Oil pressure issues?

Engines, Transmissions & Final Drive questions and answers

Moderators: timk, Stu, zombie, Andrew, The American, Lokiel, -alex, miata, StanTheMan, greenMachine, ManiacLachy, Daffy

ferg
Driver
Posts: 62
Joined: Tue Jul 15, 2008 1:26 am
Vehicle: NC
Location: gippsland victoria

Oil pressure issues?

Postby ferg » Mon Jan 23, 2012 4:48 pm

My na has 304k on it but seemingly still going well. When hot std oil guage hardly reads at idle and just over 2 unless at high revs. Should i worry or ignore? Appreciate your thoughts
'89 NA - red, '90 NA Eunos - red, 2010 NC - white

User avatar
hks_kansei
Speed Racer
Posts: 6154
Joined: Tue Feb 03, 2009 10:43 am
Vehicle: NB8A
Location: Victoria

Re: Oil pressure issues?

Postby hks_kansei » Mon Jan 23, 2012 4:55 pm

Certainly don't ignore it.

Best case scenario:
The gauge is broken and not reading correctly.

Worst case scenario:
The engine actually has low oil pressure and would be rather quickly on it's way to death.
1999 Mazda MX5 - 1989 Honda CT110 (for sale) - 1994 Mazda 626 wagon (GF's)

User avatar
aka_juffa
Racing Driver
Posts: 1005
Joined: Wed Dec 14, 2011 2:40 pm
Vehicle: NA8
Location: SE Melbourne.

Re: Oil pressure issues?

Postby aka_juffa » Thu Jan 26, 2012 11:57 pm

Try some basic stuff first.

1. The oil pressure sender unit is just near the oil filter under the intake manifold. It has a single wire running from it to the guage. Pull the wire off and clean the connetor on both the end of the wire and the send unit. A bad connection can lead to dodgy pressure readings.

2. What type of oil is in the engine and how many Km since the last change?

J.
Motor Neurone Disease chose me, I choose Voluntary Assisted Dying.

ferg
Driver
Posts: 62
Joined: Tue Jul 15, 2008 1:26 am
Vehicle: NC
Location: gippsland victoria

Re: Oil pressure issues?

Postby ferg » Fri Jan 27, 2012 7:33 pm

Hi guys,

Very pleased to report your advice taken and appears to have worked. Changed oil today to Castrol GTX 20/50 and new oil filter - immediate response is about 50% increase in oil pressure across the board. Will report back in a few days to see what it has done for rattling hydraulic lifters and to confirm better pressure remains. Also will verify on a really hot day where it was particularly on a hot day.

I was about to fit a short term oil pressure gauge to see if perhaps it was a crook gauge or sender, but don't think I'll bother (yet!)

Cleaned the connections of existing sender unit as advised however fairly certain it's the new oil making the difference.

Many thanks for your input guys - great to have such a resource available!
'89 NA - red, '90 NA Eunos - red, 2010 NC - white

evil_weevil
Racing Driver
Posts: 1401
Joined: Wed Nov 19, 2008 2:50 pm
Vehicle: NA8

Re: Oil pressure issues?

Postby evil_weevil » Wed Feb 01, 2012 1:28 pm

hey people,
while on the topic of oil pressure gauge,
my factory one on the dash was around 3bar, and my aftermarket one suddenly dropped down past 2bar and slowly dropping.

i stopped the car, shut it down.
say 20mins later started car up and both gauges worked and showed similar pressure.

Im hoping mine is just a lose connection to the a/m gauge.

thoughts?
Looking for an SVT motor for this:
viewtopic.php?f=73&t=62834

ferg
Driver
Posts: 62
Joined: Tue Jul 15, 2008 1:26 am
Vehicle: NC
Location: gippsland victoria

Re: Oil pressure issues?

Postby ferg » Thu Feb 02, 2012 12:07 am

As some one who knows very little, I'm guessing if the factory gauge showed OK, then first port of call is suspect the aftermarket one. If it's a pressure line one, I have often wondered if they should be bled to ensure there is no air between engine and gauge......just a thought. Hope it turns out to be simple.

I'm pleased to report my pressure appears to be staying good and the hydraulic lifters have not rattled once on start-up since change of oil and filter. I hope the 4-5k on "low" pressure has not done too much damage (famous last words?)

Once again, many thanks for your input all.
'89 NA - red, '90 NA Eunos - red, 2010 NC - white


Return to “MX5 Engines, Transmission & Final Drive”

Who is online

Users browsing this forum: No registered users and 105 guests