Longevity/durability of Mezger engines in 996/997 GT3's
08-16-2015, 03:28 AM
#16
Race Director
Thought I would ask those RL members in the know...
The beloved Mezger engines in our 996/997 GT3's -- if they are well/properly maintained, how long should they be able to operate without major issues or need for engine rebuilds?
The reality is that 996 and early 997 GT3's have been out there for around 8-9-10+years now...some are accumulating fairly high miles on their odometers.
These cars, being what they are, are rarely DD'ed, so when they ARE driven, they are DRIVEN HARD, and very often tracked. While the engines are certainly built for this kind of use by PAG, with good oiling systems, etc etc, is it a fair expectation that with diligent oil changes, clutch replacements, spark plugs changes etc etc, that they will continue to operate trouble free over 40-50-60-70-80k miles and up? Or at some point in the car's life cycle should an owner expect a more major, extensive engine rebuild?
We have all heard the stories of older 911's with multi 6 digit miles on their clocks...but I would suggest these are DD'ed vehicles mostly. The GT3 is a different beast, built for a different purpose...
This is all assuming, of course, that there are no significant abuses of the engine, e.g. serious over revs, poor maintenance, etc etc...
Informed opinions welcome. Thanks in advance.
The beloved Mezger engines in our 996/997 GT3's -- if they are well/properly maintained, how long should they be able to operate without major issues or need for engine rebuilds?
The reality is that 996 and early 997 GT3's have been out there for around 8-9-10+years now...some are accumulating fairly high miles on their odometers.
These cars, being what they are, are rarely DD'ed, so when they ARE driven, they are DRIVEN HARD, and very often tracked. While the engines are certainly built for this kind of use by PAG, with good oiling systems, etc etc, is it a fair expectation that with diligent oil changes, clutch replacements, spark plugs changes etc etc, that they will continue to operate trouble free over 40-50-60-70-80k miles and up? Or at some point in the car's life cycle should an owner expect a more major, extensive engine rebuild?
We have all heard the stories of older 911's with multi 6 digit miles on their clocks...but I would suggest these are DD'ed vehicles mostly. The GT3 is a different beast, built for a different purpose...
This is all assuming, of course, that there are no significant abuses of the engine, e.g. serious over revs, poor maintenance, etc etc...
Informed opinions welcome. Thanks in advance.
There is a 996 Turbo around that the owner opened up at around 402K miles to address wear and some leaks. He found no wear. Which reminds me of an article in Panorama about a 996 Turbo that had covered IIRC around 575K miles with again IIRC no internal engine work needed.
My 996 Turbo has over 136K miles on its engine. Engine is fine. I expect to get to 400K miles and possibly higher.
Tracking changes things. By how much no one can say.
The engine is being called upon to produce near its peak power and for long (relatively speaking) periods of time. No way on the street can I safely give my Turbo full throttle for more than a few seconds.
Might mention if one monitors the engine load of his car while say just driving down the road on relatively level ground at say 65mph he would find the engine is being called upon to produce maybe 40 to 50 hp.
This is true at least I have observed this with my 217hp Boxster, my 90hp VW Golf TDi, my 2006 400hp GTO, and my 420hp Turbo.
For the VW Golf TDi, to generate 40hp the engine was having to operate at nearly 50% load. OTOH, my Boxster's engine load was around 20%. The GTO around 10% as was the case with my Turbo.
The above is one reason why big and powerful engines generally run a long time. They are for the most part under stressed.
But tracking changes things. And by how much no one can say.
All I can offer is treat the engine (the car) with a bit of mechanical empathy. Avoid hard acceleration, high loads, high RPMs until the engine has plenty of time to come up to temperature. At the other end give the engine some cool down time to let it shed the considerable heat load that builds up from hard running.
The 996 Turbo manual calls for 2 minutes of idling before shutting off the engine, this to give the turbos time to cool down some.
But even NA engines can have the exhaust valves running a near dull red heat under full throttle load. While the exhaust valves cool down some with some less than full throttle running they should have a couple of minutes of idling to shed some more heat after a bout of hard running. The valves and of course the other hot parts.
Of course change the oil and filter at appropriate intervals. When I tracked, auto-crossed, my mechanic buddies all told me always show up at the track with fresh oil in the engine.
Now I "tracked" just a couple of times a year. It was not a problem at all to change the oil just before the event. If one tracks a lot more often and uses the car for the street between track events, keeping the oil fresh for the track can be a bit of a bother. But that is the price one pays if one wants to attempt to mitigate the ravages of tracking on an engine.
Keep on top of things. A small coolant leak? Don't let it go. Noisy water pump? Replace ASAP. Change the plugs when due on time or miles and if tracking often enough these can go away quicker. Other consumables: filters and other fluids, all should be addressed on a more frequent schedule.
Avoid accidents.
No one can say how long the engine will last, that is refrain from showing signs of wear or throwing a rod through the block.
But you have done what you can do.
08-16-2015, 03:30 AM
#17
Try Sonnen Porsche if you want to do a "refresh" 
i suspect that $ will be much smaller. I.e. R&R guards differential is sub $1,000 in labor + fluids
That said, I drove my prior metzger motor to 96k miles. 0 motor issues. Drove DD + track + weekend. Current owner is friend and he has 0 issues with motor and he keeps tracking + DD, sitting at 100k+ miles. There is a member on the turbo side who has something silly like 400k miles ?
Current 3, at 35k miles. 0 issues.
EntityX has 5xk miles and 0 issues on his metzger.
IMO some of you guys over think things and are worry worms.
i suspect that $ will be much smaller. I.e. R&R guards differential is sub $1,000 in labor + fluids That said, I drove my prior metzger motor to 96k miles. 0 motor issues. Drove DD + track + weekend. Current owner is friend and he has 0 issues with motor and he keeps tracking + DD, sitting at 100k+ miles. There is a member on the turbo side who has something silly like 400k miles ?
Current 3, at 35k miles. 0 issues.
EntityX has 5xk miles and 0 issues on his metzger.
IMO some of you guys over think things and are worry worms.
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Robocop305 (11-12-2021)
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Robocop305 (11-12-2021)
08-16-2015, 09:28 AM
#19
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When I am out and about, I see so many cars which, from the looks of them, never have any preventative maintenance performed. Tires worn, maybe one or more low on air, faded finish, a few dents and scrapes here and there, sagging headliner, and such. And likely uninsured. And most likely, their drivers can't recall the last time they changed or even checked their oil. And yet when the light turns green, they accelerate away just like me, sitting in my pristine, perfectly serviced cars.
Now, I have two friends who's daughter's blew up Saab motors, despite reasonable maintenance, because of those motor's absolute need for un-sludged oil. And one of my business partners, who has three vintage Porsche's yet has no clue how to maintain them, ran his Expedition with the oil light glowing for weeks, until I pulled his motor's dipstick, and explained that it should not be rusty, and his engine desperately needed oil. And yet two years later, he tows his boats with it.
So has I am out in the world, behind my own cars' steering wheels, I am just amazed at the endurance of poorly or even never maintained powerplants. When I see cars broken down on the road, I think it is usually a lack of coolant that brings them to a halt, rather than an internal engine problem.
Now, as for our Mezgar motors, i have a hunch the "innards" of the engine's are very stout, and it is the peripherals that are most likely to fail, with the complex valve train, at least likely in my now "down" motor, the culprit. The very high output of engines like ours, running right at the very limit of fueling and ignition and compression, depends on extremely precise tolerances and management of so many exact parameters. If the slightest deviation from one of many variables occurs, these engines can be just a few RPM from catastrophe.
As stated by another poster above, likely the only folks who have some idea of the weak links in Mezgar motors are those who routinely tear them down for maintenance.
and as for McMaster above, he and I go back over a decade, when we were both on Boxter Bob's forum, he with his 986, me in my Cobra.
now, sitting with morning coffee looking out over the marsh and deer and ocean breeze just south of Charleston.
All the best......
Now, I have two friends who's daughter's blew up Saab motors, despite reasonable maintenance, because of those motor's absolute need for un-sludged oil. And one of my business partners, who has three vintage Porsche's yet has no clue how to maintain them, ran his Expedition with the oil light glowing for weeks, until I pulled his motor's dipstick, and explained that it should not be rusty, and his engine desperately needed oil. And yet two years later, he tows his boats with it.
So has I am out in the world, behind my own cars' steering wheels, I am just amazed at the endurance of poorly or even never maintained powerplants. When I see cars broken down on the road, I think it is usually a lack of coolant that brings them to a halt, rather than an internal engine problem.
Now, as for our Mezgar motors, i have a hunch the "innards" of the engine's are very stout, and it is the peripherals that are most likely to fail, with the complex valve train, at least likely in my now "down" motor, the culprit. The very high output of engines like ours, running right at the very limit of fueling and ignition and compression, depends on extremely precise tolerances and management of so many exact parameters. If the slightest deviation from one of many variables occurs, these engines can be just a few RPM from catastrophe.
As stated by another poster above, likely the only folks who have some idea of the weak links in Mezgar motors are those who routinely tear them down for maintenance.
and as for McMaster above, he and I go back over a decade, when we were both on Boxter Bob's forum, he with his 986, me in my Cobra.
now, sitting with morning coffee looking out over the marsh and deer and ocean breeze just south of Charleston.
All the best......
08-16-2015, 10:11 AM
#20
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I have 51k miles on mine, both street and track. Lately it's been mostly track and it regularly sees 8000 rpm on the track. The only problem that ever kept the car off the street/track was a failed water pump, although that's really a "peripheral" item. I do engine oil and gearbox oil changes every few track days. My shop services several other GT3's and says mine feels the strongest of them all, even though mine has the highest mileage and most track time by far.
Recently I had the coolant pipes welded. While the engine was out, I had all the rubber coolant hoses, coil packs, and front and rear main seals replaced. That kind of work adds up to pretty big money so maintenance is not cheap, especially if you track the car a lot.
Recently I had the coolant pipes welded. While the engine was out, I had all the rubber coolant hoses, coil packs, and front and rear main seals replaced. That kind of work adds up to pretty big money so maintenance is not cheap, especially if you track the car a lot.
08-16-2015, 10:34 AM
#21
Three Wheelin'
Longevity/durability of Mezger engines in 996/997 GT3's
My GT3 2007 was very reliable and robust. I sold it about 2 months ago after owning it for 3 years. I was the second owner and bought it with 11K miles use with a clean ppi and no over revs. Sold it with 24K miles and no overrevs. Tracked it about 25-30 times. Had the coolant pipes welded by an experienced tech who has built exhausts and rebuilds engines and is the go to guy at his Indy shop for GT3. My PCCBs and pads were checked every few track days and the car was maintained and serviced as needed.
24k mileage is low I know but these cars are well built.
He now changes the oil in my 991 GT3 and looks over the car as I am now tracking this one 8x so far with 5K mileage. Oil change next week before a 2 day event end of August. I prefer his level of attention to detail over that of the dealer techs. I will go to the dealer for warranty work, however.
They also service my wife's manual 05 boxster. She now has 50k mileage on it over 10 years. Doesn't track it at all. Potential IMS issue never occurred. So it also comes down to luck IMO
24k mileage is low I know but these cars are well built.
He now changes the oil in my 991 GT3 and looks over the car as I am now tracking this one 8x so far with 5K mileage. Oil change next week before a 2 day event end of August. I prefer his level of attention to detail over that of the dealer techs. I will go to the dealer for warranty work, however.
They also service my wife's manual 05 boxster. She now has 50k mileage on it over 10 years. Doesn't track it at all. Potential IMS issue never occurred. So it also comes down to luck IMO
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Robocop305 (11-12-2021)
08-16-2015, 12:27 PM
#23
Nordschleife Master
All engines wear...if you question it at least do rod bearings...one bad bearing will destroy a case, crank, heads
I do rod bearings in my race car every 30 hours...and I run a much higher end bearing than a gt3... It shows wear at 30 hours
I had a 996 cup rebuilt at 100 hours. The bearings were toast...same as street car
I do rod bearings in my race car every 30 hours...and I run a much higher end bearing than a gt3... It shows wear at 30 hours
I had a 996 cup rebuilt at 100 hours. The bearings were toast...same as street car
08-16-2015, 12:42 PM
#24
Rennlist Member
All engines wear...if you question it at least do rod bearings...one bad bearing will destroy a case, crank, heads
I do rod bearings in my race car every 30 hours...and I run a much higher end bearing than a gt3... It shows wear at 30 hours
I had a 996 cup rebuilt at 100 hours. The bearings were toast...same as street car
I do rod bearings in my race car every 30 hours...and I run a much higher end bearing than a gt3... It shows wear at 30 hours
I had a 996 cup rebuilt at 100 hours. The bearings were toast...same as street car
did the analysis indicate the wear symptoms?
A street car driven like a race car will absolutely see the same wear, on ALL components not just engine/tranny. there is nothing wrong with an preventive rebuild other than the $ as you throw a rod and take out the engine you're out a substantially larger amount.
08-16-2015, 01:26 PM
#25
Rennlist Member
Check out T2's thread in 6turbo section. He's approaching 500,000 miles. I think he opened the engine block around 450,000 miles and found that the components were in good shape. Yes, it's a daily driver, mostly highway, but I think he does a bunch of track days every year. There's also the one featured in panorama at 557,764 miles, no rebuild. Both turbos, but same basic components.
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Robocop305 (11-12-2021)
08-16-2015, 02:39 PM
#26
Rennlist Member
Thread Starter
When I am out and about, I see so many cars which, from the looks of them, never have any preventative maintenance performed. Tires worn, maybe one or more low on air, faded finish, a few dents and scrapes here and there, sagging headliner, and such. And likely uninsured. And most likely, their drivers can't recall the last time they changed or even checked their oil. And yet when the light turns green, they accelerate away just like me, sitting in my pristine, perfectly serviced cars.
Now, I have two friends who's daughter's blew up Saab motors, despite reasonable maintenance, because of those motor's absolute need for un-sludged oil. And one of my business partners, who has three vintage Porsche's yet has no clue how to maintain them, ran his Expedition with the oil light glowing for weeks, until I pulled his motor's dipstick, and explained that it should not be rusty, and his engine desperately needed oil. And yet two years later, he tows his boats with it.
So has I am out in the world, behind my own cars' steering wheels, I am just amazed at the endurance of poorly or even never maintained powerplants. When I see cars broken down on the road, I think it is usually a lack of coolant that brings them to a halt, rather than an internal engine problem.
Now, as for our Mezgar motors, i have a hunch the "innards" of the engine's are very stout, and it is the peripherals that are most likely to fail, with the complex valve train, at least likely in my now "down" motor, the culprit. The very high output of engines like ours, running right at the very limit of fueling and ignition and compression, depends on extremely precise tolerances and management of so many exact parameters. If the slightest deviation from one of many variables occurs, these engines can be just a few RPM from catastrophe.
As stated by another poster above, likely the only folks who have some idea of the weak links in Mezgar motors are those who routinely tear them down for maintenance.
and as for McMaster above, he and I go back over a decade, when we were both on Boxter Bob's forum, he with his 986, me in my Cobra.
now, sitting with morning coffee looking out over the marsh and deer and ocean breeze just south of Charleston.
All the best......
Now, I have two friends who's daughter's blew up Saab motors, despite reasonable maintenance, because of those motor's absolute need for un-sludged oil. And one of my business partners, who has three vintage Porsche's yet has no clue how to maintain them, ran his Expedition with the oil light glowing for weeks, until I pulled his motor's dipstick, and explained that it should not be rusty, and his engine desperately needed oil. And yet two years later, he tows his boats with it.
So has I am out in the world, behind my own cars' steering wheels, I am just amazed at the endurance of poorly or even never maintained powerplants. When I see cars broken down on the road, I think it is usually a lack of coolant that brings them to a halt, rather than an internal engine problem.
Now, as for our Mezgar motors, i have a hunch the "innards" of the engine's are very stout, and it is the peripherals that are most likely to fail, with the complex valve train, at least likely in my now "down" motor, the culprit. The very high output of engines like ours, running right at the very limit of fueling and ignition and compression, depends on extremely precise tolerances and management of so many exact parameters. If the slightest deviation from one of many variables occurs, these engines can be just a few RPM from catastrophe.
As stated by another poster above, likely the only folks who have some idea of the weak links in Mezgar motors are those who routinely tear them down for maintenance.
and as for McMaster above, he and I go back over a decade, when we were both on Boxter Bob's forum, he with his 986, me in my Cobra.
now, sitting with morning coffee looking out over the marsh and deer and ocean breeze just south of Charleston.
All the best......
Check out T2's thread in 6turbo section. He's approaching 500,000 miles. I think he opened the engine block around 450,000 miles and found that the components were in good shape. Yes, it's a daily driver, mostly highway, but I think he does a bunch of track days every year. There's also the one featured in panorama at 557,764 miles, no rebuild. Both turbos, but same basic components.
08-16-2015, 03:07 PM
#27
Nordschleife Master
do you do oil analysis on the cup or gt3?
did the analysis indicate the wear symptoms?
A street car driven like a race car will absolutely see the same wear, on ALL components not just engine/tranny. there is nothing wrong with an preventive rebuild other than the $ as you throw a rod and take out the engine you're out a substantially larger amount.
did the analysis indicate the wear symptoms?
A street car driven like a race car will absolutely see the same wear, on ALL components not just engine/tranny. there is nothing wrong with an preventive rebuild other than the $ as you throw a rod and take out the engine you're out a substantially larger amount.
The 996 cup was mooty old car...it came out of transport and engine was refreshed. So I never did analysis
When comparing engine hours to cups, older cups ECU's time when u start car...newer cups time when it goes over a certain rev
Rpm and compression wear out rod bearings
08-16-2015, 03:32 PM
#28
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My RS has 40K Miles on it. (replacement crank case @ 14k miles)
A couple of cross country road trips, 2 tarmac rallys and about 40-50 track days.
Last january, I finally had the stock coolant pipe fail, clutch fail, spark plug and coil pack fail. All in the same week at sebring. I also had a cam cover fail and begin to lose oil.
So i was due for a big refresh.
4.0L clutch
pinned coolant fittings
refresh gear box
new plugs and coils
new water pump
new battery
repair cam cover
also did guard LSD and added 3.89 R&P.
Not a bad way to spend $20k
Car is ready for another 40k+ miles, but realiatically It will not be seeing as much track so it should run long enough for my 2 year old son to enjoy when he is old enough.....
For me, it is time for a dedicated track car.
The RS is now cars and coffee bling.
Realistically, Non tracked cars will see more years then mileage given their collectablity.
Tracked cars with proper maintenance will see just as many years with miles as long as they stay out of tire wall.
I believe this is the last of the GT engines that can be tore down and built back up which mean folks will be restoring these things long after im gone.
A couple of cross country road trips, 2 tarmac rallys and about 40-50 track days.
Last january, I finally had the stock coolant pipe fail, clutch fail, spark plug and coil pack fail. All in the same week at sebring. I also had a cam cover fail and begin to lose oil.
So i was due for a big refresh.
4.0L clutch
pinned coolant fittings
refresh gear box
new plugs and coils
new water pump
new battery
repair cam cover
also did guard LSD and added 3.89 R&P.
Not a bad way to spend $20k
Car is ready for another 40k+ miles, but realiatically It will not be seeing as much track so it should run long enough for my 2 year old son to enjoy when he is old enough.....
For me, it is time for a dedicated track car.
The RS is now cars and coffee bling.
Realistically, Non tracked cars will see more years then mileage given their collectablity.
Tracked cars with proper maintenance will see just as many years with miles as long as they stay out of tire wall.
I believe this is the last of the GT engines that can be tore down and built back up which mean folks will be restoring these things long after im gone.
Last edited by tcsracing1; 08-17-2015 at 02:17 AM.
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Robocop305 (04-22-2021)
08-17-2015, 08:22 AM
#30
Can't compare turbo motors- boost softens load on bearings and stretch load on rods at TDC (up to a point) and rpm is lower. Not surprised to see big miles in safe OEM tune with regular service.
I had near 600bhp 20v motor run near 80k miles, little to no wear on tear down. No problems. Bump to 900bp not so much, should have left a loan and saved 40k lol.
I had near 600bhp 20v motor run near 80k miles, little to no wear on tear down. No problems. Bump to 900bp not so much, should have left a loan and saved 40k lol.