ginch

This post is kind of random so please bear with me. So I've owned my 993 for almost 4 years. Love the car to death and honestly think its a forever car. At the beginning of this year I got a CEL (first one ever), scanned it and it came up as the SAI code. Reset it using a cheap scanner and the light always came back after a few miles. So I'm thinking I have clogged SAI ports. Fair enough. The car uses around a litre of oil every 1500 miles (or so I thought). I recently brought the car to one of the local Porsche specialist because I felt the car had somewhat low oil pressure (kind of random as sometime it would be at 5 but most of the time it would be at around 4.5 bar even if revved out past 6K rpm-low oil pressure light has never come on). Also, the lifters seemed kind out noisy. Anyways I brought it in and the shop told me that the oil pressure was low and the lifters were noisy because the drained the oil and only 6 litres came out. I immediately freaked out but questioned the shop as I recently topped up the oil and it read 1/2 way up the dipstick at full temp. Im thinking WTF!!! Anyways, they changed the oil and put in 5w40 vs the 15w50 I was using (thinking the thicker oil would increase oil pressure and possibly reduce lifter noise). The shop said the oil was too thick hence the lifters were not pressurizing properly. Since then, the lifter noise is a bit less but the oil pressure stills seems a little low (very rarely gets to 5 bar at full rpm).

Long story short (ish), I'm thinking its time for a top end. I brought the car to another shop and they looked over the car. They said the car seemed to be in great shape. They said it needs 15W50 not 5W40. They also reset the CEL with a Porsche scanner (not sure how different it might be than the cheap handhelds). Anyways, I've driven over 500 miles and the CEL has not returned (the first shop said that if the ports were clogged, the light would again come on immediately). I've added 1/2 litre of oil since (driven 1000 miles) and by the dipstick, I'm still 1/2 full but my oil gauge barely moves even when fully warm.

I now don't know if I should trust the guage or the dipstick. I know you will all say dipstick however last time I did that (1/2 way up the stick), the other shop said I was almost 4 litres low (seriously??).

As far as the CEL, I replaced the little rubber L shaped connector on the drivers side of the engine bay as it was slightly collapsed.I did this probably 2 years ago I'm wondering if that at some point triggered the CEL and wasn't fully reset until an actual Porsche scan tool did a hard reset (grasping I know).

Anyways, I know this is post is all over the place but I'm wondering if the car needs a top end? I guess I should probably start with a compression test and leak down.

Any thoughts?

Thanks in advance!
Derek

Martin S.

dip stick. They are very difficult to read....have another 993 geek do it for you...see what hr/she gets.

Also you want the oil to be at least 180 degrees F before you check the dipstick. A blanket of the rear deck intake speeds up the process.

Steve Weiner-Rennsport Systems

Derek,

Do a search for a post I made several weeks ago about oil levels; I think you may find it helpful. I asked the admins to make it a sticky, however that apparently went to a "dead message" file somewhere.

geolab

Hello, nice to meet you. The oil pressure sender on the 993 engine is made by V.D.O in the czech republic. These sensors are known to be crap
Every sensor reads differently, brand new out of the box.
Since you are keeping your car 'forever', there is a little taboo story on the 993 pressure sensors to know.
Malicious car dealers in Italy, used to slash prices when buying second hand 993's due to low pressure on gauge, change the pressure sensor, and sell them with huge margin. This alone, without speaking about the swapping of odometers in two minutes, made the 25% markup.
In the US with the SAI pump, it takes longer to change the pressure sensor.
As long as it does not light up and throw a CEL, you are very good.

For lifters, it is an easy assessment. If you hear the lifters, your engine is running fine. The 993 engine is a sewing machine.
But if you hear BANGING like a hammer on a train rail, then there is a broken lifter.
It is true that with different oil weight, you could more or less hear lifters or not.
But a 993 engine makes noise.
And Porsche did all to reduce this noise, with the pollution standards reducing back then.
They even adopted for a twin spark in the cylinders, to achieve an Air Fuel burning time split in half, and thus use cams with lower profiles, to reduce sound, vibration, etc.
As for oil, do a search on the forum, and choose whichever weight you want.
Do a search on ZDDP , and you will have an idea.
I used a 10W-60 since 2005 in my two 993 engines, with a ZDDP of 1000 and was very happy, on start-ups, and hot running.
From my old school books, I remembered that the wider the oil weight spread, the better the oil is, and I stuck to this idea.


you are wrong
enjoy your car


You are discussing your 993 with mechanics, more than you are driving it.
Now that the errors are cleared, abide by the dipstick, on half level when hot, and do not worry about it.



1-the dipstick
2-the shop does not know

you shouldn't care less. Now no errors, car driving fine, enjoy it

your car does not need a top end.
I would stop worrying and drive the car.
I would maybe go lower than half level on dipstick for a while, to check oil consumption.
If level reduces still, top up back to half. But maybe the sweet spot is just under half level on dipstick
and mostly, enjoy your car

P-daddy

Derek- can you elaborate on the noisy lifters? Are they making ticking noises or loud clacking as Geolab described? I spoke at length with a trusted 993 mech some time ago regarding my first 993 and was told some metallic ticking was normal.

pp000830

Other than replacing noisy lifters If they sound like a bucket of bolts rattling at start up I would not worry too much

ginch

Thank you to all that replied. I do appreciate it. Honestly my biggest concern was when the first shop told me the drained the oil and that I was 4 litres low. This scared the **** out of me as I'm very conscious about checking oil level. I owned a 964 prior to this 993 so I know about how to propely check the oil level. I usually always rely on the guage as its always been replatively accurate. When the oil level guage stops moving around even when fully warmed up I usually add 1/2 litre which will bring me to 1/2 way up the dipstick. Doing this now however will still not move the oil guage much at all if any. Last thing I want to do off course is overfill.

As for the lifters, they definitely got a little quieter when switching to 5w40 however even when they seemed louder they didn't clank or bang. Just the driver side seemed a bit noisier than the passenger side.

Again, thank you for all your information!

geolab

the test for this could be done, but you have to have equal hearing levels in both ears
without any seriousness
start engine and open driver door slowly up around 40* and let it stick there.
do the same with the passenger door
sit in the driver seat and lean to the passenger side, placing your head behind the rear view mirror.

you will hear the ticking, louder, and equal from both sides
the sound reflection on the doors amplifies the engine sound a lot
as for oil, think dipstick from now on
best regards

vincer77

Have you replaced the SAI valve?

Checking oil with engine warm and running on a level surface is the proper way to do it - and is the most accurate. Do not rely on gauge.

As others have said, keep an eye on the oil level and monitor oil usage. Use one of the recommended oils here like M1 15W50 Vtwin

ginch

No I have not yet replaced the SAI valve buts that's on my to do list.

Again, I have always checked the oil while running, up to temp and on level ground. My issue at this point is that I had a known Porsche repair shop in the city tell me that they drained the oil to put in the "proper 5W40" weight oil and when they did so, they said only 6 litres came out! 2 days prior I had checked the oil, added roughly 1/2 litre which brought the dipstick level to 1/2 way up the spiral part. That's why I am now constantly second guessing myself!

vincer77

It is the belief of some here that a failed SAI valve can lead to clogged ports, so do it asap.

Maybe your shop is a good water cooled Porsche shop, but the advice of most here and other air-cooled specialists is the heavier oil with high levels of ZDDP.

Porsche has been recommending 5w40 for a long time, but recently came out with special oils for air-cooled cars. Yep, 20W50 and 10W60 with high levels of ZDDP.

As far as the oil being low, monitoring the use will verify if there is an issue.

Foxman

The dipstick is accurate, but not so sure about the shop you went to... Is it possible that they only pulled one of the two oil drain plugs?? When my gauge barely moves, that's the ideal oil level and reads about 1/3 up the dipstick. When the oil gauge falls below the orange zone, that's the time to add a quart of oil.

jscott82

have the shop check the oil BEFORE they hit the crack pipe. Sounds like they started smoking crack first, that will never work.

... Seriously though ...

I don't know that I would loose sleep over 5w-40... especially the winter months.

If the gauge doesn't match the dipstick, fix the gauge (first read Steve's article on oil level)

Now that we know the gauge is right, you can use it to keep a written log for a couple of months... Then make an informed decision on rebuild.

As far as low oil pressure: wait till you get at least 1000 miles on this oil, then send a sample off for analysis. If your bearings are so worn that they cant maintain pressure (they aren't) , you will see that show up.

axl911

I second this crappy VDO oil pressure sensor. When my sensor went out, I replaced it with a VDO one. Before the sensor went out, I have 1.5 bar at idle. With new sensor, I have less than 1bar. Crappy sensor indeed.

I think the reason is that at a lower level, the resistance value is sooo small that 1ohm difference would account for a noticeable change in gauge movement. Don't know if they are using a crappier transducer or what.

NYC993

Nothing to be worried about if 6 liters came out. I've had this happend to me too.
During my oil chnages i put in 8.5 quarts, that fills it to mid level on the stick. There is a lot of oil in the tank. 1-2 quarts too low doen't make any difference in easy driving.

Dipstick is quite a pain sometimes, you really need that oil to be warm to get to high enough level.