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BOF

Member Since 02 Nov 2012
Offline Last Active Dec 19 2014 09:13 PM
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Posts I've Made

In Topic: Problem Finding An Egr Valve For My 2008 2.2 Tdci

18 December 2014 - 06:13 PM

Along with the obvious questions above, it might be advantageous to say why you were convinced that an EGR valve was key to your problem, originally. Is it just the limp mode thing that you mentioned, or was there something else (anything about the symptoms, basically).

 

Also, do you have any chance of getting the codes read? Codes could be a very good clue, and without them it might be a bit of a scattergun approach.

 

Is the car the 2008 you mention in your thumbnail? And how many miles?


In Topic: Battery Change On Mk4 2.2Tdci

17 December 2014 - 05:32 PM

...because it can short, somewhere...the only thing that is keeping you from having an issue with a short (eg, dropping your spanner somewhere very unfortunate) or with sparks as it connects and disconnects is that you only have one connection to the battery, so you don't the other connection on the battery flailing about.


In Topic: Battery Change On Mk4 2.2Tdci

17 December 2014 - 01:14 PM

On the subject of that video -

  • that's the wrong (for the OP) air filter and engine cover; it is pre-fl, but the 2 litre, not 2.2 (the principle is the same, though)
  • I don't think that you have to take the plastic engine cover off (it is easy enough, though)
  • I'm sure I only took the top cover off the air filter, and he takes the whole thing off - not much in it, but you don't have to remove the air intake tube (although his method gives slightly better access; I didn't need the better access, but it might be different with the 2.2 and a heavier battery, if that's what you've got)
  • He wraps the earth connection in electrical tape; I wouldn't do it that way, because you'll leave traces of glue from the tape on the contact surface; put it in a plastic bag and use the tape on that, if necessary
  • He assembles all of the battery terminals completely dry (no grease is used, at all), and I'd rather go with the old fashioned approach of a little vaseline over the top, after assembly; this might be belt and braces with the 'water recycling' of the modern batteries, but I'm in the 'why not' camp here
  • This is the big one; if you watch, at the end, his use of that ratchet on the ground connection gets very close to the other battery terminal; if that touches, you have 500+ Amps and it welds the ratchet in place (and ruins the ratchet and possibly the battery and, of course, your day). This is not a good thing. Put the front of the battery cover on first and be careful not to touch it with the ratchet (it is not the most robust thing in the world), be very careful or use something with an insulated handle (or, if you've got terminal covers on your battery, you could use those). Don't copy the video exactly. Just don't. Even if it takes fifteen minutes more to be careful, be careful (and it probably should be nearer five). It really is worth it.

In Topic: Battery Change On Mk4 2.2Tdci

15 December 2014 - 11:25 AM

Sorry, that wasn't really clear enough; I know what I meant, but you wouldn't necessarily know that from reading what I wrote. The vaseline should be put on the terminals after they have been assembled and tightened up.

 

It isn't, however, a big problem if you do it first (or have some vaseline smeared around from the previous time that it has been done and don't clean it up perfectly) because the excess gets squeezed out and the vaseline just ends up in places where there would otherwise be an air gap. If it doesn't, then you haven't got the terminals tight enough...

 

You are right that vaseline doesn't conduct electricity, and that's unhelpful, and keeping the contact surfaces apart with vaseline would be bad.

 

The problem of contact corrosion seems to have become less evident over the years, though, presumably as batteries have become better at keeping any corrosive fumes internally and not venting them. I still do the vaseline thing, possibly as much out of habit as anything else, but you do know that terminals assembled dry are going to be ok, when assembled new, but it is a little less clear how they would be after 4 - 8 years, however long the battery naturally lasts.


In Topic: Battery Change On Mk4 2.2Tdci

14 December 2014 - 10:19 PM

Had a quick google and it recommended removing the air filter cover to make getting at the battery easier. 

 

I have the 2 litre and the air filter is different (and it might be different pre- and post- fl), but...

 

You need (for convenience...maybe you don't actually absolutely need, but it makes it easier) to slide the battery in, more or less horizontally. If you were two people, maybe you could get the battery to 30 - 45 degrees, and then rotate it to level, and then you wouldn't need so much of the clear path in, but the two people would get in one another's way.

 

The top of the air filter is in the way - at least on a 2 litre - so that needs to go and there are three or four retainers that need to be unclipped. The full air filter does not need to be removed, just the top cover.

 

The front part of the battery box un-clips, and you need that out of the way, too (you squeeze it in a bit). This is easy, once you suss out the how the clips work, but, if you try to force it, you would just break the cover. 

 

From a safety point of view, disconnect the black/negative terminal first and then the red/positive. There is a 'hold down' at the front of the battery, held down by a single bolt, and that should be removed. The careful will take a photo before removing. 

 

Slide the battery out of the way (easier if it has those folding handles) by pulling it forward and up. At this point, re-fiiting is the reversal of disassembly, as Haynes would say.

 

Of course, it would be easy if batteries were light, but they aren't.

 

When refitting the terminals:

  • red first
  • even small amounts of corrosion are bad, so clean carefully, if necessary
  • some vaseline is usually advised to protect the terminals from corrosion; I've also used 'copper grease' on the terminal surface, because I couldn't see what harm it would do, but that's optional
  • tighten up the terminals, but do it carefully; it is possible to break the seal between the terminal post and the battery body (which is bad)
  • there will be a spark as you connect the second terminal; the connection order does not change this; don't have your fingers too close or have anything flammable around the area

 

The 'hold down' has to be refitted. There is no guarantee that it goes back in the same way that it came out, as the replacement battery might be a different length from the one that came out, and, in that case, you might have to play around with using the alternative mounting hole and/or flipping the bracket over, so that it fits the new battery correctly. A little grease on this bolt might be helpful, too, but won't help until you take this clip out again.

 

And you'll need the code for the stereo.