5.7 gsi black smoke coming out of exhaust?

[ratbag]

my engine back fired while i was under way. i change the fuel filter made it run better but not completly. i noticed black smoke coming out of the exhaust more so when idling i also noticed a little oil. not sure if thats from the trim tab or out the exhaust. so i did a compression check and the # 4 cylinder has 15 lps. pressure and # 6 cylinder had 0 pressure. i've heard that is two cylinder next to each othe could be a head gasket, but that is usually white smoke. there's no water in the oil and the oil level is full. not burning oil. any idea's? thanks

 

[erie_guy]

A bit of work on the engine is in your near future. I suggest you start by removing the intake manifold and head to inspect the #4 & #6 area. Inspect the head gasket, but I think the problem may have deeper roots. Also inspect the piston tops and the cylinder walls for scoring or cracking.

I once lost a valve on a 5.0 liter and had part of the broken valve head get beat-up and part of it imbeded in the piston while another valve piece got into the adjacent cylinder and imbeded in that piston as well. The remainder of the broken valve was never located and I assume it went out with the exhaust. I got lucky and only had to have two valves replaced in the head and pick the imbeded valves pieces from the piston crowns - the pistons otherwise were OK and are still in service.

Hope you have the same luck !!

erie_guy

 

[jerryjerry05]

Yup a head job is in the near future.
Being as it's 2 cylinders together it "might" be just a head gasket.
Always add the year and any particulars. Salt or fresh water?
The 98?? manifold is about at the end of it's life? Check for corrosion and blockage.
The manifold/ risers last anywhere from 15-20 years.

 

[ratbag]

thanks for the response. it's a 2000 engine i've had it for 4yrs and its alway been in fresh water. before me it was used in the hudson river around kingston. no salt there, but it could have been taken down the hudson where there is salt.