Stock compression for the QR25DE [Archive] - B15sentra.net - Nissan Sentra Forum

: Stock compression for the QR25DE


guatoncito
05-07-2004, 12:48 PM
I've developed an engine knock/rattle in my QR25DE. I'm almost embarrased to say this but it looks like it started 'cause I was running low on oil. Anyways, I checked the compression in all 4 cylinders and they were 150 straight across. I was just wondering what the compression should be. Not the compression ration, just the pressure.

cortrim1
05-07-2004, 12:55 PM
Originally posted by guatoncito
I've developed an engine knock/rattle in my QR25DE. I'm almost embarrased to say this but it looks like it started 'cause I was running low on oil. Anyways, I checked the compression in all 4 cylinders and they were 150 straight across. I was just wondering what the compression should be. Not the compression ration, just the pressure.

stock is 182psi low is 154psi with no more than 14psi varience between cylinders. Make sure you followed nissans procedure for doing a compression check or you will get low numbers

david
05-07-2004, 01:30 PM
yeah sounds like the car wasn't warmed up most likely when you ran the tests.

cortrim1
05-07-2004, 01:36 PM
Originally posted by david
yeah sounds like the car wasn't warmed up most likely when you ran the tests.

thats what I was thinking. all reading were low and the same.

bconglet
05-07-2004, 01:45 PM
Is your knock sensor still connected?

Stylee
05-08-2004, 02:33 AM
Ha ha, knock and low oil... believe me I feel your pain!

guatoncito
05-11-2004, 12:37 AM
Update: My car wasnt warmed up when I did the compression test so that may be why I had the low numbers but it seems when I tested the compression when I first got the car they were higher. Anyways, I have my car on blocks right now with the bottom end of the engine torn out. Turns out all my barrings are bent, cracked, chipped, or otherwise damaged (Not a big surprise). I ordered new barrings from the local dealership for $80.00. The crank shalf is also scratched and damaged. To make a long story short, my engine is destroyed! With a dremmel tool Im going to try and smooth out some of the nicks. With these new barrings my car should run alright but who knows what other damage is done. I looked up into the engine and saw some other damage. Id say there is a 50% chance of more problems arrising. Im stuck with a desision to make. Do I go with what I have or do I get a whole new engine cause I was quoted $1800 to fix the one I got. Need some ideas please. And also, my knock sensor was not attached on my engine.

White_03_spec_V
05-11-2004, 06:27 AM
DON'T USE A DREMEL!!!, try to polish the journels with emery cloth, and don't go side to side. Polish the way the bearings move, NOT side to side...or you can locate a short block....or you can see how much a crank kit from travis would be.

cortrim1
05-11-2004, 06:41 AM
Originally posted by guatoncito
Update: My car wasnt warmed up when I did the compression test so that may be why I had the low numbers but it seems when I tested the compression when I first got the car they were higher. Anyways, I have my car on blocks right now with the bottom end of the engine torn out. Turns out all my barrings are bent, cracked, chipped, or otherwise damaged (Not a big surprise). I ordered new barrings from the local dealership for $80.00. The crank shalf is also scratched and damaged. To make a long story short, my engine is destroyed! With a dremmel tool Im going to try and smooth out some of the nicks. With these new barrings my car should run alright but who knows what other damage is done. I looked up into the engine and saw some other damage. Id say there is a 50% chance of more problems arrising. Im stuck with a desision to make. Do I go with what I have or do I get a whole new engine cause I was quoted $1800 to fix the one I got. Need some ideas please. And also, my knock sensor was not attached on my engine.

this is a waste of time. if you had low compression numbers your ring lands are messed up. the low amount of oil damaged the bearings and crank. I would look on ebay or at a junk yard for another motor. Your block is going to need to be honed as well. in other words its sounds like you need a full rebuild.

david
05-11-2004, 09:26 AM
Yep I'm with Mike if the visual damage you can see is that bad, bearings aren't going to help you. Run your fingernail across the crank and see if there are ridges in that. If that is the case, just get a new block, it will save you a lot of time.

guatoncito
05-12-2004, 12:05 PM
Where could I get a new block from and how much would it cost?

cortrim1
05-12-2004, 12:10 PM
Originally posted by guatoncito
Where could I get a new block from and how much would it cost?

you sometimes can find one on ebay but I would start with a junk yard this will be the cheapest way to find a complete motor.