[V6-12v] O2 sensors and stuff

[Tom Christiansen]

Clive,

I've done the math. I'm 99.999% sure I ended up with a 22 mm crowsfoot. I'm 99.999999% sure I started out with a 13/16" and filed off about 1.5 mm of it. Nathan White specifies 7/8" in his write-up. 7/8 = 22.2 mm.

The two bolts holding the EGR to the intake manifold are 10 mm (if I recall correctly). But the large flare nut holding the connection between the EGR valve and the EGR exhaust tube is 22 mm. If you have the intake manifold out anyway you definitely want to clean the EGR passage in the throttle body!!

Watch out for the EGR temp sensor wire. It's pretty skinny. It disappears under the throttle body into the sensor. Just watch out for it and maybe remove the connector from the bracket to avoid damaging the wire.

The rumble when decelerating is quite common. Mine does it as well. I read through a write-up where somebody was going through the entire intake manifold honing every corner of it. He mentioned that the injectors shoot directly down on a small metal "ledge" and that this "ledge" may be responsible for the rumbling.

Tom



On Mon, 8 Aug 2005, Clive Young wrote:

> Tom
>
> I have the oxygen sensors sitting in front of me , I was going to wait to
> put them in until I get new cats . I got universal so I have to do some wire
> splicing. A bit of a pain so I have been putting it off. I have an o2 wrench
> but not sure if I can get it in their.
> 	My car actually spits and coughs ( especially when cold ) through
> the exhaust when decelerating and I have actually taken chunks of cat out of
> my muffler. I am not sure if the bad cats are causing the poping or wether
> the popping caused the bad cats ! I think the new cats may solve this
> problem so if anyone has any experience please " pipe up " :-).
>
> This EGR bolt thing seams a bit of a pain are you sure about 13/16ths ? that
> seams HUGE ! what exactly are you taking off with this thing !!!
>
> Clive
>
> -----Original Message-----
> From: Tom Christiansen [mailto:tomchr at ee.washington.edu]
> Sent: Monday, August 08, 2005 3:06 PM
> To: Clive Young
> Subject: Re: [V6-12v] Re: V6 timing belt
>
> Clive,
>
>> I asked what the effects of a vacuum leak and he said if it
>> leaks under hi vacuum there is not much chance it can hold refridgerant
> under
>> 250psi !
>
> Makes perfect sense. Afterall atmospheric pressure is only about 14.7 psi,
> so even if you had a really good vacuum pump (which you don't), you'd never
> exceed 14.7 psi. An excellent mechanical vacuum pump typically bottoms out
> at 10 mTorr or so (1 Torr = 1 mmHg; 1 ATM = 760 mmHg = 14.7 psi).
>
>> On my external temp gage it read 29.0 , we had a little humidity but not
> too
>> much at idle on the centre vents ( actually the left most vent of the
> centre
>> vents as it blows harder for some reason ) I had 45 F at idle with my
> thermal
>> probe and 39F while driving .  I'll let you know if it holds the cold.
>
> Cool!! It seems like the compressor works more efficiently once the engine
> RPM exceeds 2000 or so. Makes sense...
>
>> I figure it is a good oportunity to change the
>> valley pan gasket , but of course I am worried about what else i will
> break
>> while I am in there. it looks like a real nightmare around the EGR valve
> area.
>
> It's really not that bad. I've been through the EGR trouble myself. Have a
> look at Nathan White's write-up:
> <http://www.mnsi.net/~natwhite/Audi/egr.htm>
> He suggests using a 7/8" flare nut wrench on the EGR nut. There was no way I
> could get my (bought for the purpose) flare nut wrench on there. I ended up
> taking a file to a 13/16" crowsfoot and making it fit. I think I ended up
> with a 22mm crows foot by doing that. Make sure to use plenty of penetrating
> oil on that sucker. If you use a crowsfoot you don't have to go through the
> trouble of removing the battery.
>
> BTW; did you do your O2 sensors? If so, how did you get at the one on the
> driver's side?
>
> Tom
>