SL6 Forum,

I noticed my motor’s oil pressure doing strange things over the last month.

My motor is a couple years old (have had a bit of discussion on this forum regarding a pinging issue that has been since sorted) and previous to this would rocket instantly to 40-45psi on start-up. I am running both the original warning light gauge and a mechanical gauge. Changed oil and filter in early October 2013. Checked oil level is ok regularly (weekly). Engine temp is normal. I haven’t checked/maintained the oil pump pressure relief valve (sorry Slant Six Dan. I know…).

Symptoms…
•Initially the oil pressure would only get to 30psi on start-up and creep up 38psi when engine was fully warm.
•A few weeks later, oil pressure would take a few seconds to get to 25psi on start-up and a fair bit of time 10 mins to get to 38 psi.
•A few weeks later/currently, oil pressure would take a 5-10 seconds to get to 20psi on start-up and nearly 20 mins to get to 35 psi.

The issue seems to be slowly escalating.

Have got the car booked in at my mechanics in a couple weeks’ time (I just can’t spare the time at the minute) to get a few things done (tweak dizzy curve, etc.) to the car and have this issue looked at properly. Car will only be doing local area drives (under 80km/h). I have a spare oil pump that I know was fine when I last used it (produced constant oil pressure 45psi).

In the meantime, as added insurance/piece of mind over the next couple days, I was intending to squeeze half an hour of time on the issue in a couple days. I was hoping to simply:
•Check warning lamp was working/indicating, and
•Replace oil filter (you never know…)

Has anyone on the forum experienced these symptoms? If so what was the ultimate cause?

Also, can you purchase new pressure relief valve springs separately (not part of an oil pump rebuild kit)? Can't seem to get them here in Aust.

Any help/advice/comments appreciated.

Regards,

Bare Metal Maz

PS: Best wishes for the festive season!

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Love cruising in a bare metal Val!

This is one of those questions that probably answers itself, then.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Slant Six Dan, I'm bowing my head in shame... Will keep you posted.

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Love cruising in a bare metal Val!

Hi Maz,

I agree that it would be best to pull the relief spring and clean things. I would pull the cap, remove the spring and piston, spray out the passage with spray carb cleaner (solvent), then reinstall the same spring and piston. Look for scored walls, etc. I bet you just have a little trash in there. The spring should not be damaged, but if so you can just pull an old spring out of an old pump and use that. I have used old springs many times with no ill effects. You can also put a small washer (about 1 mm thick) between the cap and spring and that will raise your ultimate (when revved) oil pressure 5-10 psi.

Another possibility is a cracked or loose oil pickup to the pan. Much harder to check/fix that one...

Yes, try replacing oil filter first, if you have not already. I seriously doubt it is the gauge, but you can also try another one of those.

Lou

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Home of Slant6-powered fun machines since 1988

Cut open the old oil filter and inspect for bearing material or cast iron particles. (oil pump drive gear "dust"?)
You will know if you have a major issue or not, depending on what you find (or don't find) inside the oil filter.
DD

Best to be certain you actually have a pressure issue and it's not a sticky gauge. I'd put a reliable pressure gauge on it and see what you've got. Then I'd put on a decent filter and good oil...there's a lot of crap filters on the market these days and it's possible it's an issue. Lucky for you oil pump gears don't really seem to be an issue in Australia,our pumps are different and I believe the pump rotors are smaller than the standard replacement USA style pumps? Don't quote me on that....but for whatever reason we seem to be OK...maybe it's the zinc content in our oils? To take 20 minutes to reach full operating pressure really puts a question on the gauge in my book....at least as a starting point.

Thanks for the great info guys. Will definitely take/act on your advice. New filter will be going on tomorrow morning.

By the way I noticed a typo in my message. I changed the oil in Oct 2014 - not 2013!

Will keep you posted.

_________________
Love cruising in a bare metal Val!

Hi SL6 Forum,

Happy New Year!

Glad to report I started the year with a win. Changed the oil filter today and the oil pressure went immediately to 40-45psi following the change. Went for a drive later on in the day and all seems sweet. Will change the oil and filter in a couple weeks.

Have kept the filter and oil that was in it. Will try to identify the exact cause with the mechanic in a couple weeks and report back to the forum. Will take pics if I see anything interesting. Not sure what I will find...

Thanks for all the help.

Bare Metal Maz

PS: Slant Six Dan, will get the mechanic to check the pressure relief valve.

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Love cruising in a bare metal Val!

very interesting, it will be great to hear what is found in the filter. I have changed a lot of oil and filters in my 67 years and have never run into a problem that could be tracked to a oil filter that has been changed recently.

Also have not given much thought to filter quality, I guess I had better wake up.

Another lesson learned from the awesome Forum.

Thanks,
Metal Turkey

Probably reinforces the idea of running a separate oil pressure gauge. If it was left up to the original warning light (haven't got round to testing it yet...), the problem would never have been identified.

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Love cruising in a bare metal Val!

I have heard of filter media collapsing and blocking oil flow. that sounds like a possibility.

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Dave

1977 d-200 crew cab ex-army pickup wants it's /6 back
1962 Valiant 2 door, 170, three on the tree
1972 d-100 parts truck
80 volare wagon now a parts car

Was it a FRAM?

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Not sure what brand you fitted,but I've always had good results with the Ryco,Motorcraft and Cummins Fleetgard filters...all come in Z9 size....cut that old filter open and take a look inside,will be interesting to see what you find!

OIl Filter was a Cooper WZ9. I have traditiaonally used Ryco filters (and have one on there now).

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Love cruising in a bare metal Val!

SL6 Forum,

OK, apologies for the delay.

I ended up cutting both the Cooper WZ9 and the Ryco Z9 oil filters (was on there for a few weeks).

Turns out the Cooper filter was completely clogged with what looked like grease all over the paper elements. Oil would of been going through the bypass. Not sure what has happened and my experienced mechanic has never seen anything like it in all his years. I have no idea why this would occur. Was it a manufacturing issue? A reaction with the oil? We can't put it down to anything specific. It really looks weird!

The Ryco we cut up looks completely normal. Will be sticking to these filters from now on.

Oil pump pressure relief valve was perfect, and there was no metal in the filter. Lucky!

Just goes to show the importance of an oil pressure gauge as apposed to a warning light. Could of been a lot worse result.

Will upload some pics when I get a chance next.

Thanks for all the advice guys.

Lesson

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Love cruising in a bare metal Val!