Loud hissing under boost and increased smoke

Hemi345

Veteran Member
Joined
Feb 28, 2005
Location
Oklahoma City, OK
TDI
1999 New Jetta Dark Blue 5-speed
I have a 99.5 manual Jetta and I think it has a boost leak somewhere.

Recently the turbo and timing belt were replaced by the dealer (no one competant I could find nearby). I did the intake cleaning within the last six monthes as well.

I took it the dealer for this problem and got an updated plastic lower pipe (the baffled one). It did not fix it and I'm not letting them throw more intake pipes at it.

I went over the car and checked all the clamp loaded connections on the pressurized side of the intake. It hisses like a badly leaking tire only when under load in gear, at idle it is not present. I've also noticed it seems to be smoking alot and I can leave a little cloud at will. I recently had it Upsoluted and EGR disabled via Vag-Com, also he set the injection timing which he said was too advanced to put the chip in. It's now set a tiny bit on the retarded side according to him. It was done mechanically not via Vag-Com. I can't find any obvious problems with any hoses and everything seems secure.

Does anyone ahve any advice on how I could troubleshoot this issue without spending lots of money on part after part? Also do you think it's possible that my intake manifold is leaking soemwhere from when I did the cleaning? It did not hiss right after I did that work but maybe after time something is loose?

I've searched boost leaks and IC piping already and have not found anything that can help me. Any advice would be greatly appreciated.
 

KI4HOK

Veteran Member
Joined
Nov 17, 2002
Location
Sarasota, FL
TDI
2003 Reflex silver Jetta wagon
The hissing is a boost leak. I would get a bunch of the screw type clamps and replace all of the spring clamps.
 

mwalters

Veteran Member
Joined
Nov 10, 2003
Location
SE Michigan - Have VCDS
TDI
Jetta TDI 2013 Tornado Red
I had the same exact symtoms on my previous car (99.5). It turned out to be the small S-shaped rubber hose, right before the EGR. It had a small crack in it that was really hard to see. Take it off and bend it in every direction to identify the crack. IIRC, that was one expesive hose - >$50!!
 

Hemi345

Veteran Member
Joined
Feb 28, 2005
Location
Oklahoma City, OK
TDI
1999 New Jetta Dark Blue 5-speed
I would love for it to be that easy to get to hose. I'll take it off and thoroughly inspect it tonight. Maybe it developed a crack from my intake cleaning episode and/or the timing belt change at the dealer since it is in the way for both.

My game plan was to start with that hose and replace all the rubber portions of the intake hose if I can't find anything else.

I disabled the egr with a vacuum plug during lunch in an attempt to isolate that metal pipe and the cooler from the intake tract. It had no effect on the hiss and threw a CEL even though it is chipped and adapted in Vag-Com. I put it back already.

After spending so much money and time on this thing in the six months I've owned it I am going nuts because I know there is a leak and I just can't find it. This car is testing my patience but for some reason I like it still. Maybe because it's my first German car and I'm in love with the way they build em compared to the many others I've owned.
 

reddevil

Member
Joined
Sep 14, 2004
Location
Pennsylvania
TDI
2003 Jetta Wagon Desert Sand
I had the exact same symtoms with my Jetta wagon TDI. Turned out to be an air leak at the rubber hose immediately upstream of the intercooler, accessable from under the right front wheelwell. I saw some oil dripping at the joint as the clue. All I did was loosen up the clamp, move the hose around a little, and put the clamp back on. I think these spring clamps are finicky... may be well to replace them with screw clamps as another has suggested.
 

TornadoRed

Top Post Dawg
Joined
Aug 3, 2003
Location
West Des Moines (formerly St Paul)
TDI
2003 Golf GLS 5-spd, indigo blue; 2003 Jetta TDI wagon, silver; 2003 Jetta TDI wagon, indigo blue; 2003 Golf GL 5-spd, red (retired); 2003 Jetta TDI wagon, Candy White (sold)
Maybe it developed a crack from my intake cleaning episode and/or the timing belt change at the dealer since it is in the way for both.

My game plan was to start with that hose and replace all the rubber portions of the intake hose if I can't find anything else....

After spending so much money and time on this thing in the six months I've owned it I am going nuts because I know there is a leak and I just can't find it.
Recently someone mentioned spraying soapy water on the hose(s) to find a leak. I think it worked in his case.
 

Wingnut

Top Post Dawg
Joined
Oct 10, 2002
Location
Toronto & Whitby
TDI
Silver 2003 Jetta Wagon
It definately sounds like a boost leak. As already mentioned, the rubber elbow just before the EGR is a good place to start. But since you did the intake cleaning, perhaps the leak is not in the hoses, but the gasket between the intake manifold & the head? Or even the rubber gasket between the EGR valve & the intake? What solvent did you use for the intake cleaning? If you didn't remove the rubber O-ring gasket and used a solvent that wasn't rubber friendly, you could have deteriorated the rubber O-ring. I have seen that happen before. The only way to pinpont the leak without taking everything apart is to pressurize the system with compressed air and listen for where the leak is coming from.
 

Hemi345

Veteran Member
Joined
Feb 28, 2005
Location
Oklahoma City, OK
TDI
1999 New Jetta Dark Blue 5-speed
Pressurizing the system seems like a great idea. I have considered my intake cleaning job as a potential culprit. But I am not interested in doing it again and replacing the seals again. I replaced the manifold gasket and egr cooler gaskets but I may have reused the o-ring.

Is there some inexpensive way to pressurize the system? I'm thinking disconnect the hose at the turbo and setup some sort of connection using an air compressor. Has anyone tried this?
 

moondawg

Veteran Member
Joined
Oct 25, 2003
Location
Columbus, IN
TDI
2001 Galactic Blue Jetta
Maybe it developed a crack from my intake cleaning episode and/or the timing belt change at the dealer since it is in the way for both.

My game plan was to start with that hose and replace all the rubber portions of the intake hose if I can't find anything else....

After spending so much money and time on this thing in the six months I've owned it I am going nuts because I know there is a leak and I just can't find it.
Recently someone mentioned spraying soapy water on the hose(s) to find a leak. I think it worked in his case.
WINDEX, baby!

1. Comes in its own bottle
2. smells nice.
3. discourages you from running around naked (prevents streaking)
4. I have used this many times to find leaks of all sorts... including boost leaks.

moondawg
 

Hemi345

Veteran Member
Joined
Feb 28, 2005
Location
Oklahoma City, OK
TDI
1999 New Jetta Dark Blue 5-speed
I like the soapy water / Windex idea but I'm confused. To generate the leak I have to drive the car. How is spraying it going to let me see the leak when I can't cause the leak at idle?
 

Hemi345

Veteran Member
Joined
Feb 28, 2005
Location
Oklahoma City, OK
TDI
1999 New Jetta Dark Blue 5-speed
I've formed a plan! I'm going to get a hand air pump from home depot or something for cheap. Then I'm going to get an air fitting and buy an oil filter with the same diameter as the turbo outlet. Drill the end of the filter and spring clamp the intake tube to the filter and use the hand pump to pressurize the intake until the leak starts. Anyone see a problem with this plan?
 

catmandoo

Veteran Member
Joined
May 9, 2005
Location
ia
TDI
2000 jetta gls tdi,91 2dr jetta gl n/a diesel
i just went thru this,i checked every hose at least 3 times and still did it,so figured i'd let it run it's course and sure enough popped the hood one day and the coolant overflow jug had oil spray on it,got to looking and sure enough there was a little hole in the upper j hose,and after taking it off and flexing it the crack on the inside was at least 2 inchs long.
 

Hemi345

Veteran Member
Joined
Feb 28, 2005
Location
Oklahoma City, OK
TDI
1999 New Jetta Dark Blue 5-speed
In preparing my air pump pressurizer I found the problem. I took off the rubber hose at the outlet of the turbo that connects the turbo to the lower plastic tube then on to the intercooler.

There was a huge crack in this hose that faced the engine block while installed! You could not see it from above or underneath. I actually felt it while messing with the hose.

What really, really pisses me off is the dealer replaced the turbo in July. They reused the hose then. Then I let them troubleshoot the hissing leak last month and they changed that lower plastic baffled tube to one with a newer design (diff part# then my early 99.5 came with). They reused the same hose again this time and did not find the crack! So my local dealer (the only VW one in the OKC area) replaced the parts connected to BOTH ends of this seven year old hose (stamped 4/98 manu date) without finding this problem. On my receipt for the plastic tube it says car still has noise. I am going to call them the minute they open and insist they provide me with this hose and 2 new spring clamps free of charge. I'm not going to consider what I'll do if they refuse.

Thanks to everyone for the advice and help!!
 

SootFoot

Veteran Member
Joined
Aug 18, 2005
Location
Midwest USA
TDI
Sold
Some (not all) dealer svc techs are parts changers. If they can't pull an error code out of the ECU that points directly to a particular system or sensor, they're often stumped and begin throwing parts at it. Not always their fault, though, since they are under time pressure to move a job out of the shop and get to the next one asap.

But there are also a lot of techs that have the skill and instead of the above they can properly diagnose. But finding them is often trial and error. It seems to be this way across brands, not specifically VW, but most brands in general.
 

CamSmith

New member
Joined
Oct 9, 2005
Location
Lancashire, UK
TDI
Golf GTTDi 1998, Black
I am having this exact same problem with my 98 Golf GTTDI, its frustrating the hell out of me and I am considering selling the car. I took it to my local VAG specialist, who had it for a full day and couldnt find anything wrong. They said the same, they can hear it when driving (the whole street can hear it) but not at idle. I have just fitted an allard powerpipe to remove the EGR, and it has a take off for a boost gauge. I have fitted a pipe with a tyre valve onto this takeoff, anyone know if I will be able to put some pressure into the system with the engine off? Or will it wastegate into the exhaust without demmand? Any help would be greatly appreciated, I am going to try all the things I have read on here tonight too.

Many thanks in advance.
 

rdkern

Top Post Dawg
Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
Often times the loud hissing is a split in the intercooler plastic hose/pipe. You have to take it off to find it, since it's somewhat hidden. At worst you'll clean out the intercooler and scrape up your arms a bit. At best you'll find a split that doesn't open except under pressure.
 
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