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2003 - ALH - CEL - P0252 w/pump noise

9491 Views 9 Replies 3 Participants Last post by  chittychittybangbang
new to forum... greetings... have a 2003 Jetta GLS Wagon TDI... CEL/P0252/pump noise/no power

having a problem that started with the first use of BioDiesel... I switched suppliers and had some trouble in my '91 300D as well... filters changed and it's ok... not so with the TDI...

Got a CEL (check engine light) - P0252 code... looked it up, guessed filter... swapped filter... good...
for a few days... had some pump clatter...

had injectors cleaned, replaced two nozzles... mileage wasn't great before the biod so with 155k expected... $400, reinstalled injectors... ran great... but then CEL, pump noise, lose of power... talked
to the Diesel shop... recommended Diesel Purge... that worked... for a few more days...

so... I changed the filter again... better for a bit, more Diesel Purge... no happiness... pulled the fuel pickup today, replaced the filter and added a pre-filter like on my 300d... Diesel Purge 2x... still pump noise, CEL again... no power... eliminated the fuel pickup, lines, filter and injectors... all that's left is the pump... $750 for a rebuilt is the best deal I've found, then of course there's a new timing belt, the tools or labor to have it done, new water pump and setup... easily a grand... :(

NEED to find the special socket so I can pull the top off the injection pump and try to clean that, shop suggested that the fuel metering might be the issue... not worried about tearing into the pump, have had my '91 300D 2.5L TD apart a couple times: http://johnmeister.com/DieselBenz/TECH/124-series/Pressure-Valve-Seal-Replacement/

anyway, looking for more ideas before I pull the IP and send it off or buy a rebuilt pump...

here's the pix from today of the fuel pickup and new filter setup:

JUST found the tool on line, need to see if I can find it locally: Part MN3001 - Specialty Socket for Triangular Head Bolts

This unusual tool is necessary for TDI® diesel pump internal repairs. Permits access to the fuel temperature sensor by removing the screws that hold on the top pump cover. Metalnerd® Brand - USA http://www.metalnerd.com/cat05.htm
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If you remove the top of the pump, make sure you check the IQ so that it's back where you started when you put it back. The top cover can come off with no problem but the middle piece requires indexing or else the car won't run right: http://www.myturbodiesel.com/1000q/multi/IQ-adjust-hammer-mod-TDI.htm
Also, have plenty of paper towels because fuel will leak out. It can't hurt to try to clean it but make sure you have VCDS to check the injection quantity value. Even if you mess up and don't check it before removal you'll need it for installation or else the engine will be all over the place.
I've been meaning to program my TDI to cut back on the EGR and eliminate the auto door locks... have access to two different Ross Tech systems... guess a little planning is in order... excellent advice, thanx!
Don't tune down the EGR using VCDS. The ECU will adapt and many people report lower mpg. This is on the FAQ on another site and has been debunked since. The correct way to tune down the EGR is to use a small restrictor gasket (may still set once CEL a year but it won't be constant), or block it off and use a new chip tune to eliminate the CEL.
Don't tune down the EGR using VCDS. The ECU will adapt and many people report lower mpg. This is on the FAQ on another site and has been debunked since. The correct way to tune down the EGR is to use a small restrictor gasket (may still set once CEL a year but it won't be constant), or block it off and use a new chip tune to eliminate the CEL.

any how-to's on this? links?

No but all you do is remove the existing gasket, cut a piece of metal the same size but with a hole in the middle, and put them back. Basically, it restricts the amount of EGR flow. It will probably still throw a MIL once a year but if you have VCDS just reset it. The smaller the hole the bigger the chance of the light. The best way to remove the EGR is through chip tuning and total block off. Of course, this is illegal so please comply with all emissions regulations.
blocking the EGR

I've been plugging up or blocking EGRs since they came up with that ridiculous idea. First thing I do is pop a bb in the vacuum port or cut a piece of metal to cover it up... or whatever it takes... I didn't on this TDI after cleaning the intake, but can see how easy it would be. They didn't check for a CEL during my emissions test and every Diesel I've had in the last 25 years has passed emissions with the EGR blocked.

The idea of running unburned carbon particles back into the engine is what troubles me.
so, looking at this:
I'd put a plate in about here:

So, will my elcheapo OBDII tester that resets P0252 codes easily also reset the code
for the EGR?

(also, thinking about it, how do I eliminate the animated gifs to the right of this text block? they're quite distracting and totally unnecessary, like I'm going to copy them into this message? )

Also, looking at the Ross-Tech VCDS, is that what I need to deactivate the auto-door locks and dial in the pump after I replace the top part of the pump? What parts do I need? which cable? The
website is not very clear, and making an incorrect selection will get me more than I need, but at additional costs... I have not shortage of laptop devices to use...

BTW, I bought a used pump on ebay, going to rob the top part off and put it on my pump,
I figure the worse case scenario will be I have an extra core that I could sell.
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follow up on '03 wagon

ended up with an 11mm pump... mechanic didn't want to install it... pump shop in portland
convinced us it was ok... mileage varies a bit... if my foot is in the pump mileage can drop down
to about 34 in town... if I drive moderately mild seeing 38-41 in town... have trouble in first gear
if I stand on it... actually had the tires smoking up the driveway one morning when I was in a big
hurry... didn't want to back off for fear of snapping something... even in 2nd gear on wet roads
the front tires have trouble hooking up... :)

freeway mileage isn't too bad... drove it up from portland a few weeks ago and got 48 mpg.

heading back to chicago (from seattle) in a few weeks... hoping to see what kind of mileage it'll get out on level ground.

the 11mm pump with new injectors and a clean egr system is pretty nice... lots of power and reasonable economy if I don't stand on it...

may restrict the egr with a plate with small hole to see if it helps or hurts... easy enough to run some tests on the trip... will bring just enough tools...
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