05 Passat - no boost

Honey-ec

Hey All

I've a 05 Passat , 1.9 tdi 105 brake BKC engine. Turbo hasn't been getting any boost since last Sunday. Have already cleaned the EGR valve and changed the boost pressure sensor, to no avail. Diagnostic isn't reporting any specific problems. Anyone had a similar experience or have any ideas/suggestions?

Car has about 160,000km on the clock.

doOh

any problems with starting car ?

Honey-ec

doOh wrote: »

any problems with starting car ?

Yeah, actually, but it long pre-dates the trouble with the boost. The car has one of those stupid electronic keys, sometimes when I insert it it makes a series of "clicking" noises and the glow plug light starts flashing. Usually have to make a few attempts at dead-locking and re-opening the car before it will start. It's very intermittent and tbh, I always just assumed it was an issue with the key-code rather than anything mechanical.

taintabird

Have you checked the inter cooler pipes ? I have seen them splitting you can usually hear a hiss when you rev the engine in this case

-Corkie-

What about the MAF. Have you hooked it up to a VAG COM.

taintabird

taintabird wrote: »

Have you checked the inter cooler pipes ? I have seen them splitting you can usually hear a hiss when you rev the engine in this case

Was going to suggest the intercooler
By 2005 Mondeo's intercooler spat off a hose or something, no boost but loads of hissing, no light on dash or anything.

taintabird

RoverJames wrote: »

Was going to suggest the intercooler
By 2005 Mondeo's intercooler spat off a hose or something, no boost but loads of hissing, no light on dash or anything.

it could quite possibly be the inter cooler have seen them damaged by stones on passats before, however I would check the pipes first as if there is oil in the intake system which there possibly is it rots the pipes and they split as i said seen it happen before

-Corkie-

taintabird wrote: »

it could quite possibly be the inter cooler have seen them damaged by stones on passats before, however I would check the pipes first as if there is oil in the intake system which there possibly is it rots the pipes and they split as i said seen it happen before

My Passat I had years ago the 03 model split the intercooler pipe. I was driving the ring out of it that day though when it happened.

AzureAuto

As above, check intercooler pipes for splits tears, specifically the one above the undershield of OSF wheel.
Has the timing belt been changed recently? Have experienced lack of power before where camshaft timing became retarded from loose sprocket bolts, effectively inlet valves open too late and the combustion mixture is too rich, causing poor performance. Whip off the plastic cover of timing belt and double check the timing marks line up and security of sprocket bolts.

Honey-ec

First thing we did was check all the hoses, nothing doing there.

AzureAuto wrote: »

Has the timing belt been changed recently? Have experienced lack of power before where camshaft timing became retarded from loose sprocket bolts, effectively inlet valves open too late and the combustion mixture is too rich, causing poor performance. Whip off the plastic cover of timing belt and double check the timing marks line up and security of sprocket bolts.

Yeah, timing belt was done in November. Will check this today.

OH (he's a mechanic) has just informed me that the diagnostic did say the issue was with the boost pressure sensor, but as I said, we've already changed this, but it hasn't fixed the issue. Beginning to think the garage sold us a dud 'un.

Moanin

Honey-ec wrote: »

Yeah, actually, but it long pre-dates the trouble with the boost. The car has one of those stupid electronic keys, sometimes when I insert it it makes a series of "clicking" noises and the glow plug light starts flashing. Usually have to make a few attempts at dead-locking and re-opening the car before it will start. It's very intermittent and tbh, I always just assumed it was an issue with the key-code rather than anything mechanical.

Had this problem in my 06 passat and had to get the steering column replaced at a cost of €500 (Main dealer specific job). It will get worse as time goes on and is a fairly common fault on the B6 Passat.

Honey-ec

So, the mystery continues on this:

Camshaft timing - not that

Turbo propeller vanes - not that

Air filter (apparently spurious ones can cause problems) - not that

I am seriously at the end of my tether with this car. It's been off the road more than it's been on it since November and costing me an absolute fortune just to sit in the garage. OH is at a total loss as to what could be the problem, only thing left to do now is bring it to a VAG main dealer. Better bring my Vaseline with me...

taintabird

Honey-ec wrote: »

So, the mystery continues on this:

Camshaft timing - not that

Turbo propeller vanes - not that

Air filter (apparently spurious ones can cause problems) - not that

I am seriously at the end of my tether with this car. It's been off the road more than it's been on it since November and costing me an absolute fortune just to sit in the garage. OH is at a total loss as to what could be the problem, only thing left to do now is bring it to a VAG main dealer. Better bring my Vaseline with me...

Do you get any boost at all or do initially get boost and then just drop off ? also I presume its an electric egr valve , when you cleaned it up did you notice if it was cloosing properly.

Honey-ec

taintabird wrote: »

Do you get any boost at all or do initially get boost and then just drop off ? also I presume its an electric egr valve , when you cleaned it up did you notice if it was cloosing properly.

No boost at all, she's as dead as a doornail.

Yeah, EGR valve is electric and is closing fine.

Bloody car has my heart broken. Changed the air flow meter as well, which was the absolute last gasp thing to try, but still no joy.

Off to a main dealer with it... sigh.

All of that does sound like a failing/ed MAF as somebody already suggested. It's a very common issue with TDi.

Unplug it and if the engine performs somewhat better without a MAF you have found the problem.

doOh

i would check fuel pump. Friend had same problem problem with starting at first then power dropping down

Row

Have you checked all the Vac pipes...??...if its loosing vacuum then your turbo will not boost.

crosshair1

Will this rev up fully or is it struggling?
Broken turbo shaft very common possibility, fault will be neg. Deviation boost pressure.

Honey-ec

Mystery solved! A friggin broken signal wire at the block connector behind the passenger-side headlamp. Ended up being a BMW mechanic who found it.

That's €90 on a new boost pressure sensor and air-flow meter I'll never see again, but I'm just glad the car is fixed.