[urq] odd temp behavior

[Scott Justusson]

 This problem Steve noted is common to CGT/4k/CQ, and any Urq that has those digital/analog gauges installed.  IME, it's usually the common power feed to multiple gauges that is the root of the problem.  Best fix IME, is to run individual power feeds to the gauges from a 15 (switched) power source on the fuse block.  This gives more accurate temp and voltage readings.  

Before I'd suspect a problem with the cooling circuit, I'd get a IR temp gauge on the engine, or just replace the gauge with something more accurate for testing.

HTH and my .02

Scott J
Inaccurate audi gauges aplenty in...
84 urq
83 urq
87 CGT
86 CGT
87 4kq

 

 

-----Original Message-----
From: Mike Sylvester <mike at urq20v.com>
To: Steve Buchholz <urq at pacbell.net>; urq Audifans <urq at audifans.com>
Sent: Wed, Feb 29, 2012 10:49 am
Subject: Re: [urq] odd temp behavior


This experiment will have to wait until I can drive the car again.

Mike



> -------- Original Message --------
> Subject: Re: [urq] odd temp behavior
> From: "Mike Sylvester" <mike at urq20v.com>
> Date: Tue, February 28, 2012 11:19 am
> To: "Steve Buchholz" <urq at pacbell.net>, "urq Audifans"
> <urq at audifans.com>
> 
> 
> I'll have to verify if the high temp reading is linked with the blower
> motor speed or the heater temp selection.
> If it were the blower motor speed I would have also seen this behavior
> in the summer, but the possibility of a bad ground can't be overlooked
> in these cars.
> 
> The temp it doesn't jump around right away when the blower is turned on
> or off.
> When it is hot and I turn off the blower and change the heat setting ,
> it takes about 5 minutes for the engine temp reading to come back down.
> 
> Mike
> 
> 
> 
> > -------- Original Message --------
> > Subject: Re: [urq] odd temp behavior
> > From: "Steve Buchholz" <urq at pacbell.net>
> > Date: Tue, February 28, 2012 10:36 am
> > To: "Mike Sylvester" <mike at urq20v.com>,  "urq Audifans"
> > <urq at audifans.com>
> > 
> > 
> > By any chance were you running the interior blower at the same time? IME the 
ground current from the blower causes a voltage drop in the gauge's ground which 
causes erroneous readings.
> > 
> > Steve Buchholz (mobile)
> > 
> > ----- Reply message -----
> > From: "Mike Sylvester" <mike at urq20v.com>
> > Date: Tue, Feb 28, 2012 6:29 am
> > Subject: [urq] odd temp behavior
> > To: "urq Audifans" <urq at audifans.com>
> > 
> > With the mild weather we've had here in NE, I've driven the urq a few
> > times.
> > I've noticed that engine temperature has been abnormally high, which
> > seemed odd since the outside air temp was in the 30's.
> > 
> > The strangest part is that the engine temp only goes high if I have the
> > heat in the hot position.  If I move it to cold, the engine temp will
> > drop back to normal after a few minutes.
> > 
> > This seems completely counter-intuitive.  How can allowing coolant to
> > flow through the heater core cause the engine temp to rise?
> > Is is as if it ceases to flow through the radiator when the heater valve
> > is open.
> > 
> > 
> > Mike
>