Problems after installing new head gasket

93 Grand Am 2.3L SOHC. First, I replaced the head gasket on this car and when I started it up, the engine made a lot of noise. The best I can descibe it is it sounds like a diesel engine. I found out that if I turn the steering wheel, the noise would stop. As long as I kept pressure on the power steering it would be quite, but when I released it, it would start again. It didn't make this noise before the new head gasket. I made sure all bolts were tight and the belt was tight. Anybody have a clue what could be the problem?
Second, the low coolant light stays on now even though the coolant is full. I can't find out where this sensor is. All the manual list is the temp sensor. anybody know where to find it and what could keep it from working? (I guess it could have suddenly went bad but I don't know).
Other than those problems, and a little oil leak, the car runs great.

did you forget to tighten something up? Like the power steering pump? Check the fluid level on the PS pump, if its really low that'll make some noise.

check around for a loose wire on the temp sensor, the sensor should be on one of the coolant lines where it goes into the engine , small housing on driverside. Pretty sure its down there by the trans fill cap...

All bolts are tight, belt is tight, fluid level is ok. Maybe the bearing in the power steering pump has gone bad? Just seams strange to happen at this time.

I checked the temp sensor and it seams ok. The gauge reads the temp ok. Would that also make the low coolant level light come on? I figured it would be a different sensor for that but I can't find any info about that.

Sorry about that the low coolants on the overflow resivour. Should be a wire on the side of the container. If the coolants not low, disconect the plug and see if anythings bent or dirty, then hook it back up and see if its still reading wrong. If its still on you'll hav to get a new sensor at a parts store.