Should I replace the turbo?

2006 Jetta TDi 367000kms. I bought the car for $2600 Canadian last year and just replaced the rear brakes and front wheel bearings. The turbo works sporadically sometimes I have it sometimes I don't. Shop said it would need a new turbo. I've been driving since last year without the turbo working and was thinking of keeping the car for another two years. Is it really worth it to replace the turbo at the cost of almost what I paid for the car? It drives fine is a little under powered but I just bought it for the 800+kms per tank. Usually gets 850kms-900kms on the highway even without the turbo. I'm I doing more damage driving it without he turbo shop said it would be fine. If I were to replace the turbo I saw one on RockAuto for $1600 shipped to my address after taxes and all that. Car is in decent shape I might have to fix some rust next year when I get it inspected. Any input would be helpful. thanks guys.

Could be just the actuator on the TC is rusted out. Much cheaper than the whole thing.

Do you know for sure it's a boost problem and not in limp? Any lights? Scanned for codes?

of course the shop would just randomly diagnose an expensive part to replace.

go to some other shop, a TDI shop on your trusted mechanics in your area sticky thread.

driving it as is even with a bad turbo is not going to kill it, its the turbo failure that could lead to disaster, but be warned that if the turbo is failing, that you can have a epic show of destruction if it goes south. these turbos have whats called a journal bearing. its a brass collar that lets the oil pass though it, no seals. If its worn down, you will get excessive oil in the inter cooler pipes and it could lead to a diesel runaway.

so the most common issue here is vacuum lines and or the actuator going bad.
change all the vacuum lines out including the one in the ECU, you can test the n75 valve too this could also go bad. Same with the MAF. all of these things can lead to a low power situation. have you checked for codes? most of these things will trigger a code and usually but not always a Check engine light (CEL)
You should check to see what the timing graph is and you also need to check the timing marks to make sure that the belt and the sprockets are correct.

when was the timing belt last changed and how many miles ago was it. this is probably the 1st thing you should check out.
Boost leaks could also lead to this issue.
99% of all these things you can diagnose with common hand tools and a few hours in your driveway, you need VCDS and the vagcom cable, its worth having.

if your turbo actually is going south, then an upgrade is better money spent, you can get a quality turbo for less than the stock by upgrading, (usually depending on what your going for)

one more thing, does this have a CAI (cold air intake after market air filter)?

In my experience, if the actuator is stuck and you are able to replace it, the turbo isn't too far behind. I'm in that spot now. Replaced the actuator about 1.5 years ago and my turbo is coked up now.

If the 2006 is anything like an the ALH engine in the MK4s, it virtually has no power at all when the Turbo totally quits.

So, OP, are you sure the Turbo is not working at some level? The CEL engine light should be on. It should be in worse than limp mode if the Turbo is not working at all.

I've only did work on one 06 Jetta. It looked like the Turbo is up high compared to the ALH and BEW engines....... and looked like it would be a challenge to change.

As suggested, I'd methodically examine one thing at a time. But, you need to start with Vag Com Diagnostic Systems (VCDS) or something as good as VCDS to scan for codes. All systems should be scanned. Save the codes and then delete them. At that point you can restart the engine and go for a drive to see which codes return.

Wow thanks guys.. The CEL is on I'll try and get the exact codes. I had someone else look at it. He said he saw the actuator working when I revved the engine. I guess I need to hook up that tool to check it. Could it be that the actuator is not working ALL THE TIME.. Would a vacuum leak in the actuator allow it to work sometimes? I found an amazon actuator for $150 which is way cheaper than a new turbo. I was told the timing was changed 50K-60K Kms ago.

Yea but how many years was that? Its milage or age, whatever comes first. 80k or 5 years. So your nearly due for another one

Without VCDS, if you hit a certain amount of throttle that causes the turbo to quit, it's very likely your Mass Air Flow Sensor(MAF). If you restart the engine and the turbo comes right back, it's the MAF.

When the engine starts, the actuator goes to full boost position. If it's against the stop, it's not the actuator.

There are a lot of mechanics who the joke was, "If replacing the turbo doesn't do it, replace the injection pump." Don't throw parts at it. Diagnose and repair.

Any Autozone, O'Reilly's or Pep Boys usually do free OBD2 code reading. If you get an under or overboost code, that will trip a limp mode. BEW's are finicky for doing underboost. That requires usually making sure your vacuum circuit is leak free and the actuator is adjusted correctly. 4-5 inches vacuum, the actuator begins to move. 18inches, it's against the stop. That is how they should be set.

Just a hint, cause it happens so often... Check your brake booster hose to the vacuum supply. They break in two different places.

c1bl,

Mongler98 said:

....so the most common issue here is vacuum lines .........

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Not on your 2006 Jetta. Very seldom do I find a vacuum line bad on a BRM engine. That is not to rule it out but it's just not that frequent. I have run into leaky vacuum reservoirs in the valve cover, though.
The most common vacuum related issue is a faulty turbo actuator diaphragm. It will always show up when you use a MityVac on the actuator.
Actual operation can be intermittent. At lower RPMs the N75 can not provide sufficient vacuum to draw in the diaphragm and keep up with the leak. If the actuator is not pulled all the way down at idle, you can persuade it with pushing it down manually with a screwdriver and that will cover the "hole" enough to seal it until the next time that the vacuum is released by the N75 valve. At higher a RPMs the vacuum pump can sometimes overcome the leak and manage to draw down the vane lever...or it will not work at all if the actuator leak is bad enough.

Mongler98 said:

....change all the vacuum lines out including the one in the ECU,...

Click to expand...

Your car does not have one in the ECU and neither does his 98 Jetta. His is confusing it with a hose leading to a manifold pressure sensor in his ECU where yours is mounted in the intercooler piping and relays the manifold pressure through an electrical signal sent to the ECU.

When you drive around with no boost, there is a tendency for more oil to make its way into the intake system and fill the intercooler. Keep a close eye on oil consumption if you are leaving it that way. And if you do get the turbo situation fixed make sure to drain the intercooler of oil before you womp on the go pedal.

Replacing the turbo is not a terrible idea if the car has a good many miles on it. These turbos are known to have issues aside of vacuum related stuff. You would have to get the actuator up a running before you could identify it unless you pulled it of the car and opened it up and who would want to sink money into an actuator only to find that the turbo is not operating properly anyway. It would be a band-aid fix.
Here is a link to the problem that I am referring to:
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https://www.myturbodiesel.com/wiki/turbo-stop-screw-adjustment-tdi-engine-zip-tie-engine-hesitation/

Franko6 said:

Without VCDS, if you hit a certain amount of throttle that causes the turbo to quit, it's very likely your Mass Air Flow Sensor(MAF). If you restart the engine and the turbo comes right back, it's the MAF.

Click to expand...

Although it could be the MAF, the actuator on BRM turbos is a pretty common failure item. It may go against the stop when you turn the key, but it may not hold vacuum when accelerating, throwing the car into limp mode. The rest of the turbo may be fine, but the actuator isn't available separately. We have a kit to replace the actuator, but setup and calibration isn't simple. Most folks decide to replace the turbo instead.

If you want to keep the car for another two years I'd be reluctant to drive it all that time without a turbo. If it is in fact the problem you should replace it. You should be able to get a new turbo installed for $1,500 or so CAD. Or you could find a used one, but that problem with that approach is the used one may also have a faulty actuator.

Definitely check all vac lines, if your unit has a vacuum solenoid block then unclip the head and check each line, ours had a blocked line internally to the air box and did all manner of bad things...

Turbos don't stop spinning, the actuator closes the fins to increase the exhaust velocity against the impeller

There's a very good chance the boost lines could be split, the throttle/idle/flap has failed or your EGR is failing and dumping inert gas into engine feeling like it's off boost.

The first thing to do is check how much oil is in the boost piping, prior to the intercooler and MAF. There's always oily residue and a dribble, but if more, your turbo seals (sintered bushings) could be done. Our 2006 1.9 Aussie spec had turbo failure (twice because of a 2nd had repair)


Lots of pictures...

http://framepoet.org/mk5-polo-1-9-tdi-turbo-removal-and-repair/

IndigoBlueWagon said:

Although it could be the MAF, the actuator on BRM turbos is a pretty common failure item. It may go against the stop when you turn the key, but it may not hold vacuum when accelerating, throwing the car into limp mode. The rest of the turbo may be fine, but the actuator isn't available separately. We have a kit to replace the actuator, but setup and calibration isn't simple. Most folks decide to replace the turbo instead.
If you want to keep the car for another two years I'd be reluctant to drive it all that time without a turbo. If it is in fact the problem you should replace it. You should be able to get a new turbo installed for $1,500 or so CAD. Or you could find a used one, but that problem with that approach is the used one may also have a faulty actuator.

Click to expand...

Good points too!

My 2006 went into limp when I blocked the EGR.