[s-cars] RE: Oil Pump Replacement

[CyberPoet]

Dear Simon,

The first things to do are as follows:

0. Test the oil pressure sender for accuracy (see the manuals).
1. Get a can of Gunk brand oil flush, two replacement Mann oil filters,
10 liters of non-synthetic 10W30 or 10w40. The V6 does not want to live
on anything under 10 weight according to the manual (5W40 and 5W50
synthetic are too thin).
2. Find a warm place to work on the car (or beg, borrow, steal a block
heater & warm overnight).
3. Swap oil filters, drain the car's oil, refill with 5 liters of new
oil, start the engine, add the Gunk immediately, run for 5 minutes
while maintaining whatever RPM you need to keep the pressure above
minimum (2 bar or so).
4. Immediately drain the oil and yank off the oil filter again. Leave
them out. When the oil draining from the oil pan dies down to a
minimized trickle (or stops), turn over the engine with the key for
about 1/2 a second to one second, but do not let the engine start. If
you car fires easily, you may have to pull the plug wires temporarily
to ensure it won't fire. This will push out any additional reminents in
the pump (not advisable under all circumstances, but if you are
thinking of replacing the pump anyway, no foul).
5. Remove the recently installed  oil filter, cut it open with an oil
filter tool (a large form of pipe cutter, about $20), unfold the
element and examine it for metal shavings, check the by-pass valve for
activation.
6. Install the new filter, plug the oil pan plug, fill up to the
required level with at least 10w30.
7. Restart the engine, allow to run 60 seconds at whatever RPM you need
to maintain minimum oil pressure, shut off, recheck the oil level, top
off with more oil as needed.
8. Restart and check your pressure. Is it now where it needs to be?

Oil pumps of this design are not prone to failure themselves, but the
oiling system can become prone to blockage of the oil passage ways
(similar to cholesterol blockage of the arteries). This is especially
true if the car lived on a diet of standard (non-synthetic) oil for a
long time under a previous owner who ran it hot frequently, and then
you switched out to a synthetic (5W50 for example)  -- the synthetic
can cause thickened oil deposits from the old oil used to detach and
then block a passage. Most brands of economy filters for the V6 do not
have a good oil clot catcher with a by-pass valve -- the mann filters
do (if you cut filters up like I do, you start to understand the
differences after a while).

Hope this KISS solution works for you. If not, best of luck!
=-= Marc

On Monday, February 17, 2003, at 08:46 AM, <simon.adams at vertu.com>
wrote:

> Hi guys
>
> I've got what looks like a failing oil pump.
>
> This month starting the car in cold winter mornings is playing havoc
> on my oil pressure. I get the autocheck system sounding the red oil
> warning and my oil pressure gauge is reading zero bar. It's not untill
> I rev the engine past 2000rpm or on very cold starts past 3000rpm that
> the pressure picks up and everything is normal, sound familiar?
>
> I have replaced the non-return valves and the cylinder head pressure
> valves to no effect. It could be that the oil pickup screen is blocked
> but I doubt it.
>
> Seems everything points to the pump. This sounds expensive and a time
> consuming job. Has anybody got pointers and expected prices of parts
> and how to tackle the job? - The car is a 1994 European coupe with the
> 2.8V6.
>
> Thanks for your help.
>
> Simon.