I bought a fully built 2006 auto C6 last week. I was not able to talk to the previous owner as I bought it from a dealership, yes I know probably not the best move but I was blindsided by the sound and power of the car, and it's exactly what I have always wanted in a Vette, loud, aggressive, and just plain nasty. Guy traded it in for a new C7 Z06 and supposedly he paid cash, he was an older guy, I know this to be true since I found dealership receipts with his license plate of TX OLGUY. Yes I am kicking myself for buying a fully built car that I know nothing about, you don't have to tell me that, but as it is, it's mine now and I have to deal with it.

Here is what I know the car has:
Vortex CAI
SLP intake duct
Lingenflelter Mass Air Flow
Aftermarket fuel rails
Headers
Exhaust
Huge cam
Don't know if it has any head work, tranny or rear end work done, and no idea about a tune.

The first day I got it we took a little road trip, and 30 miles from home I got the reduced engine power and check engine light. Seemed to run normal but I limped the car home at 40mph anyway. Light went away on its own and has not come back on. I've read that's a common problem even on stock cars.

Third day of having it, car shifted out of park funny and then would not go back into park. Took it to the dealer today, they said something had come loose, $131 later it's working again.

I can do a little wrenching. On my C5 I did my own maintenance on little stuff that went wrong, replace window regulator, replaced headlight assembly that wouldn't work, replaced brakes, so I'm not car illiterate, but I'm not an engine builder. I can't replace a cam or lifters, tranny etc...

Maybe I'm not used to having a fully built car but it seams to make a lot of strange noises and just seems like something is off. Sometimes it starts funny, today when I gave it about half throttle it popped and backfired and took it a second to accelerate. Maybe that's just the nature of a built motor. I don't see it leaking any fluids.

How do these pressures and temps look. To me the oil pressure seems low and it gets hot
Oil pressure
40PSI cold start up
30-35 PSI hot 2000-3000RPM
16-19 PSI hot idle

Engine Temp
190-200 highway driving
220- 240 in town driving
240 idling, I haven't just let it set to see if it gets any higher than that.
Oil temp was 240 while driving in town, 30-40mph stop and go.
Trans temp from 180 highway to 200+ in town

This is not a daily driver. I have money to put into the car, I expected that, I'd rather not rebuild an engine but if I have to I will and am realizing just HOW much money I may have to put into it. I have already talked with John at 21st century motor sports in Dallas about checking out the car and starting the process on anything that may be wrong. I love the car, but think I got in a little over my head for what I was wanting.

 

Fully built would mean a built motor, trans, and rear.

If I were you I would get to a reputable shop and find out what is going on. No engine is supposed to pop and backfire before accelerating.

 

Sounds like you bought a modified car with no history and the previous owner traded it in so that he would not need to deal with the person that bought it.

Enjoy! Everyday should be like Christmas.

 

Assuming you have 5w30 oil and nothing thicker. . . The oil pressure indeed is a little low. What is the mileage? Normal oil pressure cold should be in 50s or even 60s if it is cold out. Hot idle should be 30-35psi on a properly clearance engine. If the engine was rebuilt....it could have looser tolerances built in.....hence the somewhat lower pressure. That pressure is not detrimental however......just a little below what's to be expected in a factory engine.

The temps are slightly high....but I don't know when your fans are kicking in. 240 oil temp around town is a bit high. But that could be due to the build. An occasion pop on accelerate sounds like a spark plug or wire issue to me. Shouldn't be a mechanical issue. I would tune it up with fresh plugs...wires and oil.....and then have it tuned. If the tune eliminates most issues.....no need to rebuild right away. Watch oil consumption. Good luck,...hope it was a bargain. Can you post a video of it running?

 

Your oil pressure is lower than mine and I run 0w-30. On the other hand, both my coolant temps and oil temps stay much lower than your yours probably due to my 160 T-stat and built-in oil cooler on a Z51 model. Does your pressure go above 40 psi in the higher rpms? FWIW, at one time my oil pressure read very low and it turned out to be a bad oil pressure sensor, but it also started fluctuating pretty wildly, which made it easy to diagnose.

Back on the temps, most cars with a modified engine have a cooler T-Stat installed so I'm surprised at the temps you are running. Are your fans coming on? At what temp do they come on? Does your car cool down quickly on the highway at 60 or 70 mph? Could be a stuck T-Stat, a bad fan connector, or someone messed with the air dam or fan shrouding that is causing the high temps.

A big cam should not backfire. you have an issue there. Do you know anyone with HPT or EFiLive that could log your car's data?

 

You've already bought the car, and your next plan of action sounds like a wise one. Yes, it will cost you some $$ to have the car looked at and sorted out, but a reputable shop like 21CMC can handle that for you.

The popping/backfiring and high engine temps (sounds like someone...dealership...may have flashed the ECM back with a stock tune!) can be corrected. Matt at 21CMC will get you tuned up in no time...assuming the motor is in healthy shape (as others have mentioned, hot idle oil pressure is a bit low).

 

Here's mine cold idle, 62ish psi 5w30 royal purple HPS

 

 

Maybe I used the wrong term when I said fully built, although the trans and rear end could have some work done to it. I'll get some videos up of the car running tomorrow.

 

I'll be interested to see/hear the vids. But I'll be much more interested to find out what 21st CMC says is going on, if anything, with the car and what it'll take to make it right. Please do come back on and tell us.

 

I'd interested to see some pictures and video of the car!

 

My bet is that with a little research you could find the previous owner. They most likely used HP Tuners to tune it and it has a cable serial number that they new tuner can see. Take the cable serial number, call HP Tuners, and they can tell you who tuned the car.

Just one idea...

 

If you have dealership receipts from the previous owner, isn't his name and phone number on them?

I found my C6's original owner's name and address on an old receipt tucked away amongst the owner's manual booklets. I googled him and found a valid e-mail to contact him.

 

I found my previous owner here on CF. He still has pics of my motor for his signature. Pretty cool!

 

I found the previous owners name and address on the dealer papers also. I would be trying that first if you have enough info ...

 

So I got ahold of the owners grandson, who did the work on the car. He owns West Texas Motorsports, from what I can tell it's just a small shop that does LSX engines. Surprisingly he confirmed everything the dealership told me, his grandfather traded it in on a C7 Z06, he wanted the performance of that car but in a more "refined" package, and why not if you can pay cash for a new Z06. He said the car was raced at the track a few times on street night after the build and his grandfather only drove it a few times a week. Said the build had less than 2500 miles on it. Here are the mods he gave me:
Stage 3 ported heads
Forged pistons and rods
2.08/1.60 valves
TSP Torquer V2 cam
25% under drive pulley
Stock trans with Circle D 3600
Melting 10295 oil pump
Edlebrock water pump and new thermostat
Stock rear end

 

I like happy endings!

 

So is it a happy ending?

 

I don't know. I am still going to take the car to 21st CMC and have it checked out regardless. At least I feel I can actually drive the car and I'm not putting the motor at risk everyone I do. I made a video of the car but I cannot get it uploaded on either YouTube or photobucket from my iPhone, and suggestions?

 

that cracked me up
Are there any good LS tuners in your area that could address your drivability issues? I have a heads/cam stalled circle d auto, stock bottom ls2. In town in 90* temps I rarely hit 200* with the stock rad and fan. With the Dewitt's rad and dual fan setup it's even lower now. As said earlier, your oil psi is lower than norm and engine temps are really high. If they spent the coin to build a forged bottom/heads/cam/stall I would hope they would have put a better rad and fan setup to deal with the added heat. I wouldn't have a problem buying a modded car either unless there were drivability issues with the motor or trans. I hope it's all just ECM tune. GL
Ps. I had trans temp issues from my first trans cooler location. Had trans temps of 220 on a 93* day. Got rid of my vararam and put the cooler right in the center where the vararam scoop was. My trans temps rarely get over 160 unless the car is being hot lapped at the track. It never exceeds 170, and usually is in the 140-150 range when cruising.