What have you done to your Audi A4 B7 today?

[B7Tourer]

I like the cover on the right hand side - that's an S4 or RS4 thing isn't it?

I don't necessarily think so - B6s came with these as standard - one of the few scrimps moving to the 'B7' platform - the bay was designed for them; they have a functional as well as aesthetic role - they deflect water, for example and add a modicum of further sound insulation. Anyway that right hand cover can be found across a number of models as OEM, I believe.

 

[Charlie Farley]

I leave my AC on all the time, never had any issues thus far other than the blocked heater matrix which I've replaced and which isn't part of the AC closed system anyway.

 

[Charlie Farley]

I'm sure you've checked/mentioned those before Rob, but I was just reading of a guy with a B8 and similar issue to yours; he chased the problem down the old rabbit hole too; changed everything including steering rack, and it turned out to be the worn drive shafts.

Current front drive shafts are less than 12 months old , but it has been suggested that it may well be worth going back to a pair of OE shafts, and see what occurs , so that's what I'm going to try.

 

[Matt275]

I seriously would not advise that if you want maximum longevity to the system, trust me! It doesn't use much actual 'A/C' in the winter/colder months; it's a CC after all; but in order to maintain proper lubrication the system must be used regularly.


Glad to hear it Matt and thank you for the compliment. It's what I say about careful not to overfill these systems, they are very sensitive to that and will simply stop working when nothing is essentially wrong; at least that is my experience.

Would I be right in thinking that the system does indeed have a pressure sensor that disabled the A/C until I took some gas out?

 

[northpole]

Would I be right in thinking that the system does indeed have a pressure sensor that disabled the A/C until I took some gas out?

yes it does... that all said when you put the system to hold a certain temperature ( mine is normally set on 18 degrees, because it is a pleasant temp, cold enough to not sweat, warm enough to not be cold) so it gets used more often than I actually stated. But here is the thing i do turn it off when it's not to hot in the car... eco mode is fine but when i do short trips (most of them are during the working week days) it is turned off. because i don't like the engine working harder when it's not warmed up. As i did notice the engine idles higher for longer when the engine hasn't reached working temperatures yet. So yes if the trip is shorter than 10 minutes, than nope it doesn't get used, providing it's not to hot/cold in the car.

Also this isn't my first ClimateControl equipped car so i'm quite familiar with the workings of it. And how i use it has never caused a problem before so i don't see it being a problem anytime soon, Also the topup i did was the first one the car has recieved according to the paperwork i have with it. and knowing that i should've gone for a proper aircon refill where they vacuum the system and than refill it properly. But i know the system wasn't leaking nor smelling nasty, so a simple gas and oil topup would do the trick.

 

[Matt275]

Cold air again tonight and 26.5C outside, so quite a good test. Takes a good few minutes for it to cool down, but it's more than good enough for now.
Right.... MK4 bath time woohoo!

 

[B7Tourer]

yes it does... that all said when you put the system to hold a certain temperature ( mine is normally set on 18 degrees, because it is a pleasant temp, cold enough to not sweat, warm enough to not be cold) so it gets used more often than I actually stated. But here is the thing i do turn it off when it's not to hot in the car... eco mode is fine but when i do short trips (most of them are during the working week days) it is turned off. because i don't like the engine working harder when it's not warmed up. As i did notice the engine idles higher for longer when the engine hasn't reached working temperatures yet. So yes if the trip is shorter than 10 minutes, than nope it doesn't get used, providing it's not to hot/cold in the car.

As I said before the compressor is clutchless, therefore it is always 'on'; even in eco mode; idling should never change (900 rpm) on or off; at least mine doesn't; the fan (blower motor) does change, depending, for example the speaker button on the steering wheel when pressed will drop the fan, for audibility, which is pretty cool; and pressing again will restore it. The engine drag and mpg caused by these kind of modern clutchless compressors is not huge, in any case; I don't know, maybe 5% mpg penalty; not enough to concern me too much. As they say, YMMV literally.

Most all cars today (last 20 years say) have these similar A/C compressors, I believe; some recent Alfas have clutched compressors, I think.

The main advantage of all year round A/C is demisting and lack of humidity, which can't be delivered in eco mode; plus of course the aforementioned benefit of keeping the system properly lubricated. I have had no further leaks since that first regas; and when the compressor went out; no other changes have been made to any other part since new, as far as I am aware.

Would I be right in thinking that the system does indeed have a pressure sensor that disabled the A/C until I took some gas out?

That's what I found Matt.

 

[northpole]

@B7Tourer thanks for your insights..

 

[Matt275]

B7, I saw you'd got hold of a sticker for the front grille you got recently. I need a sticker for my Golf, did you get your sticker from Zen?

Here's the one I need, plus £1.50 postage...says it's an Audi sticker, but it's definitely identical to the sticker on my Golf anyways.

Zen Graphics - Audi Caution replacement under Bonnet Decal / Sticker

shop.zengraphics.co.uk

 

[Charlie Farley]

Getting prepped to fit this tomorrow whilst I think on the way forward with the other issue.

 

[B7Tourer]

B7, I saw you'd got hold of a sticker for the front grille you got recently. I need a sticker for my Golf, did you get your sticker from Zen?

No it was from here: https://oem-carstickers.com/product/audi-tdi-warning-sticker/

 

[B7Tourer]

Ok, a bit crestfallen today; number one, the roof caved in! Or rather the headlining is going; another expense I didn't want! Well, they look sore with those pins but temporarily I found some nice ones and didn't go to town. It was a double whammy - I know how Rob feels, only there's nothing at all special about my car - just setting off fer a nice Sunday long drive, when all at once - no power; I mean no boost. She was accelerating like a 1920 model T. AA again Parts and Garage again! I ain't a salesman but, she might have been scrapped if not for that. I reckoned it was a duffed up stuffed up EGR valve, and the AA guy confirmed as much; stari8ght away he approved the claim. Bish bash bosh, in tomorrow

Crazy thing is disconnected the EGR electrical, and she is absolutely fine4, except with an EML light on.

 

[Matt275]

Could it be that the spot weld on the small flap has broken so the gasses don't get through?
I've seen where the spot weld breaks and the shaft just turns and of course does nothing....

 

[Charlie Farley]

Aborted the hybrid for now due to a problem with the oil cooler pipe, but swapped the decat pipe back on so not a totally wasted afternoon.
Also, I may have found the source of the persistent vibration, whilst crawling around underneath to undo the downpipe I thought id have a quick look at the nearside front drive shaft, and, its rattling around like it done a million miles, well the engine joint is , and its not even 12 months old yet.
Had a look at the nearside shaft and joints and its fine.

 

[Charlie Farley]

It goes without saying that i shall be having a conversation with the drive shaft suppliers with a view to getting my money back, they should be lasting for years, not months, totally unacceptable quality frankly.

 

[B7Tourer]

Could it be that the spot weld on the small flap has broken so the gasses don't get through?
I've seen where the spot weld breaks and the shaft just turns and of course does nothing....

Hi Matt, not sure if you meant me but I think they just get oil on the electrics, inside; yes often the flap breaks too, or can't move/close properly coz it gets so gummed up. In any case, fortunately, it's a straight new fit, courtesy of my AA Parts & Garage (that's twice in the space of a month; well worth the entrance fee). I know this because simply disconnecting it restores performance, although there is now inevitably the EML light on. What is even more remarkable, is there absolutely no smoke! What I thought was down to a carboned up top end that I've never touched, was simply, so it seems, a dirty defective EGR valve.

I've been a big naysayer of deletes, but it makes you wonder what they actually do, except feed crap back into the engine and prematurely age your fresh oil, black. They certainly don't seem to do eff all for the environment, from what I'm seeing; and my car's got no DPF, legally from new. I might delete later - let's see if the new one produces appreciably more smoke, first.

Incidentally, the AA have been great, but they no longer seem to get a spanner out; it's a waste of a van really, except to carry new batteries and other merch; and spare fuel for the unmechanical dozy, like my dear friend the other day. The last time one did, I had to plead and cajole him to take off my windscreen wipers to grease the spindles, to get them working, so I didn't have to drop the car off somewhere and wait a day (no tools away from home; or I'd have done it myself - I've got a puller tool now too).

 

[Matt275]

I changed my EGR last year, but was a red herring from a MAF error after I cleaned the MAF with electrical cleaner (never....ever again will I do that!) The MAF threw two codes, one of which was EGR insufficient flow or similar.

After ages of chasing dead ends, it dawned on me to try the genuine Bosch MAF (same part number) from my 2004 B5.5 Passat 130 AWX ....bingo, so got a genuine used Bosch one for the Audi, man I chased that one for months, and my cure was sitting in the driveway the whole time.
But, changing out an 18 year old EGR was fine by me to be honest, plus got some money back with exchange etc.

Not sure if my old EGR had oil in the electrics, but my anti shudder / shut off valve definitely does. I've cleaned it out twice now, and it's oily again. It must be the seals that go in the shaft and it lets oil that's going round the hose system into the electrics / motor, gears and so on.
No faults from the ASV yet.

I'm stuck with my DPF because I really don't want to go down the delete route, as I've read more horror stories about BRD DPF deletes than good ones!
It's does it's silly MPG killing passive regen thing every so often, stinks, then all good again...is what it is lol

Here's what I found a while ago in my ASV, and I bet it's the same today. The main rubber gasket is swollen / toast, but at least it leaks and tells me that oil is in it
I must change the unit at some point though, it's just a mess really.

 

[B7Tourer]

Here's what I found a while ago in my ASV, and I bet it's the same today. The main rubber gasket is swollen / toast, but at least it leaks and tells me that oil is in it
I must change the unit at some point though, it's just a mess really.

TBH Matt, I confess the whole diesel thing is a black (if you'll excuse the pun) art to me; this being the first and only diesel I've ever had in 40 years of driving. The ASV, is AKA the throttle body right? Well that's the cable I've actually disconnected, not the EGR electrical plug as I first said, while I'm waiting to get the new EGR installed. Connected, there is no boost; unconnected performance is restored for now; and there is no shudder on shutdown: someone else can explain what's going on?

 

[Matt275]

Yes ASV is throttle body...but being a diesel it's not a throttle as such. There's a flap in there that closes when you switch off which chokes the engine and it shuts down and doesn't allow the engine to run on or shudder.

After I switch mine off, I hear after a few (5 or 10) seconds the flap move back to the open position again, ready for the next engine start.
It could be that yours is sticking half shut and therefore hindering performance perhaps? If you unclip the rubber inlet hose (engine off of course), the flap should be horizontal...ie fully open.

With the ASV plugged back in, I would start the car, 10 seconds later switch off and quickly make your way to the ASV to see if you hear it open again, whip off the hose and see where the flap sits.

Do the same test with it plugged in then unplugged and observe the resting flap position. Of course only unclip the hose when the engine is off. Have you not got a fault code anywhere?

 

[northpole]

@B7Tourer The cable is disconnected so the ecu just disregards it. That is why you've got full power with the cable disconnected. The ASV is the only protection for a runaway engine though ( read engine keeps running on motoroil) it works by cutting off the air supply to the engine. So I don't recommend diesel owners disabling it by pulling the cable...

and all you need to know about diesels is that unlike petrol engines, the fuel is ignited by compression, the compression is what creates the heat needed for the fuel to ignite. The glowplugs are only there to speed up this process, and they don't ignte the fuel, it heats up the available air in the cylinders. This is why the batteries and alternator on diesels have very high CCA and AMPS. Also the glowplugs are only used for cold starts, so only forced heated for about max 2 minutes, after that the tips will stay hot, aiding the engine without them needing to be powered again. and just like a petrol engine it needs air to for the combustion process. And because of how the fuel is ignited diesels run on a lean mixture of diesel fuel.

there isn't much more to it than that above.

 

[B7Tourer]

Thanks guys

I didn't mean I know nothing of the principles of diesel, just tracing maf, ASV, vacuum errors etc, is something I wasn't brought up with.

The ASV is the only protection for a runaway engine though ( read engine keeps running on motoroil) it works by cutting off the air supply to the engine. So I don't recommend diesel owners disabling it by pulling the cable...

I know this is simply not true Northpole; there are diesels without intake valves - a lot of Mercs for example; it is for comfort and emissions only. Quite a few people even delete them along with the EGR too. If the fuel's cut off then there is no compression ignition neither and a runway situation would be impossible - mechanical fuel injection was a different matter, back in the day. In any case a runaway situation is an extremely unlikely now and rare a occurrence. Let's hope it doesn't happen to me by next Wednesday

Do the same test with it plugged in then unplugged and observe the resting flap position. Of course only unclip the hose when the engine is off. Have you not got a fault code anywhere?

Thanks Matt, but I know, the intake valve is good; I can verify this by reconnecting it and clearing codes. The car has a classic P0403 EGR code, which is a failed EGR - either electrically or mechanically; this has been verified by the AA guy and now my garage; I knew it was that before the AA fella turned up.

The reason performance is restored by simply disconnecting the ASV/intake valve is, I think, that it is mostly always open (at 45 degree sort of angle without electrical contact, except for shutdown; it closes somewhat though, I believe, when the EGR is allowing exhaust gases in. Probably my EGR is effectively closed, therefore temporarily 'deleted' and so, we are not in a no-boost situation or full limp mode. You can try it yourself if you have the misfortune of a failed EGR next; or perhaps simply disconnect your EGR too.

The engine as I say shuts down with even less of a shudder, in fact non, than I remember, and this is what surprises me, is what I meant.

 

[northpole]

In the vag case, it is... the ecu can shutdown the injectors, but if it runs of the engine oil( usually happens when the turbo pops it's seals) the only way to turn the engine of is to starve it from air... that is why the ASV is part of the setup.

And that is what I was on about...the ASV is the only protection against a runaway engine on a TDI. chances of a na diesel engine having a runaway are very slim. And when they do, they'll just run until the engine seizes or die if someone physically blocks the intake from air.

 

[ttelracs]

I'm back in the Audi after dabbling with an E500 for the past few months.

A couple of jobs done in the last couple of weeks now it nice and warm since these are all done outside the garage on the concrete.
First one was to finally fit the final brake hose to the drivers side as I used a bit of heat to free the nut at the wheel end.

Second one was to tweak the wastegate again by shortening the wastegate a bit more which finally took up the slack and made me realise what I had been missing when the turbo kicks in from about 2k rpm. I may tweak it a bit more as I'm sure the wastegate still has a little bit of play, may need to get a boost gauge or another method of measuring it.

I changed the lower boost hose from the turbo to the first intercooler as the original one was so soft and pliable I'm sure it was expanding under even mild boost. I've ordered another and will probably replace them all as the're all soft.

Finally I replaced the drivers side driveshaft as both ends had torn CVs for months as I finally felt I had the confidence and the tools to do the job.
It took me just about 2.5 hours with me taking my time, torquing up where I could and using thread lock on the driveshaft bolts fastening it to the gearbox.
Anyway a few pics of the driveshaft swap and I didn't remove the brake disc or hub assembly, I removed the bolt holding the shock absorber to the lower arm, then raised the wheel up with the trolley jack which gave me enough of an angle to slide it out from underneath.

Whilst there I noticed there's no bolt holding the anti roll bar to the stabiliser, which could explain front end roll.. I'll have to check to see if I've replaced these and it's a 'me' issue or whether it's not been there for ages and I just haven;'t noticed...

 

[northpole]

I found that one of my rear license plate lights kept popping out it's fixing... went to reposition it and noticed both need new screws. Anyone know what size screw those units have? i think they are philips M3 X 12mm but not sure... some help would be appreciated as i searched the forum but couldn't find a proper answer. thanks!

 

[PDLH]

I found that one of my rear license plate lights kept popping out it's fixing... went to reposition it and noticed both need new screws. Anyone know what size screw those units have? i think they are philips M3 X 12mm but not sure... some help would be appreciated as i searched the forum but couldn't find a proper answer. thanks!

I used M3 x 10 on my B6 when I had to change them out this year. I went with a stainless steel hex head screw as the old steel Philips screws had corroded with the aluminium mounting and I had to Dremel them out! I think the B7 switched to a plastic mounting so hopefully less corrosion issues.

I used these ones. (The thread was the same length as the black screws I removed). I just felt a hex head would be easier to remove in future than a Philips.
EBay

 

[Charlie Farley]

Not much today but I did have a nice drive on Thursday evening.
After a quick stop at Fairoaks to check out the parking format for future micro meets, I decided as it was such a glorious evening to go on a nice countryside drive, through Trumps Green, Virginia water, up to Englefield Green and back via Windsor Park and then Choham, too Worplesdon.
The roads were tranquil for a change which was nice.

On the old bus front, I have to say it is going very well, putting to one side the vibration issue, the car really goes so well, and with the decat back on it's just a rocket ship again, will only be better when the hybrid goes on with remap.
It's so nice when things work as expected, just a shame about the side issue, but hopefully, a solution is in sight there.

If the weather holds up next week, then another opportunity for a micromeet.

On the uprating front, I've ordered an ECS carbon airbox induction kit, not that it will make that much difference but will improve the look of that side of the engine bay, and every little bit helps.

So it's onwards and upwards chaps.

 

[Charlie Farley]

Also found a set of RS4 8 pots on gumtree, look nice and worth a go but need a refurb.
If I do go this route, my 6 pot 18Z's will be available.

 

[Charlie Farley]

Now just looking to source the abs pump side engine cover, some bracket parts are now discontinued though so some fabrication will be needed.

 

[Matt275]

Wash and rinse today. Got some BH Auto Wheel into the corners of the spokes and a stiff brush.... there were a few stubborn iron specs but now gone.
Used Gyeon tyre / rubber cleaner and Gyeon Wet Coat on the alloys and barrels, then BH Atom Mac on the discs - wicked stuff by the way.

Garage Therapy wheel shampoo is brilliant, so much better then the Infinity Wax offering in my experience.
Gyeon bug remover for front bumper and wingmirror casings....spray on, leave for 3 to 4 minutes and blast off bugs / guts.

Collinite 915 Marque D'Elegance holding up very well.
Final open hose rinse with the resin water vessel and walk away....oh and vacuum the inside of course. Soft brush and vacuum on the vents and switches works well.
******....didn't detail the pedals....oh well next time!

 

[Charlie Farley]

Hi Matt , im going to make a spot visit one day just to make sure you haven't missed anything.....Lol

Your car is immaculate on a dirty day let alone a dry day, full marks chap, oh and if you have time afterwards, pop over and sort out my old bus.

 

[Charlie Farley]

I've given up for the moment. I washed it yesterday morning, and drove out of the driveway, and it was covered in dust from the gravel, nightmare gravel driveways.

 

[northpole]

I've given up for the moment. I washed it yesterday morning, and drove out of the driveway, and it was covered in dust from the gravel, nightmare gravel driveways.

reesin or PFA glue it over problem sorted

 

[Charlie Farley]

reesin or PFA glue it over problem sorted

Yes, in an ideal world...
I'm not sure that is practical here, but hey feel free to contribute to it..lol

 

[Matt275]

Yes, in an ideal world...
I'm not sure that is practical here, but hey feel free to contribute to it..lol

Do they sell resin by the acre?

 

[Charlie Farley]

Do they sell resin by the acre?

I wish they did...lol

The last time I had to regravel it was 60 tons..

 

[northpole]

Lol I keep forgetting you got an abundance of space around you... nevermind

 

[Charlie Farley]

Lol I keep forgetting you got an abundance of space around you... nevermind

And it has its downsides.

 

[northpole]

If i had that much gravel around me i would deffo look into getting a certain part of it resinned so you can use that part solely for the cars/ bikes to drive up to the house & garage. From the stuff I've seen popup on facebook it can be affordable...

 

[Charlie Farley]

New front drive shafts arrived today , and this set look the best ones yet non Audi ones.
Boots are really strong and shaft quality looks good , nice rattle free joints.

 

[northpole]

@Charlie Farley what brand is that? it looks very well made... and always handy to know for future purchases