Nnbs Silverado

Deichler · August 22, 2008

Hi guys. I just had my oil changed for the first time last weekend and put in Royal Purple 5W30 and that all went fine, dealer did it that I bought it from. However, ever since I have noticed when the truck is warm and when I come to a stop at a light or in the garage or just taking off from a light I notice a pretty strong hot tar/burn't oil smell. I have looked everywhere for signs of the odor and cannot find it. I got under the truck numerous times and there was some slight residue of oil from the oil change and I cleaned that all up with a clean rag and haven't noticed anything since. It seems to be coming from the passenger side. You can also smell it when you take off from a light with the doors closed and windows up and no air on. Kind of puzzling me. I did not notice any oil or signs of oil residue on any of the exhaust pipes and I wiped them thoroughly with a clean rag.

Any ideas??

PS...it is and 08 Silverado 5.3L V-8 with AFM and Flex Fuel.

Thanks in advance for any info.

2000DV4.8 · August 22, 2008

Look by your starter motor. If you see oil here (see pic), it's your Crank Position Sensor o-ring. Common issue on these trucks.

The rear main seal is also a possibility, or at least it was on the '07s, not sure about the '08s.

Deichler · August 22, 2008

I checked all of them places and nodda. Just a little residue after the oil change on last Sat that I cleaned up when I got home, and has been dry evr since. Puzzling me. I have been watching for leaks all week and been under it just about every day this week looking at things.

VMax2007 · August 22, 2008

My oil leak I had, which seems to be common onthese trucks was the CPS sensor o-ring, as seen in the pics above. But oil leaks down there typically do not make it smell due to burning. The oil is likely originating up high and running down onto the exhaust manifold/exhaust somewhere. I would suspect a valve cover gasket, probably at the rear end of the engine. You may need a good light and a mirror to inspect back there.