964 Cylinder leaks
11-09-2008, 11:12 PM
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964 Cylinder leaks
Were the cylinder leak issues corrected by March of 1991 in the 964's. I'm looking at a purchase and the build date is 3/91.
Thanks for your help,
Scott
Thanks for your help,
Scott
11-10-2008, 12:05 PM
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I know the cylinder leak issue is not a problem in all the early 964's, however if it becomes a problem, what exactly is the fix. While researching the forum, I've seem mention of seals, different cylinders, etc. I'm assuming it's something a DIY porsche, bmw, fiat wrench of 10 years can handle if the problem surfaces.
11-10-2008, 12:09 PM
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I know the cylinder leak issue is not a problem in all the early 964's, however if it becomes a problem, what exactly is the fix. While researching the forum, I've seem mention of seals, different cylinders, etc. I'm assuming it's something a DIY porsche, bmw, fiat wrench of 10 years can handle if the problem surfaces.
11-10-2008, 12:13 PM
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911 Carrera 2/4 Model Years '89(K), '90(L) and '91(M) up to engine number:
62 M06836, M64.01 - Manual Transmission
62 M52757, M64.02 - Tiptronic.
can suffer oil leakage between the cylinder and cylinder head but not all cars leaked...
After that they came with cylinder gaskets...
Here is photo courtesy of Ritter...
62 M06836, M64.01 - Manual Transmission
62 M52757, M64.02 - Tiptronic.
can suffer oil leakage between the cylinder and cylinder head but not all cars leaked...
After that they came with cylinder gaskets...
Here is photo courtesy of Ritter...
Last edited by Wachuko; 11-10-2008 at 12:29 PM.
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11-10-2008, 02:54 PM
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Others will chime in... but I am guessing that, outside of a record documenting the change, you would have to remove a head to look...
11-10-2008, 03:14 PM
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does it really matter?
a friend of mine had a c2 with over 120K miles on it with no problems.
I have a c2 with 98K miles with no problems. both of these were early '90s. Mine has a build date of 12/89. No head/cylinder issues.
neither of these have had any updates done to them.
I have a good friend with a high mileage (over 180K miles) RSA. It has head gaskets and it has just as much sign of seepage as my '90 does without head gaskets.
even if it becomes a problem, we are usually talking about one small drip once in a while. From what I have read it was never an Exxon Valdeze kind of leak...
just some very slight seepage leading to some moisture at the head/cylinder interface.
it does not effect the performance or operation of the motor.
so why does everyone get so worried?
not like we are having M96 motor issues like IMS and cylinder sleeves moving, both causing catastrophic engine failures.
a friend of mine had a c2 with over 120K miles on it with no problems.
I have a c2 with 98K miles with no problems. both of these were early '90s. Mine has a build date of 12/89. No head/cylinder issues.
neither of these have had any updates done to them.
I have a good friend with a high mileage (over 180K miles) RSA. It has head gaskets and it has just as much sign of seepage as my '90 does without head gaskets.
even if it becomes a problem, we are usually talking about one small drip once in a while. From what I have read it was never an Exxon Valdeze kind of leak...
just some very slight seepage leading to some moisture at the head/cylinder interface.
it does not effect the performance or operation of the motor.
so why does everyone get so worried?
not like we are having M96 motor issues like IMS and cylinder sleeves moving, both causing catastrophic engine failures.
11-10-2008, 03:21 PM
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Are the cylinder leaks just a matter of a few drops occasionally or is it a major leak. Is this issue something that occured early in the cars life or can it spring up at any time? The car I'm looking at doesn't seem to have a problem with 79,000 on the clock.
Minor oil leaks really don't bother me, I've got a 77 2.7 that leaks and even appears to sweat oil through the case. I just degrease the underside occasionally, drive it like I stole it and enjoy the 911 whine!!
Minor oil leaks really don't bother me, I've got a 77 2.7 that leaks and even appears to sweat oil through the case. I just degrease the underside occasionally, drive it like I stole it and enjoy the 911 whine!!
11-10-2008, 04:44 PM
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My very close friend (the owner of the high mileage C2), is a Factory trained Porsche technician.
He told me that it is nothing more than seepage and to "beat it like a rented mule"
my early '90 shows very slight seepage, but never leaks a drop on the driveway.
I have much more issue with the cam tower seals.
his high mileage '90 was very similar to mine in the amount of seepage at the cyliner/head interface.
He pulled his motor apart (since he had his own shop,now retired)and when he rebuilt it, he used the same cylinders and heads and did not install head gaskets IIRC.
He told me that it is nothing more than seepage and to "beat it like a rented mule"
my early '90 shows very slight seepage, but never leaks a drop on the driveway.
I have much more issue with the cam tower seals.
his high mileage '90 was very similar to mine in the amount of seepage at the cyliner/head interface.
He pulled his motor apart (since he had his own shop,now retired)and when he rebuilt it, he used the same cylinders and heads and did not install head gaskets IIRC.
02-22-2009, 11:48 AM
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My '90 C4 did not leak at all for two years (that I've had it). Its not leaking was a primary reason for choosing it. Last August, I took it in to a respected indy for a 60k mile service, including replacing belts, distributor timing belt, caps, rotors, valve adjustment, plugs, fuel filter, non-synthetic oil, etc.
A couple days later, it's leaking like a sieve. I take it back to the shop on a couple of occasions to have them locate the source of the leak. They say it's very difficult to pinpoint the source. They use the dyed oil technique, and even a baby powder technique (drying the underside, dusting it with baby powder, then running it at medium rpm for a few minutes). Anyway, it appears there are multiple leaks.
They replace the chain housing bridge, a leaking o-ring for the housing under the oil pressure switch, the gaskets for the cam chain housing covers and tensioners, the o-rings and seals for those covers, and the o-ring for the intermediate shaft cover. Does that fix it? Afraid not.
Back to the shop it goes, and they inform me that I've got the dreaded cylinder to head leak due to no gaskets, etc. They show me a bulletin from Porsche that this is a known problem, and the solution is to machine the heads, and, while you're in there, replace the cylinders (and rings, if needed). This job, I'm told, can add up to more than $5,000.
Time for a second opinion. To another respected indy I go. Yes, he's familiar with this issue, but let's have a look. Maybe part of the leak is coming from the valve covers - they may be warped. So he gets them machined flat, replaces the timing cover gasket, valve cover gaskets, intermediate shaft o-ring, cam oil o-rings, cam cover tensioner gasket, and 18 case stud seals. He also tells me that the fix for the head leak, should that be necessary, would require machining of the heads, but not necessarily replacement of the cylinders. They also torque the head studs, in case that might be the problem. They also remove the undertray and the two head cover sound suppression thing-a-ma-jigs to provide better cooling to the engine. They also used Castrol 20W-50 instead of the usual 5W-30, because we have very hot, dry weather here. Leak fixed? Not even.
I'm losing two tablespoons of oil, under my car, every time I park it (it's a daily driver).
Please forgive the long ramble, but I'm at wit's end. I don't know who to trust, and I don't know what to do. I do enjoy autocross, and a couple track days each year, but this leak certainly prevent any track days. My Porsche dealership has proven, more than once, that they don't know what to do with my old car. Anyone had this machining done before? Does it require new cylinders or not? How much did it cost? Why might this problem arise after performing the 60k service?
Thanks a lot for you input,
Tony
A couple days later, it's leaking like a sieve. I take it back to the shop on a couple of occasions to have them locate the source of the leak. They say it's very difficult to pinpoint the source. They use the dyed oil technique, and even a baby powder technique (drying the underside, dusting it with baby powder, then running it at medium rpm for a few minutes). Anyway, it appears there are multiple leaks.
They replace the chain housing bridge, a leaking o-ring for the housing under the oil pressure switch, the gaskets for the cam chain housing covers and tensioners, the o-rings and seals for those covers, and the o-ring for the intermediate shaft cover. Does that fix it? Afraid not.
Back to the shop it goes, and they inform me that I've got the dreaded cylinder to head leak due to no gaskets, etc. They show me a bulletin from Porsche that this is a known problem, and the solution is to machine the heads, and, while you're in there, replace the cylinders (and rings, if needed). This job, I'm told, can add up to more than $5,000.
Time for a second opinion. To another respected indy I go. Yes, he's familiar with this issue, but let's have a look. Maybe part of the leak is coming from the valve covers - they may be warped. So he gets them machined flat, replaces the timing cover gasket, valve cover gaskets, intermediate shaft o-ring, cam oil o-rings, cam cover tensioner gasket, and 18 case stud seals. He also tells me that the fix for the head leak, should that be necessary, would require machining of the heads, but not necessarily replacement of the cylinders. They also torque the head studs, in case that might be the problem. They also remove the undertray and the two head cover sound suppression thing-a-ma-jigs to provide better cooling to the engine. They also used Castrol 20W-50 instead of the usual 5W-30, because we have very hot, dry weather here. Leak fixed? Not even.
I'm losing two tablespoons of oil, under my car, every time I park it (it's a daily driver).
Please forgive the long ramble, but I'm at wit's end. I don't know who to trust, and I don't know what to do. I do enjoy autocross, and a couple track days each year, but this leak certainly prevent any track days. My Porsche dealership has proven, more than once, that they don't know what to do with my old car. Anyone had this machining done before? Does it require new cylinders or not? How much did it cost? Why might this problem arise after performing the 60k service?
Thanks a lot for you input,
Tony
02-22-2009, 12:32 PM
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ABQ, wow. and to go from leak free 60K to the exon valdez in one day doesn't make sense...I wonder if the orignial 60k service included "retourqing" the heads, which may of expedited this problem.
I personally haven't had this problem on a 964, but I did have a 74 2.7 with the dreaded pulled head studs which resulted in basically a similar condition, a leak at the juncture of the head and the jug. It was more prevelant at two cylinders which were the ones that tended to run hotter at the corners of the motor.
I know this was a slightly different condition but it was very apparent where the leaks were, and you would get some seepage and a few drops of oil at the cyl in question. The only oil that can leak out of this location has to find its way through the rings, two tablespoons of oil seems like a lot, why they can't pinpoint them seems odd, and if a leakdown was done they you would be able to hear a leak at the cylinder(s) in question, and at the very least would tell you what cylinders are leaking, the numbers should be all over the place. I wouldn't expect all six cylinders to go all at once, thats just weird...not to mention coincidental...
Is the leak consistently in the same spot under the car? Does it get substantially worse when the car sits for more than a week or two? or does it get better? do you get a put put, or flutter exhaust sound under the car?
The dealers have all gone the way of the rest of the auto world into a electronic diagonistic/check the list/replace the modular component/tech school solutions which doesnt' really work on the old air cooled cars. I'd never take a air cooled car to a dealer unless you know the have an old grey haired guy in the the back of the shop that knows the cars.
And to get back a bit to the topic of the post, but I do think getting a leakdown and compression test is a must to do in a PP, as well as ask about documentation, it's always a point of negotiation.
I personally haven't had this problem on a 964, but I did have a 74 2.7 with the dreaded pulled head studs which resulted in basically a similar condition, a leak at the juncture of the head and the jug. It was more prevelant at two cylinders which were the ones that tended to run hotter at the corners of the motor.
I know this was a slightly different condition but it was very apparent where the leaks were, and you would get some seepage and a few drops of oil at the cyl in question. The only oil that can leak out of this location has to find its way through the rings, two tablespoons of oil seems like a lot, why they can't pinpoint them seems odd, and if a leakdown was done they you would be able to hear a leak at the cylinder(s) in question, and at the very least would tell you what cylinders are leaking, the numbers should be all over the place. I wouldn't expect all six cylinders to go all at once, thats just weird...not to mention coincidental...
Is the leak consistently in the same spot under the car? Does it get substantially worse when the car sits for more than a week or two? or does it get better? do you get a put put, or flutter exhaust sound under the car?
The dealers have all gone the way of the rest of the auto world into a electronic diagonistic/check the list/replace the modular component/tech school solutions which doesnt' really work on the old air cooled cars. I'd never take a air cooled car to a dealer unless you know the have an old grey haired guy in the the back of the shop that knows the cars.
And to get back a bit to the topic of the post, but I do think getting a leakdown and compression test is a must to do in a PP, as well as ask about documentation, it's always a point of negotiation.
Last edited by J richard; 02-22-2009 at 12:59 PM.