Been a long time since I've posted on this forum but this car was parked for a few years and I just started regularly driving it again last summer, anyways to the point. The car is bone stock as I couldn't justify swapping out what I thought was a perfectly fine motor and automatic trans with 150K on it. Today out of curiosity I decided to do a compression test on all cylinders just to see how things were doing as I had never done one on this car before. The numbers were not at all what I expected and ended up being 120 90 30 120! What's very odd is that the car has always and still runs rather great and gets 30+ mpg with a somewhat rough or thumpy idle every so often. And I would like to bring up that when you remove the oil cap with the motor running, there's a lot and I mean a lot of blow by.

The only explanation I can think of for these numbers is that back in 2011 the car ran so low on oil that when I came to a stop one day the oil pressure light flickered just a little bit and so instantly I carefully drove home 5 mins away to check the oil and sure enough the dip stick was BONE dry. I immediately added oil and ever since kept a much closer eye on it in this car and it's never even remotely run low since.

Now i'm well aware that a Y8 does not have oil jets to lubricate the cylinder walls and so this leads me to believe that when it ran this low on oil, damage was done to the rings... but here's the thing, the motor never has burnt any oil and still to this moment does not.

I'm thinking it's time to finally start the B20 vtec build or could I for get by for another 6 months or so by just honing the cylinder walls of my Y8 and installing new rings and such and hoping for the best until my b20 build?

What do you guys think or what would you do in this scenario, and just to throw it out there, I love this car and this is nowhere near the end for it lol.

 

How long did it sit not being run?

 

^^ This.. If the car sits for years and never started regularly at least, you'll most certainly have to worry about the rings needing to reseat. There is an oil additive called restorer, in a blue and silver can that is amazing to use for this. They sell it at Walmart and most parts stores. Change your oil and add a can of it to your crank case.

 

Well even though the car did sit for awhile, it was regularly started and occasionally driven somewhere and back just for the purpose of it not sitting there untouched. The most it would sit untouched was a month or so.

 

If you're losing oil, I'm sure you have an oil leak.

 

Sorry.. I didn't assume the car was driven or started occasionally; as in the first statement you said it sat for a few years and then you recently started driving it again.

Loss of compression is only a few possible items, valves, head gasket or warped head, cracked block, piston(s)/rings.. Unless I'm mistaken

 

Tell us the procedure you followed to check the compression of the cylinders.

 

I'd do a quick timing belt check. I've seen several occasions where the timing belt has either been improperly replaced, stretched or whatever and has jumped a tooth. The result is pretty much what you're describing.

 

OP...to confirm a cylinder compression leak you need to do a dry and wet (few teaspoons of oil) compression test to confirm. Do while engine is operating temp, disconnect distributor harness, hold down gas pedal to floor for five seconds before cranking, release gas pedal and crank engine for a slow count of 5 seconds.

Also, have a "leak down" test done to confirm. Google leak down test if, you don't know what it is or does. Follow Vtec Yo's advice as well for jumped timing.

 

^^^

 

To clarify: Don't you hold the pedal down to the floor WHILE cranking to disable fuel?

 

Yes.

Doesn't it suck when people start threads and then they never reply again or never follow-up when they get answers? People who do that are 0=>'s

 

The main reason to hold the throttle wide open while cranking for the compression test is to let air flow freely into the engine. You are measuring how well it can compress air, and if the throttle is closed restricting the supply, you may get a false low reading.

 

Thanks, guys.

See? I made a productive response.

Maybe OP sold the car. I know low compression and no means to change an engine (if its not a valve) would make me do that. ...