Turbo Woes Didn't Need to Change Turbo Check! Check!

Hi guys!
I recently bought a 2006 Jetta TDI with the 1.9 BRM engine and the Borg Warner Turbo. I bought it as a basket case because these conditions were not letting the car go fast at all, or even just go.

Emissions Workshop Light was on
Codes were P0299, P0671, P0101
Looked at glow plugs and one was broken, physically broken, replaced that and engine still ran like crap
Smokey and acrid smell out of exhaust

I did my research and was almost convinced that the turbo smart actuator valve was shot, since a lot of people say this goes first and gives many if not all of the conditions above.

I am inherently lazy, before I pulled the turbo completely off, which turned out to be difficult I checked to see if the valve held vacuum. It holds vacuum fine!!!!! Onto other things....

I found that the hose that attaches to the vacuum solenoid that leads to the valve had been previously broken off from the solenoid and the nipple had been jerry rigged back together. Fixed with epoxy and tested for leaks.

Continued to look for other problems and found that front radiator support had been broken. Front bumper was loose and radiator was being pulled forward, so was the intercooler, making the turbo piping stretch and not seal correctly. Front radiator support is being replaced so pipes are not stretched and caused to leak.

All of these conditions come from a car repaired badly and someone not knowing how to do the work correctly.

I am now hoping that after all these things are corrected, the car will hold boost and run properly. I will update you guys when I am done!

After reattaching all hoses, connecting all sensors and mounting frame and bumper, car still runs like crap. Here are the codes I am getting with the normal scanner:
P0299, P2425, and P0674

And now, I have to deal with the N75 valve, which I looked into upgraded ones or updated models but I have to stick with the current plug, which is flat on one end and round of the other because I don't want to start splicing and changing things around. So I bought an N75 which looks different but has the same kind of plug. Lots of posts on the N75 so I won't go there, hahaha.

I am also getting 005269 - Switch-Over Valve for EGR Cooler (N345)
P1495 - 000 - Open or Short to Ground
This one I don't like because I have very limited access to the rear of the engine, firewall area, etc... So, after careful review of my options I have decided to go the zip-tie route and see if that fixes or helps anything.

I am convinced that these faults are results of soot and carbon buildup due to a poor running engine due to the N75 valve and hopefully nothing else, ha. I will keep you guys updated!

Just a quick update!
Yesterday I spent a good chunk of my day figuring out why the turbo was not kicking in correctly, and finding lots of codes that are surely from the turbo not working correctly.

I FOUND WHERE MOST OF MY PROBLEMS CAME FROM!!!!!

Take a guess....

Looking at the N75 Valve, I found that many of the connections that had HARD hoses were cracked or broken or cracking or all of the above!!!! I patched up as best as I could and now have plenty of usable vacuum, which of course regulates the VNT actuator. So now turbo has more action than before.

Have been working with tuner to disable some of the emissions to get to the root cause of slow acceleration and LOTS of smoke. It seems things are clogged up from miles and miles of vacuum leaks and faulty turbo boost and bad turbo operation.

Turbo is now kicking in more often but will now attempt to do some physical cleaning ie. removing O2 sensors and cleaning them, seeing about decarbonizing exhaust.

Car is still not there yet but getting there!

Stay tuned!!!!

Today I decided to get back to the intake shennanigans....
Seems like all my woes come from running this TDI for a long time with underboost and vacuum leaks and such.

After tuning it, it was smoking and running terrible. Figured out that the EGR valve was stuck open and was making the engine run terrible. Decided to get to the root of the problem and after removing the throttle body and removing the EGR, it all was covered in sticky black junk. To remove the EGR is a very simple process except for the bolt that is near the valve cover, that one is a HUGE pain to remove, I removed it using a small torx bit set, torx tool similar to swiss army knife thing and two extensions. Expect to lose your tools and use a magnet to get things out. Once that bolt was off it just comes right off.

With the tune, we're removing the EGR so I decided to remove the EGR completely. It is held on with three T30 screws. I then blocked off the holes for the EGR cooler and for the actual EGR valve with epoxy and reassembled. Car run much better!!!!

Acceleration is much improved but at highway speeds, it seems like the engine revs but the transmission doesn't want to engage. You have to slowly feed the throttle to gain speed or else it downshifts and doesn't go any faster, just revs higher.

At this point I am not sure what comes next or why the car doesn't want to engage the transmission fully. It is like it wants to but it doesn't. Maybe it is a tuning issue, maybe the transmission likes to slip?

I'll keep you guys posted!

just so you will know....

Last year I spent a lot of time and energy solving engine issues that are related to your issues.

First, I had a bad cam, which I replaced. While doing so, I observed that my INTAKE ports and intake manifold were horribly gunked up with black crap. I created a pvc fitting and walnut shell blasted all the gunk out of the intake ports, then used a variety of methods to remove all the gunk out of the intake manifold and other intake components.

There were several vacuum issues contributing to the problems, including a leaking vacuum reservoir (which is integral in the cylinder head cover) and a cracked plastic vacuum hose to the brake booster.

Clean and reinstall your EGR valve, as your engine expects its contribution to its performance. Research all of the EGR issues in this forum paying particular attention to the opinions of Franko6, who also highly recommends running the engine at 2K RPM or more for minimizing problems.

I have a manual transmission, so I have no experience with or suggestions for how to deal with any automatic transmissions.

Yup, EGR valve is a prime suspect for weird power behavior, and you can remove it, leave it connected lying in plain view in the engine compartment, and run then output tests using VCDS to quickly make sure it's opening and closing properly, every single time.

They like to wear a bit and clog a bit and stick open a tad when they try to close, causing all kinds of drivability issues that are tricky to find.

Idparts has new vacuum hose for $5-6 a meter. You’ll probably need about 3 meters or so I’m not sure exactly on the BRM.

https://www.idparts.com/advanced_search_result.php?keywords=Vacuum+hose

Thanks a lot for the input!!!!!!!!!

I decided to remove the EGR completely, except have been too lazy to completely remove the EGR cooler because there is one bolt behind the downpipe that can only be removed by disconnecting the downpipe and moving it out of the way... You can't believe how badly it used to smoke when the EGR was all clogged and malfunctioning and such. Bye bye EGR valve and hello race pipe which also gets rid of the ASV.

Will tune both out with custom tune.

I have an update, sort of....

With the help of my friendly Russian?! tuner and logging, we discovered first that there was underboost and then overboost. I decided to do the zip tie fix and that got rid of the underboost condition and overboost is now rare but still does it and puts the car in limp home mode. The zip tie was a little tricky because it is in a high heat environment and the zip tie gets distorted somewhat from the heat and needs constant adjustment, and/or looking after. Couldn't find affordable user-friendly metal zip ties....

I decided to clean out the exhaust side of the turbo and did so by injecting oven cleaner into the EGR cooler port on the exhaust manifold where I now have a block off plate. I've done this twice and it seems that the car is more responsive. I don't recommend you do this unless you are EXTREMELY careful and brave of heart. Oven cleaner is extremely toxic and can burn you and your eyes. I followed a Youtube tutorial. It can also damage the coating on your DPF. So even though I am doing it, I can't recommend it without you knowing the consequences.

I will be logging again and seeing if this has fixed any issues.

Haven't really done much to the car recently, other than regular oil changes. Car is running very well! I am averaging 40MPG in the city and up to 48MPG on the highway.

When I start it up it says 'SERVICE NOW' on the dash but goes away. I believe this is due to me using subpar programs to flash my ECU. I was told by a tuner that you need to flash with KESS or similar so the ECU errors are minimal or nonexistent. Haven't purchased a KESS yet.

mextdi said:

With the help of my friendly Russian?! tuner and logging, we discovered first that there was underboost and then overboost. I decided to do the zip tie fix and that got rid of the underboost condition and overboost is now rare but still does it and puts the car in limp home mode. The zip tie was a little tricky because it is in a high heat environment and the zip tie gets distorted somewhat from the heat and needs constant adjustment, and/or looking after. Couldn't find affordable user-friendly metal zip ties....

Click to expand...

I had the same issue with the actuator, I used mechanics wire after reading that zip ties didn't last long. Been on there over a year no issues.