Not really a hard proceddure. Your biggest challenge will be to reset the timing on the engine, but can be done relatively easily if done right. Simply mark timing belt, Cam gear, and top of block with a permanent marker. Good idea is to rotate engine by using a large socket on the crankshaft until timing marks line up, then mark all items (timing belt, Cam gear, and top of block) First, you've got to remove all the items connected to the head itself, (carb assembly and any other items). A good idea is to take some digital photos of the top, side and all items connected to the head so you can reference when re-assembling later. After removing all components, remove the valve cover. Once removed, you'll have to take out all the head bolts. These will be REALLY tight due to each bolt being torqued. Remove the head, use a large plastic mallet (hammer) and loosen the head by tapping on the sides. Once loose, remove the head and place on a soft surface (several layers of cardboard) Use a putty knife and remove the old head gasket. Scrape any residual oil build up or other material from head and top of engine block. Place new head gasket on the engine block in accordance with service manual or MFG recommendations. Carefully replace head on top of the head gasket and place head bolts into holes you removed them from. Tighted down with regular socket drive until nice and snug. Use torque wrench and tighten bolts using star method as indicated in service manual or ask anyone who's worked on engines to show you. Reset Cam and timing marks with marks you made and replace the timing belt. Use photos you took prior to disassembly to place all items back on the head.
It can costs anywhere from 10 to 20 dollars to replace an oil pan gasket on a 20045 Nissan Sentra as of 2014. The exact price depends on the seller.
Yes
Replacing the head gasket on any vehicle is a long and complicated process, however if you wish to see basic step-by-step instructions go to the related question on the right side of the page "How do you replace a head gasket?"
More than likely you have a valve cover leak. You probably need to replace the gasket(s).
you will need to rebuild the whole motor. better off getting a used motor at a junkyard and replacing it like I did on my sentra.
Leak or blown gasket.
have a mechanic sheck for a blown head gasket or a craked head
either sell the car or pulley engine out
LOCATING THERMOSTAT ON A 1992 NISSAN SENTRA: FACING YOUR CAR THERE IS A HOSE ON THE TOP LEFT SIDE OF THE RADIATOR FOLLOW IT TO ENGINE. THE HOSE ATTACHED TO SMALL HOUSING ON ENGINE BY 2 BOLTS REMOVE AND YOU WILL FIND THE THERMOSTAT. MAKE SURE TO USE NEW GASKET AN GASKET SEALER. Per the repair manual. The thermostat is located from the bottom of the vehicle, off of the lower radiator hose housing. The thermostat "is not" located off of the upper radiator hose behind the housing connected with two bolts.
My 2001 Nissan Sentra GXE has a blown head gasket. My mechanic is quoting me $700 for labor plus parts (total in the $1200 range). Based on his hourly rate of $90 per hour, he must be planning on about 8 hours. Of course that's for an experienced professional. I'm sure if I were to do it myself (assuming I had the ability) it would take much longer.
you go to a Machanic.
replace head gasket