1996 Blazer. Recently, we have started to have a rubbing noise from the engine..not lifters or knocking but rubbing. Also the RPMs now race very highwhen started. Sounds like the throttle is wide open. When driving and coming to a stop, oil pressure gause will go very low, sometime the chcek guages flickers on and off. For two years check engine light has constantly been coming on. Different mechanincs have said either the cams are bad, to it needs motor mounts. They said motor mounts would solve rubbing, but couldnt guarantee it would stop racing RPMs. Both pathsare $$$. Any ideas.

 

stickey throttle cable maybe......im no expert but maybe lube er up, see if it helps....

 

With the Engine at normal Operating Temp,hood up, foot on the brakes, put it into R (watch for movement more then about 1/4 inch), then put into D (watch for same). Then with foot still on brakes take RPM's to 1,000 to 1,200 see if motor jumps sideways (1 to 2 inches means need replacements)do same for R. This will tell you if your motor mounts are bad (or just do a visual check of the mount and look for scraping marks).

As for the High Revs, what RPM range are we talking? Normal for when its colder for the RPM's to go up to 2,000 for start up until it warms up some.

As for the Oil PSI gage, try using an external PSI gage to check to see what the TRUE PSI is at idle. If its lower then what the specs say, then you should be looking at your Oil Pump, Oil Filter,and Oil Pump Pickup.