Many things-Burnt or Broken Intake or Exhaust Valves.Broken Compression Ring,Bent Push Rod,Pumped UP Hydralic Lifter,Hole in Piston or Block,,OR EVEN a small Piece of CARBON that has come loose from the Compression chamber & has gotten STUCK UNDER one of the VALVES.or a broke Valve Spring.or keepers fell off.Broken conecting Rod.
Each cylinder needs fuel, compression and spark. You are missing one of those.
How do you fix no compression in one cylinder? Yes, a dead cylinder can be fixed by checking and rectifying any defective component that falls among some of the reasons that result in a dead cylinder; in order to fix a dead cylinder, you will have to diagnose the cylinder by using a compression gauge to test whether there are any cylinders with no compression. Usually, a leaking gasket.
This all depends on why it has low compression. If the rings are worn out, the motor should be rebuilt. If one of the valves is bad, re grinding it or replacing them is the fix. Perform a cylinder leakage test to confirm it. You will probably need to take it to a shop for this, but unfortunately, there usually are no quick fixes for low compression.
Number one cylinder is located driver's side front of engine. With the # 1 piston at TDC on the compression stroke, the rotor will be pointing at #1 plug on cap.Number one cylinder is located driver's side front of engine. With the # 1 piston at TDC on the compression stroke, the rotor will be pointing at #1 plug on cap.
Check the Piston Ring.
Depends on why there is no compression.
Remove number one spark plug and squirt some motor oil into the cylinder. Now do another compression test. If the compression goes up considerably in number one cylinder you probably have bad/worn or cracked piston rings. If the compression doesn't change much you probably have burned or bent valves.
Most of the times when you have low compression on one cylinder it's an indication that the head gasket is blown. If more than one cylinder has low compression and is hard to start the you most deffinatly have a blown head gasket
That would be the top of the compression stroke on the number one cylinder.
check the compression
If you are getting insulation blown upward, you most likely have a 4 cylinder engine which has a loose spark plug in the number one cylinder.
there is no hard fast rule here. but typically with the cap off and number one cylinder at TDC on compression stroke. the rotor will point at number one cylinder on the engine.