EGR flexi-pipe: Exhaust Fumes In Cab, Hissing From Engine Bay.
- Thread starter Tourershine
- Start date
I'm glad my diagnostic skills came in handy on Saturday lol
Cracking photo. Must be a Samsung!
If you took that with the iPhone you might think it was your back wheel.
Ha ha, hook, m line and sinker.
I've got a 15o Kombi, and it makes a high pitched whistling (and hissing?) noise at around 2000RPM, especially when the engine is cold. It seems to be coming from somewhere directly in front of me as the driver. I've had the van for a couple of months, and thought I'd get used to it but it's really bugging me. It disappears as soon as I back off the gas (so is definitely engine related) and is much less noticeable (perhaps even disappears entirely) when the engine is at temperature.
Could this be a fault? Or (as a sound engineer) is this just something that annoys me, but doesn't bother anyone else? Anyone else noticed anything like it? I've driven other T6s, and haven't heard a noise like this on another one, so I'm pretty confident it's not 'normal'...
ANY thoughts / tips much appreciated!
Could this be a fault? Or (as a sound engineer) is this just something that annoys me, but doesn't bother anyone else? Anyone else noticed anything like it? I've driven other T6s, and haven't heard a noise like this on another one, so I'm pretty confident it's not 'normal'...
ANY thoughts / tips much appreciated!
@Tourershine sounds a bit like the problem you had with that split pipe?
If it was Turbo, you'd have some obvious drop in power.
Mine was down to a steel flexi-pipe on the back of the EGR valve. If it's the same as my issue, lift the bonnet and listen around the rear of the engine as someone blips the throttle. You should be able to hear a hissing sound quite obviously.
This is what you're looking for, and the black soot is where mine was leaking. The pipes are not expensive, about £17. I actually purchased 2 in case this was a common issue. It was quicker for me to fix the issue myself than wait for VW to fit me in.
It's not a difficult job, just a little awkward to reach one of the bolts.
Mine was down to a steel flexi-pipe on the back of the EGR valve. If it's the same as my issue, lift the bonnet and listen around the rear of the engine as someone blips the throttle. You should be able to hear a hissing sound quite obviously.
This is what you're looking for, and the black soot is where mine was leaking. The pipes are not expensive, about £17. I actually purchased 2 in case this was a common issue. It was quicker for me to fix the issue myself than wait for VW to fit me in.
It's not a difficult job, just a little awkward to reach one of the bolts.
Last edited:
Turbo boost noise, split pipe as above id say.
So...VW Sheffield took it out on a test run, and said they couldn’t hear it (!). They’ve asked me to leave it overnight and go out with a technician in the morning and show them what I’m hearing...is there anyone out there hearing anything that could be described as whistling on a 150 manual at around 2000rpm, that would describe it as “normal”?
My 150 manual never whistled.
The revs you are talking about is around where the turbo will come in and I think on most modern turbo diesels you will hear at least a bit of air noise from the turbo as you are basically scooping air and forcing it through pipes but not sure I would describe it as a whistle more a quiet whoosh of air being pushed around
Thanks @Pauly. This is really helpful. I can definitely hear the whoosh air noise of the turbo. But there is a definite whistle too, which to me suggests a split pipe or something like that, as per @Loz / @Tourershine / @Dellmassive suggestions (thanks guys!). Just hope they hear what I hear when I go on a run with the technician and don’t just says “I can’t hear anything”
The turbo spooling up and boost/wastegate sounds will be evident to a tuned ear, but a definite loud whistle/woosh is normally a split in the turbo, pressured charge side somewhere, (turbo, intercooler, EGR, interconnecting pipes, mating surface gaskets).
try as @Tourershine suggested above, bonnet open with a friend.
with a cold engine (so you dont burn yourself feeling around pipes) in park with handbrake on etc etc, and staying away from any rotating pulleys or belts (saftey first) get the friend to floor the throttle till the revs climb then release,
do this a few times while you listen for the sound in the engine bay, the turbo is at the back but the EGR and charge cooler are round the front,
if there is a leak you will hear it, you will feel it with your hand as warm/hot hot air leaking.
a bit random . . . . . but this guy had a boost pipe leak low dond on the front, you can hear the leak.
.
try as @Tourershine suggested above, bonnet open with a friend.
with a cold engine (so you dont burn yourself feeling around pipes) in park with handbrake on etc etc, and staying away from any rotating pulleys or belts (saftey first) get the friend to floor the throttle till the revs climb then release,
do this a few times while you listen for the sound in the engine bay, the turbo is at the back but the EGR and charge cooler are round the front,
if there is a leak you will hear it, you will feel it with your hand as warm/hot hot air leaking.
a bit random . . . . . but this guy had a boost pipe leak low dond on the front, you can hear the leak.
.
Last edited:
Turbo leaks are most noticeable with the engine under full load, . . . . ie 100% throttle up a hill,
in this case the ECM will demand 100% boost from the turbo to achieve the required output through the rev range (power band). so the sound from the leak will be louder.
But just coasting down a flat road in 4th gear at 2000rmp will only call for say 10% charge pressure so the turbo leak sound will be very low/unnoticeable.
in this case the ECM will demand 100% boost from the turbo to achieve the required output through the rev range (power band). so the sound from the leak will be louder.
But just coasting down a flat road in 4th gear at 2000rmp will only call for say 10% charge pressure so the turbo leak sound will be very low/unnoticeable.
you didnt say how old the van is?
on a new van - HPFP (diesel pump) are sometimes known to be noisy at first until they wear-in after a few thousand k`s?
on an older van - bearings and hydraulic tappets may be herd on first startup until the engine warms up ( oil pressure/thermal expansion etc)
though your description above seems to indicate a induction related issue . . . . . . . but then you say it goes away when the engine warms up, and only on light load . . . . . so.....
best thing is a trained mechanics ear in the van with you, with a cold engine, and a early test drive . . . . . keep us posted with that they say.
on a new van - HPFP (diesel pump) are sometimes known to be noisy at first until they wear-in after a few thousand k`s?
on an older van - bearings and hydraulic tappets may be herd on first startup until the engine warms up ( oil pressure/thermal expansion etc)
though your description above seems to indicate a induction related issue . . . . . . . but then you say it goes away when the engine warms up, and only on light load . . . . . so.....
best thing is a trained mechanics ear in the van with you, with a cold engine, and a early test drive . . . . . keep us posted with that they say.
