B5.5 limp mode

Shortly after starting a road trip last week end my trusty old 2.0 Tdi went into limp mode. I pulled off the road, stopped and restarted the engine and carried on. All was well until I was pushing it a bit on a hill then it went into limp mode again.
Figuring since I had a total of 500 miles or so of travelling to do I was probably better off to turn around, return home to swap my ride (the 1.8 4 motion) and carry on, albeit at reduced fuel economy.
My diesel guru is willing to help me to an extent but I think he is wanting me to try and sort it out myself. Which isn't bad since I really should learn as much as I can about keeping my diesel operational.
Some of the things he suggested as possible causes I checked out, ie, fuel pump operational?, yes, fuel filter clogged?, I replaced it, vacuum lines?, I renewed them.
So now the vehicle is still going into limp mode and I am asking what should I check next?
I have some tools but I don't have a mighty vac, which I think might be a good investment considering I drive VW's.
The vehicle has 308K km and a stage 1.5 Malone tune.
I'll appreciate any help / suggestions you guys can provide. Thx

Also, I would also like to have a schematic of the vacuum lines for that engine if someone can point me in the right direction.

If it is going into limp mode then there should be codes. What do they say?

Of course, good question. I'm leaving shortly on another 500 mile road trip (with the 4 motion, unfortunately) so I won't be able to check the codes until early next week.

I'll have that looked at that early in the week and report back.

!st step check torbo hoses.

I vote hoses. My money is a hole in the 90 degree air hose back against the firewall on the passenger side.

owr084 said:

I vote hoses. My money is a hole in the 90 degree air hose back against the firewall on the passenger side.

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thank you. I can't pic that hose from memory but I'll check it out as soon as I return.
what's at either end of that particular hose?

hughc said:

...what's at either end of that particular hose?

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That is the short 90° hose between the plastic crossover pipe at the back of the engine and the EGR valve. Another common failure is the hose between the turbo outlet and the steel crossover pipe under the radiator. There is a wiring harness that rubs a hole in it.

TheGrove said:

If it is going into limp mode then there should be codes. What do they say?

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It turns out my friend saved the original the original readings on his laptop when he did readings two weeks ago.

16683 Back pressure regulator

p0299 Control range not reached

I had another closer look at hoses mentioned above and there is nothing obvious, although there's got to be something not right.

I started the vehicle this am, with the hood open, and there was a whistling sound that I had never heard before. That is probably telling me something.

I'm sure the problem is relatively simple and I just have to keep searching.

The whistling sound is either a boost leak or a turbo going bad. Hope that it is the former!

There are four hoses in the charge air path. First is between the turbo outlet and the crossover pipe, next is between the crossover pipe and the intercooler (under the driver's side headlamp), then between the intercooler outlet and the "L" shaped plastic pipe and finally the short 90° hose between the plastic pipe and the intake. There will likely be an oily film as a telltale at the leak, making it easier to find. You will need to drop the belly pan to do a good inspection. There's also the possibility of a crack in one of the intercooler's plastic end caps.

Good luck!

1854sailor said:

The whistling sound is either a boost leak or a turbo going bad. Hope that it is the former!

There are four hoses in the charge air path. First is between the turbo outlet and the crossover pipe, next is between the crossover pipe and the intercooler (under the driver's side headlamp), then between the intercooler outlet and the "L" shaped plastic pipe and finally the short 90° hose between the plastic pipe and the intake. There will likely be an oily film as a telltale at the leak, making it easier to find. You will need to drop the belly pan to do a good inspection. There's also the possibility of a crack in one of the intercooler's plastic end caps.

Good luck!

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Thank you 1854sailor, I'll crawl under the vehicle tonight (again) and have a much closer look.

It's got to be something simple, right?

Thank you guys, it was a split in the 90* hose between the plastic pipe and the intake. Now I need a part number so I can source a replacement part.

The last time I drove the vehicle it was still going into limp mode (of course) and before I got to my home there was a terrible rattling noise coming from under the vehicle. To me it sounded like it might be coming from the clutch area so I called my friend (that did the transmission install) to ask if he would have a look at it.

He had the wagon for a few days and he in fact was the person that located the turbo leak, but he drove the vehicle and the rattling noise never returned so whatever caused it will rear its ugly head again.
It sure sounded ugly, whatever it was.
Thanks again guys.

hughc said:

Thank you guys, it was a split in the 90* hose between the plastic pipe and the intake.

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Called it! Been there, done that!

hughc said:

thank you guys, it was a split in the 90* hose between the plastic pipe and the intake. Now i need a part number so i can source a replacement part...

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3b0145838a

Thank you owr0844 and 1854sailor.

I was able to perform a temporary repair by wrapping the hose with self vulcanizing electrical tape. I know it won't last but it sure is nice to feel that turbo boost again.

I'm having a terrible time finding that hose (3bo145838a) on the net so I will drop by the dealership today for a quote. That will likely be a shocker.

I'd like to hear from any member that has purchased that pipe at a reasonable price online.
Thx

Don't google "3bo145838a" use "3bo 145 838a" instead. The former only returns a few hits from Eastern Europe. The latter gets you hits in North America.

Or try one of the supporting vendors, IDParts, World Impex.

Thanks guys, I ended up purchasing from local dealer. That hose is expensive but I paid $135 C plus taxes. That would work out to $106 US at the current exchange rate which is less expensive than some of the prices I saw from US suppliers. (Plus no shipping or import duties to pay).

Of course I should mention that because of my good looks and charming personality (and seniors discount), the people at VW gave me a slight discount.
It'll be nice to feel that "kick in the ass acceleration" again.

Gotta luv it !!