor seal and valvetronic motor gasket. I also inspected the VCG as best as I could and it looks to be okay. It seems like my leaks are coming from the eccentric shaft sensor seal and valvetronic motor gasket so I'm considering replacing these seals without pulling the valve cover. Maybe this oil leaked into the cylinder 2 spark plug well? I'll replace the plugs and tubes while in there as well.

My question is: How feasible is it to replace the eccentric shaft sensor seal without removing the VC? I've seen mixed opinions on whether it is possible but came across this TIS showing that it is.

https://www.newtis.info/tisv2/a/en/e...lid/1VnYDt5VKK

I'm just trying to gage how difficult it is and how likely I am to run into problems and end up having to pull the valve cover anyway.

Also, is there a sure way of telling whether the oil leak is coming from the seal or the ESS itself? I suppose I can replace the seal for now and then see if it recurs. But I would like to avoid that and just replace the ESS if I can find out for sure that it is the culprit.

Thanks in advance
Richard
2007 328xi E90

bluewater328 · 11-06-2018, 01:38 PM

Well, I think it's fairly possible. But keep in mind that the ESS itself is just plastic in the tabs/parts that sticks above the VCG, and you can break off a tab pretty easy. That seal should fit pretty much perfect, so you're going to spend a lot of time wiggling it up evenly. It's possible...it's just going to take some patience and slow/delicate maneuvering withe even pressure.

But I think the real concern is whether that ESS is going bad as well. Did you pop off the connection to see if you had oil in the sensor? If you have oil popping up around the seal, there's a chance that it has also been pulled up into the sensor connection area, where it means potential death for the sensor (could also be a contributing reason for your rough idle).

If the ESS is fouled, you are pulling that VCG anyway to get at it.

nuron · 11-06-2018, 08:26 PM

Following this thread. My ESS seal is leaking (none in the sensor itself) and I was putting it off since I dreaded the job of removing the valve cover again. Hoping someone can chime in where they replaced the gasket with the valve cover on.

rjahl · 11-07-2018, 07:19 AM

Quote:

Originally Posted by nuron

Following this thread. My ESS seal is leaking (none in the sensor itself) and I was putting it off since I dreaded the job of removing the valve cover again. Hoping someone can chime in where they replaced the gasket with the valve cover on.

My Indy changed the seal without pulling the cover. Took him a few minutes with the right tools. He had done the job many times in the past and he made it look easy.

I'm sure it would have taken me much longer and I probably would have Brocken the sensor in the process.

bluewater328 · 11-07-2018, 04:47 PM

I will say that I've seen a DIY where the guy preferred to put it back in AFTER he re-installed the VC. So as long as it's nubs aren't too thick, I don't see why not. Just be careful about the sensor itself and cover the ESS connection before you pull the seal.

nuron · 11-08-2018, 12:02 PM

bluewater, is there a potential for the hard plastic to break off and fall inside the valvecover?

bluewater328 · 11-09-2018, 04:43 PM

Quote:

Originally Posted by nuron

bluewater, is there a potential for the hard plastic to break off and fall inside the valvecover?

I think it's possible, but you can mitigate the problem. If you're lifting the seal straight up, even if you break the ESS plastic tabs, it would probably fall out or into the ESS plug. But the reality is, if you break it, you're taking off the cover either way so....

11-05-2018, 02:53 PM	#1
rapodac New Member 3 Rep 15 Posts Drives: 2013 BMW 335i E92 M Sport Join Date: Nov 2017 Location: NM iTrader: (0)	Eccentric Shaft Sensor Seal Replacement So I've been been driving around with what I thought was a VCG leak and have been procrastinating the gasket replacement. Yesterday my car ran real rough, especially at idle, and displayed SES on the cluster. I pulled codes and found 29CE (Cyl 2 misfire) and 2D06 (MAF sensor). Popped the hood and noticed oil around the fill cap. Cleaned the oil and tightened the cap. I proceeded to pull the engine cover and swapped cylinder 1 and 2 coils to further investigate the coil code. The problem went away and hasn't come back (yet). I assume it was vacuum related due to improper closure of the oil fill cap. I opened it the day prior and looked around just for good measure. Must not have closed it well. While I had the engine cover off I noticed fresh oil around the eccentric shaft sensor seal and valvetronic motor gasket. I also inspected the VCG as best as I could and it looks to be okay. It seems like my leaks are coming from the eccentric shaft sensor seal and valvetronic motor gasket so I'm considering replacing these seals without pulling the valve cover. Maybe this oil leaked into the cylinder 2 spark plug well? I'll replace the plugs and tubes while in there as well. My question is: How feasible is it to replace the eccentric shaft sensor seal without removing the VC? I've seen mixed opinions on whether it is possible but came across this TIS showing that it is. https://www.newtis.info/tisv2/a/en/e...lid/1VnYDt5VKK I'm just trying to gage how difficult it is and how likely I am to run into problems and end up having to pull the valve cover anyway. Also, is there a sure way of telling whether the oil leak is coming from the seal or the ESS itself? I suppose I can replace the seal for now and then see if it recurs. But I would like to avoid that and just replace the ESS if I can find out for sure that it is the culprit. Thanks in advance Richard 2007 328xi E90
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11-06-2018, 01:38 PM	#2
bluewater328 Colonel 626 Rep 2,099 Posts Drives: 2011 bluewater 328i LCI sedan Join Date: Aug 2010 Location: Hawaii iTrader: (0)	Well, I think it's fairly possible. But keep in mind that the ESS itself is just plastic in the tabs/parts that sticks above the VCG, and you can break off a tab pretty easy. That seal should fit pretty much perfect, so you're going to spend a lot of time wiggling it up evenly. It's possible...it's just going to take some patience and slow/delicate maneuvering withe even pressure. But I think the real concern is whether that ESS is going bad as well. Did you pop off the connection to see if you had oil in the sensor? If you have oil popping up around the seal, there's a chance that it has also been pulled up into the sensor connection area, where it means potential death for the sensor (could also be a contributing reason for your rough idle). If the ESS is fouled, you are pulling that VCG anyway to get at it.
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11-06-2018, 08:26 PM	#3
nuron Private First Class 80 Rep 199 Posts Drives: '07 328i Join Date: Jul 2016 Location: Washington iTrader: (0)	Following this thread. My ESS seal is leaking (none in the sensor itself) and I was putting it off since I dreaded the job of removing the valve cover again. Hoping someone can chime in where they replaced the gasket with the valve cover on.
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11-07-2018, 04:47 PM	#5
bluewater328 Colonel 626 Rep 2,099 Posts Drives: 2011 bluewater 328i LCI sedan Join Date: Aug 2010 Location: Hawaii iTrader: (0)	I will say that I've seen a DIY where the guy preferred to put it back in AFTER he re-installed the VC. So as long as it's nubs aren't too thick, I don't see why not. Just be careful about the sensor itself and cover the ESS connection before you pull the seal.
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11-08-2018, 12:02 PM	#6
nuron Private First Class 80 Rep 199 Posts Drives: '07 328i Join Date: Jul 2016 Location: Washington iTrader: (0)	bluewater, is there a potential for the hard plastic to break off and fall inside the valvecover?
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