MKV jetta tdi random shutdown

the TLDR; tdi shuts down with no warning, MIL, or other symptoms. Notice that the fuel pump is not making any noise when turn key to on position if i wait, fp starts working again. all fuses checked (#27), all relays checked(449 460). replaced in-tank fuel pump, problem improved but still happens.
long form:
I use my tdi for uber/lyft. About a month ago I was driving on the interstate when my car briefly lost power, the glow plug started blinking and beeping. it quickly went off and my car operated normally for the next hour+ till I got home, so I didn't investigate. a few weeks later it happened again, but this time the engine died completely, I was coasting and was able to easily restart. a few moments later it died again but would not restart. after sitting on the side of the road for about 5 mins, it restarts still with no MIL, this happens 2 addition times before I get home within about 6 mi. At this point, the car won't drive more than a few miles without stalling. After doing a little research i find out that relay 109 causes a similar issue, my car doesn't have a 109, but rather a 460( main ECU power supply). I install a new 460, no change. At this point, I notice that the fuel pump is not coming on, and the car won't start at all. i check fuse 27 which is good, and has power going to it, and relay 449 which i can hear clicking on and off with the key. I remove the back seat and run power directly to the pump, and it does come on, but is rather quiet. so i replace the fp. the car runs better and I drive about 10 mi from home to test it. but to my dismay, it dies again on the road ( curiously, no glow plug light this time) anyone have any ideas?
Details:
2006 MKV Jetta TDI
310,000
BRM

Can you find someone locally with a VCDS and have the car scanned for codes.

Did you check the FP’s power and ground side for high voltage drop? You don’t want to see > 0.5 volts on either side of the circuit

Get the car scanned for help



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Unfortunately, i don't know anyone locally who has a vcds besides the dealership ( who will charge me). any ideas how i could get in touch with someone who has one? i did check it with my blue driver obd scanner, and it said no pending codes

about the voltage. does the pump get constant power, i was under the impression that it turned on and off as needed. what should i expect to see when i put my multimeter on each of the 5 pins?

Any chance it could be a clogged fuel filter? When was the last time you replaced it?

sorry forgot to mention, replace fuel filter was first thing i did

Even if you replace the fuel filter, there might still be junk inside the lines going to the injectors in your engine. If you are handy, you can try running something like Diesel Purge inside the cylinder where the fuel filter goes so that it runs just on that. It is not difficult to do but can be somewhat messy. If you are able to get a more sophisticated scanner, like the Bosch they have at Oreilly, you might be able to see some codes for what your real problem is, otherwise you will just be praying one of the things work without actually knowing the more direct and maybe cheaper approach.

mextdi said:

Even if you replace the fuel filter, there might still be junk inside the lines going to the injectors in your engine. If you are handy, you can try running something like Diesel Purge inside the cylinder where the fuel filter goes so that it runs just on that. It is not difficult to do but can be somewhat messy. If you are able to get a more sophisticated scanner, like the Bosch they have at Oreilly, you might be able to see some codes for what your real problem is, otherwise you will just be praying one of the things work without actually knowing the more direct and maybe cheaper approach.

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thanks, i already ran diesel purge thru the filter housing when i changed the filter. I do have an O'reily's near by, ill see if i can get the car over there to have them scan it

If you are serious about continuing to own this car, you need to obtain the required diagnostic tool, otherwise you are always flying blind.

You can rent VCDS from some of the vendors on this site. It's usually around 5 per day plus shipping and a deposit. There's also used dongles around 150 bucks that pop up periodically in the classifieds.

Remove the air filter box and check the major chassis ground underneath it. It is an acorn nut and has worked loose twice on my BRM causing problems. It may not be your problem but is something that could be your problem and should be checked before you look at other things. Most intermittent problems are because of loose electrical connections, corroded/loose grounds being way up there on things that fail.

Wow, that sounds like you might have something there I check that asap

Ol'Rattler said:

Remove the air filter box and check the major chassis ground underneath it. It is an acorn nut and has worked loose twice on my BRM causing problems. It may not be your problem but is something that could be your problem and should be checked before you look at other things. Most intermittent problems are because of loose electrical connections, corroded/loose grounds being way up there on things that fail.

Click to expand...

As well as the grounds already mentioned, a fairly common issue on the mkv for semi-random things is the engine harness. A search on that will get you lots of reading

I have experienced a very similar issue. In May, my 2005.5 Jetta TDI would not start. I had it towed to an independent VW shop. They replaced the fuel filter. At that time, they also replaced the timing belt and water pump (166,000 miles).

About 6 weeks later, the car stalled on the highway and would not restart. I had it towed to a VW dealership. They replaced the EGR and O2 sensor.

The car ran fine for about a month and stalled on a city street. Would not restart. Towed to a different VW dealership. They replaced the fuel pump in the gas tank. Ran fine for a couple of weeks.

Refused to start one morning. Had it towed to a VW dealership. They primed the fuel system and it ran. I had them keep it and drive it for awhile. After a couple of weeks, it didn’t start for the.

After meeting with the service manager, a regional VW engineer was brought in. According to him, the PD engines caused wear on the cylinder head at about my mileage (166K), which causes soot to build up in the fuel system. His only answer is to replace the cylinder head and a few other parts, to the tune of over $10K.

My quandary now is what to do with the car. I am the original owner. The car looks new and has been serviced regularly.

Have you received any advice that you might need a new cylinder head?

Tuxedo said:

I have experienced a very similar issue. In May, my 2005.5 Jetta TDI would not start. I had it towed to an independent VW shop. They replaced the fuel filter. At that time, they also replaced the timing belt and water pump (166,000 miles).

About 6 weeks later, the car stalled on the highway and would not restart. I had it towed to a VW dealership. They replaced the EGR and O2 sensor.

The car ran fine for about a month and stalled on a city street. Would not restart. Towed to a different VW dealership. They replaced the fuel pump in the gas tank. Ran fine for a couple of weeks.

Refused to start one morning. Had it towed to a VW dealership. They primed the fuel system and it ran. I had them keep it and drive it for awhile. After a couple of weeks, it didn’t start for the.

After meeting with the service manager, a regional VW engineer was brought in. According to him, the PD engines caused wear on the cylinder head at about my mileage (166K), which causes soot to build up in the fuel system. His only answer is to replace the cylinder head and a few other parts, to the tune of over $10K.

My quandary now is what to do with the car. I am the original owner. The car looks new and has been serviced regularly.

Have you received any advice that you might need a new cylinder head?

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Oops, my eyes saw Atlanta. Ignore that part but still check for any tdi gurus in your area and talk to frank

I would guess there are tdi gurus in the Atlanta area. Probably all you need is a new cam which can be done for MUCH less than you are being quoted at the dealership.

Read the cam threads and contact user frank06 on this site. He may not be too far away from you or can potentially recommend someone.

Tuxedo said:

I have experienced a very similar issue. In May, my 2005.5 Jetta TDI would not start. I had it towed to an independent VW shop. They replaced the fuel filter. At that time, they also replaced the timing belt and water pump (166,000 miles).

About 6 weeks later, the car stalled on the highway and would not restart. I had it towed to a VW dealership. They replaced the EGR and O2 sensor.

The car ran fine for about a month and stalled on a city street. Would not restart. Towed to a different VW dealership. They replaced the fuel pump in the gas tank. Ran fine for a couple of weeks.

Refused to start one morning. Had it towed to a VW dealership. They primed the fuel system and it ran. I had them keep it and drive it for awhile. After a couple of weeks, it didn’t start for the.

After meeting with the service manager, a regional VW engineer was brought in. According to him, the PD engines caused wear on the cylinder head at about my mileage (166K), which causes soot to build up in the fuel system. His only answer is to replace the cylinder head and a few other parts, to the tune of over $10K.

My quandary now is what to do with the car. I am the original owner. The car looks new and has been serviced regularly.

Have you received any advice that you might need a new cylinder head?

Click to expand...

Thanks but this inst really whats happening to me. My car start just fine, nearly every time. it stalls after warming up, and the fuel pump won't come on for a few seconds. after waiting, ti starts and drives again fine.

Ol'Rattler said:

Remove the air filter box and check the major chassis ground underneath it. It is an acorn nut and has worked loose twice on my BRM causing problems. It may not be your problem but is something that could be your problem and should be checked before you look at other things. Most intermittent problems are because of loose electrical connections, corroded/loose grounds being way up there on things that fail.

Click to expand...

I did as You said and didn't find anything way outta the ordinary. However many of the grounds were quite rusted so i cleaned them best I could. haven't tested it quite yet. here are some pics

The ground under the air box is a cable that connects to the ground on the transmission mount. Two 10mm bolts for the battery tray and you can get to it. I remove that cable and clean it every couple years. The acorn nut is either 10 or 13mm.

To give you an idea of how sensitive these cars are to the ground connection, I had a hard start/no start issue that had all the symptoms of a bad starter. The radio and all other electronic devices operated without a hiccup. The problem ended up being the ground connection, specifically at the connection to the transmission mount.

My mk4 PD had a similar issue, just randomly shutting down, sometimes starting, sometimes not starting for a few minutes.
Mine ended up being the cam sensor, new one cured it and it never let me down again.