Blue Bullet Blog-The C6 Ownership Experience

[Hib Halverson]

No pressure differential on the high and low sides both with the a/c on can mean a bad compressor, BUT only if the center hub of the compressor is turning and not every tech will check to make sure that it is.

You state the compressor hub was turning with the a/c on, was this with the a/c not cooling? If so then it could point to a bad compressor, or a low Freon charge, just enough Freon to engage the clutch but not enough to cool the interior.

The compressor hub was turning but the HVAC was blowing ambient temperature.

Generally speaking a compressor does not go bad without making an audible noise first, or work intermittently on and off, but stranger things have happened. Bad clutch coils or low Freon levels are usually the case in that scenario.

The compressor was not making noise, but if it was and the noise was subdued, I would have never heard it over the engine. The compressor was not clutching/declutching intermittently. The clutch was either engaged, or if I turned the HVAC off, disengaged.

Looks like I won't have to drop the front cradle to get it out. I can remove the air bridge and the water pump, then unbolt the compressor, unscrew the one stud, and slide the compressor forward. Disconnect the hoses and lift out the compressor bringing the bolt and stud with it.

I'm going to replace the compressor the condenser and the two charge valves.

 

[LLC5]

The compressor hub was turning but the HVAC was blowing ambient temperature.



The compressor was not making noise, but if it was and the noise was subdued, I would have never heard it over the engine. The compressor was not clutching/declutching intermittently. The clutch was either engaged, or if I turned the HVAC off, disengaged.

Looks like I won't have to drop the front cradle to get it out. I can remove the air bridge and the water pump, then unbolt the compressor, unscrew the one stud, and slide the compressor forward. Disconnect the hoses and lift out the compressor bringing the bolt and stud with it.

I'm going to replace the compressor the condenser and the two charge valves.

It sounds like a bad compressor if the Freon level is correct. These systems don't hold much Freon and as little as 1/4-1/2 lbs lost can affect the heat removal substantially.

If the compressor let go internally you need to completely flush the system minimally if it is contaminated, and maybe replace all the components if it is really bad. When you take the hard lines off the condenser, use a q-tip and swab the inside of both lines, if the q-tip turns a dark color then the system is contaminated.

How many miles is on the vehicle?

 

[Hib Halverson]

It sounds like a bad compressor if the Freon level is correct. These systems don't hold much Freon and as little as 1/4-1/2 lbs lost can affect the heat removal substantially.

I had the refrigerant recovered. It was the proper amount.

If the compressor let go internally you need to completely flush the system minimally if it is contaminated, and maybe replace all the components if it is really bad. When you take the hard lines off the condenser, use a q-tip and swab the inside of both lines, if the q-tip turns a dark color then the system is contaminated.

My Bro-in-Law, who does HVAC work, told me that what metal the filter screen won't catch the receiver drier will catch. As I understand it, a C6, the receiver/drier is built into the condenser so I was going to replace those two, but I will do the "Q-Tip Test" to confirm.

How many miles is on the vehicle?

34912

 

[LLC5]

34912

Ouch! That's not enough.

No Goodwill from GM?

 

[Hib Halverson]

Nope. The car's a '12. It's out of the bumper-to-bumper 3/36 warranty by quite a bit.

The HVAC in this car has been a problem since the beginning. The evap core was replaced under warranty several years ago because of the same problem...loss of cooling. Twice before the HVAC has failed during high ambient temp operation, once in Corpus Christi TX during weather in the low 100s and high humidity. Then a couple years later in NV in the mid-100s and low humidity. Both times, the HVAC eventually started working again.

This most recent failure occured in the low 110s with low humidity. This time it did not start working again.

Tomorrow I'm going to start on getting the compressor off.

 

[LLC5]

Nope. The car's a '12. It's out of the bumper-to-bumper 3/36 warranty by quite a bit.

The HVAC in this car has been a problem since the beginning. The evap core was replaced under warranty several years ago because of the same problem...loss of cooling. Twice before the HVAC has failed during high ambient temp operation, once in Corpus Christi TX during weather in the low 100s and high humidity. Then a couple years later in NV in the mid-100s and low humidity. Both times, the HVAC eventually started working again.

This most recent failure occured in the low 110s with low humidity. This time it did not start working again.

Tomorrow I'm going to start on getting the compressor off.

That's too bad, 35K is not enough mileage for a compressor to fail.

I thought I remember a/c problems in the past, that's why I brought up Goodwill since you had a history with the problem.

Good luck with it, tough pill to swallow I am sure.

 

[Hib Halverson]

That's too bad, 35K is not enough mileage for a compressor to fail.

You're preaching to the choir on that.

I thought I remember a/c problems in the past, that's why I brought up Goodwill since you had a history with the problem.

I've discussed this with two different dealers. There's no love for my misbehaving HVAC.

Good luck with it, tough pill to swallow I am sure.

Well, if I DIY, I can do it fairly easily by first removing the coolant pump, then unbolting the compressore and sliding it forward, up and out. A lot easier than dropping the cradle. I can get the parts for about 500 bucks. I'll learn something from the work. That's a lot cheaper than 2000+ parts and labor for a dealer or HVAC shop to do it.

 

[Hib Halverson]

Turns out, it was pretty easy to remove the HVAC compressor without having to drop the front suspension cradle. That's the way to go if you don't have a lift and an alignment rack. Now...if you do have those two, I'd drop the cradle because, with the car up on a lift and an alignment rack in close proximity, doing that way is probably faster.

To get the compressor off w/o moving the cradle, first, get the coolant pump off. Then remove the lower two compressor bolts. If the car has Magnaride, you'll have to loosen the bracket which holds the right front suspension position sensor to get the lower rear bolt out. the lower front bolt comes out easy. Remember, the longer of the two is the lower rear.

Next, take the nut off the upper rear compressor stud, then use a 7-mm socket on a quarter-drive ratchet to free the stud from the block, but leave the stud in its hole. Remove the upper front compressor bolt. Move the compressor forward and angle it so you can reach the bolt that retains the HVAC hose assembly, then separate the hose assembly from the compressor and pull it up and out of the way. Manipulate the compressor so you can get the upper rear stud out of it. Move the compressor forward, then tilt the front of it up to clear the steering rack. Turn the compressor vertically and lift it out.

Next, I pulled the refrigerant filter out of the lower condenser pipe. There was almost no debris in the filter, which is a good sign as far as the system being contaminated.

I took the compressor down to my dealer, Bunnin Chevrolet, and had my pal, Lead Technician, Tony Esposito, inspect it. He told me the compressor didn't feel right. It was "...too loose." he said.

I ordered a new compressor, new seals along with new high- and low-pressure fill valves. When the parts come in next week, I'll put it all back together then take the car into Bunnin and have them evacuate and charge the system.

I got my finders X'ed that will fix the car's recurring HVAC troubles.

 

[Hib Halverson]

Right now I'm waiting for a new compressor and a condenser to show up at the dealer. I, also, need to wait until the HVAC flush kit I bought on Amazon arrives.

My pal, Jason, at Katech sends out a email newsletter periodically and the last issue had a little blurb on the new Katech "KT1" road wheel. The article said that Katech got with the people at Forgeline, a maker of premium racing and street wheels, and came up with a special wheel design for C6/C7 Z06es and ZR1s which makes the carbon brakes on those cars more visible.


Image: Katech, Inc.

At first I thought that Katech was just selling a version of an existing Forgeline wheel then putting their own centercaps on them, but after emailing with Jason, I found that this wheel, while an offshoot of Forgeline's VX1 wheel, is a unique offering developed by Katech and manufactured by Forgeline to their specifications. For those who don't know, Foregline is one of suppliers of wheels to road racing teams all over the world. Its products are manufactured to high quality standards and all their wheels are custom-made to order. Forgeline has a really cool web site. To see it click here

The Katech KT1 is available in the C6 Z06/Z07, ZR1 and C7 Z06 and Grand Sport sizes which are 19x10, front and 20x12, rear. The wheels are made of 6061-T6 aluminum, and, in the case of the KT1 along with other wheels in Forgeline's "Monoblock" line, are machined from single big block of aluminum. Like all Forgeline wheels, they are CNC-machined then forged in a hydraulic press with 6000 tons of force. The forging process aligns the grain structure into the wheel shape, reduces porosity and increases uniformity in the material. This results in a wheel with high strength-to-weight ratio and the most consistent quality. Generally, wheels forged like this are 40% stronger than cast aluminum wheels.


Image: Katech, Inc.

That's a damn good looking wheel.

So...what do you guys think. Do I need a set of Katech/Forgeline KT1s on the ole Blue Bullet?

 

[Tuna]

So...what do you guys think. Do I need a set of Katech/Forgeline KT1s on the ole Blue Bullet?

Absolutely!

Do they come in a different color?

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[LLC5]

Need them? Absolutely, positively not.

Want them? You bet.

 

[Hib Halverson]

So...what do you guys think. Do I need a set of Katech/Forgeline KT1s on the ole Blue Bullet?

Absolutely!

Do they come in a different color?

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A number of colors and finishes are available, but I don't know the choices. You'd have to get in-touch with Katech on that.

 

[Hib Halverson]

It's been several weeks since the ole Blue Bullet's HVAC quit in Vegas. I had the compressor off, but then the car sat in the shop for a week or so while I waited for parts and took care of some other work-related assignments. I got back on the compressor installation late last week and finished the job today, but there was one oh s**t moment.

Once the coolant pump was back on, new Continental Elite drive belts (PN 4040417, 4060798) were installed, the coolant hoses were back on, my Zip Products Mamba air filter assembly was reinstalled and the cooling system was filled, I went to start the engine and cranking time was excessive. Once it ran, the service engine light was on.

Oh crap! I thought. What in the hell is wrong now. I connected the Actron CP9680 scan tester we have here in the shop and read a P0340, a fault code for the camshaft position sensor. Well, heck, that explains the hard starting, I mused. I figured the cam sensor was at the front of the engine somewhere. I fired-up my Panasonic ToughBook and went to ACDelco's GMSi web site and brought up the factory service data for a '12 Z06. GMSi showed the camshaft position sensor on the driver-side front of the engine. I pulled my trusty miniMaglite out of the tool box and looked between the alternator and the power steering pump and there it was amongst the accessory drive pulleys and the wiring harness plug had come partially out of the camshaft sensor just enough to break the connection. WTF? :confused I thought. How in the heck can a locking connector just come loose?

After thinking about this for a while, I decided that during the coolant pump removal or reinstallation, I must have snagged the release tab of the plug then pulled it partially out of the sensor. As I continued to look at the partially dislodged plug, I starting to get ad pissed off thinking about how much work it was going to be to gain access to that plug and push it back in place.

More head scratching...

Then I hit on the idea of using some long, flat bladed tool which I could push down between the pulleys, then pry the plug back into the connector. First I tried my king-sized, extra long pry bar. Too big. Then I tried the long, small-diameter screwdriver I use to adjust Holley idle mixture screws. I was able to touch the plug with the end of that, but the tool was too flexible–I could not apply enough force to push the plug in place without bending the tool. Finally I tried my largest flat-blade screwdriver, which is smaller then my killer pry bar, but more rigid than my Holley mixture screw adjuster.

That worked like perfectly. I positioned the end of the screwdrived at the back of the plug then pried upwards and...viola! The plug snapped back in place.

As I'd just saved myself a lot of work, I broke into my happy dance.

On Tuesday, I'm going to take the car into Bunnin Chevrolet for them to evacuate and recharge the system with refrigerant.

Hopefully, that's going to solve my HVAC problems.

 

[Hib Halverson]

New compressor, new condenser, a flush of the hoses and the evaporator, clean the orfice/screen unit, a R134a recharge by Bunnin Chevrolet and the Blue Bullet's HVAC is back working properly. X your fingers that it stays that way!

The new compressor went in easier than the old one came out, likely becuase I learned all the "tricks" to make the R&R easier on the removal part. While the task takes some time, if you don't have a lift and/or you don't want to worry about having to do a front alignment after dropping the cradle, the undocumented method of removing the coolant pump then getting the compressor out works well.

In other news, I "pulled the trigger" on having Katech build me a motor for the BB. My Wife, the Fairest Sandra the Red, and I are going to do one of our early Fall road trips back east to take in the Cup races at Dover and Charlotte. After that, we're headed for the Rock and Roll Hall of Fame in Cleveland and finally, we'll leave the car at Katech outside of Detroit and fly back to California. Katech's Jason Harding says he needs about 45 days to pull the engine, rebuild it to their "Street Attack LS7" specification, reinstall the engine then do calibration and, finally, run the car on the chassis dyno.

The Wife cannot get three weeks off work, so on the first part of the trip, I'll have Tony Megowan, Southwest Section Captain for the 2019 National Corvette Caravan riding shotgun as far as Kansas City. Capt. Megowan and I are going to prerun the '19 Caravan route from Pasadena CA to KC via Henderson NV, St. George UT, Rifle CO and Goodland KS. I'll continue on solo to Cape Girardeau MO, the site of the final overnight stop in the '19 Caravan Route. After that, I stop in DC, Doylestown PA, Camden NJ to visit the USS New Jersey and, finally, Philadelphia International Airport to pick up Sandy who's flying in. After that, we go to Dover for the Cup race, then down to Charlotte to visit some NASCAR shops and then go to the second Charlotte Cup Race.

As for the Blue Bullet, the next step is to put full tread depth tires back on the car because, there's little doubt that I'll drive through wet weather sometine on this long road trip. In a recent interview with Michelin's Corvette tire expert, Lee Willard, I learned the best choice for the BB is Michelin's Pilot Super Sport ZP in the Z06/Z07 sizes. I'm going to order a set from a Michelin dealer right after Labor Day.

 

[Tuna]

As for the Blue Bullet, the next step is to put full tread depth tires back on the car because, there's little doubt that I'll drive through wet weather sometine on this long road trip. In a recent interview with Michelin's Corvette tire expert, Lee Willard, I learned the best choice for the BB is Michelin's Pilot Super Sport ZP in the Z06/Z07 sizes. I'm going to order a set from a Michelin dealer right after Labor Day.

I have the Super Sport ZPs on my 427 Vert. They are okay in the rain with full tread depth. After 20,000 miles, they get a little testy in the rain. Since I rarely max perform my 427, I'd like to find a good all season tire for it but Michelin keeps telling me that they are not making the A/S 3 or 4 ZP in the rear tire size.
Did Mr. Willard mention an All Season tire or just the Super Sport?

 

[Hib Halverson]

Most of my interview with Lee was for the V-Net. It's going to post a product review story about the non-RFT version of Pilot Sport AS3+ for use on ATS-Vs which are driven in wet, cold wet or light snow conditions.

After we discussed the PS AS3+ for ATS-V, we did get into Corvette tires. Currently the AS3+ is not made in a ZP (run flat tire) version and he cautioned against using non-RFT on C6s or C7s which are driven aggressively. He also said that the AS3+ will wear faster when driven in seasons where the average daily temperature is 75°F or more.

If I were you, I'd stick with the Pilot Super Sport. If you're getting 20,000 miles out of them before they get "testy" (not sure what that means) in the rain, I would not complain.

That said, if Michelin did have a ZP version of the AS3+ (and Willard did say such a product might be considered) it would have about 1-mm more tread depth and 7000-8000 more miles of tread life. The downside would be you'd give up 0.08-0.1g lateral acceleration and, if you ran them in the summer, you'd loose some of the increased tread life.

When I'm close to my homebase my tire choice is the Pilot Sport Cup 2. On longer road trips out of state into places where bad weather is expected, I put on the PSS.

For the '14 Caravan I had Pilot Sport 2s on the car and once we got back to California, I sold them on Craig's List and put Cup tires back on.

 

[Tuna]

Thanks Hib,
My PS2s lasted 26,000. I switched to SuperSports and that 427 now has 46,000. By testy, I mean that they hydroplane more quickly than when they were new. Of course, they only have 3-4 mm tread left. Since I don't drive it much in the winter, I'll probably be looking at new SS's come spring.

 

[Hib Halverson]

Thanks Hib,
My PS2s lasted 26,000. I switched to SuperSports and that 427 now has 46,000. By testy, I mean that they hydroplane more quickly than when they were new. Of course, they only have 3-4 mm tread left. Since I don't drive it much in the winter, I'll probably be looking at new SS's come spring.

3-4-mm tread?
Yep. They'll hydroplane.
Slow down ya old coot.


Hey...the new Captain out here is going to do Cape G, again, on the last night of our trip. Are you doing anything with the '19 trip?

 

[Tuna]

Hey...the new Captain out here is going to do Cape G, again, on the last night of our trip. Are you doing anything with the '19 trip?

That's great. Cape G really treated us well in 2014 and I'm glad to see that you new Captain is returning. In fact, I'm wearing my Cape G 2014 Caravan t-shirt right now in BG.
As for '19, we're going to participate but that's all - I hope. Ask me again this time next year as no one has stepped up to be Oklahoma Captain yet.

 

[Hib Halverson]

You remember Tony Megowan, my XO from '14? He's the new Captain out here, but...he "convinced" me to return to the Organizing Team as his "XO". In July, we preran the first two days of the new route. Next month, he and I are going to prerun six of the seven days...he added one day to the trip for '19 and completely changed the route up to Cape G.

Also, as the Museum gave us Hawaii, with all or part of four states we had to change the name from Southern California/Southern Nevada/Southwestern Utah/Hawaii to the Southwest section.

If you end up being involved, it would be fun to have our group and the Oklahoma group meet in Cape G.

By email I'll send you are eNews issues to date.