craiganator
Member
- Joined
- March 9, 2008
- Messages
- 15
- Reaction score
- 0
- City, State
- NC
- Year, Model & Trim Level
- 99 xlt
Do you agree the head gasket is the issue?
Facts:
99 Ford Explorer
230K miles
4.0 SOHC
No Oil burning
Minor oil leak from oil pan gasket
No coolant leaks
No coolant mixed with oil
Was running normal until one cold morning ~ 35 degrees F
Started skipping and surging
Threw codes P0171 and P0301
Started diagnostics and confirmed it has fire, fuel, compression, fuel pressure, good injectors, good MAF, good O2 sensors but short term fuel trim on Bank 1 was cycling with a frequency much higher than Bank 2. Checked for vacuum leak via the smoke test. Pushing smoke through the vacuum lines looking for leaks showed a leak in between the head and block on Bank 2. We isolated the test by making the smoke input be the crankcase vent on the passenger side(bank 1). (with engine not running) the test smoke travels through the crankcase and only comes out in between the head and the block near the front on Bank 2 (drivers dside)as shown in the video. Does this mean the head gasket is open to the atmosphere and is the air leak? Yet sealed enough to maintain oil and coolant where it is suppose to be?
http://youtu.be/UIsgDTdmC0M
Just hard to believe that the head gasket needs to be replaced since it has compression and no water in the oil or heavy steam coming out the exhaust.
Long story less long...Please advise if this has been seen before and what was done to remedy.
Many Thanks.
p.s. I searched for a while to see if this had came up, but there were all kinds of "its your intake gasket" threads for the P0171 code.
Facts:
99 Ford Explorer
230K miles
4.0 SOHC
No Oil burning
Minor oil leak from oil pan gasket
No coolant leaks
No coolant mixed with oil
Was running normal until one cold morning ~ 35 degrees F
Started skipping and surging
Threw codes P0171 and P0301
Started diagnostics and confirmed it has fire, fuel, compression, fuel pressure, good injectors, good MAF, good O2 sensors but short term fuel trim on Bank 1 was cycling with a frequency much higher than Bank 2. Checked for vacuum leak via the smoke test. Pushing smoke through the vacuum lines looking for leaks showed a leak in between the head and block on Bank 2. We isolated the test by making the smoke input be the crankcase vent on the passenger side(bank 1). (with engine not running) the test smoke travels through the crankcase and only comes out in between the head and the block near the front on Bank 2 (drivers dside)as shown in the video. Does this mean the head gasket is open to the atmosphere and is the air leak? Yet sealed enough to maintain oil and coolant where it is suppose to be?
http://youtu.be/UIsgDTdmC0M
Just hard to believe that the head gasket needs to be replaced since it has compression and no water in the oil or heavy steam coming out the exhaust.
Long story less long...Please advise if this has been seen before and what was done to remedy.
Many Thanks.
p.s. I searched for a while to see if this had came up, but there were all kinds of "its your intake gasket" threads for the P0171 code.