re: Audi 100 (5000 in US?), 5 cyl 10 V engine troubles

[robertwil@dido.iaf.nl (Robert Willemsen)]

Hi Audiacs,

Having read Mike Walder's askings and Phil Payne's answer, I hope to have a
small contribution in this..

Owning a 1982 Audi 100 5 cyl. 2.2 litre (the last box-design before the start
of the wind-funnel shaped Audi 100 launched in sept. 1982), I checked my german
manual:
Audi 100 and Audi Avant (fast-back):
1.9 l /74 kW (100 Hp): production 8/1980 - 8/1982
2.2 l /85 kW (115 Hp): production 3/1978 - 8/1982
2.2 l /100 kW (136 Hp): production 5/1977 - 8/1982

As you have a K-Jetronic injection system, your car must have the WC engine,
produced since 05/1977, having 2.2 litres, 100 kW at 5700 revs.; 185 Nm at 4200
revs.; needing 98 ROZ fuel.

Compression rate should be between 9 and 13 Atu (Bar); below 7.5 wear leads to
the need of overhaul. Pressure differences between cylinders should not exceed
3 Bar (doing so should be indicative for worn valves/worn piston rings or
cylinder walls in that very cylinder).
The way to test the compression:
oil-temperature about 30 degr. C.; all plugs out; starting 5 seconds with (by a
second person) floored accelerator pedal.
In doing this myself I found a prolonged starting-time tends to give higher
pressure readings on the gauge..

As the grey or whiteish 'smoke' after revving high smells 'petrol-ly', and when
under your rocker-cover-cap there are no signs of an emulsion of oil and water
(whiteish sludge), and there is no bubbling of air/gas out of the expansion
bottle of the cooling system, I guess you will have a very rich mixture..
After a starting 'session' (your engine is a poor starter) where you didn't get
her fire up: screw out a plug and see if it is wet (of fuel). You can see if it
is fuel in holding a burning match to the plug..

My manual lists the following items as defects related to the K-Jetronic
injection unit:
Test-considerations (need to be okay):
-no faulty starting procedure;
-when starting, press acc. pedal a LITTLE and keep it as is (NO pumping);
-fuel in tank;
-valve clearance okay;
-no fuel-pipe leaks;
-no contaminations in fuel;
-ventilation of engine-block okay;
-electrical mass-connection between body-gearbox-engine

Then when:

1. COLD engine will start very reluctantly:
cause may be:
CO-settings faulty;
thermo-time-switch faulty;
cold-start valve faulty;
neutral position of 'Stauscheibe' incorrect:
(is in the air-quantity-metering unit, mounted on the airfilter housing, just
aside of the wing (where the broad rubber hose is connected);
warm-up regulator faulty;
'additional-air' regulator faulty

2. HOT engine will not start (again):
CO-settings faulty;
thermo-time-switch doesn't disengage;
cold-start valve leaking;
warm-up regulator faulty;
neutral position of 'Stauscheibe' incorrect;
fuel system leaking (air leaks);
air-aspiration system leaking...

I would suggest to inspect the 'Stauscheibe'....!

Hope you will find your system's fault and you can correct it..

I have found this engine to be very reliable.
My car has done over 220000 km's and is consuming (overall) 1 litre on 11
kilometers, and doing fine..

I would like to direct some of your attention to the water-bay (room where the
battery is fitted), under the thin plastic cover..
Be careful not to let rust eat away the metal here, for you will have leaking
rain to your interior (as in my car: I will have to weld sheet metal in).
Take care of the region where the front McPherson legs fit the coachwork too
(dangerous areas when rust resides).

Hope this material will help you!

(BTW: Haynes is having a workshop manual on this type of car!)

See you,

Robert
robertwil@dido.iaf.nl


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