I'm new here so I will try to be as detailed as possible.
1) One week ago the engine started to hesitate and briefly rumble when I accelerated. The CEL would flash briefly for 30 seconds and then nothing. Sometimes it wouldn't flash at all or hesitate and everything was fine.
2) The next day, I took it to an Advance Autoparts to have the codes checked and nothing showed up on their scanner
3) Today the CEL came on (no flashing) and stayed on and there is an intermittent rattle in the engine. Car starts fine with no hesitation but still hesitates on acceleration
4) Today I took it to Autozone and it was scanned again and it gave the following 7 codes
P0300- misfire detected random cylinders
P0301- misfire cylinder #1
P0302- misfire cylinder #2
P0303- misfire cylinder #3
P0304- misfire cylinder #4
P0305- misfire cylinder #5
P0306- misfire cylinder #6
5) Car is 2005 CTS 2.8L, 101,550 miles
I don't really know what to do next and the car's certified warranty recently expired and money is a problem. Thanks for your help.
Check your oil level with the dip stick. The OLM on the radio stands for Oil LIFE Monitor, not level as some think. Nevertheless, I really hope that the timing chain is fine. Timing chain failure can be caused by oil being too low for too long. So right now, top off your oil.
I had that problem with my 3.2 liter and I had to replace coil packs n spark plugs, also the valve cover gaskets cause I had oil in my spark plugs that caused my car to misfire and made my coil packs go bad.... I think I paid 160 for each coil pack!
Good advice, but that is for the 3.2 03 early 04 CTS. The 3.2 actually had only two coil packs, which is why the cost for "each". And they also have a PVC system that can get clogged up, either by freezing temp or gummed up oil. Which can in turn push out the valve cover gasket and leak oil into the spark plug housing. So have your b/f check your PVC and it's tubes for clogging. Also make sure that it has the updated PVC, do a search on it. I don't know exactly how it's different from factory to updated.
I don't know too much about engines but a good friend of mine does and is going to take a look at this for me. I'm having a similar problem with my 2006 cts 2.8. Only mine is 2 cyl misfire. He suggested I first change the spark plugs but because of the way the block is I would also have to change the intake manifold gasket. Hopefully that'll take care of the problem. I had to order the parts so I'm waiting for them to come in. The plugs cost me around $52 for platinum and the gasket kit was about $115.
If you take off the intake manifold properly, there would no need to replace the gasket. I've taken my intake off, 06 2.8, at least 3 times with original gasket. The reason for the 3rd time was because of cylinder number 2 misfire as well. The first two times was for spark plug replacement. 1st for upgrade from factory, and second was to "fix" the cylinder 2 misfire. The 3rd time was to replace the coil pack of cylinder 2. FYI, it's front of the engine (most forward part of the car) and driver's side.
KOT
