05 Jetta wont start is sub 20 mornings

[blu_jet_92]

My fiance's Jetta wont start once it gets below 20. brand new battery. It will just barely turn over... is this just a starter problem, or do i have bigger issues?

 

[2footbraker]

Is it the proper battery? Any codes? Your car should start at that temp easily with a proper new battery. Is it a DSG?

 

[nord]

I suppose there are other things you might consider but the battery stands out as the most likely. 20 degrees isn't that cold as far as the TDI goes. Unless your crank case is filled with honey your oil will not thicken enough to be a consideration.

Starter? I sincerely doubt a bad starter as it would be obviously weak even at higher temps.

So back to the battery. I'd be willing to bet that you have a faulty cell. This is a problem that shows up most often at heavy loads. The battery will go from a nominal 13 volts to about 11 volts and the problems you describe will become evident.

 

[blu_jet_92]

It's a brand new interstate battery. Changing the battery didnt change a thing. and it DOES struggle even in higher temps... it will always start, but it seems like its turning over really slow. i'm assuming it is the starter, but i'm not very familiar with MK5s and just wanted to check and make sure theres no chronic starting problem with these cars...

 

[Tim Birney]

The Battery has to comply to the Original Battery Specs.
If it is not within those specs, game over.

 

[blu_jet_92]

what specs... it was the battery Interstate had in their catalog for the car... you mean just cold cranking amps?

 

[gregert12]

the more CCA the better but do not go less

 

[blu_jet_92]

It's more than stock cca

 

[IFRCFI]

Glow plug issues?

 

[blu_jet_92]

the colder it gets, the slower it turns over... around 20 it wont hardly turn over at all....

 

[2footbraker]

I would check my grounds. Make sure they are tight and clean. If that is all good, I would be looking at the starter.

 

[LRTDI]

Do you have a block heater?

 

[dandywriter]

What current rating in AH is her brand new battery? The BRM OE battery is 80 Amp Hours (AH).

from Varta website
Ampere hours [Ah]
Product of the current strength (measured in amperes) and the
duration (in hours) of the current. The quantity of electricity
(capacity) of a battery or cell is usually expressed in ampere hours.
Ah is the abbreviation.
Cold Cranking Amps [CCA]
Cold cranking is the discharge current given by the manufacturer.
It is emitted by a battery at a temperature of -18°C with a minimum
voltage of Ui=7,5 volt for a period of 10 seconds, according to the EN
specifications.

The reason Ah is important for the TDI is the current drawn by the glow plugs on cold start. This occurs just before the battery is also called upon to turn over a cold, high compression engine. The glow plugs draw about 50 Amps...

A battery with high CCA may not have the AHs required for the demands of a diesel. Find out what the Amp Hour rating is for the battery. It may be for the gas Jetta...

More reading at http://forums.tdiclub.com/showthread.php?t=58342

 

[jasonTDI]

It's not the battery....

replace the starter.

 

[OldMan52]

It's not the battery....

replace the starter.

Agree. Seems the starter is draining all the power.

 

[blu_jet_92]

Agree. Seems the starter is draining all the power.

OK i'll order one.

 

[blu_jet_92]

Is the starter the same for the DSG and the 5 speeds?

 

[meerschm]

from looking at a few online vendors, they are different.

(DSG vs 5 speed)

 

[Robert6401]

Any news on this? Did you replace the starter? Any progress? Thanks.

 

[blu_jet_92]

I waiting for my tax refund to show up... for the time being, were limping by.