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HKS BOV / vacuum line not working please help!

11K views 26 replies 6 participants last post by  JP88 
#1 ·
Hey everyone, so this is my first time posting, I recently just got my first VW that I've always wanted, if I'm posting in the wrong place I apologize! I'll start by saying I'm not terribly savvy with this stuff, so please be patient with me, I'm learning.

My Car:

2004 1.8T
XAS Cold air intake - from ECS Tuning

I purchased an HKS SSQV IV BOV, and after installing it, it wasn't doing anything. No 'pshhh' or any noise at all. After trying to find info someone suggested to check the vacuum line off the back to make sure there is suction. I checked and sure enough there is no suction coming from the line at all. I'm not exactly sure if the cold air intake might be responsible for any of the trouble, when I let off the gas after holding it down for a second or two, I get a noise out of the intake that sounds like a burst of air being blown out [is that normal?].

I have a check engine light, after having the codes check I was told it could be the o2 sensor [hot] or the MAF. So I bought a bottle of MAF cleaner, but honestly to my untrained eye it APPEARS to be pretty clean. So I will be putting that back in tomorrow and seeing if there is any suction. After disconnecting the intake from the MAF, I put my hand up to the MAF and felt a little bit of suction, that got a little stronger the longer I held my hand over it.

I hope I have given enough information. If this sound familiar to anyone or if you know what the problem is I would be SO grateful for your input.

Thank you so much!
 
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#5 ·
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The directions said to connect it to the hose that was coming out the top of the stock diverter. I'm beginning to think I should probably trim the length of the hose coming off the back of the BOV, there is plenty of excess. But even still there is no suction coming from the hose its connected to either. As you can see they are connected by that clear filter, which definite allows airflow. The suction is not coming from the hose those are both connected to, and THAT hose is connected to what looks like a metal tube/hose a little further down.

Hope I didn't make that too confusing.
 

Attachments

#7 ·
Romove filter and see if u get vacuum

If not then remove hose at the metal line and check for vacuum there

Its connected at the right place so it has to be that line

Tapatalk This
 
#9 ·
Romove filter and see if u get vacuum

If not then remove hose at the metal line and check for vacuum there

Its connected at the right place so it has to be that line

Tapatalk This
I took everything off up to that original thicker hose, but haven't taken that one off yet thats connected to the metal one because of that stupid one time use clamp that I need to cut off, and I haven't picked up another one to put on there once I clip the original. But I will try to get that today and let you know. Thank you.

If there is still no suction from the metal tube, do you have any ideas what it could be?
 
#10 ·
Also just today I noticed that when im accelerating in 1st or 2nd I lost just a little bit of power for a half a second or so, and it sounded like the cold air intake was making a slightly different noise during the duration of the loss of power. And again like I said I'm new at this stuff, but my cold air intake sounds like it blows off a bunch of air every time I let off the gas. Is that what its supposed to be doing? It honestly almost sounds like a crappy bov or something, but not like a wooosh or pshhh sound. Really just like a large quick dump of air. It's done that since I bought the car and it came with the cold air intake installed. Did the guy who had it before maybe mess that up? Could the problems be linked?
 
#12 ·
I took everything off up to that original thicker hose, but haven't taken that one off yet thats connected to the metal one because of that stupid one time use clamp that I need to cut off, and I haven't picked up another one to put on there once I clip the original. But I will try to get that today and let you know. Thank you.

If there is still no suction from the metal tube, do you have any ideas what it could be?
Well that hose comes from the wastegate. Are you having any boost issues with the car? If you are and no vacuum, you could have a stuck wastegate.
 
#13 ·
I'm not too sure to be honest. This is my first turbo car, and I haven't had any boost test or anything done to the car. I haven't been able to tell for sure but sometimes I feel like I don't hear the turbo spinning up as much as others. Is there a cheap or easy fix if it is the stuck wastegate if thats the problem?

What might some common boost issues be so I can either test for it or keep an eye out for it?

Thank you
 
#16 ·
I was thinking the same thing, but since there is no suction from the vacuum line either way, the DV that was on there before wasn't serving its purpose either. So either way I need to get this fixed asap.
Could be a massive boost leak
 
#18 ·
ok I can now confirm that there is no suction from the waste gate. [thats whats connected to the thicker tube that was coming off the top of the stock DV right?] What can I do to try and fix it if its stuck closed? Is that most likely the problem?

Thank you all again so much for your help.
 
#21 ·
#23 ·
I have the same problem I have CEL and the code came up as lean air fuel. It said it could possible be my MAF which I know it's not or a large vacuum leak. If I were to spray starter fluid instead of radiator fluid would that work or checking vacuum leaks?
How do you know your maf isn't the problem?
 
#24 ·
Ummm could it be that when he lets off and the throttle blade closes that the charged air is trying to just find the path of least resistance and running back out the turbo. I mean if the BOV/DV is not working then it is feasible. The whole purpose of the BOV/DV is to prevent that from happening. And with the noise that the OP is describing that leads me to think of this. Oh just FYI OP if this is what is happening then it will over time (NOT CAN BUT WILL) damage your turbo.

I agree with Volcano. Stop driving the car untill you have the problem fixed
 
#25 ·
I have had this problem already. when i got my gti it had an old hks bov the one your tighten yourself with a wrench. the P O had everything F***** it was bad, the filter kept falling off the bov not working right not making any noise. it sounded like it the air was coming from the plugged hole. the hose from the turbo inlet to the air hose. my codes said it was running to lean and something about my pre cat o2 sensor and a bad MAF. i let it run for about 2 min with the MAF unplugged then, i took everything off the bov the air filter and cleaned the MAF reinstalled everything. got new clamps a new i think it was 1" heater hose i used for the bov. never had the problem since.
 
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