Cure for low oil pressure at warm idle?

[911Freak]

I know this already has been discussed many times here, however, I'm not having any luck with a search so....

Once warmed up my 3.0l oil pressure drops below 1 bar at idle (sitting in traffic)

Sometimes as low as the half way point between 0 and 1 bar

I thought there was a fitting you could put on a oil feed line that has a smaller diameter than the oem fitting, thus increases pressure, true?

This has only been an issue now that I'm spending more time in traffic

Engine has roughly 60k miles, strong compression and is maintained properly.

Any insight would be greatly appreciated

[psalt]

Idle oil pressure is irrelevent, there is no load on the engine and flow is all that matters. Porsche has stated this many times over the years, it is OK for the Oil pressure light to come on at idle. Does the light come on ?

[911Freak]

Originally Posted by psalt

Idle oil pressure is irrelevent, there is no load on the engine and flow is all that matters. Porsche has stated this many times over the years, it is OK for the Oil pressure light to come on at idle. Does the light come on ?

No light has come on, it is just scary to see the needle drop...
So I'm ok then?
Thanks!!!

[afterburn 549]

Oil restructures to the cam. A big over all improvement

[911Freak]

Originally Posted by afterburn 549

Oil restructures to the cam. A big over all improvement

I assume only one is needed?
(On the right side of engine, correct?)

And there it is, Pelicans coming through again!

Thanks guys!

[psalt]

Yes,

Oil pressure paranoia is why BMW refused to fit OP gauges for many years. Several MFG's altered the range and markings because of the psychological effect of a below middle needle. Most people do not realize that modern gauges are non linear and designed to read in the middle unless extreme variations occur. More oil pressure at idle is not better, worry about something that matters.

[afterburn 549]

2, one on ea of cam tower.

[911Freak]

Perfect, again many thanks for all the heads up & usefull info!

This is just another reason I need to get a better oil temp gauge as heat is the true killer of our beloved flat six engines!

PSalt: excellent, makes perfect sense. Now I'm free to get back to working on suspension upgrades and paying proper attention to the traffic ahead of me not staring at the pressure gauge!

I thank you as does everyone in front of me on the roads!!!

[Gogar]

In addition, the cam oil line restrictors are a much-debated subject and if your pressure while driving is ok, then many folks here would suggest you NOT go for the cam oil lone restrictors.

[911Freak]

Originally Posted by Gogar

In addition, the cam oil line restrictors are a much-debated subject and if your pressure while driving is ok, then many folks here would suggest you NOT go for the cam oil lone restrictors.

So possibly their best application would be for engines towards the end of their life span, as a band aid of sorts?

I'll search for threads on the "cam oil line restrictors" and review the pro's and con's.

My oil pressure while driving seems to just about match 1 bar per 1k rpm, unless the engine gets to full warm operating tepms

FWIW: my engine never has gone above mid level on the temp guage

Thanks!

[Steve@Rennsport]

Originally Posted by 911Freak

I thought there was a fitting you could put on a oil feed line that has a smaller diameter than the oem fitting, thus increases pressure, true?

JMHO, but I would NOT install those.

Make sure you are using a good 15w-50 or 20w-50 oil.

[afterburn 549]

OK, there was a big thread on this couple yrs ago,,consensus was, after break inn put them in. I did. No problems, no cam wear, all is well. And it is a Porsche part , they invented it
I would have to say.. I am not all that kind to my eng and it is in good shape since rebuild. I installed them probably 2 months after rebuild.

[Gogar]

Originally Posted by 911Freak

So possibly their best application would be for engines towards the end of their life span, as a band aid of sorts?

No. Maybe a pro like Steve will tell you 'why', but if not, I can try in layperson words.

The restrictors reduce the amount of oil going to the cam towers, which is one of the areas that needs it the most. It increases the amount of oil that stays on the other side of the restrictors, which happens to be where your pressure sender is as well, thus raising the needle on your gauge a little bit and giving you a warm fuzzy feeling that you've done the right thing.

That's my understanding

Originally Posted by Steve@Rennsport

JMHO, but I would NOT install those.

Make sure you are using a good 15w-50 or 20w-50 oil.

See? Right on cue! And he's one of those guys who actually knows.

[jh225]

2 things...

First off, rule of thumb on any street engine is 10psi for every 1K of RPM. So at idle if the car is running at 750RPM, 1 bar (or 10psi) is more than adequate.

Secondly, how can you be sure your VDO is accurate? Get a separate gauge, plug it in and see what it reads.

[Flieger]

Your oil pressure is good. Do not starve your cams and valvetrain of lubrication by installing the restrictors. 10psi/1000rpm is good. Idle pressure can be less.

[HarryD]

Listen to Steve.

My thoughts on this topic are in this thread - http://forums.pelicanparts.com/porsche-911-technical-forum/337011-camshaft-oil-line-restrictors-two-thumbs-up-post3174010.html?highlight=restrictor+oil#post3174010

and this thread:

Camshaft Housing Oil Pressure Restrictors

[nimskov]

Perhaps the REAL reason for Porsche to install the restrictors on the later models are simply to make the guage drop less at idle??

[afterburn 549]

Dont know ....they must have had a reason..??

[HarryD]

Originally Posted by afterburn 549

Dont know ....they must have had a reason..??

Yes they did.

Be aware that the addition of the restrictors came after the upgraded oil pump which puts out more volume at a given pressure. I suspect the flow to the heads remained about the same with the extra flow going to the piston squirters and bottom end.

Besides, what would Steve and Grady know that many of us do not?

Originally Posted by Grady Clay

“so are you suggesting not running cam line restrictors??”

Absolutely.

In my opinion this was a “fix” that Porsche did picking the lesser of two evils. The issue stems from the ability of an SC or Carrera being comfortable to drive at 2000 rpm and sometimes less. The piston squirters are necessary to keep the pistons cool. However they don’t open until 42-56 psi. With full flow to the cams, the main oil pressure at the squirters was too low. They didn’t open until the engine was above 5000 rpm when hot – too late.

Porsche’s “solution” was to limit (restrict) the oil flow to the cams, rockers and all the parts in the top end. Note this also includes valve guides. Of course the restrictor raises the pressure in the main galley that feeds the piston squirters. They then open at lower rpm. The problem, IMHO, is there was already marginal oil to the valve train when hot and low rpm. The restrictor exacerbated the problem

I think Porsche chose to improve the piston cooling at the (evil) expense of valve train lubrication and cooling.

I’m not willing to build a nice engine with any preventable shortcoming.

Best,
Grady

Originally Posted by Steve@Rennsport

I'm in total, complete agreement with Grady on this issue.

Some of the hottest parts of the engine are in the heads and its totally counterintuitive to REDUCE oil volume & flow to these areas that need all the cooling and lubrication they can get.

Personally, I will not use the cam line restrictors and in fact, prefer to upgrade oil pumps where feasible. In addition to Grady's comments about power, improving oil scavenge in the sump by using either the 930 or GT-3R oil pump reduces oil temps and helps power output by keeping the oil level in the sump well below the spinning crankshaft.

[BLEW911]

After reading Grady's quote I'm thinking the lesser of two evils is doing a top end not a bottom end. I think I'm all for working piston squirters. Right?

Don