Lack of power

[pahanorlando]

Hello all. I am working on my brother's Jetta TDI. According to him, he was driving and heard some bang from engine area. Approximately after that, he says car is very slow on acceleration. I did some research and believe mostly issue happens because of MAF sensor or air leak somewhere and also possibly EGR.

So here is what I did, I drove it around, no issues on idle at all. Only when I accelerate, gas pedal to the floor, it accelerates slowly. I also observed a black smoke coming from exhaust, although not always the case. I then parked the car and revewed the engine, highest it goes to is approximately 4000 rpm. Check engine light is on, but for whatever reason, my OBD machine does not sync.

I removed air filter and discovered it to be dirty (appear to be black sand in air filter). I cleaned the filter. I also observed one opening in air box (under air filter) to be unplugged, the one that is closer to firewall. I plugged it back in and secured with zip tie. I also disconnected MAF sensor and there was no difference at all with engine performance.

Please let me know what else I can check. Thanks

 

[Tdijarhead]

A pop or bang and black smoke is usually a sign that a boost hose has popped loose. Check all the boost pipes from the egr on top to the turbo following the pipes down behind the passenger side headlight and front tire.

 

[pahanorlando]

Oh yeah, I also forgot to mention, I didn't drive the car before the issues were present, so I don't know if it is normal or not. But if vehicle is running at idle, and I walk in front of the car, there is sound like tires are leaking air at high rate (obviously tires are not leaking air), but there is that sound, so it does look like some kind of air leak.

If you can give me more info on tubes to check or image or video I would appreciate it as well. Thank you so much!

 

[turbodieseldyke]

1. Run the engine
2. Put a piece of hose in your ear
3. Move the hose around the pipes and engine until you find the leak

I had a leak like you describe, giving me low power, and that's exactly how i found it.

 

[Tdijarhead]

The plastic and rubber tubing/hoses are about an inch to an inch and a half in diameter. They start at the egr on the top of the engine toward the firewall, coming off the egr with a 90* elbow and passing over top of the serpentine belt area, continuing to the passenger side headlight area and dropping down behind the headlight and fastened to the top of the intercooler. The small radiator looking device behind the front wheel well. Then the hose comes off the bottom of the intercooler and going directly to the turbo.

One of those lines/joints has likely popped loose, if it’s not the joint coming off the egr it is more than likely behind the front passenger tire which you will have to remove to access the area properly.

 

[pahanorlando]

THANK YOU VERY MUCH! It was a massive air leak and was fairly easy to find it. Good thing I have a ramp. So here is a video of it.

Video

I have just two questions, second one being more important. First question, I noticed a lot of oil on the pipe, is it normal? Second, The radiator side has a metal pin or clip on the bottom of the outlet, but not on the top. How can I put the pipe back in securely? This VW system is not what I am accustomed too. Usually either zip tie or a metal clamp would work, but not here. Thank you

Actually it is just one piece, i'll try put it together and will be back with an update.

 

[sptsailing]

In answer to your questions. First, with my 2006 TDI Jetta, the bottom intercooler pipe has always seemed to collect oil, but the car has worked pretty well for the 110000 miles I've had it, so I would consider it normal. Second, in your video, I see the metal clip where it belongs. Take a look at this video to see how these connections both work and fail:

VW Golf TDI Turbo Boost Hose Replacement - How to fit Inlet pipe for Intercooler Poor running/smoke

 

[pahanorlando]

In answer to your questions. First, with my 2006 TDI Jetta, the bottom intercooler pipe has always seemed to collect oil, but the car has worked pretty well for the 110000 miles I've had it, so I would consider it normal. Second, in your video, I see the metal clip where it belongs. Take a look at this video to see how these connections both work and fail:

Year, turned out the other portion of the metal clip was further back in the outlet, but I was able to get it straight and secured everything back properly. I did test drive and it feels like it drives now extremely fast lol. I'll do how to video later, post it on youtube, and share a link here if anyone will be interested.

 

[Tdijarhead]

Checked out your video, that clip system works ok when new everything snaps into place and fits snugly and holds well. After a few hundred thousand miles things don’t snap like they did when new and are not as snug, leading to occasional pops and the resulting loss of power like you experienced.

A small bit of oil in that hose is normal, when you disconnected the hose at the bottom of the intercooler did oil run out? If so that’s probably a little to much oil in the hose and could be a sign of a failing turbo or whoever drives the car doesn’t get on it very much. Some recommend running the rpms up once a day or so, say on an entrance ramp to the freeway or a long hill. Doing so keeps the oil in the boost hoses to a minimum.

 

[turbodieseldyke]

when you disconnected the hose at the bottom of the intercooler did oil run out

Isn't that where the hose blew off?

 

[miningman]

Large quantity of black sand in the air filter??? Sounds like a serious case of lack of maintenance. Do you have a spare engine ready to drop in??

 

[pahanorlando]

Large quantity of black sand in the air filter??? Sounds like a serious case of lack of maintenance. Do you have a spare engine ready to drop in??

Not my car, just helped someone by fixing it

 

[pahanorlando]

Isn't that where the hose blew off?

Yeah, that's where it came off. I was told before that there was oil leak, but when i got it I did not see it, so probably when it popped off there was some leak. Today I just cleaned it all with brake parts cleaner and put it back.

 

[Mongler98]

1. Run the engine
2. Put a piece of hose in your ear
3. Move the hose around the pipes and engine until you find the leak

I had a leak like you describe, giving me low power, and that's exactly how i found it.

the only thing allowed in your ear "according to doctors" is your elbow..

 

[DivineChaos]

the only thing allowed in your ear "according to doctors" is your elbow..

I,. I thought it was your finger?

 

[turbodieseldyke]

I,. I thought it was your finger?

no, no, he said "your EAR".

 

[DivineChaos]

no, no, he said "your EAR".

My finger goes in my ear just fine. Qtips work better though.

 

[pahanorlando]

Driver just called and said the hose popped off again. He said it was not during acceleration, but during normal highway driving. He drove yesterday on it for about 200 miles and did not have any issues. I also did not observe any physical damage on the hose or outlet. Might have to relook into it more.

 

[Tdijarhead]

The nubs that those clips engage with wear down. That is probably where his problem is.

 

[pahanorlando]

Which means the hose (pipe) needs to be replaced?

 

[Tdijarhead]

Which means the hose (pipe) needs to be replaced?

Probably, unless you can fashion some kind of hack from a zip tie or something similar. I would take it apart and inspect it first, it may in fact be the clip itself that is worn. Idparts should have both the clips and hose available.

 

[turbodieseldyke]

unless you can fashion some kind of hack from a zip tie or something similar.

Maybe 2 or 3 screws.

 

[Tdijarhead]

Maybe 2 or 3 screws.

That jogged my memory, someone on this forum ground the nubs off put self tapping screws in their place and then ground the screw heads down to match the nubs. I don’t remember if it worked or not or if it held up long.

 

[pahanorlando]

What about using good glue all around it?)

 

[Tdijarhead]

What about using good glue all around it?)

I don’t think glue will hold 18-19 lbs of boost with occasional higher spikes.

 

[turbodieseldyke]

Heat cycles will ruin the glue pretty fast, too.

 

[Rx7145]

If you got it clean and oil free you could use red RTV. But would be a real pain getting it apart.

 

[Tdijarhead]

The top of that hose is secured with a 10mm nut to a stud on the wheel arch. When that bolt is in place it is very difficult to move that hose, if it is not in place that could explain why it keeps coming loose.

 

[pahanorlando]

I am still waiting on the car to be dropped off. Friend of mine, mechanic, told me that may be there is a pressure release valve somewhere and its clogged or closed, causing the pipe to come out. Is it possible? I'll probably try to rehook everything back in, but also use glue, to get connection stronger, but we'll see.

 

[pahanorlando]

Hello all, sorry its been awhile since it took forever for me to get the car and then didn't have time to work on it.

So finally today I looked and now the hose that came off is in different section. It also broke the plastic housing piece. I secured that part with metal screw and made sure there were no metal particles.

So 2 questions. What should I check? Seems like maybe something causing it to have way too much pressure since different section got disconnected. Second question, how bad is it to secure it with metal screws? Is there risk of metal particles flying somewhere?

Attached are two videos. First one is of hose location and second of metal screw in it.

Thanks

Video 1

Video 2