tdi 130 "blowing" noise under load

[ekki thump]

New at this but would appreciate any help you can give....

I've got a B5 tdi 130 thats suddenly developed a blowing noise when under leavy acceleration. Noise comes in at about 1500 rpm and fades out about 2500ish. The heavier you work it the noisier it is. Stops instantly when I take my foot off. Sounds to be coming from behind dash but suspect that this is just noise/flow travelling from elsewhere.
I can't replicate whilst car is stationary as its only realy noticable under load, so its not been possible to locate accurately.
Under load, the noise is more noticable with passenger window down, so suspect that side of vehicle.
I have noticed a slight blowing when parked up and revved - it seems to be coming from the general area of the intercooler. Can't see/feel any cracks in pipe between turbo and intercooler but one of the clipped joints seems to leak a bit. There's certainly noticable pressure in there as I can feel the pressure in the pipework.
Opened clip/inspected/cleaned/reassembled but still leaking a bit. Can't see this joint being responsible for the level of blowing noise that I'm experiencing though.
just to calibrate the noise for you... sounds equivalent to a/c vent on full windscreen demist.
Where does the return pipework run? Can't see it.
Is it advisable to take off front of car or can I get easier access to inspect (eg remove wheel arch liner).
Can't say for certain but think mpg is down by about 10% (there again, this could just be me making it work harder so that I can listen)
Power seems down a bit but engine otherwise happy.
130k on the clock but good condition and regularly oil changed.
Don't think i am looking at a turbo itself problem.

Where to start?
Any help/advice greatfully received.
Cheers.

[red5]

Is the clipped joint that leaks under the o/s front ? If so its probably that pipe thats leaking (oil) blowing under load.Seen a few there,eventually pipe pops off.


red5

[TheMadhatter]

I'm interested in the outcome of this as well as mine makes "a noise" in this rev range under load.

Mine is not the same sound and quite hard to describe, it sounds more like something resonating or vibrating, almost like a belt starting to slip. The rest of the time I can hear no turbo/induction noises, and the engine runs smooth and strong, and once warmed up quietly.

[ekki thump]

Thanks red5,
I'll be investigating that joint further, yes its the joint at the lower end of the pipe emerging from below engine top cover and ending at rigid box below o/s headlight (somewhere behind intercooler).
What was the solution for those you've previously seen? Is it to replace the sealing ring or the whole pipe section?

cheers.

[ekki thump]

Madhatter,

Are you due a cambelt soon?
I've had noise from the pulleys when under load.
they needed replacing (at 120k cambelt change)

[TheMadhatter]

According to history cam belt and tensioner where changed at 63000 miles the car is now at 80000, surely its not time for another change ?

[ekki thump]

Update....
After spending a couple of days listening to the blowing, I'm now convinced that the pinned joint I mentioned is the culpret.
Does anybody know if the seals can be purchased, rather than replacing the entire section?
Anybody know what's the correct term for the seal and/or pipe section.

Madhatter,
The cambelt interval is every 60k, so its unlikely to be this

[red5]

Thanks red5,
I'll be investigating that joint further, yes its the joint at the lower end of the pipe emerging from below engine top cover and ending at rigid box below o/s headlight (somewhere behind intercooler).
What was the solution for those you've previously seen? Is it to replace the sealing ring or the whole pipe section?

cheers.

You can get the seals separately,but the pipe coming apart is usually the retaining ring worn which means replacing the whole pipe.


red5

browsing instead of working (again)

[ekki thump]

Update on progress...

1. Bought and fitted new seals (£5 per pair). Noise still present.

2. When rain eventually stopped for long enough to have a decent look, I noticed what looked like a loop of o-ring protruding from rear of intercooler.
I dropped the undertray and removed front bumper to get access to intercooler. Removed intercooler.
Problem now clearly visible.
The intercooler comprises two plastic ends sandwiching an alloy heat exchanger.
The joints between plastic and alloy are formed by crimping the alloy section over the plastic.
A two inch section of the alloy lip had cracked off and a loop of the seal had blown out through the joint under pressure.
Main ******* quote for new intercooler £250.......... Ahhh...I think I'll try and repair it first.!!!!
Carefully pushed seal back into place and sealed over with superglue. Then fitted spring steel clips over the joint. (commonly used to clip headlamp glass onto plastic housing (not VW)). These located positively and kept good tension on the joint.
Refitted and reassembled. Problem now solved.
A bit messy I know - but better than £250 out of pocket.
Repair looks like it should last. In fact its probably a better engineered solution than the original.
Now a couple of hundred miles done and no recurrance.
Hope this at least helps someone else with diagnosis, even if they adopt a less "Heath Robinson" solution.

[RichardStanton]

Has your blowing problem cured now since you did a DIY job on it. I seem to have the same systoms blowing from outside when I accerate and a blowing from behind the dash. The car is also pumping out lots of black smoke.