Audi 100 Questions

Ben Doughney ben_d at
Wed Dec 29 02:37:45 EST 2004

On 29 Dec 2004, at 5:44 PM, Kent McLean wrote:

> Cold? Isn't it summer in NZ?   Hard starting may be caused by a bad
> temperature sensor failing to tell the ECU it is cold.  Poor idle may 
> be
> the ISV; clean it or replace it.

Yes, it is supposed to be summer but it is pouring down at the moment, 
and not much warmer than winter!! ;-) I will check the resistance of 
the temp sensor and compare it to my 90. I have already taken the ISV 
out and given it a blast with WD 40, and it seemed to work OK when I 
stuck a battery on it.

>> Also, the other day, while I was driving down the motorway, it got hot
>> and started to knock, but hasn't done it since so I am not sure what
>> caused it.
> That doesn't sound good.  My guess is that something (blocked
> radiator?  Low coolant level? Dead fan?) caused the car to overheat.
> The overheating thinned the oil, which couldn't lubricate things
> properly, which caused the knock.

The radiator was replaced with a new one 2 years ago, according to the 
receipts I got with it. The fan does work, but only seems to run at 
high speed- I thought these fans were dual speed??

I just thought of something else- is the smaller fan on the front of 
the evaporator supposed to run when the climate control is switched on? 
Mine doesn't seem to.

>> How do I check the mixture on this engine?
> Use an exhaust gas analyzer?

I will put my meter on it and see what it comes up like but I am not 
sure if it will be accurate enough.

On a side note, this car doesn't seem to have CIS-E, it still has the 
'plain' fuel distributor and warm up regulator on the side of the 
block, and doesn't have the self check system- I thought all of the 
later 100's had electronic fuel injection?

Ben Doughney

'71 VW 1600TL
'65 VW 1500N - Val
'66 VW 1300 Aussie Beetle
'64 VW Kombi project
'70 NSU Ro80
'71 NSU Ro80
'85 Audi 90 2.3E Quattro
'86 Audi 100CS Quattro

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