Anybody know what the compression should be on a healthy 2.4L engine? My 2.4L seems to be burning alot of oil lately, so I checked the compression of the cylinders, and they all were around 120-130. I remember when I had my 2.2L OHV, compression was around 160-170, so this seems to be low. If it is low, what could the problem be? The only thing I can think of would be the rings. And the motor only has 103K on it...
2010 Subaru Impreza WRX Limited
1999 Cavalier Z24 Supercharged
1999 Grand AM SE (Beater Car)
1997 GMC Sierra
2007 Honda CBR 600RR
2005 Honda TRX450R
So what would you say? With 120 on all the cylinders, you think I have bad rings?
2010 Subaru Impreza WRX Limited
1999 Cavalier Z24 Supercharged
1999 Grand AM SE (Beater Car)
1997 GMC Sierra
2007 Honda CBR 600RR
2005 Honda TRX450R
There was a really good artice posted awhile ago in here on compression tests. Squirt some oil in the cylinder and repeat the test, if the cylinder pressures rise signifigantly, then it looks like bad rings, if not, then likely valve seals, etc.
15.3 @ 89.97mph, 14's on the way?
Hmm..well here's the thing. It didn't start burning oil until I put on the supercharger on. As soon as I put it on, I noticed I'm burning about 2 quarts of oil every 3,000 miles.
The way I see it, I've got two options. I have a spare motor sitting at home with only 14K on it. I can either swap that into my car, or I can rip this motor apart and check out the rings. Anyone know have any idea which would be easier to do??
And if I decide to do the rings, what is all involved? Am I able to do it myself? I assume I'd have to take off the head and replace the gasket, etc. Anything else I'd have to unassemble? And does anyone have a write-up on how to change the rings??
Thanks.
2010 Subaru Impreza WRX Limited
1999 Cavalier Z24 Supercharged
1999 Grand AM SE (Beater Car)
1997 GMC Sierra
2007 Honda CBR 600RR
2005 Honda TRX450R
Well, I just finished reading some other threads regarding changing piston rings. It looks to me that it would be easier to swap in the other motor. I'll be doing this in the next few weeks, so does anyone have any advice as far as swapping in another motor? I've swapped a tranny before, but never completely pulled out a motor.
The first few questions that come to mind:
1. I just swapped in a different tranny with a new throwout bearing about 5,000 miles ago. Will I have to buy a new throwout bearing when I bolt up the tranny to the new motor? I heard that you can't reuse the throwout bearings.
2. Can I pull out the motor with the tranny attached? That would seem easiest. All I would need is a cherry picker, right?
3. The A/C lines would have to be disconnected, correct? And then I would have to have it re-charged once they are reconnected??
I'm sure I will have more questions later. If anyone has any other advice, please tell me!
Thanks.
2010 Subaru Impreza WRX Limited
1999 Cavalier Z24 Supercharged
1999 Grand AM SE (Beater Car)
1997 GMC Sierra
2007 Honda CBR 600RR
2005 Honda TRX450R
If it only happen since you got the Sc, you most likely ran lean or maybe you are still running lean. Rings don't wear out all at the same time.
Gilles
2.3 Ho
Yes I would replace the motor and use this motor for a build. You can use the throwout bearing you cyurrently have no problems. For your A/C unbolt it from the current motor and strap it where it does not hang on the lines and leave it all connected. No charging of A/C. We do this all the time. We usually pull the motor and tranny together. If that is all your doing this is a day's worth of work.
FU Tuning
John Higgins wrote:Yes I would replace the motor and use this motor for a build. You can use the throwout bearing you cyurrently have no problems. For your A/C unbolt it from the current motor and strap it where it does not hang on the lines and leave it all connected. No charging of A/C. We do this all the time. We usually pull the motor and tranny together. If that is all your doing this is a day's worth of work.
1. Do I unbolt the A/C compressor from the motor or leave it attached? I'm kind of confused about that.
2. I have the NVG T-550 tranny swap, so it fits in the engine bay quite a bit tighter. Will I still be able to pull it out attached to the motor? Hopefully...
3. I'm assuming most of the tranny fluid will drain out when I pull the axles, correct? At least that's what happened when I pulled them out of my old Isuzu. More expensive Syncromesh...
4. The motor I am swapping in is a '00 and my car is a '99. I don't have EGR or any of that stuff like the pre '99's did, so I shouldn't have any trouble with the '00 motor, correct?
I'm sure there will be more questions to come. I'm sorry about asking so many questions, but I want to be ready to do it and it it done as quick as I can. Gotta head over to Harbor Freight and pick up a cherry picker :-)
2010 Subaru Impreza WRX Limited
1999 Cavalier Z24 Supercharged
1999 Grand AM SE (Beater Car)
1997 GMC Sierra
2007 Honda CBR 600RR
2005 Honda TRX450R
Well, you will have a problem with the knock sensor hole either being too small or being too large, but either way, drill and helicoil. Also, I would do a wet compression test most deffinatly. Squirt a teaspoon of oil into the cylinder, not more than this, could get hydrolock going on. Then do a compression test. If the rings are bad, the oil will seal up the cylinder walls with the rings for a short time, and the compression will shoot up. And when you do the compression test, your going by the 3rd or 4th compression puff arent you? Also, If I was you, I would keep the tranny attached and drop them both out the bottom. And yes, unbolt the a/c compressor off the motor, so you dont have to detach any lines, because that way you wont have to charge it again. Also, when you pull it, leave the powersteering pump attached to the line, just unbolt it from intake cam tower, and zip tie it outta the way. I think your doing the compression test wrong and your taking the first reading, because all of the cylinders are having around the same number, which is a good thing, but the number is off.
Fst Cavy wrote:Well, you will have a problem with the knock sensor hole either being too small or being too large, but either way, drill and helicoil. Also, I would do a wet compression test most deffinatly. Squirt a teaspoon of oil into the cylinder, not more than this, could get hydrolock going on. Then do a compression test. If the rings are bad, the oil will seal up the cylinder walls with the rings for a short time, and the compression will shoot up. And when you do the compression test, your going by the 3rd or 4th compression puff arent you? Also, If I was you, I would keep the tranny attached and drop them both out the bottom. And yes, unbolt the a/c compressor off the motor, so you dont have to detach any lines, because that way you wont have to charge it again. Also, when you pull it, leave the powersteering pump attached to the line, just unbolt it from intake cam tower, and zip tie it outta the way. I think your doing the compression test wrong and your taking the first reading, because all of the cylinders are having around the same number, which is a good thing, but the number is off.
He should already have the correct knock sensor in his car. I know for sure his knock sensor hole will not be too small. I have looked at about 3 99's Z24's all of which had the 2000+ (guess we should say 99+) knock sensor.
As stated unbolt the A/C from the motor and move it out of the way. I know everyone has a different way of taking the motor out, truly it will be what ever works best for you and what tools you have. We have always went out fhe top, but we have a nice cherry picker and we can slant the motor and tranny sideways while going up. It works great for us.
FU Tuning
seriously, before you swapping in that motor, redo your compression test. quad 4's burn oil, and burn more depending on how you drive them. I can almost garuntee you did the test wrong, and a good sign is that you have all 4 reading the same (but that could also be a bad sigh; like excessive wear and tear). Do your compression test again!
John, I didnt realize taht he already had the 99, my bad.
Quote:
quad 4's burn oil, and burn more depending on how you drive them
That's a BS statement. They don't burn oil. No engine is suppose to burn oil except the 2 strokes.
Gilles
2.3 Ho
^^^My thoughts exactly. My motor never burned a DROP until the S/C went on. I will redo the compression check to be sure before I swap the motor, but something definately is wrong with this thing.
2010 Subaru Impreza WRX Limited
1999 Cavalier Z24 Supercharged
1999 Grand AM SE (Beater Car)
1997 GMC Sierra
2007 Honda CBR 600RR
2005 Honda TRX450R
I'd check and see if theres a leak from a seal somewhere. Could there be more oil in the system because of the S/C? Other than 2 stoke motors, and Jet engines, no engine should burn oil (wanted to add the part about jet engines, being an F-16 mechanic). Being how they were all about the same, i would suggest like above, and retest, they could be fine.
^ send one of those F16 engine this way. I need a new engine for my Gtz
Gilles
2.3 Ho
Gilles, seriously...i thought so too. I agree with you completely now, thing is when I rebuilt my motor on my 2.4 Grand am (96) the engine speacilists told me that the 2.4 was designed to burn oil; something to do with the PCV system or oil seperator. Now im beginning to think all that was shady, I paid 2500 for a rebuild, and went back to him cause I was burning 1 quart every 2500km.
But than to add, when I went to GM, and told them my grand am was burning, same story! In exact words "these engines are designed that way".
Sorry bout the confusion!
I think what they meant by that is the enigne does burn oil indirectly by the use of the PCV (Positive Crankcase Ventilation) system. When there is postivie crankcase pressure, it vents through the PCV system and reroutes it back into your intake so it is burned instead of venting into open air. But in no way does this mean that the engine is actually made to "burn oil" as you called it.
2010 Subaru Impreza WRX Limited
1999 Cavalier Z24 Supercharged
1999 Grand AM SE (Beater Car)
1997 GMC Sierra
2007 Honda CBR 600RR
2005 Honda TRX450R
you got the crankcase breather hose hooked up back into the intake ( the black part b4 the s/c).
swapping motors- let me know and maybe i can make the trip over for the weekend. brian and i swapped motors in the past, and i would love to get involved in a swap again. put it this way, we had my engine out and on the floor with in 3 hours including cleaning up.
later
jake
Fst Cavy wrote:Well, you will have a problem with the knock sensor hole either being too small or being too large, but either way, drill and helicoil. Also, I would do a wet compression test most deffinatly. Squirt a teaspoon of oil into the cylinder, not more than this, could get hydrolock going on. Then do a compression test. If the rings are bad, the oil will seal up the cylinder walls with the rings for a short time, and the compression will shoot up. And when you do the compression test, your going by the 3rd or 4th compression puff arent you? Also, If I was you, I would keep the tranny attached and drop them both out the bottom. And yes, unbolt the a/c compressor off the motor, so you dont have to detach any lines, because that way you wont have to charge it again. Also, when you pull it, leave the powersteering pump attached to the line, just unbolt it from intake cam tower, and zip tie it outta the way. I think your doing the compression test wrong and your taking the first reading, because all of the cylinders are having around the same number, which is a good thing, but the number is off.
I put a 96 LD9 in my 2000 Z24 as a replacement, long blocked it and used 2 helicoils in size proggression to fit the later model knock sensor. Works like a dream.
