Weird VAG tdi problem.........and solution

[Rocket88]

1.9 tdi pd engine.....started and ran perfectly, no lights on the dash, but was as slow as feck, with no turbo boost effect whatsoever. EGR nice and clean, N75 valve worked fine, turbo actuating rods doing they're thing, and no leaky hoses.....so why wouldn't it boost?

After exhausting [ho ho]all possibilities, we decided that there must be a blockage somewhere, so removed the exhaust, and had a look. The cat was completely blocked, in fact it's a miracle it ran at all. Rodded it out, and it now goes like a stabbed rat.

I've never seen this on a VAG tdi before, and have no idea where all of this clag has come from. The previous owner had fitted two turbos, 3 N75 valves, a set of hoses, and had the EGR valve cleaned out, but gave up in despair.

[Micrashed]

Catalysts on Diesels are the work of the Devil.

[Junkman]

Catalysts on Diesels are still angels compared with particulate filters, which, like the Brussels Bureaucrats who mandated them, are pure evil.

[Rocket88]

Catalysts on Diesels are still angels compared with particulate filters, which, like the Brussels Bureaucrats who mandated them, are pure evil.

 

 

Any new cars with a DPF are not sold over here, due to our 40 mph speed limit.

[Ian Nexus]

probably remains of the EGR valve cooler dropped into the exhaust header during the EGR valve cleaning

[Rocket88]

There's certainly evidence of the EGR being rodded out, so you could well be right

[dieselnutjob]

at about 120,000 miles my Passat TDi estate economy started to drop from about 46mpg to more like 40mpg.

When I chopped out the cat and replaced with straight pipe it went straight back up to 47mpg

[michael1703]

google doesnt help with vag's

 

https://www.google.co.uk/search?q=weird ... =firefox-a

[AeroNautiCal]

google doesnt help with vag's

 

https://www.google.co.uk/search?q=weird ... =firefox-a

 

Is that with 'Safe Search' on or off?

[Guest]

You see, the first problem was that you bought a VAG TDi.

 

The second problem occurred when you tried to fix it. Until you sell it on for a stupidly inflated price completely at odds with what the car is and what it represents, you'll continue to have difficulties.

[Rocket88]

You see, the first problem was that you bought a VAG TDi.

 

The second problem occurred when you tried to fix it. Until you sell it on for a stupidly inflated price completely at odds with what the car is and what it represents, you'll continue to have difficulties.

 

We DID fix it.........and I've had experience of a shed load of ye olde 1.9 tdi VAG lump. and they've all been fine [especially ones with a Skoda badge on]

Have told previous owner how the problem was resolved, and he's a little miffed with the last garage he used who fitted a new turbo, new N75 valve, and sundry other bits, charged him a fortune, and then handed him back a car that was still not boosting.

[Rocket88]

You see, the first problem was that you bought a VAG TDi.

 

The second problem occurred when you tried to fix it. Until you sell it on for a stupidly inflated price completely at odds with what the car is and what it represents, you'll continue to have difficulties.

 

We DID fix it.........and I've had experience of a shed load of ye olde 1.9 tdi VAG lump. and they've all been fine [especially ones with a Skoda badge on] I've yet to find any diesel, with possible exception of Frog XUD, that are as reliable.

Have told previous owner how the problem was resolved, and he's a little miffed with the last garage he used who fitted a new turbo, new N75 valve, and sundry other bits, charged him a fortune, and then handed him back a car that was still not boosting, and told him "it must be an ECU fault".

[warren t claim]

You see, the first problem was that you bought a VAG TDi.

 

The second problem occurred when you tried to fix it. Until you sell it on for a stupidly inflated price completely at odds with what the car is and what it represents, you'll continue to have difficulties.

 

You'll have to excuse Jon, when he was at North Cestrian Grammar his mum bought him Mango training shoes instead of the Pineapple brand that all the other boys were wearing. He was bullied terribly over it and it's left him with a complex over Volkswagen Group products. Even today he refuses to play golf, listen to a song by the Beatles and when a Warburtons wagon blocks him in he refers to it as "a DAF 7.5 tonne rigid LGV with a body specifically designed for the carriage of bakery products".

[Guest]

Had exactly the OP's problem on my bargain 03 C220CDI Merc wagon.

Kept having funny turns, the car then me!

Eventually wouldn't even reverse up a dropped kerb. Limp mode tastic. Fault codes were no help at all, back to plan old experience and hard work then!

 

Long and short of it was the primary cat sits straight behind the turbo, the cat itself is rolled in a thermal blanket then placed in the cylinder/silencer.

The thermal blanket fluff had disintergrated as the cat moved to and fro under boost and had sent the fluff to block the secondary cat, totally!

Smashed both cats out, obvious increase in power and at least 7 mpg! WIN!!

 

This was of course discovered after checking EGR, turbo, whole intercooler system, inlet fanimold etc. Bums.

 

I'd even be so bold as to suggest the well documented blowing of injector seals on this engine is caused by excess back pressure due to a blocked exhaust. The engine certainly was a lot quieter just don't have the car parked on grass the first time you started it after 'surgery', the soot that is emitted kills it dead and leaves a black mark. Oooopsy!

[Guest]

You see, the first problem was that you bought a VAG TDi.

 

The second problem occurred when you tried to fix it. Until you sell it on for a stupidly inflated price completely at odds with what the car is and what it represents, you'll continue to have difficulties.

 

You'll have to excuse Jon, when he was at North Cestrian Grammar his mum bought him Mango training shoes instead of the Pineapple brand that all the other boys were wearing. He was bullied terribly over it and it's left him with a complex over Volkswagen Group products. Even today he refuses to play golf, listen to a song by the Beatles and when a Warburtons wagon blocks him in he refers to it as "a DAF 7.5 tonne rigid LGV with a body specifically designed for the carriage of bakery products".

 

Like I said, you're better off selling it for the daft sums of money they fetch rather than hanging on to it and watching the fucker go wrong around you, especially if you didn't give much for it in the first place, eeeerm, Colc and WTC. I'd quite happily get one cheap to punt on for a profit, if I could find one cheap (which I can't) and had enough Isopon to fill the pock marked bonnet with (I don't have enough Isopon). I haven't got any Xenon look 800000000000000000K bulbs or knock off A8 17" rimz knocking about my shed, either.

 

And at the hire car agency I worked at, folks were bringing back TDi Passats and Golfs in droves because their high pressure diesel pumps were packing up. Forgive me for having an opinion at odds with the hushed tones VAG products are discussed in, I'm merely speaking from experience. All I know is that they're average as fuck and make a load of money second hand, for some reason. It ain't cos they're anything special, let's be honest.

 

PS: Let me know if you beat any Imprezas cross country, what with TDi Golfs being the fastest machines of eVar (at least according to my mates in Sale).

[Rocket88]

Cost the princely sum of £450, no rust, well specced, ex taxi, 180k. We've got an estate version, with an auto box that's done 250k, which over here is verging on galactic mileage [on a 45 sq mile island] Original box is just starting to show symptoms of being a bit unhappy.

We've bought a fair few ex taxis, and they've all been either fine, or easily fixable.On any make, experience is king. That, and being able to correctly analyse fault codes!