Fosco
New member
Hey guys, long time lurker here, I'm 25 yo from France, been reading stuff & troubleshooting cars with help of this forum for awhile now.
I often get to work on TDI's (even tho I'm not a mechanic), it's about 10+ cars I often work on which are TDI powered (1Z, AHU, ALH, BKC and even 5cyl AXE engines).
So let's get started with my current subject :
My company owns a worn out VW Caddy TDI from the 2000's with ALH engine.
The car is falling appart from each and every side but lately, the VNT turbo started to get stuck and the ECU went to limp mode ... pretty annoying.
Since we don't give much f*** about it, we're not going to fix it, but instead of throwing it in a junkyard, we went for a temporary crappy fix : add a "non automotive" dump valve before the boost sensor.
So here it comes, we picked up a 7 to 11 bar (100-160 psi) safety valve, replaced the original spring with a softer one laying around and began setting it
0.9bar (stock pressure IIRC), boom it's done
Then comes the piping process, the plumber way :lol:
Fitted in the car
I went for a test run, it whistles so hard, it's so much fun, then goes the boom, hose went off, oil everywhere
We added some retaining springs for the hose not to fly (yet, mostly for fun, we know this wont last), and I went for another, longer testrun and well ...
Success(ish*), the ECU won't go in limp mode. The sensor still shows some pressure peaks, yet the valve blows everything away quite quickly (a bit too hard tho, pressure goes down very fast).
* : Hoses still tend to fly away
It's a lot of fun hearing the (way too) loud whistle over 3k RPM ... now we wait for the turbo to blow (judging by the oil in the hoses, it's coming soon) :lol:
Now here comes the questions about the next step :
We'd like to keep this Caddy beater. It runs once a week to get cardboard & other garbage to recycling center and definitely won't need a turbo for that. We don't want to replace the turbo on this turd, or spend too much time/money working on it ... but at the same time, it would be a bummer to send this thing to the junkyard since the engine / brakes / drivetrains are perfectly fine ...
I had thoughts about going the N/A route on this one, like bring the maf before the inlet manifold, let the turbo blow nowhere (well atleast in some kind of box to retain the oil lol) and boom done.
Problem we had before fixing it with the ghetto dump valve is that limp mode is way too low power, I know this ALH can achieve more power while N/A than in limp mode but I don't know the in and outs of doing this.
My biggest concern being the current turbo ... we don't want to remove it ... but at the same time, it will probably blow and spill oil everywhere ... and we don't want to damage the engine.
Maybe shunt oil feed / return and let it blow ? D)
Anyways thanks for reading all this crap,
Fosco
I often get to work on TDI's (even tho I'm not a mechanic), it's about 10+ cars I often work on which are TDI powered (1Z, AHU, ALH, BKC and even 5cyl AXE engines).
So let's get started with my current subject :
My company owns a worn out VW Caddy TDI from the 2000's with ALH engine.
The car is falling appart from each and every side but lately, the VNT turbo started to get stuck and the ECU went to limp mode ... pretty annoying.
Since we don't give much f*** about it, we're not going to fix it, but instead of throwing it in a junkyard, we went for a temporary crappy fix : add a "non automotive" dump valve before the boost sensor.
So here it comes, we picked up a 7 to 11 bar (100-160 psi) safety valve, replaced the original spring with a softer one laying around and began setting it
0.9bar (stock pressure IIRC), boom it's done
Then comes the piping process, the plumber way :lol:
Fitted in the car
I went for a test run, it whistles so hard, it's so much fun, then goes the boom, hose went off, oil everywhere
We added some retaining springs for the hose not to fly (yet, mostly for fun, we know this wont last), and I went for another, longer testrun and well ...
Success(ish*), the ECU won't go in limp mode. The sensor still shows some pressure peaks, yet the valve blows everything away quite quickly (a bit too hard tho, pressure goes down very fast).
* : Hoses still tend to fly away
It's a lot of fun hearing the (way too) loud whistle over 3k RPM ... now we wait for the turbo to blow (judging by the oil in the hoses, it's coming soon) :lol:
Now here comes the questions about the next step :
We'd like to keep this Caddy beater. It runs once a week to get cardboard & other garbage to recycling center and definitely won't need a turbo for that. We don't want to replace the turbo on this turd, or spend too much time/money working on it ... but at the same time, it would be a bummer to send this thing to the junkyard since the engine / brakes / drivetrains are perfectly fine ...
I had thoughts about going the N/A route on this one, like bring the maf before the inlet manifold, let the turbo blow nowhere (well atleast in some kind of box to retain the oil lol) and boom done.
Problem we had before fixing it with the ghetto dump valve is that limp mode is way too low power, I know this ALH can achieve more power while N/A than in limp mode but I don't know the in and outs of doing this.
My biggest concern being the current turbo ... we don't want to remove it ... but at the same time, it will probably blow and spill oil everywhere ... and we don't want to damage the engine.
Maybe shunt oil feed / return and let it blow ? D)
Anyways thanks for reading all this crap,
Fosco