Oil pressure drops to 20 at idle

[john.hemsath]

Noticed recently oil pressure dropping from about 40-45 while driving to about 20 at idle...is this cause for concern?

Perhaps it's been doing this all along and I just now noticed.

My beam is a 67 SV that I've put less than 1k miles on since purchase.

Thanks in advance for your thoughts on the matter.

john.hemsath

 

[john.hemsath]

I've been reading up on Oil Pressure Relief Valves and thought I might remove mine to see if it's clogged or stuck. I'm assuming the hex item in the picture is the OPRV. Just wondering if it bleeds oil when removed?

 

[Greggers]

That's the bypass valve. The OPRV is on the passenger side (assuming LHD) of the oil filter block. Yes, yes it will spew some oil... how much depends upon the quality of the anti-drainback valve of your oil filter.

I've been reading up on Oil Pressure Relief Valves and thought I might remove mine to see if it's clogged or stuck. I'm assuming the hex item in the picture is the OPRV. Just wondering if it bleeds oil when removed?

 

[john.hemsath]

oil cooler tubing

Hi Greggers,

The only thing I see on the passenger side of the oil filter block are the fittings that are connected to hoses for the oil cooler unit...see attached picture.

The OPRV isn't part of that system is it?

JH

 

[Green67Alpine]

My 67 does about the same thing, little over 40-45 and a bit over 20 at idle.
It's done this for the 10 years I've had it, even with a recent major engine rebuild.
Tom j

 

[john.hemsath]

Thanks Tom, guess I'll stop worrying about it then.

I'm still confused about the OPRV...where the heck is it on the SV?

 

[hartmandm]

Hi Greggers,

The only thing I see on the passenger side of the oil filter block are the fittings that are connected to hoses for the oil cooler unit...see attached picture.

The OPRV isn't part of that system is it?

JH

The OPRV is on the oil filter block that is mounted to the top of the oil cooler distribution block.

Mike

 

[alpine_64]

It is worth checking the oprv but the engines do drop psi a little at warm idle but more so with some wear.

More importantly, what is the psi at cold idle ( over 40) ? What is it at full operating temperature at 3000rpm ( 40+ at 3000 rpm you should be fine)

Also what oil are you using ? If it's a higher mileage a 20-50 might be advisable.

.

 

[bashby]

From what I understand if you have 10 psi oil pressure per 1,000 RPM all is alright.

 

[john.hemsath]

Come out come out wherever you are

Found the OPRV...see picture...hiding under the lip of the oil filter. I hadn't contorted myself enough to spot it previously. Looks like removing the oil filter makes removing it a bit easier.

Off to O'Briens today to look for a filter wrench. Anyone familiar with Wix brand filters and the quality of the anti-drainback valve in them (per Greggers)? Curious what to expect (re: oil dripping) once I loosen the filter.

Alpine_64,
I'm not sure what the mileage on the engine is as the block was replaced at some point (block number does not match chassis #). The speedo said ~ 13k when I bought the car a year ago and I've put less than 1k on it so far. I was told the car had received an oil change just prior to going on the market so I did not change the oil. It looks clear and has no foul odor. Perhaps I'll go ahead and do an oil change and replace with a 20-50 per your advice.

Pressure has always been in the 40-45 psi range, cold or hot when tach is above 3000...only at idle does it drop to around 20.

Thanks everyone for your comments...have a great week.

JH

 

[hartmandm]

I'm able to remove the OPRV using a socket, without removing the oil filter. However, your oil cooler line routing may interfere with a socket and ratchet.

I guess you never saw the photo I posted yesterday.

Mike

 

[john.hemsath]

To err, they say, is human

I did see the picture you posted Mike, thanks, it led me to looking under the oil filter for the OPRV plug.

Cheers,
JH

To err, they say, is human but to really make a mess takes a gallon or so of engine oil.

 

[alpine_64]

Pressure has always been in the 40-45 psi range, cold or hot when tach is above 3000...only at idle does it drop to around 20.
JH

The gauges are a little hard to get accurate measurement on psi... but if you are around 50psi at 3000.. and 45 probably is then it's within expectations. 20 psi hot idle is OK... means there is some wear , but as long as you keep up regular maintenance it will be OK.

It's still worth checking the oprv and giving it a proper clean, put new oil and filter and at least you know what's in it and when it's done so you have a reference moving forwards.

 

[john.hemsath]

It's still worth checking the oprv and giving it a proper clean, put new oil and filter and at least you know what's in it and when it's done so you have a reference moving forwards.[/QUOTE]

Thanks Michael,
I will be doing this service once I have all the items needed.

John

 

[Jimjordan2]

Yes, removing the oil filter is a bit messy. I usually wrap the whole area in paper towels. Gotta turn that filter over fast once the screw threads are out.
I've got about a 1000 miles on my rebuild, with a new oil pump. Same thing, getting about 40-45 # with about 20# at a hot idle. I'm running a straight 30 weight oil here in California.

 

[RootesRooter]

20 at hot idle is normal.

Noticed recently oil pressure dropping from about 40-45 while driving to about 20 at idle...is this cause for concern?

Perhaps it's been doing this all along and I just now noticed.

My beam is a 67 SV that I've put less than 1k miles on since purchase.

Thanks in advance for your thoughts on the matter.

john.hemsath