best procedure to push start for weak battery

What is the best procedure to push start a manual trans CR TDI because of a weak or dead battery?

I am guessing that you can pop the clutch while in 2nd or 3rd gear depending on how fast you are pushing. I'm less sure about the electrical needs to do this. Obviously you don't need to worry about enough power for spark plugs and the fuel pump is mechanical.

Is the ECU critical for this method? If it has little or no battery power will it prevent the engine from being started?

On the other hand, the lift pump is electrical but is this not a factor because when the car starts and the alternator is working the lift pump and other electrical systems will fire up?

Finally, what should be the procedure if you have a DSG transmission?

If the battery is that dead, I don't think it would be possible regardless of what trans is in the car.

In addition to the ECU and liftpump being electrical, the injectors are electrical. There are also several necessary sensors that send required signals in order for the ecu to trigger the injectors.

Lastly, if the vehicle has DSG, it is not possible at all.

The best course of action (for all CR TDI's) is to get a jump box, battery charger, or call roadside assistance.

***? Push start? This isn't the 1930s anymore.

There was a member who posted on the mk5 folder that he infact was able to pop the clutch to start his 2009. He reported the car didn't burst into flames and melt a hole through the earths crust so who knows. I can't remember if his battery was completly dead or just dead enough that it couldn't quite turn over the engine.

Personally I'd use the AAA service I've been paying for.

WIth a diesel's compression and no glow plugs push start? I wouldn't do that to mine.

If it's happening frequently perhaps invest in a GOOD QUALITY jump box. My Jump n Carry 6600 (I think) is awaum and will start 12v diesels withput issue. And it'll also let you run the glow plugs forst.

I'd buy a good jump box(very handy to have) or take a known good battery to the car.

davebugs said:

If it's happening frequently perhaps invest in a GOOD QUALITY jump box. My Jump n Carry 6600 (I think) is awaum and will start 12v diesels withput issue. And it'll also let you run the glow plugs first.

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This.

I've done it after a Winter of storage on my TDI as well. Just connect it to your battery, go and get yourself some coffee or tea (wait about 15-20 minutes) and then fire it up.

Note that lead acid batteries HATE to be flat. Very bad for them. In my case I invested in a solar conditioner for this Winter so the battery will not go dead. This may not work in your case depending on what the problem is though - it appears as though the 12v outlets inside the car are diode protected so you can't hook up a solar panel unless you do it right to the battery.

As for push starting it, I have a long story about trying that with another (gasser) VW (involving a loading ramp). The lesson I learned after just about killing myself is that if the battery is dead (enough) the computer is not working, nor are the injectors and it is not going to start no matter how fast or how far you push it.

Keep a pair of jumper cables in your car, and a power box plugged in in your house (or wherever your car lives).

Whenever I replace a battery I always get one with the highest CCA that I can. That has worked very well for me. A pair of jumper cables in the car would be a good idea too. The other thing is to replace the battery before it lets you down, either way you need to buy one so do it before you find yourself stranded.

Thanks guys, I will keep a set of jumper cables in the car for emergencies. In case the battery is not dead (just can't power starter motor) and no one is around and while waiting for the tow truck to arrive it would not hurt anything to try a push start?

Or is some critical component going to explode in front of my eyes?

As long as you have some power to cycle the glowplugs you will be fine push starting the car.

maxedtdi said:

***? Push start? This isn't the 1930s anymore.

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I was at a McDonalds months back and saw a needy family driving a (gasoline powered) heap that wouldn't start. The father could barely speak English, but I coached him on the push-start procedure and it started the first time. There were big smiles all around and they were on their way.

I frankly hadn't even thought about all of the hurdles and worries attempting this with a TDI.

If it were a life & death situation, it would be worth trying.

Otherwise I'd call AAA or flag down someone for a boost. Considering how crappy VW DMFs are, I wouldn't want to push my luck with it.

It takes alot of torque to get a tdi spinning. Lots of compression. If you need to bump start, try to get as much speed as possible and use 2nd or 3rd. That will be less hard on motor mounts and tranny internals than using 1st.

If there is enough charge in the battery to power up the ECU, a standard shift TDI will push start quite easy. Tried it with my 2006 a few years ago, worked fine.

I've push started farm tractors.... by myself and I wasn't even old enough to drive then.

Be careful and THINK about what you are doing.

Bill

First gear works fine. As does reverse.