# rough idle and vacuum leak under intake manifold



## fetah (Sep 10, 2006)

BEA 225Q 2003
My wife calls me today complaining about the car not boosting properly and running super rough. 
I switched cars with her and immediately heard the vacuum leak under the manifold. 
Before even removing it I got my hand under there and essentially stopped the leak I decided that wasn't enough and proceeded with removing the intake manifold to get a good view of everything. Everything was going smoothly until I disconnected the fuel line and fuel sprayed all over the place so I put it back. Do I need to disconnect the fuel pump. Never really messed with this area of the car.
Does anybody have any idea whats causing this. I put everything back together and took the car for a drive...drove it super rough and hard, ran great until I parked it in the garage and it came back so I got my hands under again messed with the hoses and it went away again.







I have no clue which hose is torn or what exactly is the problem. I've replaced the PCV valve on my bros GTi but honestly unless I forgot the BEA 225 engine is quite a bit different. 
Any ideas on what the problem is or at least a hint at cutting the fuel.


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## Doooglasss (Aug 28, 2009)

*Re: rough idle and vacuum leak under intake manifold (fetah)*

If a vacuum leak is affecting your idle then the leak is somewhere directly off the intake manifold. It's hard to see stuff down there or catch a leak with your eyes. You need to examine each hose very closely and squeeze it and stuff to reveal cracks ect.
If you want to pull the intake manifold off the best thing for you to do is keep the fuel rail connected the entire time. What I do is just remove the two bolts that hold it to the intake manifold and disconnect the vacuum line that goes to the FPR. Now just pull the whole assembly out of the intake manifold and flip it up on top of the valve cover out of the way with no fuel mess!
I would replace almost every line down there once you're in there! Common leaks with the stock setup are the braided FPR line which should be immediately tossed for something silicone! Since it's wrapped in fabric you can't even see the cracks in the rubber. Also the brake booster three way splitter off the left side of the intake manifold. That thing apparently splits a lot in places that nobody can see it until they remove it. I've had the bottom port of the intake manifold leak too because I put a clamp on so tight it tore through the hose overtime! 
For future leaks/issues grab a http://www.modshack.info pressure tester - that will help you A LOT + a spray bottle of soapy water = awesome!


_Modified by DougLoBue at 10:26 PM 4-29-2010_


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## fetah (Sep 10, 2006)

*Re: rough idle and vacuum leak under intake manifold (DougLoBue)*

http://****************.com/smile/emthup.gif sweet thanks for the info. Its definitely in that area just under the manifold so as long as I can get a good look at it should be relatively easy to find the leak.
Had a fairly large oil leak after my attempt yesterday. Seems like it happened when I was trying to remove it. I disconnected several hoses but still a little confusing. I didn't see the leak until I put everything back together. Maybe cam seals?


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## Doooglasss (Aug 28, 2009)

*Re: rough idle and vacuum leak under intake manifold (fetah)*

Where was the oil coming from? Got a picture? 
The only oil line down there is the stainless steel braided line that goes from the oil filter housing to the turbo & that's the turbo's oil feed line. You wouldn't have taken that off without unbolting it.
It sounds like you have a leak coming from the PCV system which connects to the bottom of the intake manifold (center port). That would shoot oil out of it and make a big mess down there!


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## fetah (Sep 10, 2006)

*Re: rough idle and vacuum leak under intake manifold (DougLoBue)*


_Quote, originally posted by *DougLoBue* »_Where was the oil coming from? Got a picture? 
The only oil line down there is the stainless steel braided line that goes from the oil filter housing to the turbo & that's the turbo's oil feed line. You wouldn't have taken that off without unbolting it.
*It sounds like you have a leak coming from the PCV system which connects to the bottom of the intake manifold (center port). That would shoot oil out of it and make a big mess down there!* 

Pretty sure that's it. Didn't mess with the turbo oil return line. Whats causing the PCV system to leak oil. It was pretty clean oil, somewhat clear. WTF is going on. I didn't remove anything just put pressure on all the hoses to try and feel where the leak was and after I put everything back one of my sockets fell down and when I went to look for it I saw this puddle and a trail of oil from the oil filter area to the oil pan. It was obviously coming from the intake manifold area. Maybe thats my rough idle and boost leak problem. 



_Modified by fetah at 8:10 AM 4-30-2010_


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## Doooglasss (Aug 28, 2009)

*Re: rough idle and vacuum leak under intake manifold (fetah)*

Well... You know how the PCV system works right? It's job is to bleed off the pressure from the oil filter housing and feed the oil back into the valve cover. As the PCV gets older it doesn't do it's job right and sends more oil into it's pressure source - the intake manifold. Essentially if the PCV was leaking you would have a bunch of splattered black oil all around there - there would never be a pool!
If there is a pool of fresh oil either it was poured in and split everywhere or your oil filter is not on tight enough. Even if the filter wasn't on tight enough the oil wouldn't be fresh looking - it would be close to black!
The rough idle & boost leak is due to the vacuum leak you have down there. There is a guy (John) w an aviator Grey TT on here. I think he commented in the Aviator thread the other day... Back in the day on the old Audiworld.com he had a writeup for replacing all of the PCV stuff down there with part numbers and everything.


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## fetah (Sep 10, 2006)

*Re: rough idle and vacuum leak under intake manifold (DougLoBue)*

I mean it was dirty but not sludge like. It all relative what might be clear like might not be to someone else. 
I've been looking for diy on it for awhile and I've found some stuff but nothing super extensive. The other issue is the PCV valve (t valve) isn't available over ecs. They have one but it has the AMU only note attached to it. Hopefully the dealer has them for a good price. I've rounded up a few parts I'm going to buy so I'll replace everything as I remove it.


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## Doooglasss (Aug 28, 2009)

*Re: rough idle and vacuum leak under intake manifold (fetah)*

The PCV cost me 35 at the dealer...
Also this is John: http://forums.vwvortex.com/zer...19427
He has the writeup I was talking about here (Love google!): 
http://forums.audiworld.com/sh...46776


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## fetah (Sep 10, 2006)

*Re: rough idle and vacuum leak under intake manifold (DougLoBue)*

Awesome, thats exactly what I need. The parts list should help out quite a bit. I bought 100 bucks worth of hoses off ECS but not everything was on there. http://****************.com/smile/emthup.gif 
Thanks again. Can't wait to tear into it.


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## JohnLZ7W (Nov 23, 2003)

*Re: rough idle and vacuum leak under intake manifold (fetah)*

Hey good luck with the repair, I'm actually doing this (again) this weekend but using uprated valves from http://www.et-performance.com/turbo.html . 
I'm curious to see how your swap goes since you have a BEA engine, my writeup is for my AMU and I have not been able to find out how different the BEA system is.


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## fetah (Sep 10, 2006)

*Re: rough idle and vacuum leak under intake manifold (JohnLZ7W)*


_Quote, originally posted by *JohnLZ7W* »_Hey good luck with the repair, I'm actually doing this (again) this weekend but using uprated valves from http://www.et-performance.com/turbo.html . 
I'm curious to see how your swap goes since you have a BEA engine, my writeup is for my AMU and I have not been able to find out how different the BEA system is.

I'll try and get some pics when I do it. I'm not sure what exactly is torn or loose at this point but I've bought new a check valve, pcv valve and various hoses. I'm planning on removing it Sunday and at that point its just waiting for the parts. http://****************.com/smile/emthup.gif


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## fetah (Sep 10, 2006)

*Re: rough idle and vacuum leak under intake manifold (fetah)*









Pretty sure this was my problem it came out while I was removing all the hoses around the manifold. Everything else looks really good. No idea what this is but its a single part number. This would explain when I got my hands under and put pressure on everything I essentially squeezed it in. Hard to explain what I mean but it was exactly in the area I was messing with.


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## fetah (Sep 10, 2006)

*Re: rough idle and vacuum leak under intake manifold (fetah)*









Good way to get to the manifold, only way unless you want to mess with the fuel.
http://****************.com/smile/emthup.gif


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## fetah (Sep 10, 2006)

*Re: rough idle and vacuum leak under intake manifold (fetah)*









225 BEA engines are nothing like AMU
They don't resemble this whatsoever ^^^

Suction pump part number on mine is 
06a 133 753
Its the part that I need to replace.
It appears due to the common problems with worn out hoses they've replaced most of the rubber hoses with plastic ones. Its a nylon like plastic identical to part number ending in 789 in the picture above. Its extremely hard and not flexible whatsoever. 
The rough idle I was experiencing is most likely do to the suction pump or one of the three fittings going to the actual manifold. 2 large and one small that loops to the suction pump. 
Should get the parts on Monday and put it back together that afternoon or the next day. Thats if I don't forget how it all fits together











_Modified by fetah at 5:27 PM 5-1-2010_


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## JohnLZ7W (Nov 23, 2003)

*Re: rough idle and vacuum leak under intake manifold (fetah)*

Very interesting, from digging around under the intake manifold in my wife's car (BEA) it didn't seem to be similar to my AMU but I couldn't tell what was going on in there. If you've got more pics please post them.
I finished replacing the entire PCV/vac line setup today and have a much simpler solution in place, hopefully it's all correct and nothing explodes








I'll post pics later, feel a bit beat after standing over the engine for 6hrs today.


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## fetah (Sep 10, 2006)

*Re: rough idle and vacuum leak under intake manifold (JohnLZ7W)*

John,
I'll take more pics on Sunday. It was a pain to remove, not that it was difficult just hard to get to it. I had to break some of the fittings because there wasn't another way to remove the hoses. Maybe with a heat gun. My impatience didn't help.
Its not the same. Like I said most of those parts from the DIY AMU motor are very different on the BEA. Other than the rubber hose coming from the pressure regulator valve, the rest are hard plastic. 
I'm debating whether I should fully remove the intake manifold and powder coat it black










_Modified by fetah at 7:34 PM 5-1-2010_


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## JohnLZ7W (Nov 23, 2003)

*Re: rough idle and vacuum leak under intake manifold (fetah)*

Yeah that nylon hose is horrible stuff to work with. Rubber hoses bond to it and there's almost no way to get them off without cutting something. Pull on the nylon hose too much and it just folds over.
Powedercoated intake manifold sounds like a good idea


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## l88m22vette (Mar 2, 2006)

*Re: rough idle and vacuum leak under intake manifold (fetah)*

Wow, I hod forgotten how messy the OEM 225 bay is







Here is mine after cleaning (in stages), maybe its something to work towards (and yes my chargepipe needs a new finish) http://****************.com/smile/emthup.gif


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## fetah (Sep 10, 2006)

*Re: rough idle and vacuum leak under intake manifold (fetah)*

The part number on the suction pump is obsolete. I just bought the part from the dealership and it was 240. You have to buy the entire assembly with the suction pump. I'll post the part number later today. Won't come for another couple of days.


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