Oil pressure question 87 Carrera

[svt4cam]

Greetings, first time poster here. A good friend of my wife's recently acquired an 87 Carrera with a bit over 100,000 mile on it. Since I'm a motorhead, Porsche fan and a decent wrench and manage to keep my Fox Mustang and my wife's Spitfire spinning, I've become a caretaker on this 911. Did it's first oil change this weekend along with an air filter. (I know now why decent Porsche mechanics make so much money) Used Valvoline 10w30 full high mileage synthetic. I'm getting around to my question now. By poking around on the net I found the oil pressure gauge is in bar. so at idle when hot I would guess the motor is at .5 to .6 bar so back of the envelope that's about 8-9 lbs of oil pressure? Is that pretty normal for a bit higher mileage motor? When revved it picks up around 1 bar per 1000 rpm. Motor is dry underneath, no obvious leaks, pulls strong. Should I be using a bit higher viscosity next go round? It has used oil since she bought it about 5 months back, I drained maybe 6-7 quarts when you figure in the filter. I had topped it up when she purchased it. I have no idea of the history of this car and wasn't involved in it's purchase, so since I know which end of a wrench to use but have no experience with 911 motors, I'm trying to be the best caretaker I can, because she might tire of it and sell it to me. lol.

[cabmandone]

I've never heard of anyone running 10w30 in a 3.2. I run 20w50. Did you pull the plug in the engine when you drained the oil? If you only got 6-7 quarts out you were low on oil by about 3 quarts. When you check the oil make sure the car is warmed up. You want the oil to be about half way up the dipstick when the car is warm. Much higher and you can end up with oil in places you really don't want oil.

[juanbenae]

you only got 6 quarts out of it? did you drain the oil tank and case? if I recall the 87 you need to possibly remove the entire sump plate to drain the crank case. somebody more familiar than me on that will chime in. you should have gotten at least 9 quarts out of the motor, tank & filter. something seems strange, or it was very low on oil only getting 6 quarts.

I have run 20/50 in all my 911s so the 10/30 could be your issue if in a warm climate. these cars like a thicker oil unless you are in a cold environment. additionally you really should research a couple oil threads on ZZDP (zinc) content in the preferred oils. the newer oils are light in that component and the tappet valves and cams in our cars will suffer w/o it "added". I quote added because it was pretty much always in motor oils but the newer motors don't benefit as greatly from the zinc, and it is harmful to catalectic converters over time apparently so it's all but disappeared in todays newer oils.


do some research and if in a warmer climate get the 10/30 out before the heat of the coming summer. the 20/50 will hold viscosity better when temps are elevated and will help the oil pressure readings.

good luck & welcome

[svt4cam]

Yep both plugs, we are in SF area my looking at the net I got a consensus of 10/30 since it doesn't get crazy hot here. Should have asked here first apparently. I have spent some time around 911's when I was younger had a good friend with a 74 targa, so I do know how to check the oil. It certainly looks like the sump plug on the motor should drain completely as it's the lowest point on the cover. So even in 87 the motors still need zinc additive? Have to do Brad Penn on the Spitfire, but didn't realize the 911 needed it. My wife's friend was kind of sold on the vintage 911 mystique by the person selling the car, and I'm afraid she's a bit over her head. I showed her how to check the oil when I rescued it from a horror story coast to coast transporter when the car got impounded in Phoenix. Trailer-ed it back here and tidied it up took inventory and noted that the oil level was low then. Topped it up and in about 1800 miles it's sucked maybe 3 quarts. No visible smoke on start up or drop throttle, air filter was fairly dirty but not oily. Did not pull the plugs, because it's not my car. That being said seems to run great and pull strong. What causes consumption on 3.2's, primarly valve seals?

[boyt911sc]

Originally Posted by cabmando

I've never heard of anyone running 10w30 in a 3.2. I run 20w50. Did you pull the plug in the engine when you drained the oil? If you only got 6-7 quarts out you were low on oil by about 3 quarts. When you check the oil make sure the car is warmed up. You want the oil to be about half way up the dipstick when the car is warm. Much higher and you can end up with oil in places you really don't want oil.

+1.

And don’t forget the motor running and car parked at a practically flat or even ground when checking the engine oil level.

Tony

[J-Mac]

Yes, valve seals. I recommend you change to the correct weight oil (brad penn 20 50 is what I use) now to half way on dipstick, filter too. After 1000 miles recheck the dipstick to see where the oil level is for a true oil consumption check. A quart every 700 miles is generally acceptable on high mileage engines.

[juanbenae]

im in the bay area too and with our climate you should run the 20/50 year around. the b. penn oil is a good choice IMO.

where in the bay? are there any service records?

if the valves have not been adjusted in 15k or so miles it is due. you could suggest she take it to the right shop depending on where you guys are for a valve adjustment, the new plugs you note, cap & rotor and a look over by a good independent shop to have it properly checked out.

we call what she needs a PPI... a post purchase inspection as opposed to a pre purchase inspection PPI. if the car has not been well maintained a few things that come to mind besides what I've noted above could be--- brakes, pads? fluid flush? belt(s), fan & AC compressor. gearbox fluid? that could run $1k or a bit more with the oil change required during the valve adjustment and depending on brake system needs. it would be money well spent to make for a safe, reliable car for your buddy's wife.

the oil consumption issues on a 3.2 with those miles on the clock is well documented. she can make sure the valves are adjusted, good oil is maintained and checked regularly and topped off it could go another 100k miles. as long as compression is decent and it passes CA smog keep an eye on stuff and drive it.

[svt4cam]

Thanks everyone for the prompt and helpful replies. Just to make sure I'm understanding, even in 87 the motor still needs zinc additive? If that's the case as it's still in the 60's here I will order several quarts of Brad Penn 20/50 synthetic which she can refill with and a zinc additive for the moment? With preemptive oil checking, what is a decent mileage to tell her it's time to have a good shop drop the motor and refresh it? (Somewhere between now and catastrophic failure) As a rough ball park what does a no internal damage stock rebuild go on a 3.2?

[svt4cam]

Thanks Juanbenae. You posted while I was writing. I'm in Half Moon Bay, car lives in S.F. I'm not sure if there are records or not from po. It's an east coast car that sort of involved me in it's story (it's complicated and I don't ask a lot of questions) In my initial start with it I flew to Phoenix where the truck driver who had been transporting it broke down and the car got impounded. After 7 hours in 104 degrees trying to spring it I finally trailer-ed it home 4 wheels up. Going through her. Brakes and clutch feel great very clean fluid. I'm not going to look at the transaxle fluid unless it's dead easy, Shifts well, syncros seem good. Initially it was killing it's battery, the drivers side interior light switch was keeping the windows live, poke it a few times and it fixed that. So my only worry is the oil and if a quart every 700 isn't crazy for that mileage, then I feel much better. My wife has had several Subies with high miles and I think the oil consumption is a feature of high mile flat engines.

[svt4cam]

Did Porsche get the cam chain tensioners sorted pretty well by 87? Also looking at MDT Zinc additive, I notice zinc doesn't play well with cats and emission controls, thoughts?

[ChrisHoover]

Once you get it sorted, have her join PCA GGR and go on some vintage fun runs!

[gomezoneill]

high mileage synthetic

Could be a problem right there. These engines were not designed to use synthetic oil.

[famoroso]

Seems to me that you / she need to track oil consumption. Also, seems to me that you should have the right oil / viscosity in there before you can trust the results of said consumption figures.

Also, unless she has records evidencing a valve adjustment in the past 15k miles, I'd have it done. Then, you can start tracking oil consumption too (as you'll fill the system with the proper oil). I'd also consider replacing cap, rotor and plugs (and maybe plug wires too).

Also, what sump plate on the bottom of a 3.2?...

[cabmandone]

^^^^^
That's too clean. I'm calling fake news!

[svt4cam]

Originally Posted by famoroso

Seems to me that you / she need to track oil consumption. Also, seems to me that you should have the right oil / viscosity in there before you can trust the results of said consumption figures.

Also, unless she has records evidencing a valve adjustment in the past 15k miles, I'd have it done. Then, you can start tracking oil consumption too (as you'll fill the system with the proper oil). I'd also consider replacing cap, rotor and plugs (and maybe plug wires too).

Also, what sump plate on the bottom of a 3.2?...

Famoroso, I mispoke not being under it and looking at it. The drain plug on the drivers side of the case halves. I'll ask if she has record of a valve adjustment from p/o. Plug wires at least the heat shielding where it goes over top of fan housing was dry rotted and cracked, so I told her that would be on the list soon, so cap and rotor are a natural at that point. How nasty are the plugs to change? left bank looks pretty accessible with a few myriad extensions, right side a bit more of a challenge, probably aided by having oil filter off? She and her husband picked it up last night and we had the chat and demonstration about oil consumption and to keep a close eye on levels. I'm pretty sure I'd have her take it to the shop for the valves, as I'm too old to lay on my back and get a face full of oil for that long..

[svt4cam]

Originally Posted by gomezoneill

high mileage synthetic

Could be a problem right there. These engines were not designed to use synthetic oil.

Was first oil change since her purchase of the car, not sure what was in there prior, it was dirty though.

[Hendog]

I ran Bradd Penn 20w50 for years. It’s semi-synthetic. I switched to Mobil1 15w50. It’s fully synthetic. Both oils have the right ammount of ZDDP. My oil consumption and temperature dropped with Mobil1. I’m sticking with Mobil1. ‘87 3.2, runs great. But that’s just my experience...

[Walt Fricke]

One bar oil pressure per 1,000 rpm is really good. I'd not worry about it. Porsche's recommendations for oil have varied over the years, lately tending to be a light low figure for a multi-grade, probably for better mileage. Racers favor heavier upper ends, as their engines spend all their time at the high end of the temperature scale.

The 3.2s are notorious for valve stem wear, leading to excess oil consumption. So the advice about watching consumption fairly carefully is good. It serves as a diagnostic for the health of the guides, but mainly prevents you from running the oil down too low.

[proporsche]

famoroso..clean engine and etc but what about that broken bracket on cat-shield..????did you miss that?;-) or you just did not put it there..i see
Ivan

[famoroso]

Originally Posted by proporsche

famoroso..clean engine and etc but what about that broken bracket on cat-shield..????did you miss that?;-) or you just did not put it there..i see
Ivan

Good eye Ivan!

That cat & shield was soon removed in favor of a Dansk SS pre-muffler. And... Since swapped out for a few different configurations, including a Gillet OE pre-muffler and a modified (baffle delete) stock muffler. The original parts, including the bracket that was MIA in the pic, are bagged, tagged and stored.