I have a 2004 Chevy Suburban 1500 with 90K miles. In November 2008 at 80K miles I noticed the heater wasn't heating. Checked af to find it was a gal low. No leaks detected anywhere and no smoking from exhaust. A few weeks later the same thing happened. After taking the vehicle to 3 garages including one authorized GM dealer, all diagnostic test were negative for cracked heads or head gaskets. Suggestive of problem but not definitive. The GM dealer started an oil consumption study D/T having to add 1 - 1.5 quarts oil every 1500 - 2000 miles. In and out of the shop until June 2009 when we experience sudden loss of oil pressure, engine started knocking but not smoking. I changed the oil again and drove the vehicle the next morning. Made it 25 miles when oil pressure dropped again and engine started knocking. I actually drove the vehicle back home under full power but alarms going off and no oil pressure. I pulled the oil pan off and found the rod bearings burned and crystallized. Now looking at new engine. GM denies problem with that model engine and refuses to offer any assistance. Just prior to experiencing the engine problems we did have to replace the catalytic converter. All of instances started around 80K miles.

- Charleston, WV, USA