1999 Dodge Neon knocking?

Question

Although I don't really know what knocking means, but, this car when running seems 'knocking'. I measured the compression pressure, they are 200, 200, 60, 200...aaah...3rd cylinder has problem. I poured a tea spoon of oil, rechecked the pressure, still 60, so, piston rings are not the problem. So, could it be the crankshaft bearing? and, also, the cause of knocking?

Is there any dangeous to drive it? Since I can have it into the shop only one week from now?

Answer 1

if you poured oil in the cylinder and the compression didn't come up, you have a valve sealing problem. i just put valves in a neon not long ago because 1 exhaust valve was burnt. bearings will not cause a compression problem. its really hard to say if the knock has anything to do with the compression problem or not. best thing to do is use a leakdown tester to see if the valves or rings are leaking. eaither way, the first thing to do is get the head off, remove the valves, look at the seats and valves. if you don't see anything wrong, you'll have to get the oil pan off and pull the rod and piston to look at the bearings and the piston/rings.

Answer 2

If you have a cylinder with only 60 lbs., you have a problem with that cylinder. It should have been no less than 150 if the rest were 200lbs. It could be a buster piston, which will make it knock. That's what I would be checking out.

Answer 3

if you have that much of a loss on one cylinder you more than likely have a bad valve problem,thats a bad loss for compression,as for the knocking there's no way to say if that's whats causing it or not,,you could have a small hole burnt in a piston also,but it needs to be tore down and checked,there's no guessing at this one, too much,either way its got to come down,good luck with it.

Answer 4

cracked head might account for loss of pressure poor grades of fuel will make it knock