Well, as the title states... I just did a wet / dry reading of my cylinders' compression on my 88' D15B2 with the throttle held open. Cylinders 4 through 2 were at near the minimum mark (around 130 psi). Cylinder 1 had No compression at all, zero. Funny thing is, even though that cylinder doesn't fire, it idles and drives alright except for a lack of power on hills. Any ideas on what might cause this? This engine has 300K on the clock too.

I've narrowed it down to:
- Bad rings / oil rings
- Major leak on the head gasket surrounding Cylinder 1
- A valve / auxiliary valve caked with carbon and stuck open.
- Valve seals / guides are shot to hell.

Also as of late, it has been leaking small amounts oil over all corners of the engine just letting it idle in the garage for 10 or so minutes at a time.

What do you think?

 

...anyone?

 

Don't think this is a head gasket, all the rest is very probable. 300K on engine? I guess swap will be cheaper than rebuild, unless you have some emotional attachement to the current engine

 

300k? thats not a whole lot is it? like 160,000 miles right?

 

a head gasket would cause it to run real ****ty, and blow white smoke.

bad rings would usually be accros all cylinders not just one

valve seals only keep oil out of the combustion chamber so that would not cause it, but can cause oil consumption

i say a burned valve or some carbon buildup on it. run some seafoam through it and see if it helps. most guys just do the seafoam like the directions say, but the inline 6 jeep guys use a turkey baster and put some dierctly into the cylinders when the plugs are removed. then turn the engine over a few time BY HAND, wait a hour, do it again, wait another hour, do it again. reinstall the plugs and start it up. then follow the directions on the can. and definatly change your oil after your done.

 

Um, k means thousand. As in 300,000 miles.


Jared how do you turn the engine over by hand?

 

Socket and wrench on the crank pulley bolt with tranny in neutral.

I'm thinking a burnt exhaust valve. But I'm still a small fish in a cloudy pond with this Civic stuff.

 

Honestly, for the money I would just swap in a new motor. If its just a commuter you can get a non vtec D for dirt cheap. Hell, I know a guy with a del sol who did a B16 swap......he "sold" his non vtec D series engine for a pack of smokes.

 

i know that engine - just rebuilt mine.
you can leave the engine in the car. can follows my posts by using the search here with my name and with "rebuilt engine" or something like that.
did not have the money to replace the bearing - all except for one was ok. and the one had a scar down the middle, just put it back in.
carefully keep the bearing order and put them back in the same location.
i followed Haynes; except changed the oil as soon as i returned from sealing in the bearings.
if that is the original distributor - i would replace it.
you probably have bad rings

edit; error above.
i followed haynes except changed the oil as soon a i returned from sealing in the rings, not bearings

 

Yeah, by the "300K," I meant 300,000 miles. But yeah, I am also thinking it's the exhaust valve. As of lately, it's been blowing alot of water / carbon out the exhaust too. I already bought some new valve seals (probably wouldn't hurt to replace those anyway) but I've yet to disassemble anything so far.
I was fearing the fact that I may have to remove the engine, but I'll read up on your post on how to get around that, because I don't own an engine hoist, nor do I really wanna take it out anyway.

I was told by a good friend / excellent mechanic, that by replacing just that valve / all the valves, it's likely to blow the bottom end out of it once it's started and on the road, due to it's extreme amount of miles. Any opinions on that?

PS - I have already ran a mild amount of Seafoam through it as well. 4oz. through the fuel tank, 2oz. through the vaccum line to the brake booster and another 2oz. into the valve cover's oil cap. Made a small improvement, but the cylinder was dead when I bought this car a month ago on the lot, so this probably isn't due to the carbon / gunk deposits breaking loose and clogging the valve. The plugs were also replaced after about 100 miles of driving it with the Foam.