Paranoia?

[daveiow]

I know these cars can induce various stages of mental illness but some opinions would be greatfully received.
I have always kept a reasonable close eye on the oil pressure gauge incase of the dreaded oil cooler pipe fracture and it has always seemed about right- 7bar start up, 5 bar cruise, 2-5 tick over.(oil unknown) 60k miles
An oil change was due so prior to the Brands festival I changed to Mobil 1 10w 60 FS Extended Life and a coopers/fiam filter.
On start up the lifters seem noisier but worse is the gauge. It registers 7 on start up then seems to jump up and down in increments of about 2.5 bar. In general terms the readings are broadly the same and it never drops say from 2.5 to zero at tickover or obviously I would know I had a major drama but it is a bit disconcerting .
On a fairly concentrated push down to Pompy for the ferry the gauge seemed to settle at just below 5 bar and I thought it had settled down but today it's back to its strange new neurotic behaviour .
Questions-
Is the oil suitable?
Is it the gauge?
Is it the sender?
Is it just coincidence?
I want my sweet sounding rev happy sowing machine of an engine back !

daveiow

[Specky]

Incorrect oil is my supposition... Our engines and gucci engine oil don't appear to get on.

Have a glance at the Wiki... Just to see what people are running and where they went a stray.

I'm now back on halfrauds 10/40... I don't know who actually manufactures the oil but they're going to be reputable one would guess. I know Bosch make there batteries.

And in true LEC fashion the oil threads run and run, but what is clearer... there are groups of oil that work... And groups that don't...

TTFN

[tigerdog]

If it's any consolation, Smaug had a different (autometer) gauge and sender when I bought it. Everything looked absolutely normal with that instrument. I replaced it with the stock unit (sender was still in place) and I get the jumping bit, but only at idle with a warm engine. I also haven't found the root cause but because the other gauge did not exhibit the behavior, I believe it has more to do with the gauge/sender than the oil itself.

[Rice crispy]

Must be catching as i've recently posted on m100ndra's post with the same symptoms My paranoia started when the breather grommet on the left side of the rocker cover split in half and i couldn't find the inner half ( did finally so i know nine went into engine ) and since then ive noticed the gauge playing up .

Ive tried wiggiling the connectors on the gauge and what i think is the sender above the oil filter which faces the near side above which seems to have made the minimum pressure when warm from 2.5 bar to about 2.7bar
David

[muley]

Incorrect oil is my supposition... Our engines and gucci engine oil don't appear to get on.

Have a glance at the Wiki... Just to see what people are running and where they went a stray.

I'm now back on halfrauds 10/40... I don't know who actually manufactures the oil but they're going to be reputable one would guess. I know Bosch make there batteries.

And in true LEC fashion the oil threads run and run, but what is clearer... there are groups of oil that work... And groups that don't...

TTFN

It's COMMA. Incidentally the Halfords website recommends 10W60 or 15W50. Go figure..

HTH

Jim

[madbilly]

Here's an early morning thought. If you're using "thick" oil, like 10w60, then could the pump be causing cavitation (bubbles) which would then cause an erratic reading from the pressure sender when the bubbles reach it? If so then that's another good reason for not using thicker oil than spec (here's an ego-plug for my own research into it).

[DeanG]

I've never had a problem with the M100 (using Mobile 1 filters). Once upon a time my 1977 MGB that had fluctuating oil pressure after changing the oil. I replaced Fram oil filter and all was OK. I suspect that the filter had a bad pressure relief valve.