Leaking Oil (A little long)

[Chris_911]

I had my 1988 Carrera 3.2 serviced at a very well known specialist back in October 04. It was a 6000 mile service so basically a check and oil & filter change. The car is showing a genuine 49k miles. The engine, prior to this service was absolutely leak free - no sign of oil leakage whatsoever. Car was run on 10w-40 semi-synthetic oil - last changed by me about 3k miles previously.

Before the service I had a conversation with them regarding the oil that they would use - Millers 5w-50 fully synthetic. I voiced my concern over the use of a thin and synthetic oil as I was worried about leaks. The specialist said that it had developed the oil in conjunction with Millers and reassured me that I would not get any leaks.

Guess you can see what's coming.

The engine is now leaking oil. I've used it precisely three times since the service, including the journey back from the service itslef. I now have three patches of oil on my garage floor.

The bizarre thing is that the car does not appear to drip oil stratight away. The last time I used the car (at New Year) I kept a vigil on the garage floor. After two weeks - no signs of leakage. Then I ntice oil on the garage floor after about three to four weeks. I've not had any opportunity to get the car up in the air, but the oil is dripping off the main crankacse joint (but I obviously don't know where it's coming from).

After I first noticed a leak I contacted the specialist and let them know I wasn't happy that my car was now leaking oil. The specialist is adamant that this is NOT due the use of the 5w-50 synthetic oil.

AM I just unlucky. Is it just coincidence that I now have a leak? Am I right to )in my mnd) believe the oil used is to blame?

I would value your thoughts and how I should approach the specialist in question.

 

[Black80XSA]

I am going to repeat the info supplied by simon from opieoils on another forum...

There is abosolutely nothing wrong with using synthetic oils in fact I would only recommend that you use them.

They are superior lubricants.

However beware of the term synthetic as it's widely used these days on oils that are not, they are petroleum oils. Synthetics are man made in laboratories by chemists and in automotive oils the most commonly used are pao (poly alpha olefins) and esters.

This short article explains why this is the case:

A word of caution "" You get what you pay for!

Below is an article written by John Rowland, Silkolene/Fuchs Chief R & D Chemist for 40 years.

Quote:

Costs of synthetics vary considerably. The most expensive are the "Ester" types originally only used in jet engines. These cost 6 to 10 times more than high quality mineral oils.

The cheapest synthetics are not really synthetic at all, from a chemists point of view. These are in fact specially refined light viscosity mineral oils known as "hydrocracked". These have some advantages over equivalent mineral oils, particularly in lower viscosity motor oils such as 5w-30 or other oils with a low "W" rating such as 5w-50 etc and they cost about 1.5 times more than good quality mineral fractions.

We use several different grades of this base oil, where appropriate. This is the "synthetic" which is always used in cheap oils that are labelled "synthetic". Yes it's a cruel world, you get what you pay for!

Now, you may ask, why are these special mineral oils called "synthetic"?

Well, it was all sorted in a legal battle that took place in the USA about ten years ago. Sound reasons (including evidence from a Nobel Prize winning chemist) were disregarded and the final ruling was that certain mineral bases that had undergone extra chemical treatments could be called "synthetic".

Needless to say, the marketing executives wet their knickers with pure delight! They realised that this meant, and still does, that the critical buzz-word "synthetic" could be printed on a can of cheap oil provided that the contents included a few percent of "hydrocracked" mineral oil, at a cost of quite literally a few pence.

So, the chemistry of "synthetics" is complex and so is the politics!

The economics are very simple. If you like the look of a smart well-marketed can with "synthetic" printed on it, fair enough, it will not cost you a lot; and now you know why this is the case. But, if you drive a high performance car, and you intend to keep it for several years, and maybe do the odd "track day", then you need a genuine Ester/PAO (Poly Alpha Olefin) synthetic oil.

This oil costs more money to buy, because it costs us a lot of money to make, very simply, you always get what you pay for!

 

[Black80XSA]

and another segment..

Indeed, synthetics are the way to go for better protection. The problems with earlier seals was shrinking/swelling. The types of synthetics used in these cases are important (as with the old rotary engines).

The point here is that esters swell seals and pao's shrink them. The correct blend of synthetics has a counter balancing effect. I discussed this recently with an eminent oil chemist who stated that seal damage is very rare however it seems to have been written in history as another of those "synthetic myths". His words not mine I might add!

As I think you are saying, why would you buy anything else other than to save money which is likely to be a false economy.


Also bear in mind that Porsche changed the type of seals they used around about 1985. Rebuilt engines will feature more modern seals, those still on originals may be incompatible with synthetic oils.

In your case you should be OK (given your model year). Perhaps the oil used is not sufficient blend for your seal type ??

I'd email Simon for advice - sales@opieoils.co.uk

 

[Chris_911]

Thanks for the info, but, erm, I'm not sure how it helps me.

The specialist in question is very well known and very well-regarded.

Oops - couldn't see the second part of your post when I replied - ignore!

 

[bones]

Chris , I don't think it's a coincidence your engine leaks after being serviced , where as before it didn't. Insist that your Independent puts the car up on a lift whil e the source of the leak is located, decide your course of action from there. If it's coning from the crankcasings the synthetic oil is the problem but perhaps it is a badly adjusted oil pipe connection.

 

[Black80XSA]

The point i was making is that different oils (even within synthetics) have different make-ups. Some agree with seals, others do not. You might just be unlucky with the oil type they have used, or they just got clumsy with the oil pipe as stated above.

Hope its sorted soon

 

[Guest]

I expect the leak is more to do with the temperature in your garage. My own car has a minor leak during the winter as the seals on the oil return tubes probably harden and/or shrink.

You could consider getting them replaced or buy a garage heater or live with it. I'd bet they disappear as the weather warms up.

 

[Chris_911]

Hi Brian

That's an interesting theory!

I'm absolutely mystified by the pattern of leakage. The car shows no sign of leakage after a run. Of the three patches of oil on my garage floor the latest is appreciably larger, but doesn't represent the longest period of storage. This patch also took the longest time after its last run to appear. Ambient temperature could be a factor, though it still points to the fact that the oil used is a problem, as I've had no leaks whatsoever with 10w-40 semi-synthetic.

 

[bones]

Brian may well be right Chris the detergent effect of a modern synthetic may well have washed away the crud that will have collected around your oil return tube seals (incidentally after refurbishing my SC lump last year, renewing the oil return tubes was a must , they were no better than paper thin, corroded and rusty, god knows what would have happened if a rock had hit one). The only way to check this is to GET IT ON A LIFT, sray brake cleaner under there and run the engine till you spot the leak.

 

[Chris_911]

How difficult a job is to replace the oil return tubes?

 

[911sse]

I believe its fairly easy when you use the collapsable tubes.

 

[Guest]

Just a point to consider - there are VW collapsable tubes and yes, they are an 'easy-fix' for this 911 problem. However, they are no where near as strong or ridgid as the Porsche tubes and I would be concerend about high speed stones etc. that could easily damage them - they are in a VERY vulnerable position! I have seen a few Porsche tubes with damage from road debris!

The advantage with these collapsable tubes is that they can be fitted without taking the engine out or indeed apart.

ADVICE HERE IS NOT TO TO RISK IT

 

[Guest]

Just to add my two penneth (sic) worth - terms not normally used with a porker - I have used Mobil 1 for some years now, and the car has has always gently leaked. By gently, I mean a few drops on the garage floor every so often; I can't predict when it will drip, or when I will notice it.
Also, it uses (burns ? drips ?) less oil when using Mobil 1 than the previous non-synthetic oil I used (Shell, I believe), and this has always been the case since I changed over. This is most noticeable when I check the oil levels, as I used to get a bit worried when, in the early stages, it stopped going down as fast as it did on Shell oil.

Whether any seals etc. were changed when the supercharger was fitted, back in 94, I can't remember (but I doubt it), but they haven't been changed since (just 2 oil pipes, due to normal corrosion), and the car has done approx. 120,000 miles.

 

[bones]

Have to disagree there []
Collapsible oil return are a common and safe fix for older 911s where the stock item has heavily corroded. I fitted these to my 911 last year as many other 911 owners have with no hesitation and they are a LOT stronger than the corroded paper thin mess that I removed. However fitting them with the heat exchangers on will be tricky. Removing the HEs may involve creating other problems you hadn't bargained for if time isn't taken over carefully removing the HEs. Collapsible oil return tubes are available in aluminium or steel.

 

[Guest]

Have to agree with Bones here.

Absolutely nothing wrong with collapsible oil return tubes.

As for replacing them I did one of mine last summer and although in concept a very simple job in practice they are a pain to do. Lots of potential for swearing and cursing when working in a confined area with tubes that just dont want to expand.

I did mine with the headers on and managed to get one in with the rubber seal squished. Some here might remember my white 3.2 weeing oil all over the rollers on the dynoday last year!

In the end I redid the job but removed the entire exhaust (a whole other area of pain in the butt issues) as I needed new headers anyway. With the headers off it is very straight forward.

The key with the tubes is that you need a very good lube to allow them to slide when you expand them. Without (even with to a certain extent) you need a lot of force to slide the halves apart and into the seats. With the headers on its hard to get any leverage and this is what makes it a pain.

To sum up if I can do it anyone can but don't underestimate the effort.

Cheer

Andy

 

[Guest]

Yeah alright, as I said they do the job, but so do re-treads, and I wouldn't fit them to my 911.

Of course a new collapsable tube will look better when replacing an old original tube, but that does not make them right. The OE part is not collapsable and rigidly designed to cope with the potential stresses of a 911 travelling quickly - I doubt any OPC or specialist would fit the collapable tubes as a proper fix. Sure, to cut corners - but never with his hand on his heart. These things fail and where's the oil going?

I have seen damaged original ones - damaged by stones etc. I wouldn't trust the collapsable version no matter how easy to fix.

These are 911s guys - be carefull.

 

[bones]

Bit late now for you Andy but for anyone else use silicone lubricant and try this trick with jubilee clips and a screw driver, 'piece 'o' cake guv'. You just prise the tubes into place adjusting the clips as you advance into their retaining crankcase sockets.


http://www.classical-audio.pwp.blueyonder.co.uk/expoiltubes3.jpg

 

[micky]

Hi all I have only had my car for 3 months and it started dripping oil only after a run but not all the time,
and smelt of oil on start up burning of the heat exchangers I now have learn't

I have just fitted alloy oil tubes on my 88 3.2 they looked stronger than the steel ones.

so far no problems

 

[Guest]

Well aware of all the tricks and like I said lube is the key but even with silcone lube with the exchangers and exhaust still on its a pain in the butt. With them off it was no problem at all (30 mins top including draining and refilling oil)

Cheers

Andy