Sunday, February 12, 2012

I need to fix my 1993 Nissa Quest, can you help?

The tapping could be the timing off, the lose of power could be a dozen different things, the loud exhaust is most likely a hole in the pipe or muffler. Lets hold off on the muffler since that is the easiest. You had the vehicle turned up and still have a tap. This is either the valves or connecting rod bearing. Neither is fun and it is difficult to be sure which it actually is unless you rebuild the motor. Step 1: Get the Haynes or Chilton's repair manual on your vehicle. Step 2: Do a compression check and compare the readings with the ones the book says it should have. Step 3: Do a leak down test on all cylinders. Your going to need a compressor to do this leak down test. You connect the compressor line to an adapter like you used for the compression test and pressurize each cylinder 1 at a time and watch for the pressure leaking out. If you lose pressure on any cylinder your valves need repair or you have bad rings. Your going to have to check these 1 at a time and it should take about 30 min per cylinder. You'll need to rotate the motor by hand to get each cylinder. Use the recommended Firing order when testing the cylinders. If you pressurize a cylinder and hear leaking you have a bad valve, blown head gasket or bad set of rings on that cylinder. The end result is the same, you end up removing the head and replacing the head gasket, exhaust manifold gasket, intake gasket and since your going to have it apart anyway you might as well replace the rings and connecting rod bearings at the same time. If you have to replace 1 ring set replace them all. If you have to replace the rings, replace the connecting rod bearings. these are just standard rules. If you have 1 set of valves that need adjustment or repair, have the whole head done at the same time. It cost the same either way.I need to fix my 1993 Nissa Quest, can you help?
While I am not certain what your question is, it does sound like you have a handle on the approach to the problem. Do you have the tools and experience to tackle this problem? If not, you should consider taking the vehicle to a shop, or getting rid of it. Good luck!

No comments:

Post a Comment