'04 Sir Limps A Lot; the saga continues

[Zeitgeist]

We just bought an '04 Passat TDI wagon w/188k miles, which I've been lusting after for nearly two decades. I had to drive it back home in limp mode for over 60 miles, and it was bellowing embarrassingly large amounts of smoke. My OBD eleven scanner indicates that it has a P0299 Turbo Underboost, and P0101 MAF A-circuit Range/Performance as problematic. I cleaned the EGR valve and fixed some vacuum issues from the pump to the turbo actuator--no change. I'm going to order a new MAF just to have one on hand, but besides firing the replacement parts bazooka what else can I do to diagnose the limp issues?

I'll be ordering a Bentley...especially since we bought for our daughter, a '98 Passat 1.8t wagon w/125k miles on the same day as our TDI.

 

[MukGyver]

Get underneath get your hand on the vnt actuator rod and move it back and forth thru its range. Vanes could be stuck open if it was granny driven babied etc.

Edit: just notice it was underboost its late im half asleep lol. You need a vcds to look at things like the requested vs actual boost is doing.

 

[Scubanero]

Look for leaks in the charge air circuit; turbo outlet to anti-shudder valve.

 

[Zeitgeist]

I guess I should mention that I checked the turbo actuator and observed that it was moving its full range and held 20in. of vacuum. I'll check the IC plumbing next. Is there a good place to splice in a test boost gauge? Sorry for all the dumb noob questions, but I know nothing about PD engines, except that I periodically serviced my neighbor's Mk5 Jetta and for some reason his actuator was hard-wired into a fixed position--dunno what that was about.

 

[Tom in PT]

Look at the many "limp mode" threads in this forum for some further ideas. One is a leak in the large rubber hose underneath the engine, passenger side. It can split or chafe through from rubbing on a ground wire that is right next to it. I can't recall if this is the hose scubanero points to or not, I sold my 05 a couple years ago and so cannot check.

 

[Zeitgeist]

Follow up to the follow up: It has a burst hose from the turbo to the steel crossover pipe. Also, there a lot of oil underneath the IC, which implies there might be a leak there, as well.

 

[Scubanero]

Some oil in the charge air circuit is normal from the crankcase vent. Get ready for sticker shock when you source a new hose. Some after-market ones are tolerable, others only last a few weeks.

 

[Zeitgeist]

More follow up to the follow up: I temporarily fixed the burst hose with a section of an old Saab IC pipe, but the engine still smokes. I kinda think the cat might be clogged up from all the limp mode driving in an underboost situation.

I just tried driving it with the EGR blocked off, and it went into limp mode and threw an overboost code. EGR is not your friend.

 

[Zeitgeist]

I ordered a hose from the fine folks in Lithuania. It will probably be here in seven months.

Any recommendations for where I can send the ECU to have the EGR and Imo deleted? Even though I owned a '96 B4 TDI, it was back in the late '90s before all the savvy cats figured out how to tweak them, so I have very little experience with eTDI. The ALH in my van has a manual pump.

 

[Mozambiquer]

Send the ECU to rocketchip.com Jeff is known for doing a pretty good job. I've got a couple b5.5 passats he tuned.
As far as the smoke, I'd check the camshaft condition for a start. If that's worn, it'll cause a lot of smoke and throw a p0101 code.

 

[Zeitgeist]

So, as I mentioned before, I blocked off the EGR tube which cured the smoking problem, but went back into limp mode with a code for overboost. I drove it today like I had a raw egg on the accelerator pedal and was able to make it 8 miles before the CEL and Engine Emissions Workshop lights came on. It didn't go into limp mode, though. The CEL was the an EGR related code. I want to believe that this can be narrowed down the the EGR itself as the sole culprit at this point, with a theory that the valve isn't sealing fully and leaking boost.

BTW: I finally broke down and bought an unlimited version of VCD$, as my OBD Eleven is just too glitchy.

 

[Zeitgeist]

I pulled the EGR unit and found out that the valve was sticking open at its full stroke setting. I cleaned and lubed all the pivot points, and then shimmed up the return spring so that the tension was enough to overcome whatever was sticking. I gingerly drove it around town and didn't get any CELs, but right before home I gunned it off the line and left those behind me in a dark cloud of smoke. I guess my next step is to pull the turbo and see if the vanes are sticky.

 

[Zeitgeist]

I took it out on the highway last night and it threw an overboost CEL as I was pulling a hill on 101...and then it went back into limp mode until I pulled over and cycled the key. How are you guys deleting the EGR without tuning it out of the ECU and still able to drive?

 

[Mozambiquer]

I got an egr delete plate, plated it off, but kept the egr valve plugged in. It'll throw a check engine light, but I drove it 50k miles like that. Tuned it got a lot better fuel economy, but it'll work without a tune.

 

[Zeitgeist]

Today I went for a test drive with the EGR blocked again, and it was fine until I applied more throttle, which of course threw a code, but no limp mode. I pulled over and cycled the key, which was fine until it just went into limp mode with no CEL...and then it threw an overboost code. This is maddening. Damned if I EGR and damned if I don't, but different damnations.

When I got home I booted up a generic OBDII reader (Foxwell), cleared the code and then looked at live data with the engine idling. The MAP readout was 15.4psi at idle and when I revved it the pressure peaked at 36psi. These readings seem all wrong, for idle and peak. Again, I'm flying blind here without a manual or VCDS, yet. Could the MAP sensor be wonky, or are the turbo vanes stuck?

Sincerely,
Flailing and traumatized.

 

[Tom in PT]

If your close to Redmond WA take the car to Matt at Zahntech. It might be time to stop flailing and have someone who knows these cars well do proper diagnostics and repair. If your in Oregon, Portland has some good TDI repair shops too, Fixumhaus etc.

 

[Zeitgeist]

I'm in Oly, and I'm definitely not driving it 60 miles in limp mode...again. I'll definitely fix this after my VCDS gets here next week, but I'm just getting impatient to feel this thing operating at full potential. This is the first eTDI I've driven since my Vanagon's donor Jetta, and this has been really underwhelming in the power dept.

 

[Zeitgeist]

Thanks, all of this input is helping me understand how the system operates.

 

[borninabus]

hey there. isn't thesamba.com that way ---->

sorry to hear your troubles. i also had issues with my BHW EGR but was able to just block it off and live with the CEL. doing so would not cause any limp problems......but the torque converter sure would!

maybe you should start with the basics and pull the valve cover to get a look at the cam & lifters and do a compression test just so you know there are or are not any underlying issues. unfortunately, the learning curve is steep but worth the price of admission, IMO. once you have your VCDS and have done the basics, troubleshooting this issue should be pretty easy.

of course i have to mention that you should be aware of the BHW balance shaft issues.....and the cam/lifter issues......and the autobox/torque converter issues. my engine was all good @ 150k, but i had the BSM deleted and the cam changed as a preventative measure. next and last on the list for me was going to be the trans but alas, it wasn't to be.

welcome aboard

 

[Zeitgeist]

Thanks, I knew about all the other maladies, but now I get to research torque converters. Oh joy...

 

[Zeitgeist]

While I'm waiting for the VCDS to arrive this week, I decided to follow your advice and pull the valve cover. The cam is definitely showing some scoring on the lobes, but I don't think it's enough to affect performance...yet. I'll do the cam, lifters and bearings at the same time I do the timing belt, which is soon. I'll change the oil at the same time and will snake a camera up the drain hole to see if the BSM has already been removed. The idle is kinda shaky, which might be due to a lack of balance function, but then again that might be where the worn cam exhibits its symptoms. I should mention that this engine fires right up under all scenarios.

While I'm in there, should I be doing something with the injectors?

 

[Tom in PT]

I would leave the injectors alone. Get everything else sorted out first. If,after you fix everything and it is running with no CELs, you have any rough running symptoms then you might want to look at them for correct spray pattern, re-balance, or replace or rebuild as necessary.

 

[Zeitgeist]

Thanks, that makes sense.

Ugh...I just grenaded the trans on my TDI Vanagon. It's completely toast. That means we're down to just the Eurovan and my limpy-mobile. The VCDS should be arriving tomorrow, so I'm hoping I can get up to speed with the soft/hardware and resolve which of my issues is behind the flaccid performance.

Last weekend I got the distinct pleasure of swapping out the steering rack on my daughter's '98 Passat with only 125k. That's not a job you want to tackle without a lift. No sir.

 

[Zeitgeist]

VCDS finally showed up today, but I'm still trying to figure out how the WiFi part works. My new timing and cam kits also arrived.

Since I'm new to the B5 platform, is there any particular issue with these cars wrt either the horn or power mirrors? Neither work, and the "fuse card" isn't very helpful, not to mention my owners manual is missing the section which discusses the fuse box. More flying blind.

This car is on lowered springs, which looks cool, but isn't much fun to drive. Actually, I'd like to raise it up slightly above stock height so we can drive on our local logging roads. Are there spring spacer kits available to raise up the B5?

 

[borninabus]

this may be shocking to you, but there are some known grounding/corrosion isuues with the wiring harnesses & control modules under the carpets in the front footwells. there are some factory splices on the passenger side especially. TCM & CCM live under both the seats and get wet over time via leaky sunroofs.

lift springs & spacers are certainly available. i would start by calling IDparts or maybe Cascade german if you're up PNW way.

owner's manuals are available online for cheap too.
i have the PDF for my 05 if you want it.

my VCDS is the just a cable so i'm not sure about any wifi problems?

 

[Brian's96TDIPASSAT]

I may have a 05 Sedan which ran perfect up until 6-10-21 when my daughter totalled it. Might be able to strike a deal with the insurance company.

 

[Zeitgeist]

I'd love that owners manual pdf if you can PM me.

I haven't looked to see what brand lowering springs I have, but they appear to be blue. If someone from a non-rusty area has a set of good stock Variant springs, I'd be willing to do a straight swap. That aftermarket front grille is also up for grabs.

This seems like an unusual exterior color. Most of the B5.5 models I've seen have a much lighter shade of metallic green.

 

[Mozambiquer]

I'd love that owners manual pdf if you can PM me.

I haven't looked to see what brand lowering springs I have, but they appear to be blue. If someone from a non-rusty area has a set of good stock Variant springs, I'd be willing to do a straight swap. That aftermarket front grille is also up for grabs.

This seems like an unusual exterior color. Most of the B5.5 models I've seen have a much lighter shade of metallic green.

Wow, that is a really nice color! I don't think I've seen many in the dark evergreen color!

 

[Zeitgeist]

Yeah, it's real pretty in person, and the tinted windows really are a nice enhancement of the combo.

Is there a way to defeat the auto-locking "feature"? No matter how many times I drive the car, I can't get used to having to push a little button in order to open the door.

 

[Zeitgeist]

With VCDS, go to "46 central convenience" and then "adaptations" scroll down the list or enter adaptation value 4 "auto locking" or something like that. Change the "1" to "0", save new value and exit.

Cool, thanks!