Marine Blue

So a couple of days ago I changed the oil and filter in the Shark, just routine maintenance and baselining. The oil coming out wasn't too bad but 9 months old and I wasn't sure if it was synthetic so I changed it. Also not sure what the weight of the oil was as it wasn't on the receipt. No metal shavings and everything went smooth except for the PITA belly pan.

Anyways today I'm driving the car for about 20 minutes in high temps (88 F and humid) with both front/rear A/C on and I watch the oil pressure slowly start to drop. I noted it was worse after sitting at a stoplight for a while. It did climb back up to 5 but only when the RPM's were over 3200. At idle it floated around 3 to 3.2. Prior to the oil change the pressure never dropped below 4 even after spirited driving. No low pressure warning light or low level light. Checked the level when I got back and noted it was just above the midpoint on the lines which is exactly what it was when I changed it.

I used 0W40 Mobile 1, 5W40 wasn't available at the store. Is this weight too low? Porsche is listed on the back of the bottle and I thought since the operational weight is 40 it should be fine. I did a search and noted that most everyone uses 15W40 for Mobile 1

Anyone know if this is the cause?
Should I changed to 15W40 or 5W/40?

Changing won't be difficult this time around since I won't need to change the filter I can suck it out from the top but I hate to have to spend another $50 on oil if what I'm seeing is normal.

Any help would be greatly appreciated!!!

Marine Blue

Oh and the car is running as smooth as butter, seems to love the new oil and air filters and no clicking from the engine. Also not as loud on startup, probably due to the lower pouring weight.

stealth

Most 928s run at around 3 bar once warmed up (all of mine have, with 15w50). Anything above 2 is ok. It should be at 5 when below normal temp or when revved (usually it takes less than 3200 to get it to 5 bar, but that may be the lower viscosity oil). No worries with 3 bar.

The 0W is a bit thin, certainly for summer, I wouldn't run less than 10w40 and 15w40 or 15w50 is preferred.

I just bought a house in Quincy (with a two-928 garage ), glad to have some shark company down there.

Marine Blue

Thank you Shane!

Glad I can live with the current oil but I will probably end up ordering some Amsoil 10W/40 if I see it drop further.

Very cool to know there are a few other Sharks nearby. We're actually searching for homes around Hanover where my job is. The car is up in Maine right now which is mostly why I chose the lower weight, doesn't usually get this warm up here and I thought for fall startups the lower weight would be better. Oh well, live and learn I guess.

When the Shark is finally down there we definitely have to plan a GTG, I already know a few guys that are in the general Boston area. Actually curious when the next big GTG will be, I saw the last one had a great turnout! SITP I think it was?

Anyways thanks again for the help, I feel better now.

stealth

Check the 928 Owner's Club site, www.928oc.org, there is one coming up out near Springfield, MA, look in the "Event Notices" section of the forums. Last year we met up at Porschefest at the Lars Anderson museum in October, 35 sharks showed up (more than any other P-car model, I believe).

IcemanG17

Afshin
The oil is too light......10-40 at a minimum....typically Mobil 1 15-50 most people use. The shop manual states 1 bar of pressure per 1K rpms as a guideline....but that tends to be a bit low.....when fully warm on a hot day I've never seen less than 2 bar at idle (typically 2.5-3.5), but my guage never goes over about 4.8 anyway?

Next time you change the oil change the springs in the oil thermostat....they age and stay open longer than they should, which typically causes low oil pressure at idle after sitting for a short time (say after stopping for gas in hot weather).....heres a link:

http://members.rennlist.com/v1uhoh/oilp.htm

It sits under the oil pressure sender.....the springs are cheap....a couple bucks each.....don't worry about the little plates....only buy the springs & remember the spring is tapered when you install it (narrow end down towards ground)

I also forgot that pic you wanted here it is.....also there is a set of drilled zinc plated brake rotors on ebay...take a look

Marine Blue

Cool, I know Western MA well! Worked in E. Longmeadow directly south of Wilbraham. Haven't been there in 6 years so it will be interesting to go back, hope I can make it!

mark kibort

put in 15-50 redline and watch the pressure go up. (or amzoil)

Just saw another porsche engine blow up this weekend at the SCCA races. guess what oil? you got it, Mobil 1

when using mobil 1, my oil pressure warning light came on a few times at buttonwillow with the 79 racer. never again using dyno or redline!

mk

MK

Marine Blue

Thank you Brian, I actually read that thread about the oil thermostat but I didn't realize it was that simple to change. I will make it a point to change this out.

Those caps look great, I'll have to look for them when I'm ready to updgrade to some different wheels. You really do need to address those rotors, you'll be so amazed at the difference and the finished appearance.

I'll search out the rotors, not sure how well Zinc plated rotors will hold up and to be honest I'm surprised they are zinc plated. I had heard this was outlawed in most countries years ago due to the waste it generated. For now I am happy with the drilled rotors on my car and since the D90's have solid centers I can barely see the rust anyways!

Brian I was actually thinking about taking the D90's off and having them fully restored. I was thinking to have them re-chromed and have the areas which are now black painted to match the car. Chrome with Marine blue should look cool, what do you think?

Anyways need to go and change the oil on the mower, getting too comfortable sitting here ;-)

Marine Blue

Mark I think I have to agree, have never been impressed with M1 even in my 500E, always had the lifters clicking in that car with M1 or even the Valvoline but when I switch to the Amsoil all was perfect. Even dynoed nicely!

I'm debating between the 10W/40 and 15W/50 Amsoil, any thoughts?

Chuck Schreiber

Afshin,

I agree with Mark. Redline is probably one of the better, but a little expensive. I started using Royal Purple in the 79 a few years ago (20W 50) after using Mobil 1 (15W 50) for years. Oil pressure better, smoother and faster revving engine. I always thought any synthetic must be good until I switched. Really happy with the purple.

Mark, must have missed you this weekend. I was in the wine country for the weekend and stopped at the track. Saw lots of Miatas but no 928's. We were there on Sat.

UKKid35

Thanks Tony for the write up, and thanks Brian for pointing it out. There's no excuse for not replacing parts that cost so little, so that goes on my to do list.

IcemanG17

Afshin
I almost didn't post that pic because my rotors look so crappy!!! Heres the link to those rotors....I dunno but they sure look SWEET...bummer is my rotors are all in very good shape....I might do some sanding & use high temp engine paint as a temporary solution?

http://cgi.ebay.com/ebaymotors/ws/eB...RK%3AMEWA%3AIT

I like the D90's.....a rechrome with marine blue insides would look SWEET!!!!! Might be a good winter project for ya!

I really think those rotors would look so sweet on my car....BUT I have good rotors on the car AND an extra set of brand new rear rotors!!! The last thing I need is a complete set of rotors....but it sure would look nice!

Bill Ball

Brian:

Now you've done it! Those rotors look like too good a deal to pass up.

Robert_H

Oh my god, those are pretty. Must resist urge to buy...