Help Please - I love my Bug and also, I'm broke.

I apologize in advance, this is going to be difficult for me to describe without using sound effects and interpretive dance...

I have a 2002 VW Beetle that broke down 2 years ago. Quit starting, and at the time we were less broke and we bought a lightly used truck instead of fixing the Bug. This is mostly important because it sat for 2 years with a mostly full tank of diesel fuel, so obviously that was an issue.

We got it running again about a month ago by replacing the fuel filter and fuel pump assembly (in tank unit), air filters, and oil filter. It ran okish for a couple of weeks, but it was really cold and was having trouble starting. By ok-ish I mean that the rpms jumped back and forth between well under 1k to just under 2k and puffs of smoke shot out the exhaust once it was put in gear (idled cleanly, the jerking didn't happen until it was put in reverse or drive). It jerked around like this until it had gotten up over about 40 mph for roughly 3-5 minutes, and then it drove fine.

Then it quit starting reliably so we replaced the starter (the battery is new-ish and we got it tested, so we knew that wasn't the issue). Now it starts like a dream, but the chugging and jerking has gotten worse, along with a knocking sound that sounds like chewbacca if he was a robot, along with throwing a Turbo/Super Charger Overboost Condition code. Also, the chugging and jerking quit going away after whatever amount of driving, so I had to stop driving it.
Yesterday we changed out all of the vacuum hoses (3mm and 5mm), but that did not change the chugging, which is also happening while idling now.
We can't afford to take it to a mechanic, and we are new to the area so we don't even know one that we could trust not to fleece us if we could. We are running out of relatively inexpensive things to try. We can afford to get more parts, but not in a willy-nilly maybe this thing is bad/I'll just throw in a new one and see if it fixes the problem kind of way.

We have a BAFX Products Bluetooth Diagnostic OBDII Reader/Scanner for Android devices, so we can read codes. We didn't run it yesterday after replacing the vacuum tubes didn't fix anything (though they were old and ****ty and totally worth replacing anyway), but we will tonight and I'll update the thread with whatever it gives us. We also have supplies for cleaning the fuel injectors which hopefully we can get around to doing tonight as well.

This might have been the worst description of car issues this forum has seen in awhile, but if you have questions I can answer them, and if you suggest things to help narrow down the problem, I will follow the advice and report back.
Aside from being broke and really needing a running car, I love this Bug and I want it to run again. It only has 160,000 miles on it and driving it reminds me of my first car (1991 VW Passat). It's one of those stupid things where I could totally sell it and by some other super cheap old commuter instead, but I don't want to. I want this one.

You may want to check the snorkel tube for a mouse nest. You can detach the air box from the snorkel tube and take a leaf blower and give it a reverse blow job. Blow from the where the snorkel was attached to the air box.

Worth a try for starters.

dweise

Without a real good scanner (VCDS) to give you guidance, check the big diameter hoses from the turbo outlet to the intake for leaks, splits, disconnections, etc. Make sure they are not leaking as a leak with cause turbo boost problems.

I will do that today, but in the course of troubleshooting we have run it briefly without the airbox attached and that did not seem to change anything. That was several weeks ago though, so I'll still blow out the snorkel before I run it to pull codes.

my two cents...

https://www.bp.com/content/dam/bp-country/en_au/media/fuel-news/long-term-storage-diesel.pdf

Two year old diesel wouldn't/shouldn't be bad unless it was contaminated before sitting.
Unless prior mods have been done your NB didn't have an in tank fuel pump, only a fuel pickup/sender unit.
I'm assuming it's an automatic?? If so, I wouldn't get too further attached to the Beetle if finances are tight. Current issue(s) are probably not expensive once diagnosed. Future tranny repair/replacement/swap will be expensive.

earthtobase said:

syphon fuel out of tank, i think the fuel is probably rotten. refuel with fresh diesel and fuel conditioner/octane boost/antigel.

it's possible your turbo is clogged with baked carbon, thus turbo over/under boost code. make a determination about turbo clog by looking inside egr and upper intake, if these are a blocked with sticky carbon, chances are turbo is clogged. look for pictures on this website.

if turbo clogged, it's best to replace with brand new, to save you future heartache.

my turbo was clogged at 67.5k from mostly putting around city driving, replaced with brand new borg-warner vnt15, about $900 altogether including tools.

good luck!

Click to expand...

Diesel fuel NEVER goes bad. It can sit for years and still be good. Only problems with fuel would be with water or algea growth. Also caused by water problems.

I've had diesel stored in a 500 gallon tank for a very very long time. In 22 years I've ran over 11,000 gallons through that tank.
Double filtered. One water block filter one regular filter. NEVER EVER HAD ANY FUEL RELATED PROBLEMS.

dweisel

Yeah, diesel fuel doesn't really go bad. I'd picked up a generator that had fuel in its tank for 6 years (the seller informed me of that- he'd bought it at a State auction and it was stated that it had been in storage for 6 years). I ran most of the fuel out but decided to empty the tank out completely just to make sure it didn't have crap in it.

If there's no air incursion problem (seeing any air bubbles in clear section of fuel line? assumes, of course, that you've got a clear section, not all cars seem to) then it might be the injectors. I'd look to run some diesel purge.

Another thing I'd look to do, because it's just way easy, is to disconnect the MAF and note if that makes any difference (a bad MAF can create rough running- unplugging it will result in smoother, and, most likely, significantly reduced power [that's by design]).

UPDATE:

Blew out snorkel. Did not see anything happen from that, but did do it. Hooked air box back up and ran it to catch codes and was planning on pinching the hose connected to the inlet of the EGR, but it threw no codes and the jerking and rpm jumping/hunting was gone. Put it in reverse (up on jacks, carefully), expected it to do the jerking and smoke blowing thing, did not do it. Took a lap with it. It's underpowered but I don't think limp mode. Still threw no codes.

Took it to pick up a kid, about 9 miles of country highway a bit of residential. Check engine light came on after about a mile, still driving underpowered, but still no chugging or smoke blowing.

Unhooked the MAF for the drive home. Drove better-ish and had a little more power, but still underpowered. Hooked MAF back up in driveway and tried to redline it in neutral - make it to 4k, then to the very start of redline at 4750rpm (where I may or may not have chickened out) and then was unable to get it to go over 4k on a couple more tries at that.

We added a bunch of fuel cleaner stuff and anti-gel stuff since we got it running again and I've gotten fuel...twice since it started running again? It gets good enough milage that I am having a hard time going through fuel.

Another update, with a question. We attached a vacuum tool to the valve actuator and it closed the EGR when we pulled a vacuum on it, but it didn't hold it shut. I don't know if it's supposed to stay shut if pulling a vacuum on it shuts it, but it doesn't. So, the car was not running, and we were looking at the butterfly plate directly while we were doing this. There are too many youtube videos of EGR valves that don't work exactly the same, so I don't know what exactly this one is supposed to do.

jettawreck said:

Two year old diesel wouldn't/shouldn't be bad unless it was contaminated before sitting.
Unless prior mods have been done your NB didn't have an in tank fuel pump, only a fuel pickup/sender unit.
I'm assuming it's an automatic?? If so, I wouldn't get too further attached to the Beetle if finances are tight. Current issue(s) are probably not expensive once diagnosed. Future tranny repair/replacement/swap will be expensive.

Click to expand...

It was a fuel pickup/sender unit. We did not replace the fuel pump.

It's an automatic. Finances are tight right now, but they won't be indefinitely. Anybody have a best guess how long in the future before the tranny goes, so I can meter out my love appropriately?

Pull a vacuum on the turbo actuator and see if it moves easily and holds the vacuum. The actuator should start to move at about 4" hg and stop at about 18" hg. If it's not smooth and holding, that may be your power problem (turbo not responding to requested boost).

We did this thing with the turbo actuator, we couldn't read the actual numbers on the tool, but it held a vacuum. We assume it moved. I wish we would have done it when we had the bottom cover off and I was underneath there replacing the vacuum hose. :/

If your test drive to pick up the kid had the vacuum system disconnected then that's why you had low power. I'm not clear on this.

There's a small vacuum hose going to the bottom of the air filter box. If that hose is plugged or the fitting in the box clogged it caused surging for me.

Search for the vacuum diagram of the car and make sure all the hoses are correct.

Also look at the large diameter hose that exits the back of the vacuum pump and goes to the brake booster. That hose has a habit of splitting and is a big source of lost vacuum. It can also be a loose fit in the vacuum pump and cause a vacuum loss.

If unplugging the MAF results in the car running better, more stable, then replace the MAF (only with a good, new BOSCH). As this car is an automatic a misbehaving MAF has an even bigger impact.

Low power and limp mode...

wonneber said:

If your test drive to pick up the kid had the vacuum system disconnected then that's why you had low power. I'm not clear on this.

There's a small vacuum hose going to the bottom of the air filter box. If that hose is plugged or the fitting in the box clogged it caused surging for me.

Search for the vacuum diagram of the car and make sure all the hoses are correct.

Click to expand...

No, nothing was disconnected when I went to pick the kid up, and on the way back I unplugged the electrical pigtail to the MAF only. All of the vacuum hoses were connected and were replaced the day before. The vacuum hose diagram is printed on a sticker that is right there when you open the hood. The little hose to the bottom of the air filter box was one of the ones replaced, and it was connected still.

I just found Oilhammer's post about my transmission.

It's a good thing this forum software bleeps out cusswords.

It's not the MAF I don't think.

I think that I have a dirty EGR valve and possibly turbo. I may still have a leak on the goesout side of the turbo, but I don't think so.

Regardless of the rough, underpowered engine running, it already has the (apparently telltale) hard jerk engaging first gear after being in park or reverse or just starting after a stop, in drive.

*Sigh*

Changing the transmission fluid is easy and cheap to do, and it sometimes puts problems into remission.

optimism said:

I just found Oilhammer's post about my transmission.
It's a good thing this forum software bleeps out cusswords.
It's not the MAF I don't think.
I think that I have a dirty EGR valve and possibly turbo. I may still have a leak on the goesout side of the turbo, but I don't think so.
Regardless of the rough, underpowered engine running, it already has the (apparently telltale) hard jerk engaging first gear after being in park or reverse or just starting after a stop, in drive.
*Sigh*

Click to expand...

I tried to break it to you gently.

If a tdi runs better with the MAF unplugged it needs a new one. That sounds like it is not the only issue as it will run fairly well with out it connected. I have had a lot of trouble with the turbo actuator sticking when these cars sit too long. The actuator must move the full range when it has full vacuum and then released. Try pulling off the egr hose and see how it runs with that disconnected. If air passages are clean, egr and maf disconnected, fuel filter good, the next place to really check is the turbo for a sluggish engine. Codes can help but sometimes they don't reveal some issues. As far as trans issues it may be just your valve body needs a rebuild. Check with cool air found on this forum. I know the autos have issues but some are only minor. I have one that I put a new valve body in at 260000 and my son is still driving it with about 320000 on the clock.

optimism said:

UPDATE:

Took it to pick up a kid, about 9 miles of country highway a bit of residential. Check engine light came on after about a mile, still driving underpowered, but still no chugging or smoke blowing.

Click to expand...

What was the fault code? Is your intake clogged?
Brett

Sorry, I disappeared under the Bug there for awhile.

Took out and cleaned my EGR valve. Would post before and after pictures if I knew how to do that on this forum...it was bad.

Did the exhaust outlet side Seafoam cleaning of the Turbo.

Replaced the MAF.

Blew out the snorkel.

Possibly some other stuff, I don't know. I work my job and then I work on my car.

It was running AMAZING. Like new? I don't know but better than it ever has since we owned it. Quieter. Smoother. More power.

It lasted like a week. I got a low coolant light flashing. I added coolant. It's louder and rougher again now, but still has power and drives fine. I get a big puff of white smoke when I start now, and it takes longer than it should to start. I am afraid it's a leaking head gasket.

WHY BUG? WHY MUST YOU, DON'T YOU KNOW I LOVE YOU?

*sigh*

On the bright side, if it is the head gasket, it gives me an awesome, weekend-long opportunity to clean out my intake and exhaust manifolds and literally whatever else I have to take apart to replace that. I have heard it's super fun.

Have you checked your TB and water pump? A leaking pump can cause the belt to fail/ loose teeth after sitting for a long time. Don't ask me how I know.

If your EGR valve was junked up with carbon, then your whole intake is carboned up. Remove and clean the intake and strongly consider cleaning the intake ports in the head as much as possible... and do it very carefully to avoid my adventure.

https://forums.tdiclub.com/showthread.php?t=475063&highlight=intake+clean

Or, get a good, clean used intake (ebay or local salvage) and just swap intakes. Then take your sweet time cleaning your original intake for when you need it again.

Brett