Valve Guide & Top End - In Your Future ~ The Cheap Man Pays Twice
12-05-2007, 10:30 PM
#31
Racer
Thread Starter
Sobering for sure Garth. Even more sobering, wait . . . maybe the opposite by 9:00 PM, is driving with the wife, gently explaining to her the discourse which has gone on here at Renn and radomly dropping in the $10K figure as a, "by the way, you know . . . ", on something that I said was "an investment" when I bought it. Yes sir, an "investment of money" sez I. Don't get me wrong, I love the car and plan to keep it, especially as I find I have an affinity for the wrench, but this sure has been a "wake up" week and, no I was not aware of, or did not fully comprehend, the nasties that are almost assured to befall the check book four years ago! Ha!
12-05-2007, 10:48 PM
#33
Rennlist Member
I bought my car about two years ago with 42k miles on it. It's just about to turn 70k. I changed the SAI valve at about 60k and the ports were just fine. I'm convinced that if the SAI valve is working you aren't getting any carbon buildup in the ports (no flow). My car doesn't burn a quart of oil between changes. I do everything I can to keep it running right and and prevent failures.
I drive it as fast as I can get away with on the street and do DEs as often as I can afford it. I can't afford a $10k+ rebuild so if that comes around I guess I'll find out what a well loved 993 in need of a rebuild is worth.
I drive it as fast as I can get away with on the street and do DEs as often as I can afford it. I can't afford a $10k+ rebuild so if that comes around I guess I'll find out what a well loved 993 in need of a rebuild is worth.
12-05-2007, 10:58 PM
#34
Drifting
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I'm sorry to say, but it really is that black and white. Your guides are worn. They probably weren't fit properly from the factory -- the QC in this regard is said to be terrible. I've talked to a couple of techs with a lot of experience on 993's and they've said that in doing some 3.8 conversions and top ends that involved tearing down very low mileage 993 motors, they've routinely found guides that were already badly worn. Such is life. That quart that is burned every 900 miles -- that oil is getting into the combustion chamber and ignited along with fuel and air. It doesn't get there magically.
12-05-2007, 11:19 PM
#36
Burning Brakes
I'm puzzled by this discussion. I've never heard of an engine that doesn't wear out (not to mention, a high performance one). There are only a handful of cars out there, however, that I would bother spending good money on an engine rebuild, and a 993 is one of them. I think the value has to be calculated in something other than $$$ in this case.
(But if you must consider the fiduciary angle, the flat-ish depreciation curve of these cars more than makes up for the cost of a top end or two...)
(But if you must consider the fiduciary angle, the flat-ish depreciation curve of these cars more than makes up for the cost of a top end or two...)
12-05-2007, 11:41 PM
#37
Three Wheelin'
Ahhhh don't be so hard on Porsche about parts prices, it's mostly due to a weak dollar.
12/5/02 100 euros = 100 dollars
12/5/07 100 euros = 147 dollars
Your parts now cost almost 50% more today than 5 years ago just due to the dollar. If Porsche increased prices only 10% over that 5 year period then the $100 part you bought 5 years ago now costs about $162. What makes this feel worse is that it can take a while to work off old inventory so the increases can sometimes be back loaded. Porsche parts have never been cheap but the bulk of the recent price increases are the result of our questionable economic policies, not Porsche greed.
12/5/02 100 euros = 100 dollars
12/5/07 100 euros = 147 dollars
Your parts now cost almost 50% more today than 5 years ago just due to the dollar. If Porsche increased prices only 10% over that 5 year period then the $100 part you bought 5 years ago now costs about $162. What makes this feel worse is that it can take a while to work off old inventory so the increases can sometimes be back loaded. Porsche parts have never been cheap but the bulk of the recent price increases are the result of our questionable economic policies, not Porsche greed.
12-06-2007, 12:09 AM
#38
Rennlist Member
Valve guide material withstanding, what is it about a 993 engine that would cause it to require major engine work at 100k miles while many SC and Carrera engines last 200k+ miles before a major rebuild? There's not that much difference in redline RPM and there's only 100 or so more HP in the 993.
I guess I don't buy into the theory that I should anticipate a major rebuild sooner rather than later. Every engine wears, I thought it had more to do with the cylinders wearing evenly than just the fact that compression is not the same as it was day one. If it happens it happens, but I haven't seen anything yet that would lead me to think a well maintained 993 engine won't last like my SC.
I guess I don't buy into the theory that I should anticipate a major rebuild sooner rather than later. Every engine wears, I thought it had more to do with the cylinders wearing evenly than just the fact that compression is not the same as it was day one. If it happens it happens, but I haven't seen anything yet that would lead me to think a well maintained 993 engine won't last like my SC.
12-06-2007, 12:44 AM
#39
RL Technical Advisor
Is there a "safe zone" for valve guide wear that kicks in once a car reaches a certain mileage?
For example, my new-to-me '95 C4 just turned 90k and has only used 1 quart of oil in 3,000 miles of mainly in-town driving. Is it naive to assume that relatively low oil consumption at this mileage means that the guides are in decent shape at as a result I should be ok for the near future?
Or does valve guide wear accelerate at some point and one day you're in great shape and the next there's white smoke billowing out the back of the car?
For example, my new-to-me '95 C4 just turned 90k and has only used 1 quart of oil in 3,000 miles of mainly in-town driving. Is it naive to assume that relatively low oil consumption at this mileage means that the guides are in decent shape at as a result I should be ok for the near future?
Or does valve guide wear accelerate at some point and one day you're in great shape and the next there's white smoke billowing out the back of the car?
Sounds like you got a "good one".
Just keep track of your oil consumption and you'll be just fine.Some of these issues are not just due to guide wear, some of these are due to poor tolerance control when the engines were built. Last year, we did the guides on a 993 with 3K (yep, 3000 miles) on it and the exhaust valves wobbled all over the place in their guides. I saw almost .020 clearance so clearly, this was not a wear problem; the individual who built the engine at the factory didn't pay close attention when the guides were honed.
I've seen the same things in 20K or 40K engines where the valves were not fitted very precisely and these motors all had premature SAI and oil consumption issues.
Its just like the cam timing variances on these things; some engines were clearly stronger than others and we traced a lot of that to sloppy cam timing issues at the factory. Thankfully, these problems are fixed when the engine is apart for the valve job.
Sooooo,..if one has a car with low oil consumption (2K-4K/qt), ignore all the hyperbole and keep on driving,....
Just change that oil regularly, use the good stuff(!) and you'll have a good ownership experience.
12-06-2007, 02:55 AM
#41
RL Technical Advisor
High operating temps have proven to accelerate guide & valve wear, all kinds of oil leaks from every gasket, seal & O-ring, and ring wear.
For those reasons as well as maintaining maximum performance, an additional front cooler is always recommended for folks who do DE events or drive the car "in anger" in hot climates. IMHO, the monies spent for that cooler kit & installation are less than half of the cost of resealing the engine and doing the valve job. Thats a no-brainer for me,...
12-06-2007, 04:14 AM
#42
RL Technical Advisor
12-06-2007, 05:48 AM
#43
Rennlist Member
Does it happen to you that while your car has no problem at all, and you buy new parts and change them just for the attachment and the itch to wanting that 993 in front of you to reincarnate in a brand new one?????
Well to me it happens all the time. When I say all the time, I mean I have brand new parts in excess of
10k @ home just taking dust.
And those parts are not installed on my car because the ones on the car are new.
BTW, I bought two distributor caps, rotors, sparkplugs and leads, belts, pulley, battery, alternator, just yesterday.
I see a lot of people with the same attitude around here, and I understand why this forum is active, especially
that the 993 is one of those production cars that depreciated the least after ten years.
What I think about this thread is mixed feelings, but I would like to address the information I have to those
as mentioned above, simply attached to their 993 without knowing why.
This has ZERO commercial intention and ZERO personnal or pretensious aspect.
Dave when you say your 993 with 16k uses 1 quart of oil every 900 miles, hell I tell you your car is better than a Brand new one.
For those who are telling you any wawa, just point your finger on page 7 of the workshop manual (or the user manual)
and show them that it says " Oil consumption = up to 1.5 litres every 1000 kilometers"
Bluejam as well, if your engine is consuming oil, keep the manuals handy.
If it bothers you, go get the engine inspested thoroughly by a specialist, and don't let the specialist
diagnose the engine over the phone.
A leak test cannot diagnose a worn valve guide.
Because of this forum, I have learnt a lot every single day, and one of the peculiar things I learnt is that forums exist for money money.
I have seen hoaxes on this forum as nowhere before, and honest people swearing by an info that has been imbedded
in their mind by a SUPER magnificiant source, without ever thinking that these sources are generating something behind, or their friends are.
What pushes me to speak, is that those profiting, think they are more intelligent than honest people here.
Just think how many front protection bars have been sold several years back because of this forum.
How many bilstein HD's and M030 springs?
and so on and so forth, loads of examples...
How many are surprised to knowing that Porsche offered the 2 bilstein (normal + PSS9)setups since the 993 existed,
yes it is in the PET. People think that Porsche suspension is trash, and the solution is to call X and maybe
organise a group buy.
How many organised a group buy to get his share of parts free?
One of the best improvement to the 993 in my opinion is the later 996/997 3 spoke steering wheel.
Do you hear about it much here?
NO, heck there is no margin.
Now for the witty...
I was convinced thru this forum that the original 993 valve guides are a total mistake.
I learnt new words like phos. bronze, Magnesium Bronze, etc. etc. and wrote these words down for futur ref.
Then I went to lublijana, and on my way, I stopped at RUF and inquired to change those little suckers one day.
Well according to all at RUF, and later, Porsche techs in dusseldorf I spoke to, the valve guides originally installed
are the best there is.
They say these are soft on purpose. This is one reason why these engines last. They speak of 100k mile engines still running. They speak of hydraulic lifters, why they chose that way, which is less precise but less trouble.
According to them, if you want a race engine, change the valve guides, remove the hydraulic lifters, lwf, RS mounts etc etc, but
a race engine will last how much, 20k miles? 30k miles?
They removed a sparkplug (@ the parking lot with my friend in the car) from my engine and it was light pinkish grey.
I told them all my sparkplugs are that color having changed them a year before.
They said that if so, my guides are healthy at 75k, the burn is perfect. My car uses 1 quart every 900 miles. SO?
You go at RUF to ask for a valve guide change, and they say NO, all is well go home.
should I believe them? BTW no SAI here.
In my personnal opinion, since any engine split job is going to cost 5 figures, then what the heck, drive it,
not until it breaks, but until REAL symptoms appear.
Definition of real symptoms is a hasty generalization though, real symptoms is unique to every 993 owner.
Well to me it happens all the time. When I say all the time, I mean I have brand new parts in excess of
10k @ home just taking dust.
And those parts are not installed on my car because the ones on the car are new.
BTW, I bought two distributor caps, rotors, sparkplugs and leads, belts, pulley, battery, alternator, just yesterday.
I see a lot of people with the same attitude around here, and I understand why this forum is active, especially
that the 993 is one of those production cars that depreciated the least after ten years.
What I think about this thread is mixed feelings, but I would like to address the information I have to those
as mentioned above, simply attached to their 993 without knowing why.
This has ZERO commercial intention and ZERO personnal or pretensious aspect.
Dave when you say your 993 with 16k uses 1 quart of oil every 900 miles, hell I tell you your car is better than a Brand new one.
For those who are telling you any wawa, just point your finger on page 7 of the workshop manual (or the user manual)
and show them that it says " Oil consumption = up to 1.5 litres every 1000 kilometers"
Bluejam as well, if your engine is consuming oil, keep the manuals handy.
If it bothers you, go get the engine inspested thoroughly by a specialist, and don't let the specialist
diagnose the engine over the phone.
A leak test cannot diagnose a worn valve guide.
Because of this forum, I have learnt a lot every single day, and one of the peculiar things I learnt is that forums exist for money money.
I have seen hoaxes on this forum as nowhere before, and honest people swearing by an info that has been imbedded
in their mind by a SUPER magnificiant source, without ever thinking that these sources are generating something behind, or their friends are.
What pushes me to speak, is that those profiting, think they are more intelligent than honest people here.
Just think how many front protection bars have been sold several years back because of this forum.
How many bilstein HD's and M030 springs?
and so on and so forth, loads of examples...
How many are surprised to knowing that Porsche offered the 2 bilstein (normal + PSS9)setups since the 993 existed,
yes it is in the PET. People think that Porsche suspension is trash, and the solution is to call X and maybe
organise a group buy.
How many organised a group buy to get his share of parts free?
One of the best improvement to the 993 in my opinion is the later 996/997 3 spoke steering wheel.
Do you hear about it much here?
NO, heck there is no margin.
Now for the witty...
I was convinced thru this forum that the original 993 valve guides are a total mistake.
I learnt new words like phos. bronze, Magnesium Bronze, etc. etc. and wrote these words down for futur ref.
Then I went to lublijana, and on my way, I stopped at RUF and inquired to change those little suckers one day.
Well according to all at RUF, and later, Porsche techs in dusseldorf I spoke to, the valve guides originally installed
are the best there is.
They say these are soft on purpose. This is one reason why these engines last. They speak of 100k mile engines still running. They speak of hydraulic lifters, why they chose that way, which is less precise but less trouble.
According to them, if you want a race engine, change the valve guides, remove the hydraulic lifters, lwf, RS mounts etc etc, but
a race engine will last how much, 20k miles? 30k miles?
They removed a sparkplug (@ the parking lot with my friend in the car) from my engine and it was light pinkish grey.
I told them all my sparkplugs are that color having changed them a year before.
They said that if so, my guides are healthy at 75k, the burn is perfect. My car uses 1 quart every 900 miles. SO?
You go at RUF to ask for a valve guide change, and they say NO, all is well go home.
should I believe them? BTW no SAI here.
In my personnal opinion, since any engine split job is going to cost 5 figures, then what the heck, drive it,
not until it breaks, but until REAL symptoms appear.
Definition of real symptoms is a hasty generalization though, real symptoms is unique to every 993 owner.
Last edited by geolab; 12-06-2007 at 06:34 AM.
12-06-2007, 06:05 AM
#44
So, do I understand that to mean that there is not an SAI/port issue with the '95 MY?
This is a great thread, with a TON of very informative wisdom. Just the kind of input I needed while looking for my first 993. It doesn't scare me. I would rather know going in, just what I am looking at, long term... because I hope to find a good one and hang onto it for a good long time.
12-06-2007, 07:19 AM
#45
Rennlist Member
Does it happen to you that while your car has no problem at all, and you buy new parts and change them just for the attachment and the itch to wanting that 993 in front of you to reincarnate in a brand new one?????
Well to me it happens all the time. When I say all the time, I mean I have brand new parts in excess of
10k @ home just taking dust.
And those parts are not installed on my car because the ones on the car are new.
BTW, I bought two distributor caps, rotors, sparkplugs and leads, belts, pulley, battery, alternator, just yesterday.
I see a lot of people with the same attitude around here, and I understand why this forum is active, especially
that the 993 is one of those production cars that depreciated the least after ten years.
What I think about this thread is mixed feelings, but I would like to address the information I have to those
as mentioned above, simply attached to their 993 without knowing why.
This has ZERO commercial intention and ZERO personnal or pretensious aspect.
Dave when you say your 993 with 16k uses 1 quart of oil every 900 miles, hell I tell you your car is better than a Brand new one.
For those who are telling you any wawa, just point your finger on page 7 of the workshop manual (or the user manual)
and show them that it says " Oil consumption = up to 1.5 litres every 1000 kilometers"
Bluejam as well, if your engine is consuming oil, keep the manuals handy.
If it bothers you, go get the engine inspested thoroughly by a specialist, and don't let the specialist
diagnose the engine over the phone.
A leak test cannot diagnose a worn valve guide.
Because of this forum, I have learnt a lot every single day, and one of the peculiar things I learnt is that forums exist for money money.
I have seen hoaxes on this forum as nowhere before, and honest people swearing by an info that has been imbedded
in their mind by a SUPER magnificiant source, without ever thinking that these sources are generating something behind, or their friends are.
What pushes me to speak, is that those profiting, think they are more intelligent than honest people here.
Just think how many front protection bars have been sold several years back because of this forum.
How many bilstein HD's and M030 springs?
and so on and so forth, loads of examples...
How many are surprised to knowing that Porsche offered the 2 bilstein (normal + PSS9)setups since the 993 existed,
yes it is in the PET. People think that Porsche suspension is trash, and the solution is to call X and maybe
organise a group buy.
How many organised a group buy to get his share of parts free?
One of the best improvement to the 993 in my opinion is the later 996/997 3 spoke steering wheel.
Do you hear about it much here?
NO, heck there is no margin.
Now for the witty...
I was convinced thru this forum that the original 993 valve guides are a total mistake.
I learnt new words like phos. bronze, Magnesium Bronze, etc. etc. and wrote these words down for futur ref.
Then I went to lublijana, and on my way, I stopped at RUF and inquired to change those little suckers one day.
Well according to all at RUF, and later, Porsche techs in dusseldorf I spoke to, the valve guides originally installed
are the best there is.
They say these are soft on purpose. This is one reason why these engines last. They speak of 100k mile engines still running. They speak of hydraulic lifters, why they chose that way, which is less precise but less trouble.
According to them, if you want a race engine, change the valve guides, remove the hydraulic lifters, lwf, RS mounts etc etc, but
a race engine will last how much, 20k miles? 30k miles?
They removed a sparkplug (@ the parking lot with my friend in the car) from my engine and it was light pinkish grey.
I told them all my sparkplugs are that color having changed them a year before.
They said that if so, my guides are healthy at 75k, the burn is perfect. My car uses 1 quart every 900 miles. SO?
You go at RUF to ask for a valve guide change, and they say NO, all is well go home.
should I believe them? BTW no SAI here.
In my personnal opinion, since any engine split job is going to cost 5 figures, then what the heck, drive it,
not until it breaks, but until REAL symptoms appear.
Definition of real symptoms is a hasty generalization though, real symptoms is unique to every 993 owner.
Well to me it happens all the time. When I say all the time, I mean I have brand new parts in excess of
10k @ home just taking dust.
And those parts are not installed on my car because the ones on the car are new.
BTW, I bought two distributor caps, rotors, sparkplugs and leads, belts, pulley, battery, alternator, just yesterday.
I see a lot of people with the same attitude around here, and I understand why this forum is active, especially
that the 993 is one of those production cars that depreciated the least after ten years.
What I think about this thread is mixed feelings, but I would like to address the information I have to those
as mentioned above, simply attached to their 993 without knowing why.
This has ZERO commercial intention and ZERO personnal or pretensious aspect.
Dave when you say your 993 with 16k uses 1 quart of oil every 900 miles, hell I tell you your car is better than a Brand new one.
For those who are telling you any wawa, just point your finger on page 7 of the workshop manual (or the user manual)
and show them that it says " Oil consumption = up to 1.5 litres every 1000 kilometers"
Bluejam as well, if your engine is consuming oil, keep the manuals handy.
If it bothers you, go get the engine inspested thoroughly by a specialist, and don't let the specialist
diagnose the engine over the phone.
A leak test cannot diagnose a worn valve guide.
Because of this forum, I have learnt a lot every single day, and one of the peculiar things I learnt is that forums exist for money money.
I have seen hoaxes on this forum as nowhere before, and honest people swearing by an info that has been imbedded
in their mind by a SUPER magnificiant source, without ever thinking that these sources are generating something behind, or their friends are.
What pushes me to speak, is that those profiting, think they are more intelligent than honest people here.
Just think how many front protection bars have been sold several years back because of this forum.
How many bilstein HD's and M030 springs?
and so on and so forth, loads of examples...
How many are surprised to knowing that Porsche offered the 2 bilstein (normal + PSS9)setups since the 993 existed,
yes it is in the PET. People think that Porsche suspension is trash, and the solution is to call X and maybe
organise a group buy.
How many organised a group buy to get his share of parts free?
One of the best improvement to the 993 in my opinion is the later 996/997 3 spoke steering wheel.
Do you hear about it much here?
NO, heck there is no margin.
Now for the witty...
I was convinced thru this forum that the original 993 valve guides are a total mistake.
I learnt new words like phos. bronze, Magnesium Bronze, etc. etc. and wrote these words down for futur ref.
Then I went to lublijana, and on my way, I stopped at RUF and inquired to change those little suckers one day.
Well according to all at RUF, and later, Porsche techs in dusseldorf I spoke to, the valve guides originally installed
are the best there is.
They say these are soft on purpose. This is one reason why these engines last. They speak of 100k mile engines still running. They speak of hydraulic lifters, why they chose that way, which is less precise but less trouble.
According to them, if you want a race engine, change the valve guides, remove the hydraulic lifters, lwf, RS mounts etc etc, but
a race engine will last how much, 20k miles? 30k miles?
They removed a sparkplug (@ the parking lot with my friend in the car) from my engine and it was light pinkish grey.
I told them all my sparkplugs are that color having changed them a year before.
They said that if so, my guides are healthy at 75k, the burn is perfect. My car uses 1 quart every 900 miles. SO?
You go at RUF to ask for a valve guide change, and they say NO, all is well go home.
should I believe them? BTW no SAI here.
In my personnal opinion, since any engine split job is going to cost 5 figures, then what the heck, drive it,
not until it breaks, but until REAL symptoms appear.
Definition of real symptoms is a hasty generalization though, real symptoms is unique to every 993 owner.
Can you clarify your statement?