outtatime617

I own a 2001 Boxster S, 34,000 miles. The oil light flickers and the temp creeps up when stopped in traffic after driving the car for a while. If I rev engine oil light goes off. My indy put oil pressure gauge on it and the engine oil pressure drops to near zero when warm and 2.5 bar of pressure at 4,000 rpm. Oil pressure is ok when engine is cold. The car drives strong, never rough, no tapping or other indications from engine. My indy is not a full time Porsche mech. Any thoughts would be welcome. Thanks!

Schnell Gelb

Did you post this same question elsewhere?
Anyway the standard advice you got still applies.
Change the oil and filter is an easy 'do no harm' response . Research the correct oil an consider a filter upgrade.
Inspect the old filter carefully.
Then report back.We'll try to help.
https://rennlist.com/forums/996-foru...p-upgrade.html

outtatime617

Yes I did post similar question but in wrong forum and I have additional info from my mech. At the point I posted the original post I didn't have oil pressure info. The Actually I did try 0w-40 oil vs 5w-30 and it made no difference in pressure. My mech keeps reverting back to needing an engine overhaul but all my research with fellow owners that advice hasn't come up. As I said the engine runs strong. Never rough. No oil drips or unusual sounds. Thanks for any advice!

Schnell Gelb

Suggest you Search upgrade (chamfer) 997 oil pump piston + spring. Easy fix and inexpensive.
https://www.renntech.org/forums/topi...-relief-valve/

Macster

2.5 bar at 4K could be true low oil pressure.

My info is the oil pressure for the Boxster engine should be approx. 5 bar at 5K with the oil at 90C.

The indy tech should have had the correct hot oil pressure spec and tested the engine for the correct oil pressure at the specified RPMs and temperature.

However, I doubt another 1K of RPMs would have had the oil pressure climb by 2.5 bar.

The other question is what was the engine oil temperature? You mention the temperature creeps up in traffic. There could be an overheating problem that results in a lower than normal oil pressure.

Yet another puzzle is the lack of signs of low oil pressure at idle. With the oil pressure low enough to cause the oil presusre light to flicker I would expect the lifters to be noisy. They are located quite far away from the oil pump (as is the oil pressure sensor) and are sensitive to insufficient oil pressure and supply.

In my opinion the oil pressure test raises as many questions as it answers.

You need to know the severity of the apparent overheating problem. An OBD2 code reader/data viewer can be connected to the OBD2 port and the coolant temperature monitored in real time to actually know what the coolant temperature is. My expeirence with my 2002 Boxster is under very high ambient temperature conditions (or when the car is pushed hard in less than very high ambient temperature conditions) the coolant temperature can climb to 226F. However, it doesn't go above that.

A severe engine overheating condition could possibly could account for the low oil pressure. You don't want to rebuild an engine if one or both radiators are blocked with a severe case of radiator duct litter build up or one or both radiator fans are *not* working right and letting the engine coolant (and oil) run too hot.

If the overheating problem is not materially affecting the oil temperature and pressure then the engine is experiencing low oil pressure.

While this can be due to a worn engine there can be other explanations.

To possibly confirm or eliminate a worn engine an oil analysis of the "old" oil might have been of some value. My thinking is if the oil contained a high level of "bearing" metal or ferrous metal this could be a sign the engine is experiencing true low oil pressure and it is affecting (causing wear) of the bearings or wear at the cam lobe/lifter bucket interfaces.

Other possible explantaions can be a bad oil pressure relief spring, a worn oil pump. The usual oil pump wear is at the ends of the gears the gap between end of the gears and the oil pump housing. If these clearances get too large (they should be on the order of just several thousands of an inch) this can let too much oil bleed out from the oil pump gear teeth and lower the efficiency of the oil pump.

Without knowing the history of the car another explanation can be a camshaft cover internal oil leak that lets pressurized oil leak inside the cover. However, I have to believe if there were an oil leak this severe under the camshaft cover one or more lifters would be short of oil pressure and supply and you would hear valve lifter noise (ticking) at least at idle.

Another possbile explanation -- yet another "internal oil leak" -- is the valve that controls the amount of oil routed to the piston oil jets is not working properly and letting too much oil to the oil jets. The oil passage that feeds the oil jets should have a valve that closes when oil pressure drops too low to avoid starving the main/rod bearings (and other critical bearings) of oil.

Unfortunately to determine what is going on is going to require some investigation.

While the oil pump pressure relief valve and even the oil pump may be accessible with the engine in the car the piston oil jet valve is not.

I guess what it boils down to is whatever possible explanation for the low oil pressure that can be eliminated (or confirmed) with the engine in the car needs to be done with the engine in the car.

If one fails to determine the cause of the low oil pressure by this time then I guess the engine needs to be removed and disassembled and the cause of the oil pressure found. Certainly main and rod bearings will be checked for signs of wear and their sizes checked.

Perhaps you need to find a full time Porsche tech and one very experienced with these engines. If you don't get the right info from the tech you can end up embarking on a very expensive and unnecessary engine "repair".

outtatime617

Wow! Thanks for that very detailed reply. And also taking time out from your Saturday to help me! Your suggestions are a lot to digest. I have printed it out to go over with my mechanic. I will certainly post his response here in case other owners have similar issue. I hope this can be solved soon...summer is a short season here in Boston! Thanks again!

Mike Murphy

I agree you should start with oil pump spring and piston. Too bad the choice of oil was only 30w. I agree that change from 0-40 wouldn't have made much difference. A 5-50 might have, but still, thicker oil probably won't boost pressure much anyway, and is usually only a band-aid

outtatime617

Thanks murphyslaw1978! I appreciate your advice.

Macster

After years and thousands upon thousands of miles running 0w-40 in both my cars for a while I then started using 5w-50 in the summer months. Then a year or so back just decided to run 5w-50 all the time. (I can do that here where I live/drive because it doesn't get that cold.)

Not scientific but the Boxster engine sounds about the same.

The Turbo has an oil pressure gage and based on its behavior I can't tell you which oil is in the engine. The HTHS number for 0w-40 oil is 3.8 (mPA @ 150C). For the 5w-50 oil it is 4.4.

txhokie4life

I track a Boxster S in Texas, I run 50w oil.
Even when it's a 100 degrees out, idle after a 25min track run oil pressure is 12-15psi at the absolute lowest and 50psi+ revving on track.

I've got 109k miles with 9k of those full throttle track miles.

Something isn't right with your engine.

I would get an oil analysis done and see what material is in the oil and get an idea what is not right with that engine.

I've had 3 944 engines fail on track. The last one had symptoms just like yours. Even after rebuilding the last 944 engine, it continues to have oil pressure issues. Ultimately I found a chipped cam journal. Took me 2 long years to find it but I saved that engine and the car as

I don't agree with the change the filter and oil and hope things improve.

Mike

outtatime617

Thanks Mike for your reply. I've been without the car for a month with no answers. As I've said before, it seems that an engine without oil pressure would fail almost immediately yet I hear no engine noises and the oil light just blinks on idle in traffic. No oil leaks as well. But an external gauge says little or no oil pressure. I am going to pass on your note to my mechanic.

Thanks again for taking the time to reply.

Schnell Gelb

The first noise to listen for (after a low oil pressure incident) is ticking (Lifter tappets)
The first thing to look for is 'glitter' in the pan = bearings.
The longer you run it with low oil pressure the greater the risk...

San Rensho

Change the oil pressure relief valve. Drop the sump and check for "noodles" of sealant clogging the oil pick up tube.

brianmch

This is an excellent topic. Not having probs but I'm now wondering how to install a pressure gauge in my 01 Box.

I've got 82Kmi and have a little ticking. My mech just said this morning to quit using Mobile 1 and switch to Driven as he sees lots of probs from prolonged M1 use.

Macster

Well, I haven't installed an oil pressure gage since gasoline was under a buck a gallon but maybe you'll find this of some benefit...

(If you can hang on I'll touch upon the ticking futher down...)

For normal usage I didn't find, and this is still true for my 996 Turbo has an oil pressure gage, an oil pressure gage all that useful. Oh it was cool to begin with but the main thing I use it for is to know when the Turbo engine is fully up to temperature by the idle oil presure.

(I got a chance to drive a Macan and a Cayenne both loaners and at least one (maybe both) had an oil temperature gage (display on the dash) and I found the oil temperature information much more interesting.)

The only time I really cared about oil pressure was when an engine had a problem or symptoms that suggested insufficient or low oil pressure. Then I'd use a test gage to measure oil pressure at hot idle and at some higher RPM to confirm the oil pressure was within the auto maker's specs. I tested a couple of engines for the experience but they both had good oil pressure.

If you want to installl an oil pressure gage here are a couple of links that might be of some value you to you:

https://www.renntech.org/forums/topi...ressure-gauge/


http://forums.pelicanparts.com/boxst...struments.html


For this one I'm a member but I didn't sign in and view the response. If you are a member you can sign and view the response. If not then....

https://www.pca.org/tech/additional-gauge-installation


http://www.pedrosgarage.com/Site_5/Gauge_it.html


For the ticking it doesn't have to be due to low oil pressure. It is a characteristic of hydraulic lifters that in some cases hydraulic lifters "tick". Years ago when BMW was moving away from mechanical lifters to hydraulic ones Mike Miller who wrote (and maybe still does) a technical column for a noted BMW magazine wrote about this change over and ticking. While the hydrauic lifters eliminated the need to have the valve lash adusted periodically they would eventually tick and possibly require replacement.

I don't normally like to disagree with a pro tech but I will say that a number of owners have covered a number of miles with Mobil oil in the engine. My Boxster has over 315K miles and my Turbo over 157K miles and both have up until a year or so back had nothing but Mobil 1 0w-40 oil. I switched to Mobil 1 5w-50 (not a typo for 15w-50!) because while it doesn't get that cold here it gets plenty hot. 102F yesterday. 113F forecast for today and maybe tomorrow and above 100F for maybe Monday and Tuesday. See link below:

http://forecast.weather.gov/MapClick...7#.WamBNK2B2Rt


What is important is to not run the oil too long and this is true of any oil.

If your engine suffered from the oil you've been using switching oils will not undue or reverse that.

An oil change might be of some benefit depending upon how many miles the oil has. Over the years I have observed both engines get noisier as the oil accumulates miles. Then after an oil change the engines are notably quieter. This just highlights how much contamination the oil experiences even in 5K miles which is how often the oil is changed in my cars.

Install the oil pressure gage if you want.

If oil presusre is within spec -- the factory manual has a call out but I can't recall the temperature and RPMs that pressure Porsche expects (my Boxster factory manuals are boxed/stored) -- then the lifter is just a bit noisier than the others. If the noise is too bad you might consider replacing the lifter or both intake or both exhaust lifters or even all of the lifters in the noisy cylinder. In cases where one or more intake lifters are noisy ("chattering" I think is the term used) Porsche calls for all lifters (intake lifters) on that bank be replaced.