Low Compression

[Mark R]

Hey first time post and new member. So I purchased a 2010 SHO 149k with an alleged bad transmission for 2500.00. I brought the car home and unfortunately the car wouldn't start. Later determined the car had misfired and was not the transmission at issue. I figuess out the exhaust was plugged with black sooty carbon so after having a shop remove it the car turned over. As the car idled near operating temp the check engine light would flash. After doing a compression test I learned cylinder 1 was at about 90 cylinder 2 was at about 120 and the rest were at 140. I also noticed a good amount of oil was splashing out of the oil fill at the front valve cover. Do I have a bad cylinder or head or what? Does the engine have to be removed to pull rear head off ...any help would be appreciated thanks

 

[Johnbigdog]

Hey first time post and new member. So I purchased a 2010 SHO 149k with an alleged bad transmission for 2500.00. I brought the car home and unfortunately the car wouldn't start. Later determined the car had misfired and was not the transmission at issue. I figuess out the exhaust was plugged with black sooty carbon so after having a shop remove it the car turned over. As the car idled near operating temp the check engine light would flash. After doing a compression test I learned cylinder 1 was at about 90 cylinder 2 was at about 120 and the rest were at 140. I also noticed a good amount of oil was splashing out of the oil fill at the front valve cover. Do I have a bad cylinder or head or what? Does the engine have to be removed to pull rear head off ...any help would be appreciated thanks

Well, the forum can't tell you if it's a head/valve fault of a piston, ring or cylinder wall fault. A cylinder leak down test will. Spec is nothing greater than 20%. Where the air is going will tell you where the fault is. Then you have to figure out why that part failed.

I can't say that I've removed the oil cap with the engine running, or if I've looked in the hole. If there is valve train behind the cap, oil will spurt out.

The bigger problem is the low compression.

 

[luigisho]

This is no bueno. Keep us updated as this unfolds. Sounds expensive

 

[SHOdded]

Time for a new engine most likely. You can discover the problem, but can you fix it? That's the rabbithole.

Http://Car-part.com

 

[Mark R]

Thanks for the info I'll have a leak down test done on it and let you all know. Worse case I will buy a wrecked one off from copart and swap engines.