TROUBLE while on Road Trip w BORROWED 2000 Jetta 1.9 TDI - need info!

[RTIII]

Hi All,

I posted here about my troubles in some detail and a kind soul there, Rockerchick, pointed me here for ALH TDI information.

Note that I am a competent wrench but DO NOT have very many tools with me, and NO WORKSHOP MANUAL! Further, as the title says, this is NOT my car!

I'll leave it to your visiting that other thread for more background, and focus here on solid info...

In short, everything was fine until I got to the pot-hole capital of the USA (New Orleans) and after repeated shocks from unseen road damage, there were new rattling noises but it still ran fine. Then a day or three later, the engine suddenly lost most power and sounds like a diesel truck! I stopped driving it, though it did take me around 8, maybe 10 miles to park it until I could deal with it.

I just got it up in the air and a preliminary inspection shows no obvious damage, but I haven't gotten deep into it yet.

What I'd like to know pertains mostly to the exhaust system:

+ Are the stainless mesh covered sections just heat shields or are they flexible sections? (They appear to be flexible, which would be GREAT news as it would therefore be unlikely that fatigue cracks have broken parts of the exhaust manifold or worse.)

+ Is the turbo inexpensive, if I need to replace it?

+ I was told that an old muffler (MIGHT even be the original!), upon disintegration, can clog the exhaust enough to cause EXACTLY all the observed phenomena. And, therefore, take it off and test! If it runs well with it removed, PROBLEM SOLVED! Comments?

+ I've also heard that various hoses having come loose can cause this, too, but without a shop manual... uh, ... Pointers?

+ The Check Engine light is on, but it's Sunday; I'll get the code and diagnose more from that but an O2 sensor seems most likely; where's the sensor and its wiring so I can check it?

+ I presume the muffler and remainder of the exhaust track is held by several thick rubber doughnuts which have likely failed; can this cause more problems due to the system hanging weight on up-stream components, like the turbo housing? Manifold?

... If I've failed to ask the right questions, please inform! ... I'm ignorant, not stupid!

TIME is of the essence here; incomplete responses, hunches, ANY and ALL replies welcome ASAP!

THANKS!

 

[jmodge]

There is a flexible joint just downstream of the turbo. No O2 sensor.

 

[JETaah]

Stainless braided sections of exhaust are flex sections

A replacement turbo of any good quality will be on average of $750-1100 depending on where you get it plus installation. Garrett or Mahle are pretty much your options as far as drop-in fit brands go. Yes you can get cheaper but reliability is suspect. Not recommended.

unless a pipe has collapsed on the muffler there is little chance that it would have clogged to cause an issue.

Hoses? Vacuum related can cause a performance issue and cause limp mode if they were disturbed or hooked up incorrectly.
There is a sticker on the top of the core support with a diagram of how they are to be hooked up. This could cause a check engine light to illuminate.
By this late date it may no longer be there.

Intake air hoses cant go far from their position and might have come loose if they were initially not attached properly. Splits in the intake hoses will also cause power problems. That could cause a check engine light to illuminate. With intake boosted air hoses look for oil residue on the surrounding area.

There is no O2 sensor on an ALH engine.

 

[jmodge]

Your other post doesn’t give much detail, but I will guess it may have gone into limp mode for some reason or knocked a vacuum hose or wire harness plug loose. At least that’s where I would start before throwing parts at it.

 

[jmodge]

If it’s limp mode cycling the key may do it. Like Jetah said, check your boost tract, vacuum hose connections, and electrical connections along the tract, as well as the MAF. Has it lost boost completely or just derated?

 

[ts888]

If the catcon core broke up, it can plug the exhaust pretty well. If someone revs the car, do you feel a decent amount of exhaust at the tailpipes?
EDIT: I see on your Vortex thread you say it has no cat, but if it has stock exhaust it did. Are you 100% certain it has been removed?

Check the output side of the turbo, it goes from a hose to a plastic duct (which if old might crack) to the intercooler, which hangs down fairly low. Also, if the engine mounts are worn the engine can move enough to unseat the upper cold side hose.

 

[braddies]

Could be a clogged snow screen before the air filter.. but let's save time and start with the codes and go from there

 

[Abacus]

It's doubtful that it's a simple vacuum hose as they would not cause a truck-like sound.

The flex connection absolutely can crack under the car. Wrapping it in some aluminum ducting tape will tell you if it's cracked underneath if the sound changes.

Did the exhaust come off at any part? I have seen where the cat will snap off just before, creating the loud sound, but it's easy to see as it's usually hanging down quite a bit. I've seen a fair number of exhaust related problems due to rust and potholes, albeit on other TDI's. I can't remember how many Campbell's soup can repairs I've done just to get people home.

But one other thing, pull the intake pipe to check for turbo shaft play, there is a possibility it made contact with the volute and damaged it. It doesn't take long to pull the pipe and have a look.

Good luck with your diagnosis, and if you can have it scanned, that will tell you volumes.

Oh, and on your other post you asked about the jet black oil...that's completely normal for an older TDI. Mine will turn jet black in about 500 miles but the oil can handle the soot-load just fine, nothing to worry about

 

[RTIII]

First, an update on where I am right now, then comments on the above:

Work yesterday was slowed by various factors but the ONLY thing visibly wrong are a bunch of cloth-wrapped "vacuum hoses" up above the engine at the firewall, slightly driver's side, with some perhaps going down to lower components.

What are the sizes? Looks to be at least three in total. My guesses: 3.5mm, 4mm, and 6mm... Anyone? Lengths to buy?

Headed out this morning to buy what I can find!

PRESUMING that doesn't cure it, my plan (comments, please!) is:

It took a while yesterday to get the car set safely on blocks so I could get underneath and work safely - one house-jack and a stack of large, FLAT ceramic bricks with a small standard size at the top and a bit of wood against the car's bottom, thus making a solid support for the front, and I can now lift either the trailer bracketry or the rear axle to get the butt up in the air. ... If I can lift via the trailer hitch, I'll do that and provide a backup support on the rear axle and leave BOTH in place for safety... Thus, it'll be supported by FOUR points, two in front, two in rear.

What do DO under there? ... It DOES have a catalytic converter after all and I was thinking I should try disconnecting ahead of the cat, leaving the cat and muffler out of the picture, and then test. If, with new hoses, it seems back to normal, but noisy, then YAY! If not?

What do I do if it's NOT OK after that?

 

[jmodge]

Have someone turn the key on and watch the turbo actuator to see if the vacuum canister pulls it against the stop screw. You will need vacuum built up to do this. So you might as well run the car to see if the vacuum pump on the drivers side of the head is supplying vacuum. I think you’re jumping ahead pulling the exhaust, I prefer to start with the simplest diagnosis and go from there. But, who knows, maybe your exhaust is plugged. But I would be looking at vacuum and turbo controls because it’s simple, least intrusive and the most common fault when you lose power/boost. Do you have access to a vacuum gauge?

 

[GlowBugTDI]

Does this car have the egr system still intact? A crack in the egr cooler pipe will cause truck like sounds and loss of power, but won't necessarily throw it into limp mode. I had this happen to me. Albeit a rare occurrence I believe.

 

[RTIII]

There is a flexible joint just downstream of the turbo. No O2 sensor.

Great news! Got it! As JETaah said, that's all the stainless braided sections. And no O2, fine! Less to go wrong / check.

A replacement turbo of any good quality will be on average of $750-1100 depending on where you get

I spoke with the owner who says he replaced the turbo not too long ago with one that has a larger capacity, but modesty so among the choices - he couldn't remember detail but he didn't skimp on price - seemed to think he'd gone with Mahle as that's a known quality (if expensive) OEM brand.

He also said that when they go, as the past one did, "you KNOW it" and "it dumps oil everywhere", which isn't seen here.

THEREFORE, we are not suspecting the turbo at this time - the unit itself anyway.

unless a pipe has collapsed on the muffler there is little chance that it would have clogged to cause an issue.

Owner said it's POSSIBLE it's the original muffler! And therefore, its internals may have rotted pretty far and collapsed, clogging - at least that's a theory.

Hoses? Vacuum related can cause a performance issue and cause limp mode if they were disturbed or hooked up incorrectly.

They were definitely hooked up properly when I left - strong power, perfect performance, good fuel economy... However, as noted in my update post above, there are some clearly original hoses, and not in good condition; I found ONE of them super bad / failed - cracked at a bend AND showing other signs of deterioration. It'd be easy to believe this happened due to one of the WHAM! pot-hole events.

There is a sticker on the top of the core support with a diagram of how they are to be hooked up. This could cause a check engine light to illuminate.
By this late date it may no longer be there.

Good hunch; present but not easily legible! Diagram anyone?

Intake air hoses cant go far from their position and might have come loose if they were initially not attached properly. Splits in the intake hoses will also cause power problems. That could cause a check engine light to illuminate. With intake boosted air hoses look for oil residue on the surrounding area.

Thanks; they look to be in great condition and all hooked up properly. Splits? Easy way to check?

[...] or wire harness plug loose. At least that’s where I would start before throwing parts at it.

Can you point me at this harness plug or plugs of which you speak? ... I have no manual!

If it’s limp mode cycling the key may do it. Like Jetah said, check your boost tract, vacuum hose connections, and electrical connections along the tract, as well as the MAF. Has it lost boost completely or just derated?

Limp-mode doubtful; the boost is GONE!

As for MAF - please inform! Pointer, something... NO MANUAL!

As for the various electrical connections ALL of them look to be in position and in good condition. Hints?

It's doubtful that it's a simple vacuum hose as they would not cause a truck-like sound.

I'm thinking multiple causes maybe!

The flex connection absolutely can crack under the car. Wrapping it in some aluminum ducting tape will tell you if it's cracked underneath if the sound changes.

They look great... will try that if nothing else pans out.

However, see my plan above. ... I'm thinking maybe the cat has collapsed? Test for that?

Did the exhaust come off at any part? I have seen where the cat will snap off just before, creating the loud sound, but it's easy to see as it's usually hanging down quite a bit. I've seen a fair number of exhaust related problems due to rust and potholes, albeit on other TDI's. I can't remember how many Campbell's soup can repairs I've done just to get people home.

The whole underside, including the exhaust, looks pristine, like a two to four year old car or something like that! And other than replacing the turbo, since the owner speculates it MIGHT even still be the original muffler, I doubt it's been touched since new, but then, who knows?

But one other thing, pull the intake pipe to check for turbo shaft play, there is a possibility it made contact with the volute and damaged it. It doesn't take long to pull the pipe and have a look.

With my limited resources here, sure would not be quick for ME to "pull the pipe" but a proper shop, I guess, sure. But, as already noted, we're not suspecting the turbo at this point, as it was replaced not too long ago.

Good luck with your diagnosis, and if you can have it scanned, that will tell you volumes.

Thanks, Abacus, and for your comment about oil, too!

I plan to get the code scanned TODAY! But first I want to do what I can while it's up in the air, THEN drive it somewhere... This afternoon, I suppose.

 

[RTIII]

If the catcon core broke up, it can plug the exhaust pretty well. If someone revs the car, do you feel a decent amount of exhaust at the tailpipes?
EDIT: I see on your Vortex thread you say it has no cat, but if it has stock exhaust it did. Are you 100% certain it has been removed?

Check the output side of the turbo, it goes from a hose to a plastic duct (which if old might crack) to the intercooler, which hangs down fairly low. Also, if the engine mounts are worn the engine can move enough to unseat the upper cold side hose.

Looks like a catalytic converter to me! Owner fessed up that "well, maybe it does have one," etc. That exhaust volume trick sounds like a quick and easy test! Will do, THANKS!

Mounts seem to be OK.

 

[RTIII]

Have someone turn the key on and watch the turbo actuator to see if the vacuum canister pulls it against the stop screw. You will need vacuum built up to do this. So you might as well run the car to see if the vacuum pump on the drivers side of the head is supplying vacuum. I think you’re jumping ahead pulling the exhaust, I prefer to start with the simplest diagnosis and go from there. But, who knows, maybe your exhaust is plugged. But I would be looking at vacuum and turbo controls because it’s simple, least intrusive and the most common fault when you lose power/boost. Do you have access to a vacuum gauge?

You're speaking to the ignorant; what's the "turbo actuator," where do I find it, etc? No shop manual! ACK! And no, no vacuum gauge. I really don't have a good feel for what's where, though I do have SOME diesel experience, just VERY limited. (I work on very early Porsches mostly. This is my shop. But you're not happily pulling a camping trailer behind an old Porsche across the continent and back!

But overall, I STRONGLY agree with your strategy; do the quick, cheap, easy things first!

 

[RTIII]

Does this car have the egr system still intact? A crack in the egr cooler pipe will cause truck like sounds and loss of power, but won't necessarily throw it into limp mode. I had this happen to me. Albeit a rare occurrence I believe.

VERY glad for this input: YES, the car passed CA smog about a month before heading out on this trip, so I presume it has EVERYTHING intact. ... Now, what do I need to know to address this circumstance because it sounds JUST LIKE what has happened to this car!

None of the engines I work on are young enough to have an EGR, but I do know what it is. ... Where is it on this beast? Easy to replace?

 

[braddies]

Turbo actuator used vacuum to control boost

 

[RTIII]

Called the local VW dealer to ask about the hoses and possibly EGR cooler pipe, but these idiots demanded the VIN number to even check if they have the hose! How stupid is that?!

 

[GlowBugTDI]

VERY glad for this input: YES, the car passed CA smog about a month before heading out on this trip, so I presume it has EVERYTHING intact. ... Now, what do I need to know to address this circumstance because it sounds JUST LIKE what has happened to this car!

None of the engines I work on are young enough to have an EGR, but I do know what it is. ... Where is it on this beast? Easy to replace?

Using braddies pic above...

20230501_083710.jpg

• GlowBugTDI
• May 1, 2023

Circled in purple are the 2 exhaust portions of the cooler that can crack. The cooler is down in the corner above where it says egr cooler. This is on the back side of the head behind/below the bulk of the intake.

Where is the majority of your noise seem to be coming from? When my car broke the egr pipe it sounded from under the hood and front of the car and didn't resonate from under the car or the back.

 

[braddies]

Ok if either of those are cracked there will be some black soot around the area of the break. When one cracked on me I used a bunch of shiny silver Duct tape (the good stuff for ductwork) and a few wraps held up until I pulled a replacement from a junkyard.
But start with the vac lines if you see one thats faulty! 3mm,3.5mm, 3/16", fuel line will work on a pinch

 

[RTIII]

This is WONDERFUL, braddies! YAY!

Yes, I want to replace a BUNCH of that!

Turbo actuator used vacuum to control boost

It also includes the EGR system, which GlowBugTDI says may very well cause this very issue, namely the EGR cooler pipe... THANKS!

 

[braddies]

Post some pics, let's see what you're dealing with! And be gentle with the vac lines that you don't break any plastic nipples off while messing with the rubber lines, the plastic can be delicate, usually you can get the rubber to Twist first to break it free before pulling/twisting it off the nipple

 

[RTIII]

Using braddies pic above...
[...image...]
Circled in purple are the 2 exhaust portions of the cooler that can crack. The cooler is down in the corner above where it says egr cooler. This is on the back side of the head behind/below the bulk of the intake.

GREAT! This is JUST what I needed - from just the above, I would have only thought about the one going down from the EGR... Any tips for the experience and tool-limited wrench from getting to these parts to deal with them?

Where is the majority of your noise seem to be coming from? When my car broke the egr pipe it sounded from under the hood and front of the car and didn't resonate from under the car or the back.

I don't know... But when driving, it seems to be from the engine, in front. I haven't got any helpers at the moment to help me check (nor for the exhaust volume check, but that will change today.

Ok if either of those are cracked there will be some black soot around the area of the break. When one crack on me I used a bunch of shiny silver Duct tape (the good stuff for ductwork) and a few wraps held up until I pulled a replacement from a junkyard.

GREAT tip, thanks, though it sure looks like a tough area to work in. And, ... 2400 miles or so across the continent?! It's ONLY 30 hours or so of driving but... I think I'd be pushing it! Thoughts on that?

But start with the vac lines if you see one thats faulty! 3mm,3.5mm, 3/16", fuel line will work on a pinch

Great data... 3 and 3.5 ... and maybe the big one is 7mm? It may have some other function, but it sure is bigger!

 

[RTIII]

Post some pics, let's see what you're dealing with! And be gentle with the vac lines that you don't break any plastic nipples off while messing with the rubber lines, the plastic can be delicate, usually you can get the rubber to Twist first to break it free before pulling/twisting it off the nipple

I took a whole bunch yesterday but had trouble processing them for posting - perhaps today!

And thanks for the tips about the plastic; I do / did know that but I might not have! ...In my experience, plastic in engine compartments tends to get brittle from the heat!

 

[jmodge]

There is a vacuum canister bolted to the turbo. The arm coming out attaches to a small lever on the turbo which opens or closes vanes internally to increase or decrease boost. Key off, vanes are open, key on stored vacuum pulls the lever against a set screw to close the vanes. Don’t concern yourself wether they are open or closed for the moment, just look to see if it moves. If you have cracked vacuum hoses, that could be your issue

 

[GlowBugTDI]

GREAT! This is JUST what I needed - from just the above, I would have only thought about the one going down from the EGR... Any tips for the experience and tool-limited wrench from getting to these parts to deal with them?



I don't know... But when driving, it seems to be from the engine, in front. I haven't got any helpers at the moment to help me check (nor for the exhaust volume check, but that will change today.



GREAT tip, thanks, though it sure looks like a tough area to work in. And, ... 2400 miles or so across the continent?! It's ONLY 30 hours or so of driving but... I think I'd be pushing it! Thoughts on that?



Great data... 3 and 3.5 ... and maybe the big one is 7mm? It may have some other function, but it sure is bigger!

I'd just start it up and pop the hood. Listen to that area. It'll definitely be louder in the engine bay, look for black soot along the fire wall and different components back there. In my case when i would turn the air on inside it would make the air have a hint of diesel exhaust.

Use a flashlight and look around. On a cold engine put your hand back there and feel around the different spaces for wishing air. Or a strip of paper ir something.

 

[JETaah]

I'd just start it up and pop the hood. Listen to that area. It'll definitely be louder in the engine bay, look for black soot along the fire wall and different components back there. In my case when i would turn the air on inside it would make the air have a hint of diesel exhaust.

Use a flashlight and look around. On a cold engine put your hand back there and feel around the different spaces for wishing air. Or a strip of paper ir something.

Probing around with a length of hose up to your ear as a stethoscope will also help to pin point noises.

 

[jimmyfine]

Sounds to me like a vacuum issue but the others about the EGR system are also correct as that can cause these symptoms. When my EGR pipe broke at the accordion section it was because it wasnt bolted onto the intake, it was only obvious when someone hit the pedal and it started pushing the pipe apart, slight boost but mostly none. Recommended start with vacuum hoses, post codes when you can.

Other boost issues I had:
- MAF sensor dirty/bad just after the air filter
- Vacuum lines collapsing, can run vacuum directly to turbo around valve to make it work
- Tube off the turbo blew off because the clip was not fully on
- Wire going to MAP sensor chewed by mouse (unlikely for you)

 

[RTIII]

HEY!

Someone I know from racing Porsches said, "a dirty fuel filter could do that!" SO... Where is it on this thing? Do I need a special type or will any adequately sized unit work? Inexpensive recommendations?

MEANWHILE: ...I went to my own profile to figure out how to load images but it's non-obvious... Gimme a push and I'll post images!

Today was a day to go find hoses and I sort of struck out. ... The dealer claims, based on the vin, that they're all 3.5, but some look bigger to me! I'm hesitant to drive it just now but do I drive it to a store with the _wrong_ inch based stuff and try whatever fits?... I DID order the 3.5mm stuff in from VW - price worked out similarly to a third party with shipping. But I won't get it until Wednesday.

In a few minutes I'm going back to where the car is and do the flow checks.

More soon.

 

[JETaah]

3.5mm and 5mm

 

[braddies]

The IDParts vacuum line kit says it comes with 3 and 5mm