1996 Honda Civic CX
Engine: D16Y8

Yesterday my timing belt broke. When it happened I did try re starting the car several times. Just turned over freely no bangs or noises.

So Last night I changed the belt and started it up. It ran rough, sputtering. So I quit thinking maybe I just put it a little out of time and I messed up on the came TDC.

This morning tore all back down re did timing. Started it did the same thing ran rough.

I just need some assurance. Is my head done for? Meaning valves is basically bent? I thought these motors were non interference.

 

is this a 100% stock factory original engine? And are you certain you have the timing lined up using the correct markings, and that everything you had to remove or disconnect to do the job have been correctly reinstalled and not damaged or altered in any way? I.e sensors, plug wires etc

 

Also how fast were you going engine speed wise when it broke? As far as I know the stock d15s ARE interference motors, so you should do a leak down test if all of the other stuff I mentioned checks out and see what the results are.

 

Do a compression test.

 

They are interference. If you have verified everything is timed correctly and reassembled correctly, you can verify if the valves are bent/damaged with a leak down tester or doing a simple compression test. With the compression test you will be able to narrow any issue down to at least the cylinder it's occurring in. You can follow that up with the leak down tester to determine things a little more closely. In the time being if you don't have immediate access to either tool, you can remove the valve cover and look at the clearances of the valves. If a valve is truly bent, it's reasonable to think that the valve wouldn't fully seat and the valve lash would be bigger due to it not closing. Of course if a valve was chipped it would still fully close but allow compression to escape out of the combustion chamber.

 

Leak down....bad news awaits

 

Compression test the cylinders.

 

I finally got around to doing a compression test.

Cylinder #1: 180
Cylinder #2: 0
Cylinder #3: 175
Cylinder #4: 180

Leak down test: Correct me if I am wrong, Put some oil in the cylinder and run a compression test again. That's a leak down test, correct?

 

No, that's a wet compression test, which is useful for diagnosing ring seal issues. A leakdown test involves using an air compressor to force air into the cylinders, so you can listen for where it's coming from. With a snapped timing belt, and a completely dead second cylinder, though, safe bet you bent a valve or two.

 

I would second that. Without even doing a leak down test you now know there is an issue with cyl #2. Those numbers are good for compression on a stock engine and more importantly are very close to each other with the exception of # 2 so you can bet you damaged/bent the valves on that cyl, and possiblly the piston depending on how hard the engine was spinning when the belt snapped. I wish you the best!

 

Thanks guys.

 

Call it an excuse to B swap

 

I'm too cheap to do that. I've quit modding things and leaving them stock.

 

So I tore the head off and did a visual inspection of cylinder #2 and it looks fine. Do you think its safe to throw another head onto it?

 

Or rebuild your current head. Probably, but you won't really know until you do it. There might be other things that got messed up, that you can't diagnose without having the head on, or without completely tearing down the motor.

 

I tossed the idea of rebuilding it in my head. Same time I have (3) heads laying around. Is rebuilding the head hard? When I first started working on these civic's I thought doing a head gasket was hard and scared to do it. That's where I'm at with rebuilding a head.

 

Not particularly. Buy/borrow/download an FSM. It's a pretty straight forward process.

 

If I put this vtec head on my bottom end, I need the matching year intake manifold. So if the head is 96-98 I need the 96-98 intake manifold. Correct? Also my motor In this car is a Y7 non Vtec. I messed up. So I couldn't put my y7 intake manifold on the vtec head.