[urq] intermittent start issue

Wed Sep 15 08:53:02 PDT 2010

 IME with urq's intermittent starting problems during hot start is a hot start problem from the exhaust heat soak.  Urq's used a metal heat shield around the solenoid.  I've seen many urq's over the years come to me for hot start issues that end up being a starter replacement.  9/10 times the quote is "I just replaced that a month ago"....  Heat kills it.  Keith, FYI SS is a bad material for a heat shield, because it's a heat sink.  Galvanized steel is probably your best attack.  I use Galvanized steel and the 5ktq insulated solenoid bandage with a hose clamp for help here.  Cheap and effective

Interesting observation in Urqs/5ktq's I've owned and serviced. Hood vents directly above the IM, never seem to have heat soaked starter problems.  Trapped convection/radiated heat seems to reduce this issue significantly.

I say forget the load reduction relay unless you measure a low voltage at the starter.  Usually, that's the 'final' result of a heat soak issue that won't be solved by a load reduction relay fix.

HTH and my .02

SJ

-----Original Message-----
From: Keith Lloyd <spotatashleys at hotmail.com>
To: urq <urq at pacbell.net>; urq at audifans.com; audionly at gmail.com
Sent: Mon, Sep 13, 2010 2:02 pm
Subject: Re: [urq] intermittent start issue

Pete/Steve Thanks for the replies. I'll try the positive lead clean up tip 
first and if no good then I'll perhaps get a new starter.
I have already converted my car to run the headlamps via relays  - but do 
you have a circuit diagram to illustrate how to wire a load reduction relay? 
I think it might be worth doing.
When I rebuilt my car I remade the heat shields and in fact increased their 
size a bit. I have a stainless one protecting the motor mount and an ally 
one protecting the starter and solenoid so I don't think it is a heat soak 
issue per se. However the worn brushes in the starter is probably a more 
likely cause.
Thanks again for the suggestions.
All the best
Keith

----- Original Message ----- 
From: "urq" <urq at pacbell.net>
To: <urq at audifans.com>
Sent: Sunday, September 12, 2010 10:49 PM
Subject: Re: [urq] intermittent start issue

> Over the years and several older Audis I've come to understand that there 
> is
> not a single issue, rather it is the combination of several factors that
> leads to hot start cranking issues.  Time and temperature cause the 
> voltage
> drop across the start switch and wiring to the solenoid to increase, 
> thereby
> reducing the voltage available to the starter.  I measured less than 9.5
> volts at a starter that was not pulling in.  The heat soaked starter 
> causes
> the magnetic field within the starter to work less efficiently.  Many 
> times
> the heat shield Audi originally installed on the starter disintegrates, or
> is not reinstalled when the starter is replaced.  This increases the 
> effect
> of the heat related issues.  Your experience with moving the car in gear 
> and
> getting a starter to pull in is a sign that the brushes in the starter are
> getting bad.
>
> VW had a TSB for our Audi's cousins which added a "load reduction" relay
> between the starter switch and solenoid if the voltage at the solenoid was
> less than 9.5 volts.  If you are considering adding headlamp relays to 
> make
> headlights brighter you may want to add a starter load reduction relay at
> the same time.  Doing so will likely make your cranking more reliable, but
> eventually other things will deteriorate and cause starter issues.
>
> I must say that IME, simple replacement of the starter restores the car to
> reliable starting.  The early US urqs had a stamped sheet metal heat 
> shield
> that covered both the solenoid and the motor itself, but the newer cars 
> seem
> to protect only the solenoid.  I found a nice insulation and foil sandwich
> heat shield for the 5000TQ that goes over the solenoid.  When I install a
> replacement solenoid I install one of these heat shields.  I did not find
> them in the garage to get the P/N, but they are in the FA.
>
> Steve Buchholz
>
> -----Original Message-----
>
> Chaps
> Bit of an issue with getting the old girl fired up.
> I used to use my WR every day but since last October I spent a lot of
> time,effort and cash having it resprayed and have decided to look after 
> it -
> it is now garaged when not in use and is only used at weekends when the 
> sun
> is out and no rain is forecast for a fortnight. Anyway, it seems this 
> might
> not be the best policy because I now have in intermittent starting issue.
> Fine starting from cold. Go for a run, get it up to temp. Stop, park up 
> and
> leave for a few minutes and then sometimes it will not start. The solenoid
> will click but the starter will not engage. If I rock the car with it in 
> 1st
> gear - something that used to work on my my first car (VW 412LE) it will
> start.
> Is this a sign of a low charge battery (because of all the standing 
> around),
> a dying solenoid, a dying starter or something more serious. Once started 
> it
> goes like a train.
> Any suggestions gratefully received (especially ones that solve the 
> problem
> with minimal time, effort and cash!)
> Look forward to hearing from you
> All the best
> Keith
>
> '87 WR
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