Rep Power: 0

I just got a 98 civic hx that i was told had low compression. I just did a compression test and had to do it cold because the car wouldnt start but im having trouble with what to do with the readings. cylinder 2 and 4 both read 160psi while cylinder 3 was 120 and cylinder 1 was somewhere in that ballpark as well. I poured a little oil in cylinder 3 and ran the test again and it told me 300 psi which didnt seem right but i moved on to cylinder 1 and did the same thing and got zero psi. I have no idea where to even start with this from those readings, does anyone have any idea where to begin?

 
Rep Power: 518

If you read 300, you got way too much oil in the cylinder.


You remove all plugs and disconnect the distributor wire harness
Dump about a tablespoonfull of oil into each spark plug tube
Crank the engine over with the starter several times to distribute the oil evenly and blow out any excess oil
THEN try your wet compression test.

If you manage to get it to run again, it's gonna smoke.
A lot.




Did you check valve adjustment?
Is spark present and will it jump a 1/2 inch gap?

 
Rep Power: 0

Have not checked valve and spark yet was going to get into that this weekend. How long would it take for that oil to drip back into the pan so I can get an accurate reading?

 
Rep Power: 518

Drip? Longer than you want to wait, and may vary depending on oil used and condition of the rings. Days or weeks?

 
Rep Power: 0

Ok well I will check spark and valves this weekend. If it does come down to a rebuild how much am I looking at? Pistons, rings, rod bearings, gaskets and oil pump.

 
Rep Power: 518

Pull all the plugs out and crank it for 10-15 seconds. See if it blows some of the excess oil out of the cylinder.


No clue here.

I strongly suggest you figure out why it quit running first. You could drop in another engine and still not get it to run if you don't.

What happened to it anyway? What was the last thing you did before it quit running?

 
Rep Power: 0

That's where it's a little harder to diagnose. When I got the car I was told it doesn't run. I asked a few questions and he said it started sputtering and lost power no check engine lights and no smoke.

 
Rep Power: 518

Oh, poop. That sure doesn't make it any easier.
Any signs of overheating?
Got spark?

 
Rep Power: 0

Have not checked for spark yet and no signs of overheating. I'm thinking rings but with pouring too much oil in the cylinder it's hard to say

 
Rep Power: 518

Here's a pretty common scenario:

If the ignition coil goes bad and loses spark (a pretty common failure), the engine gets flooded (lots of unburned fuel), which washes the oil film off of the cylinder walls so the rings can't seal well, which causes low compression.

Adding a little oil to the cylinders can help restore compression enough to get it started....after fixing the coil problem so spark is restored. It may still be very hard to get started the first time.



That's certainly not the only possibility though. Check it out thoroughly.

 
Rep Power: 0

I hope that's the problem. I'll check spark when I get a chance. I did notice one spark plug had a black liquid residue on the plug threads not sure if that means anything or not

 
Rep Power: 0

checked spark and its good on all 4 cylinders