2004 PD Hissing Sound on Acceleration

[VeloManEric]

Yesterday afternoon while driving to lunch, my car suddenly started making a hissing or whooshing noise on acceleration. It also seemed to have less power, but that may be because I am hesitant to run up the rpm's when the car is making an unusual noise. At first, I thought the clutch was slipping, but I can hear the noise while parked in neutral with the clutch pedal depressed, and it is a much quieter hiss when not under load. The noise is not present when I downshift under load. I drove to my mechanic's shop and he said it sounded like an exhaust leak or plugged catalytic converter. The car has 165,000 miles on it. I live in the SF Bay Area, so I'm not driving in extreme conditions on salty roads. Any ideas? Would an exhaust leak or plugged cat be a reasonable explanation? Could there be another explanation? If the cat is plugged, will it damage the engine to drive the car until I get it to the shop (in a couple of days)?

 

[puter]

Sounds to me like you have a boost leak.

Check the piping all the way from the turbo to the intake. I believe the PD has a history of one of the brackets coming loose (one connecting to the intake)? A search will help you here, I have an ALH so I don't really know the PD well.

 

[chudzikb]

It's that large hose that goes right into the intake manifold, that clip goes bad and it blows out. That would be my bet...

 

[OttTDI]

Yes the intake hose uses a quick lock mechanism that wears out over time. I just replaced my hose when it happened to me. It's kind of expensive though, so some people use a hose clamp and a piece of sheet metal to make a dog collar out of it.

When you look at the motor (even with the cover still on) you will see the hose going into the left hand side of the motor. If it's popping off, you should be able to pull it right away from the intake. If it's solid in there, check other spots for leaks.

 

[d-man]

mine popped off once too, it was the lower intercooler pipe behind the passenger wheel

 

[VeloManEric]

I got stuck last year when the tabs failed on that coupling and limped home from work with the help of duct tape. I replaced it then. This is a much quieter sound (no engine noise) and I have more power. The sound is not coming from the engine, but may be under the car and is more of a hiss.

 

[cfm56]

Egr exhaust cooler thingy majig accordion looking pipes tend to crack with time. Take off your lower plastic engine shield and look for soot/exhaust trails which indicate leak. Change pipes that leak and you should be good. Note the lower pipe is above the turbo and looks like a stretched s. The upper pipe can be viewed from the top of the engine.

 

[jwal278]

i just replaced the lower egr cooler pipe twice in the last month. I know the sound you are talking about. if it is the lower egr cooler pipe it is an 85 dollar part plus two gaskets that bring the total to a little over 100. be sure to check the allen bolts on the EGR cooler itself. if they are loose you will end up with another broken pipe. there is 4 bolts i believe they are 5 mm. tough to see but if you look on IDparts.com to look at the egr cooler you will get an idea of where the bolts should be and you can check that they are tight. good luck.

 

[halzg]

I just made a temp. repair on my lower EGR pipe that was making the same noise, that would be my bet. On a cold start, open the hood and look for smoke coming up from the back of the engine.

A plugged catalytic convertor will make the same sound, but won't leak exhaust (unless they are rusted through, in which case they aren't really plugged anymore) and the performance drop is dramatic. As you press the pedal further, it feels like you're dragging an anchor.

 

[Dimitri16V]

if it's an exhaust leak from the EGR cooler pipe lower or upper , PM me, I have a new lower one and a slighty used upper

 

[slpopp]

Yes the intake hose uses a quick lock mechanism that wears out over time. I just replaced my hose when it happened to me. It's kind of expensive though, so some people use a hose clamp and a piece of sheet metal to make a dog collar out of it.

When you look at the motor (even with the cover still on) you will see the hose going into the left hand side of the motor. If it's popping off, you should be able to pull it right away from the intake. If it's solid in there, check other spots for leaks.

Does someone manufacture (or be willing to start manufacturing) a collar to beef up the connection here? The tab on the top of my hose wore completely through. This is a retarded design in my opinion, stamping a boss into a thin collar. Luckily the bottom tab is still intact and the hose didn't pop off completely.

~$100 for a hose that is less than two feet long and will probably fail again is too much for something with such flimsy securing methods. Why don't they make a collar that has solid tabs?

You can see where the tab sheered/wore off on the top of the collar.

 

[GregNew2TDI]

http://www.kermatdi.com/servlet/-strse-378/Pumpe-Duse-Intake-Hose-fdsh-Manifold/Detail

I installed one on my PD. Be careful about tightening the bolts; I broke a head off and it was a PITA to get out. Instead of the hex bolts provided you might consider getting some allen wrench heads instead.

 

[slpopp]

http://www.kermatdi.com/servlet/-strse-378/Pumpe-Duse-Intake-Hose-fdsh-Manifold/Detail

I installed one on my PD. Be careful about tightening the bolts; I broke a head off and it was a PITA to get out. Instead of the hex bolts provided you might consider getting some allen wrench heads instead.

Thanks.

I started my own thread about this incase it didn't get any attention in this thread.

http://forums.tdiclub.com/showthread.php?t=308844

 

[JWS]

My lower EGR pipe was replaced @ 185K miles, again at 204K and it just broke again this AM @ 211K. ...always starts with the the same hissing on acceleration as mentioned in the title of this thread...and gets worse over time.

Just curious how hard the EGR cooler is to get to?

My daily commute is 70 miles each way and my mechanic is right at the 1/2 way point, so dropping off a car, getting a ride home, blah, blah, blah, is a real pain. If it is something that is doable in a couple of hours, I would much rather just wait while he makes the repair.