TDi Engine hose blows off at 3000rpm!

[DaveJB]

Hi, first post so please be kind!

51 plate Passat 1.9 TDi (130hp) 123k miles

driving home last night and the engine made a couple of weird sucking noises at about 2250 rpm (turbo just coming in) and then went dead - no power and no turbo noise, limped home (luckily only a couple of miles or so)

looked at it this morning and the large (2.5" diameter) s-shaped hose running from the top right of the engine (just in front of the coolant tank) was disconnected at the lower end (front right of the engine)

reconnected and started her up and all seemed ok but then when revved the engine the hose popped off again - seems to do this everytime at about 3000rpm and kicks out black smoke when it does it!

Im no mechanic so its off to the garage in the morning but i was interested to know exactly what the hose was so I can tell the garage and also check that it will be ok for me to drive it with the hose disconected (if it comes off again) any guess at the cause?

I'd appreciate any help or suggestions
cheers
Dave

[devonutopia]

It will be OK to drive it in limp mode - that's what it's their for, and can be "limp to garage" mode if need be.

Might need a modified clip. None of my pipework is standard, so I use marine grade clips, rated to 8 bar.

[Carps]

It will be OK to drive it in limp mode - that's what it's their for, and can be "limp to garage" mode if need be.

Might need a modified clip. None of my pipework is standard, so I use marine grade clips, rated to 8 bar.

Fitting a stronger clip might work, but surely the answer here is to find out what is causing the pipe to pop ! This is not a common problem, so there must be something going on to cause the problem, and strapping it up with a stronger clip may not be the right answer in this case...

[DaveJB]

ooh! non standard pipework!

any idea what this particular pipe is called? it does look like it should be clipped up properly rather than just push-to-fit, esp if its a pressurised bit of the engine

[neilp]

Hi

The black smoke is nothing to worry about, its just rich mixture due to the engine not getting enough air when the pipe has "blown off", there should be a circular spring ring that holds the pipe in the socket check this has not gone astray.

Best of luck

[guyg]

The pipe sounds like it's blown off from the intercooler. The pipe is terminated in an aluminium ring either end and is secured in place by a couple of 'ears' pressed out on each side of the ring. There is a circular metal clip that slides over a groove on the receiving body, retaining the 'ears' in place. These can wear down after the vibration over 1000's of miles and this allows the pipe to pop out under high boost conditions.

http://www.vagcat.com/epc/cat/vw/PA/...26/49/2840532/

You need to check each end of the pipe and see if the retaining ears are in tact. If not, you will have to change the whole pipe [~£40].

Cheers

Guy

[DaveJB]

Hi all,
cheers for the advice, it does seem that the pipe has worn where the clip sits and also the clip has been fatigued and part has now broken off!

So its a new pipe and clip and hopefully sorted - though the garage did suggest I may want to check that it isnt over-boosting - do you think this is worth doing?

so all in all quite a dull solution to the problem - but a whole lot cheaper than I feared when I was spreading clouds of smoke on saturday night!!!

[guyg]

I'm fairly sure the cause is a combination of vibration and crap design of the pipe, as the retaining edge is pressed from thin aluminium sheet.

If your turbo is overboosting, your ecu will go into limp mode, so you'll be in no doubt. I think this is unlikely though, mine was fine once I replaced the pipe.

Cheers,

Guy

[msbbarratt]

Hello All,

VW Bora 150 TDI, 02 plate

Do you know, exactly the same thing has happened to me just today. Instead of the normal turbo whine there was merely a sound of rushing air... The clip is still there, but one quarter of it is missing, presumed lost on the M25. This problem is not catching is it?

The clip broke just where one of the retaining lugs on the hose engages with it. A bit of the plastic pipe where the hose plugs in has broken but looking at it I don't think it's critical so I think I'll just get a new clip and give that a go. I've had a quick look and I can't see the missing part of the clip, so hopefully it's fallen out and not got caught in alternator belt on the way down....

Anyone got any bright ideas for reinforcing the clip? I'm considering wrapping a jubillee clip around it....

Cheers,

Matthew

[oxoboy]

same happened to my 2001 130 tdi @ 70k miles, small piece of plastic broke itself off the intercooler, meaning the turbo pipe's ring had no groove to sit in, result: new intercooler!!! Bah, UNBELIEVABLE how parts are built up, SO SO wasteful and annoying