> wrote in message
> news:22602116.2072.1321826084873.JavaMail.geo-discussion-forums@prfx4...
>
> On Friday, July 1, 2011 9:44:10 AM UTC+10, Bill Leary wrote:
>> The car is a 1987 16 valve Scirocco.
>>
>> When the engine gets up to operating temperature, and it's run between
>> 2200
>> and 2800 RPM the oil pressure warning activates. Get it above 2800, it
>> shuts up. If it falls below 2800, it activates again. Gun it, to get it
>> above 2800, then shift so it's running below 2200, it stays off. Bring
>> it
>> up to 2200, and it activates again.
>>
>> Any ideas?
>
> If the OP is low, you should be able to hear the bigend bearings
> hammering. It wont necessarily
> be that loud, but present all the same. You warm the engine, then using a
> jerky motion, gun the
> throttle so it goes to about 2500 rpm. If they are crook, you'll hear a
> soft "brapatatatat" noise.

I'm haven't noticing that, but now that you've described it, I'll check it
out.

> As to how this is happening? Its likely due to advanced wear of the BE
> shells and or the
> crank-journal is worn out of spec. There are other possibilities, like
> blocked oil-galleries due
> sludge, stuck pressure-relief valve, too thin an oil. Engines that have
> advanced wear *should
> not* be run with synthetic oil,..use mineral 20w-50 or 20w-60.

I'm running 20w50. I usually do in water cooled VW's. I've never been
quite convinced about synthetic oils and have been a bit leery about using
them in an engine that's been run on traditional oil for a long time and
lots of miles.

> Oil pump wear is not a common cause. But oil-pump pick-up gauze blocked
> due sludge, and
> a lackof oil-tight mounting of pump,..ie drilling may have the mounting
> bolts bottoming in their
> threaded holes [had a Valiant doing this]. Some3 times other bearings like
> the cam and or
> auxilary shaft bearings can rob the rest of the bearings of presure. Toss
> a new filter in her,
> in case its faulty...

I did do an oil and filter change, which didn't seem to help or hurt the
problem.

I managed to get a VW factory original oil pump. The guy who got it for me
said there were only two of them left in stock in the US. When I take it
apart to do the oil filter, I'll investigate the sludge issue.

Thanks.

- Bill