Compression test results :(
05-02-2008, 04:44 PM
#16
Addict
Rennlist Member
Rennlist Member
The overall numbers are effected by the open throttle. So you would maybe have gotten higher numbers across the board, but still a bit lower reading of cylinder #1.
The difference in cyl #1 from the average of the others is about 5.5%. This was sorta obvious with your #1 plug posted before, but 5.5% would be NOWHERE NEAR what it would take me to pull the head.
As far as it being your first time doing it, it doesn't matter its a no brainer and your results show that you did it correctly.
If you want to know where the loss may be, then a leak down is in order. Should it in fact be some build up on a valve, then Seafoam may be able to fix your problem
The difference in cyl #1 from the average of the others is about 5.5%. This was sorta obvious with your #1 plug posted before, but 5.5% would be NOWHERE NEAR what it would take me to pull the head.
As far as it being your first time doing it, it doesn't matter its a no brainer and your results show that you did it correctly.
If you want to know where the loss may be, then a leak down is in order. Should it in fact be some build up on a valve, then Seafoam may be able to fix your problem
I agree that pulling the head isn't necessary. It is just with a modded car when you can spend less than $750 (of course with you doing the labor) and redo the head, o-ring it, put on a widefire headgasket, redo the exhaust and intake gaskets and crossover gaskets, replace your studs, nuts and bolts and get a good look at your cylinder walls it is money and time well spent. This gives you a chance to look over your exhaust manifold and crossover as well if you wanted plus check for harness integrity and coolant hose health. Wouldn't hurt while your in there to loosen up the oil cooler lines and add another oil cooler to help with the modded everything theme.
Another thing to do at the same time is pick up a spare crossover and exhaust manifold and have them ceramic coated.
I was pretty shocked at the condition of my stock headgasket on my car at 130k miles. I suppose it is a 20 year old gasket and who knows what coolant the PO ran - not that any of us know for sure unless we are the only owner.
05-02-2008, 05:28 PM
#17
I agree that pulling the head isn't necessary. It is just with a modded car when you can spend less than $750 (of course with you doing the labor) and redo the head, o-ring it, put on a widefire headgasket, redo the exhaust and intake gaskets and crossover gaskets, replace your studs, nuts and bolts and get a good look at your cylinder walls it is money and time well spent. This gives you a chance to look over your exhaust manifold and crossover as well if you wanted plus check for harness integrity and coolant hose health. Wouldn't hurt while your in there to loosen up the oil cooler lines and add another oil cooler to help with the modded everything theme.
Another thing to do at the same time is pick up a spare crossover and exhaust manifold and have them ceramic coated.
I was pretty shocked at the condition of my stock headgasket on my car at 130k miles. I suppose it is a 20 year old gasket and who knows what coolant the PO ran - not that any of us know for sure unless we are the only owner.
Another thing to do at the same time is pick up a spare crossover and exhaust manifold and have them ceramic coated.
I was pretty shocked at the condition of my stock headgasket on my car at 130k miles. I suppose it is a 20 year old gasket and who knows what coolant the PO ran - not that any of us know for sure unless we are the only owner.
05-03-2008, 06:35 AM
#19
Addict
Rennlist Member
Rennlist
Small Business Partner
Rennlist Member
Rennlist
Small Business Partner
Please DO NOT USE RESTORE IN YOUR CAR.
Your compression numbers aren't that bad for a higher mileage, low compression car. Especially since you didn't have the throttle open when doing the test.
Unless your car is burning oil, or you just want to burn some cash, I don't see the need to go for a rebuild at the moment.
-Rogue
Your compression numbers aren't that bad for a higher mileage, low compression car. Especially since you didn't have the throttle open when doing the test.
Unless your car is burning oil, or you just want to burn some cash, I don't see the need to go for a rebuild at the moment.
-Rogue
05-03-2008, 02:18 PM
#22
Please DO NOT USE RESTORE IN YOUR CAR.
Your compression numbers aren't that bad for a higher mileage, low compression car. Especially since you didn't have the throttle open when doing the test.
Unless your car is burning oil, or you just want to burn some cash, I don't see the need to go for a rebuild at the moment.
-Rogue
Your compression numbers aren't that bad for a higher mileage, low compression car. Especially since you didn't have the throttle open when doing the test.
Unless your car is burning oil, or you just want to burn some cash, I don't see the need to go for a rebuild at the moment.
-Rogue
-Darwin
05-03-2008, 03:20 PM
#23
The throttle should be held open to allow clean airflow into the cyclinders. Your air preasure at 3,000 ft will be around 11% lower (room temp.20% humidity) so this will make the reading lower then at sea level. I would say keep driving it but keep the readings for future reference.
05-03-2008, 03:28 PM
#24
Addict
Rennlist Member
Rennlist
Small Business Partner
Rennlist Member
Rennlist
Small Business Partner
The throttle should be held open to allow clean airflow into the cyclinders. Your air preasure at 3,000 ft will be around 11% lower (room temp.20% humidity) so this will make the reading lower then at sea level. I would say keep driving it but keep the readings for future reference.
ModdedEverything951S, what weight oil are you using?
-Rogue
05-03-2008, 03:46 PM
#26
Addict
Rennlist Member
Rennlist
Small Business Partner
Rennlist Member
Rennlist
Small Business Partner
Lol, ok. I didn't even notice your name there - maybe I need another cup of coffee....
Just curious, how do you know that cylinder 1 is burning oil? Under acceleration most turbo cars will have some smoke - but its just from a rich condition.
-Rogue
Just curious, how do you know that cylinder 1 is burning oil? Under acceleration most turbo cars will have some smoke - but its just from a rich condition.
-Rogue
05-03-2008, 03:50 PM
#27
Changed plugs and wires the other day and number one had some fairly decent carbon build up while the other 3 were a nice even tan. Had a friend watch my exhaust while I accelerated and he said he saw "puffs of light grey" nothing that was constant, just puffs. Then I did the compression test and also when I pulled the plugs number one was slightly oily.
