[halfwaythere]

Hi, apologies in advance if I am posting in the wrong section.

I have a 97 civic that lost compression in cylinder 4, I could replace head gasket and see if that is the problem. I figure since I would be going to all the trouble to remove the head, why not just rebuild the whole engine, it has about 170k miles on it. Vehicles are so expensive right now I figured I would finally take a shot at my very first rebuild.

I am sure this information is available somewhere on this site, but does anyone had any good videos/guides that would make it easier for me to successfully do this? I am not a mechanic but have worked on my own cars for about 15 years. Never tried doing anything with any internals, block or head.

Also, I am not trying to upgrade or go for any type of power boost. I just want an economical, quality build that will be reliable.

Thanks

 

[slo_eg8]

how do you know its the head gasket and not a broken ring land or an out of spec valve?

 

[halfwaythere]

how do you know its the head gasket and not a broken ring land or an out of spec valve?

Oh, sorry I should have specified, I don't know whats causing the loss of compression.

 

[slo_eg8]

how do you know its down on compression?

Compression Testing vs Leak-Down Testing | Pegasus Auto Racing Supplies.

 

[halfwaythere]

how do you know its down on compression?

Compression Testing vs Leak-Down Testing | Pegasus Auto Racing Supplies.

Compression tester. Cylinders 1-3 were 118 psi. Cylinder 4 was 0

 

[Oldcivicjoe]

Probably a fried exhaust valve, blown head gaskets don't generally read that low unless something is wrong with the tester.

 

[halfwaythere]

Probably a fried exhaust valve, blown head gaskets don't generally read that low unless something is wrong with the tester.

What about a blown ring? Would a simple inspection of the head by removing the valve cover let me see if the exhaust valve is bad or would I need to remove the lifters and rockers?

 

[slo_eg8]

no. do a leak down test before you start tearing it apart. find out where the problem is.

 

[halfwaythere]

no. do a leak down test before you start tearing it apart. find out where the problem is.

Ok, I will do that. Thanks

I probably should’ve mentioned before that the whole reason for doing the compression test was because I was getting a code thrown that said cylinder four misfire. It’s getting spark and fuel but not firing.

 

[slo_eg8]

Engine Misfiring | How Do I Know Whether My Engine is Misfiring?

 

[halfwaythere]

Engine Misfiring | How Do I Know Whether My Engine is Misfiring?

Thanks for that, I’ve already changed both O2 sensors, the plug/wires and put on a new distributor cap and rotor button. The plug i pulled out was black and gunked up. The engine starts with difficulty but the misfire is obvious. Once i try to drive it there’s little power and it will stall when taking it out of gear.

I made sure it was getting fuel and spark before doing the compression test

 

[halfwaythere]

how do you know its down on compression?

Compression Testing vs Leak-Down Testing | Pegasus Auto Racing Supplies.

About to do the cylinder leak down test now on number for to see what happens.

 

[Oldcivicjoe]

While you are pumping air in open the oil cap, throttle body and radiator cap, listen at all of those and the tail pipe for sounds of air escaping, will give an idea of where/how the air is escaping.

 

[halfwaythere]

While you are pumping air in open the oil cap, throttle body and radiator cap, listen at all of those and the tail pipe for sounds of air escaping, will give an idea of where/how the air is escaping.

We adjusted the crank a little bit just to make sure it was a top dead center and it was off just a little bit. We did the test again and there’s a noise of air coming out of the exhaust. The leak down test reader is sitting at 80%.
How hard would it be to tear off the head and replace the valve? Would I be able to just do the exhaust valves for cylinder 4?

 

[slo_eg8]

sounds like the exhaust valve is shot lol.

 

[halfwaythere]

sounds like the exhaust valve is shot lol.

How hard would it be to tear off the head and replace the valve? Would I be able to just do the exhaust valves for cylinder 4?

 

[slo_eg8]

yank the head, take it to a shop, have them hot tank it, mill it and replace the valve....maybe ask them to lap the rest of the valves whilst theyre there, if you have extra change.
new head gasket, new head bolts, new timing belt, tensioner, and water pump since youre there


napa (down here anyway) has machine shops in some of their stores that can do it

 

[halfwaythere]

yank the head, take it to a shop, have them hot tank it, mill it and replace the valve....maybe ask them to lap the rest of the valves whilst theyre there, if you have extra change.
new head gasket, new head bolts, new timing belt, tensioner, and water pump since youre there


napa (down here anyway) has machine shops in some of their stores that can do it

Well, thank you so much for your help and advice. Otherwise I would’ve yank the engine and start rebuilding it, put the engine back in and still have the same issue lol. You saved me a bunch of time and money.

 

[slo_eg8]

or, find someone selling another y7 and chunk it in and hope for the best

 

[halfwaythere]

or, find someone selling another y7 and chunk it in and hope for the best

I called a local machine shop here in Houston and they quoted me 220 to do the milling and the other tests on the head. They said it would be $10 to replace the broken valve and another $10 if the guide needed replaced. Does that sound reasonable?