ej1995

2000 Civic EX had a used engine installed a few years ago. Stock D16Y8.

Started running poorly, now won't start, sounds a little funny cranking and sounds like it wants to start, but it won't.

It was towed to me. It has a known good, new distributor in it from a month ago. I also tried one from a running car, no change.

New cap, rotor, plugs, and wires. New crank position sensor, he wanted that installed regardless. I have good, strong, consistant spark to all 4 plugs.

I'm getting fuel into all 4 cylinders.

I checked the mechanical timing and it is exactly where it needs to be.

My compression test says
#1. 115
#2. 60
#3. 100
#4. 165

Thoughts and opinions?

24TEN

iTrader: (2)

Are you a mechanic? If not why was it towed to you specifically?

Anyways, those numbers should already be a dead give away. I'd recommend a leak down test if you still want to pin point things. Personally it's already going to be torn down or replaced in my head.

Former User

This^ (assuming cylinders 1-3 are not just flooded with fuel).

ej1995

Not sure what difference it makes why the car was towed to me. I'm not a mechanic by profession, but for the sake of answering the question, I fix things for people.

My thoughts on the subject being that I'm going to have to pull the head to determine anything further. The way I look at it, all the cylinders should at least be 150, but I've got 3 that are seriously lower. Obviously the lowest value is too low for it to run, but would the middle two values be low enough to cause a no-start condition?

Former User

The huge PSI differences between cylinders 1-3 and cylinder 4 are the reason the engine won't start or run.

Did you rule out cylinder flooding?

ej1995

The spark plugs had fuel on them, but there was not an abnormal amount of fuel in any of the cylinders.

TomCat39

Those numbers are a sure sign of a no start or run condition. If I recall, anything over a 20% variance can cause the no start or run condition. 65 psi to 165 psi is a touch over 20% to say the least.

Anyways, a leak down test can help you isolate whether the problem is head related or piston related before tear down.

Did you check to see if the mechanical timing is still correct?

24TEN

iTrader: (2)

I was just asking because the variation/deviation on those compression results should already be telling you something (I'm guessing that's what you wanted to confirm?). Again, leak down test to pin point if you want a better idea of what's going on. "TomCat39" is on the money.

ej1995

Well everybody is pretty much confirming what I was asking. That lets me know that basically, I'm not crazy and I checked pretty much everything that I could/should have checked in the situation.

As mentioned in the original post, I did in fact check the mechanical timing.

Former User

Add a teaspoon of engine oil to each cylinder and redo the compression tests. How do the numbers change?

Did you remove the ECU fuse to disable fuel during the compression tests? Did you hold the throttle wide open for the tests?

TomCat39

Missed that detail, my apologies.

ej1995

I figured on doing the wet test tomorrow just for piece of mind. I'll post it when I finish.

I unplugged the injectors which achieved the same objective.

I checked it with the throttle plate open and closed, there was not much variation. You got the open set of numbers.

Former User

Sounds good.

tony_2018

How long have you had this car? A leakdown test for sure because some people here open my eyes to other possibilities that it could be a bent valve or a valve not completely seated against the head.

ej1995

I'm still going to do a wet compression test later today and most likely a leakdown test because this guy is fairly certain that he wants me to pull the head and go through everything.

TomCat39

If the numbers shoot up significantly on the wet compression test, you can skip yanking the head unless the owner wants the motor fully rebuilt.

I'm sure you know if the numbers don't change then the leak down can help you pinpoint whether it's an exhaust side or intake side problem assuming no cracks anywhere.

ej1995

I was going to post earlier but got sidetracked. Wet test was nearly identical. Pulled the head, gasket issues, replaced everything, now it runs again.

What I am pretty sure happened is this, the car was running, then went to barely running (blew between 1-2 or 2-3), then quit running all together (the seperation in the gasket worked around the other side of cylinder which put it down 3 cylinders).

But after completing the job, it started up and ran smoothly, so I am fairly pleased. I appreciate any input towards confirming my suspicions.

TomCat39

Time will tell the best.

I'm guessing you didn't test the block or the head for flatness?

D16Y8 already came standard with an MLS gasket so is not as common to blow like the graphite gaskets of the non vtec motors from 88-95.

This info would get my suspicions up as to why the mls gasket blew.

ej1995

Used a machinists flat edge tool, head and block are fine.

It's hard to say the mileage of the engine, because it was a junkyard engine. I am fairly certain that the cylinder head had never been removed from the block though.

I've repaired a few 96-00 head gasket issues. Previous to this one they all blew thru to the water jacket, not between cylinders though.

TomCat39