2000 Beetle 1.8L Manual just shuts off

[webweever]

2000 Beetle 1.8L Manual with about 121,000 miles on it.

My daughter says it will just shutoff while she's driving. I've driven it multiple times and I can't duplicate the problem.

The only thing I do notice is if it's running and the lights and the rear defroster are on the headlights will cycle between slightly dim and and regular light with a slightly rough engine idle. When it's doing this the voltage on the battery will fluctuate between 13 - 14.5 volts.

When it's idling OK with the rear defroster off it's steady at 14.5 volts.

Is there some sort of safety switch that would shut it off like this randomly or does it sound like a battery or fuse or something like that?

[Blugg]

The Diverter Valve (Air Intake Valve) can get clogged up on the older Bug's. Takes about 8 years to do it. I'd check that. At a standstill you can watch the rev counter fluctuate up and down. Sometimes it will just stall. Easy fix, buy a new one or have it cleaned out. As it either stays open or closed.

Also check your pipes for tears, splits or cracks. Loss of air is never good. Also on older Bug's the pipes tend to give up.

Check the battery connections, wire brush if needed. Check the fuse box on top of the battery for corrosion to the wires.

Also, wanted to add, sounds like 2 problems, rather than one

My Guess

[webweever]

Thanks for the response... Where do I find this Diverter valve?

[IndyTom]

Originally Posted by webweever

Thanks for the response... Where do I find this Diverter valve?

ECS Tuning has the Genuine VW OEM Diverter Valve on Sale this week:

Volkswagen New Beetle 1.8T > Search > Diverter Valve > ES#581 Diverter Valve, 225hp Audi TT Version-Priced Each - 06A145710N

This is an updated model and is more heavy duty than the one that came with the car from the factory. The old ones did fail prematurely. Symptoms usually include loss of boost and power, honking sound made by a failing DV sounds like a duck call or like someone is blowing into an empty coke bottle. Easy to replace. You may need to cut off the clamps that are holding it and replace them with worm clamps.

The DV is located towards the back by the firewall on the drivers side. Can't miss it.

Here is a nice PDF file by AWE tuning that explains the location and removal process. Your beetle is the same year as mine so the vacuum box is on the left side but everything else should be close.
http://www.awe-tuning.com/media/pdf/..._tt_G_j_NB.pdf

This probably looks more like our set up. The DV actuation line goes into the Diverter Valve. In this picture it is an aftermarket Forge Diverter Valve which is nice but also a bit pricey. If you aren't tuned or chipped the stock Diverter Valve will be just fine.



Here is the original source for this photo: http://forums.vwvortex.com/showthread.php?782502/page2

[webweever]

I got the diverter valve off and I don't see any outward signs of problems. All the connections are clear.

Is there a way to test it or clean it? What should I use to clean it? In other words how do I know whether it's bad or not?

[IndyTom]

Originally Posted by webweever

I got the diverter valve off and I don't see any outward signs of problems. All the connections are clear.

Is there a way to test it or clean it? What should I use to clean it? In other words how do I know whether it's bad or not?

You can't clean the OEM Diverter Valve. It is sealed and has a diaphram inside so don't spray anything in it. You can push with a dull object from underneath and see how much resistance there is and if it makes any funny noises like blowing through a coke bottle. If it does you probably have a torn diaphram and the valve needs to be replaced. If there is plenty of resistance and no funny noises it probably is okay. You could also have it pressure tested but I have no clue where.

Normally a Diverter valve will not stall out your car. Your car would still operate just with reduced performance.

[2004NBTURBOS]

Originally Posted by IndyTom

Normally a Diverter valve will not stall out your car. Your car would still operate just with reduced performance.

Thats what I was thinking. Have you had the car scanned for codes? I would tend to think it would be a fuel problem. Maybe a dirty fuel filter? When the car shut off on your daughter, was she moving along or was it as she came to a stop?

[dbmcd]

Intermittent or faulty ignition switch