Turbo or clogged intake?

busyditch

Member
Joined
Sep 11, 2004
Location
NJ
TDI
2000 Golf black
I have a 2000 Golf TDi with 80k miles. It has had a decreased amount of power recently, especially on hills. I have a suspicion that it is a clogged intake, but my friend/mechanic says he thinks its the turbo. I have a boost guage and the highest the boost gets is about 16.5 lbs. Is it possible the clogged intake will restrict the ability for the turbo's vanes to open completley for maximum boost? I plan on having the mechanic clean the intake soon. Should I go ahead and change the turbo while the engine is apart? Thanks to you all for your support.
 

Drivbiwire

Zehntes Jahr der Veteran
Joined
Oct 13, 1998
Location
Boise, Idaho
TDI
2013 Passat TDI, Newmar Ventana 8.3L ISC 3945, 2016 E250 BT, 2000 Jetta TDI
MAF sensor...You will need a VAG-Com to diagnose it.

Turbos don't go bad they grenade! No doubt you would notice that!

Most gasser mechanics have no clue how a TDI turbo works, turbos don't just stop producing boost.

There is a check you can do on the VNT ring to verify proper movement. This is perhaps the only situation where replacement of the turbo is warranted. However if the turbo is taken apart and cleaned it can be reinstalled with many miles remaining of useful life.

Again start at the MAF sensor or N75, also do you have a check engine light? If not this also point to a bad MAF sensor since a code willl NOT be triggered.

DB
 

jasonTDI

TDI GURU Vendor , w/Business number
Joined
Apr 26, 2001
Location
Oregon, WI
TDI
20' RAM 3500 CCLB dually HO/Aisan. 2019 Cherokee 2.0T
I'd also say the intake with 80K. Seems to be the point I clean a LOT of them. Could be a combination of the two.
 

TDIRyan

Veteran Member
Joined
Jan 28, 2005
Location
Memphis, TN
TDI
02 Jetta TDI Black
Clean the intake while it's out.
Reaplce the MAF ($80).

It's probably not worth replacing the turbo at this point unless you really just want to spend the money.

Unless you see a cloud of white smoke in the rear view mirror and get 0 boost, you haven't destroyed the turbo yet...
 

Drivbiwire

Zehntes Jahr der Veteran
Joined
Oct 13, 1998
Location
Boise, Idaho
TDI
2013 Passat TDI, Newmar Ventana 8.3L ISC 3945, 2016 E250 BT, 2000 Jetta TDI
The key is "Reduced power recently". Intakes don't plug overnight, it takes thousands of miles and you will never detect it unless you drive another TDI and realize how aneamic your car is.

Maf sensors when they go bad cause the same symptoms as a clogged intake.

A plugged intake causes a narrowing of the passage way which reduces the volume of air entering the motor WITHOUT reducing the stock boost pressure which is in the area of 16.5 psi. The reduction in air volume also causes the maximum injection quantity to be reduced as well and this every so slowely causes power to drop off over the course of 50,000 miles. It occurs so slowely that you never detect it.

Get the MAF sensor checked by performing the load test as described in the Bentley manual along with using a VAG-Com. This is the only way to know exactly how the MAF sensor is doing.

IF the intake is in resonable shape don't let your average mechanic mess with it. THe reason is dropped carbon pieces or improper assembly of the components leading to a blown motor. Take it to somebody that has experience with EGR removal and de-coking. The intake can be cleaned without removing it from the car, the only thing that needs to be done is removing the EGR valve and scraping out the soot. It takes about 45 minutes and keeps you from turning this into a major project with all the power being restored as a side benefit.

DB
 

TDIRyan

Veteran Member
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Jan 28, 2005
Location
Memphis, TN
TDI
02 Jetta TDI Black
Drivbiwire: How can yo clean the intake with it on the car without getting all that crap into the head?
 

TooRoundTDI

Skunk Rocker
Joined
Jun 8, 2005
Location
Broad Brook, CT. I have vag-com, PM me.
TDI
1998 Jetta
I had severe overboost problems with the clogged intake, now the highest it will go is 21. DBW you mentioned the maximum injection quantity being reduced, does this fix itself after cleaning or is there something I can do with vag-com?
 

cody

Veteran Member
Joined
Nov 27, 2001
Location
MO
I second the info for a 45 min intake cleaning.? Our 00 Jetta has 171,000 miles and we are original owners. I know it is long past the need for an intake cleaning.
 

Drivbiwire

Zehntes Jahr der Veteran
Joined
Oct 13, 1998
Location
Boise, Idaho
TDI
2013 Passat TDI, Newmar Ventana 8.3L ISC 3945, 2016 E250 BT, 2000 Jetta TDI
I have made posts on this before. The simple part of it goes like this:

-Remove EGR

-Use a paint can opener, long rod with a 90 degree angle to scrape out the soot and pull it out the opening.


-Remove as much soot as possible (metal should be visible to bottom and sides) then,

-Cap off the EGR cooler outlet with a piece of metal

-Have somebody get in car and start it and keep rpms around 1500.

-Using a long flathead screw driver scrape away the rest of the small buildups which are easily passed through the motor and out the tailpipe

-Once the intake is scraped clean shut the motor off and put the EGR valve back on.

People freak out about soot getting down into the motor but they forget it happens all the time! You don't want large pieces falling in obviously, but small pieces are fine and easily passed on through and blown out the tailpipe the first time you get on the power.

Total time for this is around 45 minutes and accomplishes a complete intake cleaning.

As far as the ports go they don't get that much build up, the other thing is nobody ever gets the soot out of the head. The main restriction occurs at and just after the EGR valve, this is why VW made the valve removable so that you do not have to remove the entire intake manifold...They know this would happen on US spec high sulfur fuels.

DB
 

cody

Veteran Member
Joined
Nov 27, 2001
Location
MO
45-47 mpg, last May got 52 and the motor had about 150,000. At around 100,000 I had the EGR disabled. Didn't start using diesel purge and klean until after 100K.
 

jasonTDI

TDI GURU Vendor , w/Business number
Joined
Apr 26, 2001
Location
Oregon, WI
TDI
20' RAM 3500 CCLB dually HO/Aisan. 2019 Cherokee 2.0T
I'd not recomend that procedure for the average joe though. Sometimes the carbon is not soft, powdery, or oily. Sometimes it's rock hard and that is the stuff that bends valves. That's what happened to the engine I helped rebuild this summer.
 

cody

Veteran Member
Joined
Nov 27, 2001
Location
MO
I tried to search for more info on the quick cleaning but haven't been overly successful. Is there any more to it/more details needed? Thanks for your help as I know it gets tiring answering the same questions over and over but you guys that know a lot are invaluable.
 

jlaman

Active member
Joined
Nov 9, 2005
Location
PA
TDI
2003 Golf GL TDI 5spd
Clogged Intake Help?

I am fairly new to this forum, so pardon me if I am asking a question that has been asked before. After searching, I found some advise on the issue of build up in the intake. My 2003 VW TDI GL 5spd with 48200 miles has had starting problems - maybe 5 times in the past 4 mnths or so. The dealer says it is due to build up in the intake ( I don't believe this is the cause). I am reading on this forum that this intake cleanout can be done by the owner and is a 45 minute job. The dealer just called to tell me that cost will be $350 :eek: for a 5 hour intake cleanout job. Is this real?! VW Dealer says this is not covered on the warranty either. Seems like a serious flaw with the car and makes me think twice about a diesel. There goes all the fuel savings - should have bought a Honda says my wife. I think she is right. Anyway, any advice or opinion on this matter would be appreciated. Also, could it be expected that the newer formulated, low sulfur diesel will not clog the intake as fast? Thanks!

Jeff L in PA
 

mparker326

Veteran Member
Joined
Feb 28, 2005
Location
Knoxville, TN
TDI
Golf 2002 Gray
My 2003 VW TDI GL 5spd with 48200 miles has had starting problems - maybe 5 times in the past 4 mnths or so.
Describe your starting problems.

Also, could it be expected that the newer formulated, low sulfur diesel will not clog the intake as fast?
Yes.

What is your driving style?
 

gdr703

Veteran Member
Joined
Jun 13, 2002
Location
Vancouver, Canada
TDI
Golf 2 door 2002 Indigo
busyditch said:
I have a 2000 Golf TDi with 80k miles. It has had a decreased amount of power recently, especially on hills.
It could also be a faulty vacuum. Check over you vacuum lines, as a cracked vacuum pipe, or dislodged vacuum pipe could be causing this decreased amount of power, esp on hills, and with a "recent" onset.

Could also be the MAF.

Unlikely to be clogged intake. imho

cheers
 

busyditch

Member
Joined
Sep 11, 2004
Location
NJ
TDI
2000 Golf black
Thanks to you all for your help. I forgot to mention in my original post that I replaced the MAF last year at 63K. I have an onboard diagnostic computer and have not gotten any codes despite the reduced power, which leads me to believe its a clogged intake. I removed the pipe from the intercooler to the EGR and there is black crud inside when you insert a screwdriver. The mechanic who will do the job has a lot of experience with diesels, both US and European. He thought that the line leading to the turbo that controls the vane pitch may be the culprit, so he will check the movement of the diapragm after he reinstalls the cleaned intake. I will let you know what happens
 

busyditch

Member
Joined
Sep 11, 2004
Location
NJ
TDI
2000 Golf black
FOLLOWUP
I had the intake cleaned today. It was WAY overdue- as bad as the picture posted above. Soaked it in acetone for 2 hours before we could clean it completely. It was worth the effort. My Golf now has acceleration and revs like it should. The downside is, it still was not pulling well on a steep hill (route 280 in north Jersey) and it lost power suddenly.(no code lights thrown) It has done this before, only worse due to the previously clogged intake. So the mechanic says come back and he will test the actuator on the turbo. ANy other suggestions? I imagine there may be other clogged lines due to the egr mess. What should I look for? (note:new fuel filter, K and N air filter, and MAF), Thanks to you all
 

rdkern

Top Post Dawg
Joined
May 21, 2004
Location
Humboldt Co CA
TDI
Passat 1997 silver (sold after 11 years), Jetta 2000 atlantic blue
Dump the K&N and go stock - it probably will wreck your MAF, according to may reports here. It sounds like your mechanic has a clue, so let him go at it with respect to testing the actuator. You could also have a small crack in the intercooler line that opens more under boost, which will through you into limp mode, as will bad lines around the N75, as well as an N75 going south.

Good luck.
 
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