Rough Audi A6 tickover and duff replacement parts;(..

Jul 30, 2012 8 Replies

A cautionary tale;!..


Quite somewhile ago I posted here re my vintage Audi A6 and an a rough idle problem.



From the start this would very rapidly start to "hunt" i.e. rev up to say 1500 and down and then up and down and so on.



Several part's were changed and checked to no avail, so I just decided to live with it as its an old motah and prolly not worth the cost of a main dealer looking at it..



Now theres a new garage just started up locally specialising in German cars and I thought I'd take it there just to see. One of the mech's said "Idle valve", has it been changed yet?, yes said I months ago now. Was it a gen Audi one asked he?, err dunno, sez I. Was it around 200 quid?, 'err No, more like 60 ish .. and off e-bay said the mech?, umm yes Said I.


Have you got the original one still?. Yes, never throw anything away me. OK says he, Heres what to do take the replacement one off and put the old one back on but first dump a can of carb cleaner in it to flush out all the crap that's prolly in there. If its still no go bring it back and we'll look further.



OK sez I, then he said that they had a skip full of poor quality Chinese and far eastern knock off parts over there, change them most days and then fit Gen German ones. Just done that BMW over there with a Gen BM alternator the replacement knock off unit was s**te..



So this afternoon did just what the man said and .. RESULT !!!



Its fine, ticks over right on the mark and runs that much better:)



A very Happy bunny.



Moral of the tale as above, be careful what you fit to your car;!!....



I'll pass that one onto my brother, he is VW/Audi trained mechanic. Ta.

In article , tony sayer writes

Good tip, are you going back with beer tokens?

Pal has had problems with a pattern hot wire sensor for his old Rover. Snag is new genuine ones are hard to come by. And of course much more expensive.

The one part on my BMW which gives regular problems is the heater fan speed controller. Not a simple resistor, but a SMPS. I'm on my 5th in 12 years. But it seems to make no difference if it's a genuine BMW part at 70 quid or a pattern one at less than half. They all last about 2-3 years.

Any idea what dies in it, or is it one solid lump of epxoy? I wonder if it contains adequate protection from motor back-EMF?

Sadly, yes.

It seems to fail in a variety of ways. Usually you just lose speed control so the fan runs at full speed - very noisy. Sometimes you can't even kill it with the ignition switch, as the system allows the fan to be switched on (along with an electric pump) to have heating without the engine running. Until the coolant temp drops below a predetermined level. So the only option is to pull the fuse.

The device is mounted in the heater intake air stream in an attempt to keep it cool.

In article , fred scribeth thus

Indeed;)...

"Dave Plowman (News)" wrote: [snip]

Common problem - when the controller is producing most heat (low fan speed) it is getting the least cooling. It's a fault common to some Fords and Jags using similar control units.

Well, it controls the speed, so it's self harming. ;-)

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required