motor trouble, what could be the problem?

[chmercer]

i have an s14 with a ka24de, to start. anyway, the problems are that my compression seems bad, highest was 150, lowest 110. also i get a lot of blowback out of the oil cap.

also, i pulled my spark plugs to check that out and one of them has white crusty residue on it, needless to say i am going to change them tomorrow, but i was just wondering if anyone had heard of this before.

[MikeMurphy]

read this for your plugshttp://www.gnttype.org/techarea/engine/plugs.html

Im not familiar with the term blowback regarding the oil cap. Bad compression is sometimes associated with a failed headgasket. You may have coolant mixed in with your oil. Have a quick look at your coolant and take a dip into your oil. This would make the most sense with the likely diagnosis of your spark plugs.

[chmercer]

by blowback i mean exhaust recirculating into the oil; when i took off my oil cap when i was running there was a relativley large amount of air comming out.

[NISTECH]

"Blow by" compression blowing by the rings on the compression stroke.

If your car is still in one peice add a little oil to the cylinder with 110lbs and do the compression test again. see if your compression comes up to where the other readings are. if so you have bad rings in that cylinder. that would be time for overhaul or replacement.

the white crusty on the plug indicates coolant into the cylinder. which may indicate a bad head gasket or cracked head. This may also be your loss of compression. if the oil doesnt bring up your comp this is your likely problem. Did you at any point overheat this engine?

[chmercer]

have not overheated it but did buy it used. thanks for all the info nistech, will check it out.

[yozsi]

sounds like you have a blown head gasket. look in the oil cap and see if it looks milky.