2008 Pontiac Solstice GXP - Mysterious (with unkown origin blue sparkle in rear bumper cover paint)
Am curious, is the GM cleaning performed for you available to end users or only direct through GM dealerships?Finally got everything squared away. Turned out to be a combination of carbon and the ecm. I had the gm intake and valve induction service done first. He said my pistons and most likely rings were pretty built up with carbon. The chemical is poured into the cylinders and left for a few hours. Normal build up the outcome is a tea colored liquid. Mine was closer to dark coffee. I also saw the residue on my intake manifold where it all wasn’t cleaned off. Then they run the chemical through the throttle body and let it heat soak for another hour or so. I noticed a difference from this when driving home. Much smoother acceleration and it does seem to pull harder and smoother idling without the burping that I had regularly. The crc I used a few times helped but it came back shortly.
After this was done he hooked up his scanner and test drove. Still getting all cylinder misfires but no noticeable misfires. All cylinders misfiring at the same time most of the time too. He did an injector test where he briefly shut off each injector and obviously felt that when performed on each injector. Injectors checked out fine. Next item to look at was the ecm. He replaced the ecm and did whatever programming was involved with that and voila no more misfires on the test drive. First time he’s ever had an ecm reading misfires that weren’t actually occurring. He’s been doing this since ‘77 and he’s had plenty of carbon issues especially with the 3.6 gm but has never had an ecm be the issue.
I had a nice talk with him before I left and found out gas plays a huge roll in the carbon issue and as luck would have it Florida has some of the worse gas in the country. GM actually sent an engineer here because the 3.6’s were getting warranty work on carbon issues as early as 5-6,000 miles. They called in a fuel engineer who tests fuel and what they found out was the fuel was considered well below what many other states are getting quality wise. He didn’t know the details of the fuel and what made it not so great. Also, on the carbon cleaners, gm’s cleaner is about the best you can get snd he’s tried just about all of them professional and over the counter. It’s better than BG, amsoil, etc,,, it’s not as great as what they once used but that cleaner was banned from use as it was considered very toxic. Catch cans can help some but won’t eliminate carbon buildup. There is zero chances of preventing carbon buildup on these motors other than having them cleaned every 10k or so. I was curious about how many times he’s performed this and he said a ton. The 3.6’s get so bad that he pulls the intake and actually floods the heads with the cleaner and uses zip ties to scrape off the carbon sometimes. Walnut blasting and dry ice is also great for removal he said but messy can be messy with the walnuts.
BTW, be glad you don’t have to deal with love bugs. 40 minute drive and I just washed her last night🤦♂️🤦♂️
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