I have a 93' Ford Ranger with a 2.3l and 230,000 miles on it. It's a 5 speed manual and it is 2 wheel drive. I recently did a compression test on it and 3 out of the 4 cylinders read 160 and cylinder #2 read 30. What are my options from here. I think that I may have a bad ring or bad valves. I could even have a bad piston. It has brand new plugs and wires. It is missing really bad. I didn't know if there was a way I could test for the valves or the rings or piston to be bad.

 

Could also just be valve train, rocker has come off.

30psi reads like a valve is not closing all the way or burnt, not a ring issue, if you were between 100-130psi then maybe rings.
You can add a teasoopn of oil via the spark plug hole and then retest that cylinder.
If pressure jumped up to 130psi then I would say yes it is rings, if it only goes up to 35-45psi then it is the valves or valve train.

The oil seals the rings better, giving false higher compression, but it can tell you if rings or valves are the problem.

After pulling the valve cover, check all the rockers, it will be obvious if there is a problem.
But you can rotate the engine manually and watch them opening and closing to be sure.
Worst case will be if you have to remove the head, I doubt engine will need to come out.

 

You'd want to do a Leak Down Test to pin-point where the problem is. You need a LDT tester for that. You can pick them up at Harbor Freight, Northern Tools, and any of your parts houses.

A compression test will tell you whether you have a problem or not, it won't tell you what the problem is. A LDT will tell you very closely where the problem is.

Instead of having to diagnose as you disassemble, this will tell you where the problem is before you do anything more than removing a spark plug and fuel-injector connector.

I like Eric The Car Guy, he does a good job explaining things. Here's his video on how to do a LDT. It is a little long at 27 minutes.

ETCG has a website with a lot of very good instructional videos. I've done a bit of learning from his videos. Many of them are up on YouTube.

If this stuff helps you guys, please click on the "+" sign in the bottom right of the posts (called Props) so I'll know whether or not I'm being helpful.

Hope that helps. Merry Christmas!

-Jimmy

 

Merry Christmas

You also need an air compressor for a leak down test.

A Leak down test pumps a set air pressure into a cylinder that is at it's compression stroke TDC so both valves are closed and piston is at the top of cylinder.
You screw a compressed air line into the spark plug hole.
You have an air pressure gauge on that line, or two gauges if you don't have a gauge on the air compressor.
If you apply 100psi(easy number to use) of pressure to the line and if the gauge at the cylinder shows 93psi then cylinder is leaking 7psi, or 7%, that would be a newer engine.
when you get into the 15% or higher range it would be a concern.
And if you listen at the intake and then the exhaust pipe, you can often hear the air escaping if it is a valve that is leaking and which one.
That's the Dry test, then you do the same test after adding some oil to the cylinder.
% will get better but by how much tells the tale of rings or valves.

A Dry then Wet compression test doesn't require air compressor and will tell you if issue is rings or valves.
Leak down test does give more details but certainly not a good reason to buy an air compressor.
And if either test shows valves as the issue then head(s) need to come off, if rings then engine has to come out so.................you will need any extra money to fix the problem, lol