Hissin' and Poppin'

[filipharvey]

Just took the A4 out for a short run and there is now a popping sound coming from the cat area of the exhaust.
Drove it home and the popping has seemed to have quietened down a bit, but there is a major amount of hissing coming from the petrol cap, as if it is trying to suck in a lot of air. There is half a tank of fuel which was put in yesterday.

When idling it seems to occasionally miss a beat, and as it was hissing, I removed the petrol cap whilst the car was running and the engine cut out. Put it back on, the car started and so did the hissing from the cap.

Any ideas? Its quite worrying as it seems to be in the fuel department!!!

Any help seriously appreciated

 

[joost]

This thread might give you some ideas...

 

[filipharvey]

Thanks for that! I just went out side to have a look at that valve and had to turn the car around to get it under the light, and it doesnt seem to be doing it now that it has cooled down a tad.

Will have to see if it happens again tomorrow, when it has a longer run!

 

[joost]

Any luck??

 

[filipharvey]

Yes, I think so! The hissing and popping have stopped, however on the day in question, it was quite wet (huge puddles etc) and I'm just wondering if water had got in somewhere, possible into the electrics to that valve (all symtoms pointed to the valve).
But it seems that for now, all is ok!

 

[joost]

Yes, I think so! The hissing and popping have stopped, however on the day in question, it was quite wet (huge puddles etc) and I'm just wondering if water had got in somewhere, possible into the electrics to that valve (all symtoms pointed to the valve).
But it seems that for now, all is ok!

Nice one, glad it's back to normal again.:thumbsup:

 

[filipharvey]

It has started to do the above again! And now it keeps saying that the fuel tank is empty and then going back up to where it should be! Very irritating! Anyone know where the fuel level sensor is situated?

 

[SteveS]

its normally in the tank. just depends on if you can get it out without removing the tank, sounds as tho there is a tank breathing issue to me. check and clean the electrical plugs that conect to the fuel tank first.

 

[filipharvey]

Yeh, well I'm guessing that the hissing is down to that valve, if I hit it or shake it about a bit whilst it is causing problems, it usually stops, so I have asked my local stealers for a price of a new one. As for the fuel level, are the connectors easy to get too? (Never ventured under the audi before!!!) If they are I will give them a good clean, but do you think that irregular pressure would cause the sensor to mis-read the level?

 

[joost]

Just consulted the oracle (aka Haynes Manual) and it says there is an access hatch in the load space floor (presume it means the boot) to get to the fuel sender unit. HTH

 

[filipharvey]

WOW!!!! Just got a price from audi for that extraordinarily small part (recirc valve 058 133 517) and was quoted £72.30 inc VAT!!! Don't think so bud! So just nipped down the scrappy and picked one up, hopefully that one is ok, thats the problem with scrappies isn't it!

Had a look in the access hatch and its is easy to get to, just can't work out how to get the damn thing (fuel sensor) off! After all, if it ain't broke, I don't want to break it!!!

 

[Jimbo.King]

I had the same problem the other week with my fuel sender unit, guage reading empty when it was half full, on the sender unit there is a small link wire to the float arm, this is soldered on and with the arm moving so much it breaks the wire, i put a new one in but could have easily repaired it.

Once you have removed the cover on the top of the tank you will have to disconect the plug connector that goes to the sender, then put your hand into the tank and run your finger down the side of the sender and you will feel spring loaded plastic lug that you will have to press in then the sender will slide up off the plastic fuel pump housing, re-fit in reverse, it is alot easier if you have a torch so you can see inside the tank.

Jim

 

[filipharvey]

I'll have a look. Thing is it is intermittant and as the recirc valve was causing a pressure problem, I am wondering if that may have been the cause of the false level reading. Will have to wait and see the outcome of the new valve!

 

[joost]

it is alot easier if you have a torch so you can see inside the tank.Jim

also much safer than a ciggy lighter or match...

 

[Jimbo.King]

also much safer than a ciggy lighter or match...

LOL, or a 240v light, smash, burn,