Yogi

I just recently had to rebuild the cylinder head of my daughters Equinox 2.4 liter engine. The cylinder head was tanked / deep cleaned and new valves, rocker arms, seals, etc. were installed to the head. It was done due to bent valves caused by a broken rocker arm and it's broken parts getting hung up in the timing chain. That said, I have put the engine all back together with new timing chain, guides, and timing chain tensioner with the chain tensioner activated prior to installing the valve cover. The engine starts right up without issue. But, after running a bit the service engine light comes on. The scanner shows only one code that indicates no reads for the cam and crank sensors. Both sensors are new and the cam solenoids area also new OEM parts. What I would like to know is anyone else has experienced that problem and if it comes down to the PCM doing a relearn due to the new sensors. Or, could it be due to the chain tensioner not activating or working after it had been activated. I been working on the engine an hour or two everyday to get in back on the road. I have taken it for a test drive. It doesn't stall, but, will idle rough at a stop like it's surging and then have an rpm drop. The test drive was for maybe 5 miles.

oilcanhenry

Bent valves hit the pistons. Also you might have corrosion issues after so long. All those parts flying around could have damaged the camshaft

Yogi

The cylinder head was completely rebuilt ( all the valves were replaced with new ones) along with the oil pan being removed to clean out any broken parts that made their way down to it. I even pulled out pick up tube in the oil pan and cleaned it out of debris. While I had it apart, I installed a new timing chain, chain guides, and the the chain tensioner. The new timing chain was installed with crank and camshaft marks in sync. The engine had been previously pulled and rebuilt a year earlier. The camshafts have not been damage and are not pitted. I replaced both the crankshaft and camshaft sensors with GM OEM parts along with the cam solenoids. I even took that oil pan back off after first starting it up because the engine was leaking at the front right corner. There were no broken parts, needle bearings from the old rocker arm, or plastic from the broken timing chain guides in the oil pan when I took the pan back off. So, I am confident that the engine is debris free. I am just not real up to speed on the computer side of managing how the engine is put in sync and if it needs to relearn itself after replacing sensors. I will be checking for loose wire clips in that one not plugged all the way in might be the problem. Other than that, I am not sure what the problem might be.