JimG73

new member here.

i recently purchased a 2010 grand sport. I love the car. I have some questions. I apologize if it's in the wrong forum.

Having a manual, I know the engine is hand built, but are the parts identical to the automatic engine or are there better/stronger parts in this engine?

What type of longevity are people seeing? Are these engines capable of big mileage? Any 200K+ cars out there?

also, I understand the transmission is different from the base car, how so? I know that in the zr1, 6th gear is a top speed gear, not an overdrive. How about in the GS? I read an article on the GS that said 5th AND 6th gears are overdrives but that doesn't make a lot of sense to me and 4th seems too low to get to the 180 plus this car does.

Lastly, are there any major issues with these cars? Would it make sense to purchase a warranty or are these things pretty much bullet proof?
Any and all input is appreciated.
Thanks,
jim

icntdrv55

I'm not an expert--there are many on this forum who are and live and breathe this kind of information--but my understanding is that only the dry sump LS3 engines found in the M6 coupes are hand-built. All M6 convertibles and automatic coupes/convertibles are wet sump and not hand-built. I presume that the internal engine components--aside from the dry sump system--are the same as the standard wet sump motors, but have no link to prove this.

The driveline components are the same basic small block push rod V8 engine design that dates to the 50s. Solid as a rock...as the commercial and Bob Seger implies. I believe there is a thread here that documents the +200K miles Callaway demo car. If you use your car as you would any other Chevrolet, it'll last with typical maintenance. There are some known weak areas: the hydraulic clutch mechanism design is "less than elegant" and requires some regular maintenance (search "Ranger method" in this forum). One of the other known weak areas--and an expensive fix--is the fuel tank system/cracking fuel pump housing. The nice thing about both of those issues is that GM has issued TSBs that cover repairs to both systems for 120K miles or 10 years from the in-service date. The one "fly in the ointment" is the unknown of electrical issues. Some folks have 'em, some folks don't. You can spend a lot of money chasing electrical gremlins in a car with as sophisticated a wiring harness as these. Obviously, if you use your car for track events, drag racing, or do any extensive modifications, you're more likely to encounter problems.

The various models do have slightly different transmission ratios. The GS has lower 1-2-3, presumably for slightly quicker acceleration around town, than either the ZR1 or the Z06 and base models. 4th gear ratio is always 1.0 across models. The Z06 and base models have slightly higher 5-6 gearing than the GS, whereas the ZR1 has slightly lower 5-6 gearing; I would describe the ZR1 transmission as more a "road race" tranny with closer half-step gearing to eliminate gaps in power on the track. As for top speed, I'm pretty sure that all Vettes reach top speed in 5th, not 6th, because they don't have the HP to overcome the drag. Here's a link to the gear ratios for the various models: https://www.corvetteforum.com/forums...post1593884170

There are both yea- and nay-sayers to spending money for an aftermarket warranty. I agree with the view that the warranty companies aren't in the business of giving away free money. My view is that the cost of the warranty is what is the big deciding factor. I've seen folks quote numbers in the $2000-$3000 range for a warranty. I was able to add about 5 years and 40K miles of GMEPP coverage to my car for about $900. If you can buy a warranty for a reasonable sum, you may or not recover your outlay in repairs, but it will be worth something if you decide to sell prior to the warranty expiration. In the end, you kind'a have to be like Harry Callahan and ask yourself one question: "Do I feel lucky? Well, do ya punk?"

Curt D

Check out some of the stickies at the top of the 'general discussion' page. There are a few things, if they ever happen, that may have a TSB or you can fix yourself.
I have had a grinding/chattering rear diff and clicking sound from the rear axle. Both remedies were found on here and cost me like 55 total to fix. One was a change of diff fluid (easy) and the other was replace the rear axle nuts, grease the splines, and tighten to new torque spec.
Mine is an 08 w/29k but I went with the option of saving 3 grand in the event I have a big ticket repair that I can't handle in my garage.

HOXXOH

Other than the pan, crank, and oil pump, the dry sump uses the same basic parts as the wet sump engine. The hand built reason stems from being a low production engine and that the crank length would have required a separate assembly line. It doesn't make it better or worse, just different.

icntdrv55 gave you a pretty good rundown, especially the warranty part. Although one additional thought is if you have any intentions of modding the drivetrain, be aware that you could void the warranty. Read the limitations carefully and completely.

extrapilot

I believe that the cranks are forged steel in the dry sumps, cast in the wet ones..

JimG73

thanks for all the input!

jim

Speedthrill

Yes...forged crank in dry sump GS.

JimG73

Thank you again for all the valuable info. This car did have the clutch master cylinder repaired, so hopefully that problem is behind me. As far as electrical issues, I do have an issue with the passenger seat heater. The light goes on for a second and then goes off. The seat will also move up and down and back and forth, but lumbar and bolster do not work either. I haven't dug into it yet to see what's up.

with respect to the fuel tank issue, what symptoms would tell me I have an issue?

also, I ended up with a 4LT. I'm experiencing the leather pulling away a bit where the dash meets the windshield. What should I use to treat the leather on the dash? Should I simply use a leather treatment similar to what I'd use on the seats?


thanks,
Jim

Turbo6TA

Here is some info that you may find interesting:




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dmoneychris

The passenger seat heater has blown fuses multiple times on mine (2013 DS GS). I replaced the blown fuses many times. A good time later, I did a full blown heat insulation/sound deadening installation. When I had the seats out, I double checked all the wires on the passenger seat to make sure they were laying correctly. It hasn't happened since then, but I don't know that I fixed anything...