HUGE 3k-5k power loss/dip

[Cadeez]

Car currently has 104,700 miles, all maintenance is up to date, never had any mechanical issues. Supposedly the DME was updated right before I bought the car about exactly a year ago. Vanos has not been touched. No CEL's on or ever triggered. Car has always had excellent, clean, linear power all the way through the range, with maybe just a tiny bit of the standard 4k dip...but only barely. However all of a sudden, now it seems to have lost all power. I recently installed a GruppeM intake, so I've been doing some spirited driving in order to hear that sweet sound. Over the weekend I hit it hard in first, then when I shifted into 2nd and punched it...blah. Nothing. Foot to the floor and the car is accelerating, but its very flat and I've got no torque feel pulling me back in my seat. Usually 2nd gear just rips all the way through, now it's dead flat. 3rd gear is the same, there's just nothing there. It feels like I'm driving a stock Civic... There is a significant power loss right about 3k, in 2nd gear you feel the car wanna go, and then as soon as you get around 3k it just dies and flattens out, hardly even feels like you're accelerating. It picks up slightly once you get over 5k, but it's nothing like it used to be. 1st gear feels pretty normal, with only a slight hesitation, but it's such a low gear it's hard to tell. Basically I've just lost all power, bottom & top end. Anyone ever experienced anything like this?? I thought maybe it was an air leak in the intake tubes from putting the intake on, but I snugged them all up, so it's not that. I'm truly stumped, and saddened, the car is a shell of what it was a week ago. I'm afraid to take it to a shop because i know they'll tell me some shit like, "well it's hard to say, first I'd try this, if that's not it we'd move on this, etc... I don't have the time or money to have someone replace half my car "looking" for the issue. Please help!

[ZHPizza]

First of all, check for codes, duh.

Another easy check would be the DISA valve.

Beyond that I don't have any easy ideas. It has normal power under 3k? No difference?

[SaltyNC]

It could be the MAF sensor, but as Pizza says, checking codes would be the first step. I have the Gruppe on an S54 engine, and using the mesh insert to get laminar air flow and making sure the MAF sensor isn't fouled with excess oil is important. It might be worth a shot of MAF sensor cleaner to see if that is the problem. Hopefully the MAF sensor wasn't damaged.

Salty

[Newjack]

OP swap in your old stock intake and see if that changes anything. I can't speak from personal experience, but I have heard from a number of people that the Gruppe M intake, while it looks gorgeous and sounds amazing, actually loses some power. Just swap back to the stock box and see if the power comes back.

Vanos would be something to look into, but that's primarily low end torque, and you won't notice much of a difference unless your in 5th or 6th gear at highway speeds and try to accelerate from sub 2k rpm's.

It could be MAF, but I doubt it. I would try other things first before trying to clean the MAF. MAF's are pretty expensive and usually just fail outright unless you were running an oiled filter.

Taking a look at your DISA valve would be another good suggestion. Make sure it still holds vacuum (easy test once it's removed) and if it doesn't replace it with the G.A.S. kit which is highly recommended.

[SaltyNC]

MAF's are pretty expensive and usually just fail outright unless you were running an oiled filter.

The Gruppe for the S54 uses an oiled filter. I assume the one for the M54 does, too. Excess oil on a newly installed Gruppe was what I was thinking. It's a long shot, though, I agree.

[san]

The Gruppe for the S54 uses an oiled filter. I assume the one for the M54 does, too. Excess oil on a newly installed Gruppe was what I was thinking. It's a long shot, though, I agree.

Yup, M54 gruppe m filters are oiled...


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[Newjack]

Yup, M54 gruppe m filters are oiled...


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That might explain the power loss across the entire power band then. I know Dane ran an Afe oiled filter at one point and swapped off because he didn't want to damage his MAF. I can't remember if the oil actually did any damage or if he just switched to the dry filter preventatively.

[Oltorf]

My brother's 99 Z28 was having power loss issues at strange points, so we cleaned his MAF and it worked fine after that.

[SaltyNC]

Cadeez, if you or the person that sold you the intake oiled it recently, you might want to take it out and blow some air through it with a strong leaf blower placed right up against the cone or an air compressor held about a foot away. Over oiling of oiled filters is a very common problem.

[Cadeez]

First of all, check for codes, duh.

Another easy check would be the DISA valve.

Beyond that I don't have any easy ideas. It has normal power under 3k? No difference?

I don't have a way to check for codes myself, and I'm not going to pay a shop to do it. Plus I never had any CEL's come on. DISA was removed (along with the ICV) when I purchased the car a year ago. I checked it out, cleaned it and added a new o-ring. It's all good.

Right now the power is totally all over the place, sometimes it's flat and sometimes I'm getting some good pull.

OP swap in your old stock intake and see if that changes anything. I can't speak from personal experience, but I have heard from a number of people that the Gruppe M intake, while it looks gorgeous and sounds amazing, actually loses some power. Just swap back to the stock box and see if the power comes back.

Vanos would be something to look into, but that's primarily low end torque, and you won't notice much of a difference unless your in 5th or 6th gear at highway speeds and try to accelerate from sub 2k rpm's.

It could be MAF, but I doubt it. I would try other things first before trying to clean the MAF. MAF's are pretty expensive and usually just fail outright unless you were running an oiled filter.

Taking a look at your DISA valve would be another good suggestion. Make sure it still holds vacuum (easy test once it's removed) and if it doesn't replace it with the G.A.S. kit which is highly recommended.

I actually borrowed a GruppeM from BMWCurves and his worked flawlessly, put my BMW Perf back on, all good. I ran this new GruppeM for about a week and that's when this all started. I'm going to pull the MAF and give it a thorough cleaning and blow out the filter. I believe the guy I bought it from said he had just cleaned it. DISA is solid, see above comments

Cadeez, if you or the person that sold you the intake oiled it recently, you might want to take it out and blow some air through it with a strong leaf blower placed right up against the cone or an air compressor held about a foot away. Over oiling of oiled filters is a very common problem.

I'm going to pull the MAF and give it a thorough cleaning and blow out the filter. I believe the guy I bought it from said he had just cleaned it.

Thanks Everyone!!