My car has developed a leak. The drip comes off of the right side orange rubber hose, so it is something above that. On my '75, a drip here meant that the oil pressure sender was leaking, and the only way to get at that was to have the engine out of the car.

Is the sender on the 3.6 in the same place? I have no way, at this time, to get under the car to even look. The only independant shop in the area won't work on 993's, so I am going to be stuck going to the dealer to even get this diagnosed.

Any tips or eprvious experience? Thanks!

Aaron

 

Could be anything, but to narrow it down, it could be the oil tube that runs from the head to the carnk case. Could be the filter leaking, really could be a number of things, would worry to much until someone qualified looks at it.

 

Went to the dealer...Diagnosis is that the seals for the mounting "console" for the on-engine oil filter are leaking. Fixable only with engine out, I am told. No biggy, lived with leaks-a-plenty on the '75, and fixed them when I had engine out for new clutch.

As long as I was there, and car was on the lift and ready, I had them do the oil change with both filters. Normally, I do this stuff myself, but with no lift (or proper jacks right now) and since the "Auto Craft Shop" (A cool DIY garage available on most major military installations, run by the Morale, Welfare, And recreation folks at no cost to the govenment..self supporting across the MWR system) at the old Ft. Ord is shut down, it just made more sense to have them do it.

All OK after I leave until I get to school (about 3 mile drive) and smell burning oil and have heavy smoke. Open engine compartment to find the standard overfill mess. ARGH! They can't have pulled such a bonehead move at the dealer?!?!? I was watching them, and they seemed to do it right, warming the engine properly and using the dipstick...

Go back at lunch, pissed, and leave the car with them with promises to figure out what they did wrong (their first thought was that the thermostat didn't open as expected, and they didn't give it enough time...Fair enough, small error.) They promise to clean up the mess.

When I got back to pick up the car, more bad news. They have (preliminarily) diagnosed the problem as being that the cause of the oil coming out of the filler was not an overfill. They have determined that there is too much pressure in the crankcase due to faulty PCV valve or another problem related to that. They say that since they filled the engine to the top mark on the dipstick (as is correct), combined with the fact (?) that the excessive pressure, since it can't vent properly, gets into the oil tank, that is what caused the cause of the overflow. (I had the car about 1/2 quart below the full line, so I wasn't getting the overflow.) They also said that the increased internal pressure is probably also causing the other oil leak.

Seems that the only way to access the PCV valve and related bits is to remove the intake and other top of engine stuff. From looking at it all, that seems to be true. Though this could be done with engine in the car, it seems like it would be a lot faster and easier with the engine out.

So, any input on the PCV valve being bad? (I did a search on "PCV" and got very little on on the 993 forum, which makes me think that this problem is uncommon) Any other possible causes? Since neither the increased crankcase pressure nor the relatively minor oil leak should cause any damage to other components, it seems that both of these will go onto the list of things to do next time the engine is out. (probably 12-18 months at least for me) Anybody have an opinion on that thought?

(Oh, and when I left the car the second time, I needed some of the keys on the ring, and without even thinking, I just left the ignition key, taking the remote with me along with the keys I needed at work. So, they couldn't move the car to go clean it up for me, so now I get to do this myself. Stupid on my part for not leaving the remote, so I get to do the clean-up...yay!

 

So the crankcase pressure was fine before they did the oil change and now it's suddenly too high? Perhaps they filled the car to the top with the engine cold, they certainly sound incompetent enough to have done that.

Vic
95 C4

 

You've shown another reason to have oil changes and other basic maintenance done by the only person who really cares about the car...you.

I learned long ago not to have basic stuff done by the dealer. It all started long ago when I first picked up my 2 year old 993 at the dealer and found that after careful prep, they still had the car 2 quarts low on oil. But, as the prep sheet noted, they had carefully checked and confirmed that the antifreeze was full. Duh. Sorry for my anti dealer rant, but service has not always proven to be their strong point.

 

I don't think they were wrong on this one. I was able to watch the the techs, and all appeared to be done correctly. They used the bulk filler with a digital guage to do the first fill. They then started the car, let it idle for about 10 minutes, and started checking the level with the dipstick and adding oil to get to the top line on the stick. The tech did several checks using the dipstick after warming the engine, so I think he did it right.

As I understand it, the "overpressure" situation caused by a faulty PCV valve/system probably caused the leak in the filter console/housing. This has probably been ongiong since I bought the car, or even longer. (I don't think it is something that would be part of a PPI type check.) I did not ever get the overflow from the tank into the engine bay because I keep the oil level about halfway between the marks on the dipstick. (This is the first oil change since I bought the car) The tech says he put the level at the top mark. As explained to me. since the excess pressure in the engine can't get out the normal way (through the PCV system), it goes into the oil lines and to the tank, and, with the oil level all of the way up, pushes some of the oil out.

Yes, this initially looks like the tank was wrongly overfilled, but, assuming the diagnosis of a problem in the PCV system causing higher than normal pressure in the crankcase is correct, I don't think it was overfilled. The service director said that I should not fill the engine up to the top mark until this problem is sorted out.

BTW, they base the diagnosis they made on the fact that, when the oil filler cap is removed with the engine running, the is an audible release of pressurized air. They recommend further diagnosis to confirm that it is the PCV valve/system. I don't want to pay for a fishing expedition until I have a bteer idea of the validity of this preliminary diagnosis.

Does anyone else have ideas or othee experinces with this problem?

Thanks!

 

BlackCar - you are right, this is definately the kind of thing (oil change) I should be doing myself. I am quite capable of this, and much more. I just don't have the equipment or a place for this right now. One downside to being a military gypsy and trying to be a car guy is I can never set up a decent garage with good jacks, etc. Moving all of that stuff is difficult (especially when doing it every 12-24 months) and I often have little choice about my living arrangements. In my last duty station in Germany, I had no garage and only a small basement room for storage. (And I didn't know WHAT I was getting until I got there) If I would have purchased and shipped a nice floor jack and stands and stuff, I would have had to get rid of all of it there at giveway prices because of no room for it.

Even though I do have a garage here, I am reluctant to buy the kind of good low profile jack and other stuff I need for the 993, because when I move back to Europe next year, I'll have to either sell that stuff or stick it into storage for 3+ years. The MWR Shops I described above are intended to make up for this problem, but there isn't one here. So, for the next 10 months, for any work beyond minor maintenance, I'll be stuck going to the dealer. (The only local independant shop won't work on 993s)

 

Aaron,

Welcome to CA. Previousely you mentioned that you'll be here in the summer after visiting family in AZ?. I guess the time is now.

Good thing the base commission recommended that both Monterey bases stay open, or else you'll be moving soon again. Bummer.

Now for the leak, which dealership was that? It may not be too far to come to our area for a second opinion. Guys at DEVEK, Don Wise etc. are real pros in 993s. I somehow have little faith in dealers.

Good luck and hope to meet you one day around here.

CP

 

They over filled it! Ten minutes idling is not enough time to warmup and check level. PCV Valve??????? I've had five 911s, worked on all of them and never, never found a PCV Valve on any of them.
The crankcase ventilation trick they pulled by removing the oil filler cap does not prove anything. First, it is a sealed system that does count on intake vacuum to vent. Older 911s would idle roughly if the cap was left off. So the cap removal with consequent rush of air (vacuum) is either an intentional ploy or just based on ignorance.

 

By reading your posts, my vote goes to over filling. Could be other problems but for suere I would chek the level myself before letting them do anything.

At least in my car it takes waaaay more idling to get the thermostat open.

And since they (and you) are not sure about overfilling or not, that's another sign they screwed up.
It's very clear (by reading the temp. gauge) when the thermostat opens.

I'd drain some oil out (1 quart or little more), clean everything, drive it until thermostat opens, then see where the oil level is. If the level is corect or too low and it still smokes like before, take it to the shop.
If it doesn't (smoke), get to the shop and let them hear what you think about them and their service.

 

What I'd like some input on is this idea of overpressure in the crankcase because of a malfunctioning PCV valve and/or system. I don't know anything about this, and haven't yet found anything in the manual. IIRC, on the older cars, there wasn't a valve or anything in the oval fitting on the "back" of the engine that vented the case with a hose to the intake. I know on "regular" cars, this is a $5 part that can be changed easily.

I'll keep digging into the manuals, but any tips or ideas would be grat.

 

The dealers story sounds like BS to CtheirA, just MO.

There is no PVC valve on a 993, the cc breather connects directly to the oil tank, the oil tank also has 2 smaller vent lines to the intake manfold and throttle body.

Overpressurization can be a problem w/ the 993 when displacement is increased. What happens in that event is the cylinder base seals get blown out. Never would have believed it if I hadn't seen it w/ my own eyes.

The GT3Rs use a trick cc breather w/ a one way valve to enhance cc vacuum

 

Avenger6,

Armed with the knowledge from Bill, why don't you go down to the dealer and ask them to point out the PCV valve, if not on your engine, at least in a service manual, then let them clean up your engine when they can't find one?

 

kkim.you nail it .its no doubt that the dealer made a mistake and know the are trying to cover their mistake with plain BS,go let them fix their mess

 

The dealer techs simply don't know the older cars. They don't see very many of them, and they are scrambling to try to learn the new models. Their story about overpressure causing the engine to blow out oil is just plain old CYA BS.

911 engines don't like too much oil. If they are overfilled, they will blow the oil out all over the place, including into the intake, and make a big mess along with lots of smoke. The bottom mark on the dipstick means "add a pint", and the top one means "too full". The ideal level is halfway between the two marks. These cars have so much oil in the system that there is no danger of losing pressure, even if you are a couple of quarts low.

Overfilling the oil is a very common mistake, usually done by a new owner trying to keep the oil level gauge reading high when the car is at cruising speed.

It is easy to correct the oil level. Get a fluid oil pump from your local parts store for $10 or so (Sta-Lube makes a decent one), and pump out a quart or so. Get the engine up to operating temperature, let it sit idle for a minute or so, check and adjust the oil level.

Also, it's not difficult to clean the engine in a 993. Get the engine warm (but not hot), tape off the air intake, spritz it down with Simple Green, and hose it off. It is hard to drown this engine, but don't blast the ignition parts with a full-force spray. Blot off any standing water, then start the engine to help vaporize remaining water.

I'll bet once you get the oil level correct and the spill cleaned off, the engine will run just fine with no smoking. The little oil leak could have been that the filter needed to be tightened a quarter turn.