Oil leaks

[kevin]

Chaps,

Whereabouts does the now legendary cylinder oil leak eminate from, curiosity now has the better of me, and I wish to see if mine suffers from it.

Kevin

 

[Elliot Davies]

" If a 964 was built before approximately June 1991 (check VIN plate) and amount of these cars have oil leaks develop between the cylinder heads and the barrels, if so engine strip is required, piston and cylinders to be replaced and the heads machined (see pics, before ,during and after) to accomodate the new cylinder design as well as an added head gasket."
Taken from a well know book.

 

[kevin]

Hmmm,

I have a slight weep between barrels and crankcase on the two rear most cyls, I' ll have to investigate more thoroughly, but it' s definately not the cyl head barrel mating surface.

Thanks anyway Elliot.

Kevin

 

[Guest]

I found this whenI did a search on head gaskets - I am just about to investigate a suspected blown one on my 90C4. Where can I find more info on head condition and examination as per your data shown here? You mentioned that they come from a well-known book. Can you provide me with more details?
Thanks

 

[kevin]

Simon,

I reckon that would be Adrian Streathers book, about £35 or so depending upon where you buy it. Pretty good resource if you intend to buy, as well as those of us who own a 964.

My oil leak is just weap though, not a problem I've been told.

Well it dosen't leave any oil on the garage floor.........

kevin

 

[Guest]

[FONT=Arial"] What actually happens is the seal between the barrel and the crankcase (which starts off life as a round flexible silicone seal), goes hard and leaks. The same is true of the crankcase throughbolt (the bolts that hold the two halves of the crankcase together), seals. They then allow oil past. The mod to the barrel / cylinder head join is thought to stop the barrel "rotating" slightly and thus (supposedly) preventing the oil leaks from occuring.

I would suggest this isn`t the case and it`s quite possible to have oil leaks on a later engine (as indeed it is on a 993 model 911 engine).

To put the whole thing into perspective when and if oil leaks occur it would have been prudent to have been planning a top end overhaul anyway to address likely wear in piston rings, valve guides, timing chains, tensioner ramps etc.

A 3.2 carrera engine for instance whilst unlikely to be leaking oil (on account of metal barrel base gaskets), is still going to be in need of some spanner lovin` to the metal bits once it`s done some work.

Keep smiling - Henry. PCGB member and Bright Orange race car register secretary !!

 

[kevin]

Hi Henry,

IMHO this top end overhaul business is vastly oversung, as you would say in your sales pitch, condition is king (or similar) I've seen engines with astronomical mileages on them, they weap a touch, but are in generally fine fettle. If a piece of equip has been well maintained it should last for yonks, given this how does one tell when repairs are due? Who in their right mind would accept being told to do leakdown/compression tests every year or so, just to find out when work is likely to be required?

Question, is this a self fulfilling prophecy designed to keep people in work I wonder?

Kevin.

Still no drips on the garage floor with his undertray removed.......