My friend Jon put this video up on YouTube a few months ago, showing me driving a certain magazine’s long-term C7 at Shenandoah from the perspective of his C5 Z06. (A video from my perspective is after the jump.) It’s readily apparent from the way it scoots away into the distance just how fast and how pleasant to drive the newest Corvette is. That alone has been enough for me to recommend it over any of Porsche’s current offerings, the same way I recommended the C6 Z06 over any of the Porsches available at *that* time. Recently, however, I’ve been taken to task for wearing rose-colored glasses when it comes to the reliability of the fantastic thermoplastic near-supercar, and I’m afraid my critics have a valid point.
At just six thousand miles, Car and Driver‘s long-term Vette suffered an engine failure:
an investigation by GM pinned tentative blame on a piece of metal debris (likely from a bad oil filter) that worked its way into the oiling system and wrecked a connecting-rod bearing, which created even more debris that damaged the engine’s bottom-end. Given the LT1’s tight tolerances and high-performance design, it didn’t take much to upset its workings. We’ve heard of a few similar accounts throughout the Stingray community and GM says it’s aware of the issue and is analyzing its manufacturing process for a root cause
Aspiring autojournos could learn a lot from the way in which Mike Sutton manages to praise the LT1 even as he discusses a complete engine failure. Sure makes you paranoid about your oil filter, doesn’t it? All of a sudden, the fact that my local Porsche dealer charges $32.90 for a cartridge filter makes sense — or it would make sense if Advance Auto Parts didn’t sell the same thing for $5.49, anyway. This would make for a good local news segment. “Are rogue oil filters killing your tight-toleranced, high-performance engine? The Six On Your Side news team finds out.”
A website called Corvette C7 Fiasco, run by a fellow who obviously and passionately hates the Corvette, its chief engineer, and General Motors, is tracking a variety of issues with the car, from “illegal wiretapping” courtesy of the Performance Data Recorder option to failures of the engine and torque-tube assembly. The site’s owner claims that ten percent or more of C7 Corvettes will eventually fail. He alleges that a second C7 provided to C/D also experienced engine failure during the “Lightning Lap”. He blames polymer bearing coatings for failures in the LT1 and LS7 engines.
Long-time TTAC readers will recall that I have beat the drum long and hard about fundamental problems with Porsche’s M96 engine as it was installed in the Boxster and 911 from 1997 to 2009. I’ve gone as far as to suggest that TTACers avoiding joining me in the far-from-exclusive Boxster Owners’ Club due to the high percentage of intermediate main shaft failures in these engines, and that they adopt a wait-and-see approach to the all-new, direct-injected engine that replaced the M96. (Would-be buyers of the 996 Turbo and GT3 models, with their “Metzger” engines, have my recommendation, my blessing, and my envy.) I’ve also suggested that Porsche’s handling of the M96 issues has clearly indicated their contempt for the people who purchase their products, particularly those of us who don’t always buy our Porsches from a Porsche showroom.
During a discussion on a small Porsche forum last week, another member straight-up challenged me to apply the same kind of critical thinking to the Corvette. “Go back and look at the LT1 failures.” When I responded that — unlike Porsche with the M96 — GM was assuming full responsibility and replacing the engines without question, much as Porsche has done more recently with the 991 GT3, he then told me to look into failures of the LS7 and LS6 engines from the previous generations of Z06 Corvette. So I took his advice, and I didn’t like what I found.
The LS7 that powers the mighty, high-performance, super-cool C6 Z06 (see what I did there?) is subject to valve guide failure. GM claims that the problem affects a small percentage of LS7s built before Feb 2011, when a new inspection procedure “100% eliminated” the failure. The problem is that this might not be true, with some mechanics reporting heavy valve guide wear on all LS7 engines regardless of age. There’s even a suggestion that the faulty head design continues into the Camaro Z/28, which would be a shame.
What about its predecessor, the LS6? Turns out that engine has become Internet famous for dropping valves. The valve spring breaks at the friction valve and, much like Jabba the Hut pressing the button on the Sarlacc Pit’s trapdoor, allows the valve to fall into the cylinder, where it has a brief but remarkably intense meeting with a piston. This happens to the first-gen CTS-V as well as to the Z06. In this case, the fix is easier and better-understood than with either the LS7 or LT1 issue — you just go buy some better valve springs. It’s a $185 solution, as long as you’re comfortable installing your own valve springs. What? You’re not? Sissy. Still, if I bought a Z06 it would be the first thing I’d do, and by “do” I mean “have done”. Although maybe it’s easier to work on the valve springs in a pushrod Chevy than it is to fuss with them in an SOHC Neon.
I should note that Z06es of both generations are neither claimed nor known to be bulletproof on track. The C5 in particular requires additional transmission cooling. Eleven years ago I looked into the idea of using a C5 Z06 as a combination SCCA National Solo/trackday car and although I knew nothing about the dropped-valve issue, I found out that the mods you need to make the car run well on a track take you outside SCCA’s Stock class. Which scotched that idea. So I got something reliable that could run in both — a Boxster S.
Yes, you can laugh now.
And this would be a good time to note that, at some point, I put a Porsche Motorsports baffled sump onto the Boxster. Naturally I did not do that while I was running the car in National Solo, because that would have been a violation of the letter if not the spirit of the rules. This would also be a good time to note that installation of that sump did not prevent the Boxster from doing the “DRIVE ME TO WORKSHOP NOWWWWWWW” thing at both Watkins Glen and Summit Point, in high-g loading situations caused by the fitment of Hoosier DOT-R tires.
As a result of looking through all this information, I’ve come to the conclusion that were I in the market for a new performance car, I would take a wait-and-see approach to C7 ownership. Were I in the market for an LS7 Z06, I’d consider swapping the heads for higher-performance aftermarket re-ports from Lingenfelter or Vengeance or someone else. Were I in the market for an LS6 Z06, I’d swap those valve springs pronto. Only time will tell if the LT1 issue is easily fixable, or whether the Feb-2011 “inspection” from GM really cured the problem in later C6 Z06es, but at least in the latter case there’s currently a prophylactic step possible. With the LT1, it’s just wait and see until somebody figures out what’s really going on. Hint: I doubt it’s the oil filter.
Despite all the above, I’d still feel more comfortable buying a Corvette than I would a Porsche, and the reason is simple: GM’s doing something. The problem with the M96 fiasco wasn’t the IMS or RMS issue itself. Every manufactured good is subject to problems and nobody is perfect. The problem was the attitude that Porsche took toward the problem. They treated customers like enemies, like they were the problem. They denied the issue for years, they did little or nothing to fix it, and they didn’t retreat from that stance until their own customers got together to sue them. That sort of mindset is more damaging than any individual manufacturing defect could ever be. I want to believe that the quick action they took regarding the problems with the GT3 is indicative of a change in that mindset, but I fear that had the problem affected all the DI 911s — or if it does affect them all — they’d check their balance sheet long and hard before doing the right thing.
Not that I’d buy either a new Corvette or a new Porsche with my own money. I’d buy a Viper. At eighty-four grand for the recently re-priced base version, it’s an outright steal. And the Viper TA continues to be my favorite production automobile. Do Vipers have problems? If they do, as the man once said…
Mr. Baruth, I don’t want to derail your article but I do have a question. I am curious what the issue was with your Boxster and the Service Now lights at Watkins Glen and Summit Point. Was there any engine damage?
I sold my ’99 Boxster some years ago and I’m kicking around the idea of getting another used Boxster or even a Z06. I did know about the Boxster engine issues but not about the Z06 ones.
If I could venture a guess, the high g loading in sweeping corners sloshed the oil far enough to one side that the oil pump was no longer submerged at the pickup. This causes cavitation in the pump, as well as short term lubrication and cooling issues.
A baffled oil pan helps mitigate this issue, and a really good baffled pan with trap doors and extra capacity helps a whole lot. However, nothing beats a dry sump system for maintaining lubrication.
I don’t think there is a single car in this price/performance category that I would have absolute 100% faith in, as far as long-term drivetrain integrity goes. That’s just part of the compromise you accept when you decide to buy one of these vehicles. Even the Supra and the NSX had some issues. Even so, they are improving all the time. We talk about a potential 10% failure rate for the ZO6, but that’s nothing compared to the hot big block cars of the 60s. As long as you are pushing the performance envelope, mistakes will be made. At that point it’s just a question of customer service.
Great read, Jack. Thank you for putting out some of the best content on this site.
Agreed. My favorite auto-journo (is that even a word?) around.
“Sure makes you paranoid about your oil filter, doesn’t it? All of a sudden, the fact that my local Porsche dealer charges $32.90 for a cartridge filter makes sense — or it would make sense if Advance Auto Parts didn’t sell the same thing for $5.49, anyway. This would make for a good local news segment. “Are rogue oil filters killing your tight-toleranced, high-performance engine? The Six On Your Side news team finds out.”
Wanna start the herp and derp mother of all shiat storms in the comments section? Write an article about oil filters.
Oh no. Then there will be side discussions about when to change your oil and what kind to use. Then thousands of Bob the Oil Guy links. Nooooo.
This topic gets bad enough on RX7Club where we’re dealing with long-known and solved problems on a small number of cars. It would be much much worse here.
Motorcycle forums are just as bad when it comes to oil. Comments will range from how daft you’d have to be to follow the factory service intervals to how using anything but “Royal Amsoil 1 T6” is destroying your engine and probably deflowering your daughter every time you ride.
Doesn’t seem to matter what brand/type or bike, either. Pedants gonna pedant; sh*tposters gonna sh*tpost
I admittedly love BIGOG even though I’m not a member/commenter.
However, and keep in mind that I’m ABNORMALLY OCD about maintenance, maintenance & repair parts, etc., some of the things they debate on that site is akin to how many debris laden, oil analyses spec sheet holding gnomes can fit in between the pleats of brand X vs. brand Y oil filter.
sorry for 3x posting. Haven ‘t a clue how that happened (or was possible).
Twitchy finger, :)?
OCD.
Lol!
I like Bob the Oil Guy. It is a good reference point for some things. However, there are also sixty five page discussions about a 1988 Tempo’s engine oil analysis from Blackstone Labs.
LOL BITOG is used by psychologists as the prime example of internet OCD.
I love when they use a micrometer to measure the width of the metal can holding the oil filter and then engage in physics to determine its protective value given the vehicle speed and size/shape of rock or other road hazard or debris that may strike said oil filter.
Yes please, write about this and oil in general. I love being taken to task for choosing to put 10w60 in my car by people I’ve never spoken to before on other internet forums, why not here.
I’m not going to give you a hard time, but I will wonder why the 60 weight? 10 seconds on google shows that some BMW M cars require it. Other then that I would think that the only other reason would be serious engine wear.
On my E39 my E39M it’s recommended but not required. M5board seems to erupt in debate over this every couple of months…all I know is I had a valve cover leak with 30 weight, and with 60 weight it stopped leaking for 2 years and 25K miles. Eventually did the valve cover gaskets anyway.
Honestly the leak story is quite odd because the 10 still remains in it, right? Why cannot the low fraction leak past the heavy fraction? How long are those molecules anyway?
The 10W part is simply the winter rating, meaning it’s functional down to -30C. A modern 10W-60 wouldn’t just be a SAE 10 oil with viscosity index improvers anymore. It probably needs very little, if any, of that. I’d expect the synthetic molecules to also be much more uniform than in earlier conventional oils.
Viper TA favorite production car?? Wow, high praise. I’ve only spent a short time driving one at the speed limit. I think that was the problem. Doesn’t seem like a good road car when driven normally. Why the Viper, Jack?
Easy solution. Don’t drive at the speed limit. Baruth never has.
Some say…He can play guitar with the clutch…and his carbon fibre beard is chizelled in the most streamlined way… All we know is he’s called JB!
Some say he bought his second Phaeton off a now-deposed African dictator …and that Cash for Clunkers resulted from his taking George W. Bush for a ride in his showroom-condition malaise-era Brougham…
” Every manufactured good is subject to problems and nobody is perfect. The problem was the attitude that Porsche took toward the problem.”
These sentences pretty much sum it up.
Even worse was the Battered-women-like response from Porsche owners and ‘Enthusiasts’ at the time. You could not convince them that their dear company had done anything short of perfection, even as the service bays at the dealers had waitlists.
Most (all?) new cars tend to have problems that don’t come up until real-world ownership. I would suspect that owning a high-performance car just magnifies it. Going to be interesting to see how tough the Hellcat is – I imagine engine failures on that thing will not be subtle.
I was talking to the proud owner of a new Macan, who informed me he also had a 2003 911. When I delicately said to him that I’d been scared off the Boxster because of the IMS bearing, he didn’t seem to know what I was talking about, and even said that his 911 had a different engine. So, he’s happy.
And Porsche is wise and used Boxsters come cheap.
Your friend’s 2003 911 would be a 996 generation, which is smack in the middle of IMS-land. I would do myself a favour and just keep quiet. He doesn’t seem to want to care.
Long time reader of yours, Jack. I remember your previous articles about this Porsche engine stuff.
I’ve been looking at 997.2 Carreras recently and I wonder if the problems with the Boxster engines carry over. I see on certain Porsche forums threads about IMS (intermediate shaft) failures, although this tends to be linked more to the 997.1 cars. If you have any insight into this issue I’d appreciate it.
Regardless of the truth about the C7’s reliability, it seems to me that this is yet another area that the automotive media is letting down its readership. Rather than having to try and figure out quality problems like this from enthusiast forums (not a representative sample of ownership for any particular car), automotive websites should have ongoing, fact-checked reliability reviews for cars that appear to have these sorts of issues. I know that Consumer Reports does this after a fashion, and sites like TrueDelta are trying to offer this, in a sense those are self-selecting groups of owners. It would be great to have a journalist actually look at NHTSA complaints, service records and other hard documentation to see if there is any truth to the anecdotal evidence you hear about on the internet. As it is, we only hear something in the headline auto websites and magazines once a recall has been made or someone files a class action lawsuit.
Mike Levitas from TPC told me that it’s no longer an issue as there’s no intermediate shaft… he also said this engine is much better than the M96 but not as stout as the Metzger which explains why you can’t push them to 1000hp on stock internals the way you could the old 997.1 Turbos.
Thanks. As I’m only ever going to drive around my midwestern town like a yuppie (golf clubs in tow, listening to Renee Fleming’s greatest arias, natch) I won’t worry about how the engine would handle massive boost.
I have Ms. Fleming’s popular music album. Includes “The Moon Is a Harsh Mistress”.
Would hit that like the fist of an angry G-d.
As a 07 Cayman S owner, I,m enjoying the schadenfreude. JK and I hope no one here gets dinged. I’ve given up worrying about my car and have just been enjoying it. Plus if it blows up, I can always have Renegade Hybrids put an LT1 in. Oh, wait a minute….
I think TD’s methodology is pretty good at dealing with the self-selection. Its downside is the low response rate. Well, response rates were trending down across the whole polling industry. Thank you, direct marketers.
I’m afraid we (automotive enthusiasts) are at a point where we need to make automakers to release some kind of true reliability stats that they gather from dealerships. Lawsuits, legislation, extortion, whatever. Just start coming clear.
“I’m afraid we (automotive enthusiasts) are at a point where we need to make automakers to release some kind of true reliability stats that they gather from dealerships. Lawsuits, legislation, extortion, whatever. Just start coming clear.”
I’d love that but believe it’s got a snowball’s chance in hell of happening.
Two groups know that. Number one is are the numbers crunchers in accounting. The second are the Service Managers, and you’ll only find out if you somehow end up at the same bar they do after a conference.
“They all do that” or “Never seen that before”…
My dream is to buy a 996 with a pre-blown engine and buy + rebuild one as Porsche should have. IMS and all that stuff bombproofed, cylinders punched out to net 4.0L displacement, Turbo fenders and big black ground meats suspended by Bilstein. Doable for $40K I think… one day.
Why not just start with a beefier 996TT or 996 GT3?
Had never heard of that website. The current rant is that factory (museum) delivered Vettes come with summer hi perf tires and we’re heading into winter. Wrecks will occur (picture displayed). God and NHTSA please save us from evil GM!
Tort attorneys are standing by to take your call….
Apparently he spends so much time denigrating the intelligence and income of anyone who buys American cars in general, and Corvettes in particular, that he fails to notice that the National Corvette Museum is located in Bowling Green, Kentucky, not Buffalo or Minneapolis. I’m pretty sure that Bowling Green, Kentucky, isn’t hit with ice and snow as early in the winter season as municipalities located farther north.
He also doesn’t seem to like senior citizens very much – particularly if they have the gall to actually buy a Corvette.
While I am by no means validating Mr. Anti-Vette-Man, indi500fan’s post brings up a particular annoyance of mine. Car manufacturers in general needs to pay more attention to their OEM tire spec. ContiProContacts, while nice and quiet, are borderline useless in rain and worse than useless in even a tiny bit of snow. Can we maybe get a different OEM tire in Canada?
(Note: I am buying winter rubber right away, but that awkward transition time in late October has me thinking about sucking up a bit of extra wear to not get caught off guard.)
Bro, future tip: Buy your snow tires in May, June or July.
I’ve purchased three sets of dedicated snows from either Discount Tire Online or Tirerack.com for at least 35% off and as much as 50% off by doing this (and they were good snow tires, too – even Nokians, which rarely go on “sale” at local tire shops).
Yeah, I know. Its been a crazy @ss summer, and I only got the car in April. I am normally MUCH more on the ball.
That, and I’ve been really hesitant to buy an expensive second set of tires for a car with a MANUAL FREAKING TRANSMISSION (100 year old tech!) that GM can’t seem to make operate quietly.
>Buy your snow tires in May, June or July.
Got mine for a screaming deal at the beginning of August. Oh yeah.
Interesting article. The author of that Corvette C7 Fiasco blog, however, comes across as so obsessed that he is almost scary. Did GM fire him? Did Tadge Juechter run over his dog?
Well, now we know whose wife Tadge Juechter slept with…
My L76 wouldn’t start in damp weather; but when it did -look out.
Wow, that C7 fiasco guy really hates Corvettes and GM. Wonder what crawled up his butt to be that obsessive.
I want a hachiroku. Or a Civic Si.
Speaking of SOHCs Neon, I had the valve adjuster seize. The enthusiast suggestion was to rip a used one at U-Pull. The dealership suggestion was an engine swap for $4,500. I sold the car (with full disclosure).
I don’t get the idea of taking a $75K production car to the track, no matter how “high performance” the manufacturer claims the car is. Complaining that the car broke under such conditions is even more baffling. Even cars designed for racing frequently break.
If I were inclined to race, I’d buy a bare bones, purpose built race car that would be cheap to fix when it inevitably breaks on the track. I don’t want power leather seats, GPS navigation and a back up camera in my race car.
This is why most guys track Miatas (bare bones, cheap, easy to fix). However if you read any automotive publication or watch any TV ads of just about ANY car (even some CUV/SUVs) it appears they are good enough to run on the track. However as mentioned its just not true. For example your stock brakes: nearly worthless under track conditions. I think the real issue/point of the article is regarding KNOWN problems and when/if the OEM is going to fess up and fix them.
There is a difference between a manufacturing defect and something that broke as a result of track level abuse. IE: what is the expected MTF (mean time between failures) of said piece. Track days will decrease the MTF. Thus I expect I will need new brakes as they wear quickly but an axle shouldn’t snap in two because its assumed to be built to last much, much longer in the first place.
” The site’s owner claims that ten percent or more of C7 Corvettes will eventually fail.”
I’m sure I know what he *means*, but…
100% of all cars will eventually fail, if driven.
I seem to remember reading a while ago that Delco filters use plastic end caps inside as oppose to metal found in other filters and there was a risk that if that plastic were to shatter it could send debris into the engine. I wonder if that has anything to so with this.
There is one big reason for me with recommending a Porsche: price. Take the 991 GT3. That is a $150K car. I’ll admit the GT3 is a better car than the Vette, but it’s not even close to being twice the car. Give me a new Vette with the potential problems down the road. My bet is that any problems can be fixed for a hell lot less than the $75K needed to move from a loaded Vette to a GT3. The real question is whether you would prefer the Vette to a 4-5 year old Porsche Turbo or maybe a GT3 of similar age. Both can be had with the much loved Metzger engine which might give some confidence that your out of warranty Porsche won’t blow up.
Hmmmmmmmmmmmmmmmm I think I’ll stick with my fantasy C4. Sure it has a crappy interior but I’ll take the money I save and stick it into modifications.
RE: the IMS failure in the 911. If you bought a 1999 911, the chance of engine failure was much less than 1%. This per the documents submitted in the class action lawsuit. You may recall (or not?) that all 1999 911 had a dual row IMS bearing. Whereas later cars had a single row bearing…which was much more prone to failure…around 8% @ 90,000 miles per the documentation.
So if you’re buying (or bought, like me!) try to find a 1999 911 to mitigate the issue.
Is the dual roll design identifiable from the outward appearance of the engine block? Model years alone tend to be an unreliable indication of manufactured date or design.
ALL 1999 had the dual bearing. The only time there is some confusion is in the 2000 model cars. This is when the switchover started and some had the dual row, others had the single row.
No way to tell until you drop the tranny to do the clutch. This is the time when most people do the IMS inspection.
My car has 165,000kms on it, and I never hesistate to run it to redline. With aftermarket exhaust, it sounds wonderful. I specifically sought out a “base” 1999 911 because of the lower weight and more robust bearing. After owning a 1986, I wanted the most “pure” driving I could get in a 996. If was VERY difficult to find an option-less car…the only option that was a must-have for me was LSD. After awhile, I finally found one…the only options I have is LSD and full leather interior.
This is a wonderful daily driver.
RE: the IMS failure in the 911. If you bought a 1999 911, the chance of engine failure was much less than 1%. This per the documents submitted in the class action lawsuit. You may recall (or not?) that all 1999 911 had a dual row IMS bearing. Whereas later cars had a single row bearing…which was much more prone to failure…around 8% @ 90,000 miles per the documentation.
So if you’re buying (or bought, like me!) try to find a 1999 911 to mitigate the issue.
I know, pretty hilarious right? Usually you don’t want to buy the first model year of a new car but the 99s were the lightest (under 3000 lbs) and had the dual bearing IMS.
I never dug into why they changed it to single bearing after that (“hey look we made the headlights nicer! ….sorry about your engine tho’ ” but all the other standard Porsche crap plastics still break with regularity.
No worries, I’ve had my 99 since 2003 and bounce it off the limiter at least once a month. The longest I’ve ever owned a car and I enjoy driving it every day even with almost 97000 miles on it.
If you know what you’re getting into as a second or third owner it’s fine but no way would I drop the coin in it new.
Should have had old Buick engineers design the engine.
I have read that the LT5 from the C4 ZR1 liked to explode early as well.
False
What keith said. While I don’t have any first hand experience maintaining them long term, the owners I’ve talked to have had good things to say about the longevity. From what I’ve read, the LT5 is pretty stoutly constructed.
My Porsche owning friend claims that to repair the IMS failure before it happens is about a $750 job. Seems that isn’t much of a price to pay considering the savings you can get on IMS-risky Porsches, if one was so inclined to own one.
Of course this friend of mine purchased a 997 Turbo without the IMS issue, and his previous car was a C6 Z06. While racing at Sebring the Z06 cracked the block due to an oil starvation issue IIRC, which then caused oil to drip on the hot exhaust which then caused the car to set fire, burning to the ground. He was fine, but then swore off Corvettes for life.
The Porsche is amazing on the track, but even he admits the Vette was faster.
I’ve been messing with cars for almost 45 years, and I have no idea what this is:
“The valve spring breaks at the friction valve”.
????
Friction weld.
ACK! WordPress!
Out of curiosity I went over to the referenced Corvette haters blog. 7 posts in 1 DAY about how sorry Corvettes, the owners, GM,etc, are?
Obsess much? Fella needs to get outta the house once in a while.
I recall several Porsche magazines stating that without question, the IMS failure was a result of driver abuse. Who knows how many people had their “dream car” completely screw them over financially.
It was a despicable period in Porsche’s history – only to eclipsed by the future flood of automatic transmission 911’s sun tanning on used car lots
Heh, I’d take the Viper, too. Love those. The 991s don’t seem like they’re as much of an enthusiast/trackwhore car anymore and I can’t get past the Aztek-butt of the C7.
A V10, a manual, and a nice, well done but simple interior sounds like the right combo to me.
Or I’d just take an aircooled 911. Get off my lawn! Haha.
If I could swing it I would trade the 427 Cobra and the long hood 911 for the new Viper ACR (should the actually sell it again). In black, with the name Vader above the door.