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Truck has been running at low RPM with a random hard start. It tossed a P0230 code. I thought it was going to be a fuel pump issue. Ran a compression test and this is what I got. 5% low on cylinder 7. Freaking out that this is going to be a serious concern. Any ideas? Thanks.
needs either a cylinder head or a complete motor more than likely, i have seen a few 5.0s here at the dealer that have lost compression due to bad rings
needs either a cylinder head or a complete motor more than likely, i have seen a few 5.0s here at the dealer that have lost compression due to bad rings
Don't stick your head in the oven yet...Five percent low is nothing. If cyl #7 is 95% of the highest cylinder, life is good. As long as the lowest cyl is less than 10% below the highest, your engine is considered to be in decent mechanical health, compression wise. P0230 is a fuel pump voltage code, and probably indicative of a failing FPDM. Don't sweat a 5% discrepancy in compression. It certainly won't cause anything you can feel, or trigger a code. It's well within the normal range.
If you have access to a leak down tester you can hook it up, run the air through the tester, and listen for where the air is coming out. Exhaust = bad exhaust valve, throttle body = bad intake valve, oil fill cap = bad rings.
Don't stick your head in the oven yet...Five percent low is nothing. If cyl #7 is 95% of the highest cylinder, life is good. As long as the lowest cyl is less than 10% below the highest, your engine is considered to be in decent mechanical health, compression wise. P0230 is a fuel pump voltage code, and probably indicative of a failing FPDM. Don't sweat a 5% discrepancy in compression. It certainly won't cause anything you can feel, or trigger a code. It's well within the normal range.
Don't stick your head in the oven yet...Five percent low is nothing. If cyl #7 is 95% of the highest cylinder, life is good. As long as the lowest cyl is less than 10% below the highest, your engine is considered to be in decent mechanical health, compression wise. P0230 is a fuel pump voltage code, and probably indicative of a failing FPDM. Don't sweat a 5% discrepancy in compression. It certainly won't cause anything you can feel, or trigger a code. It's well within the normal range.
This is exactly what I was thinking initially. I took the truck to the ford dealer who actually did the test. It’s showing 5% on the sheet but they wrote it down in their notes as 4%. I am extremely in touch with this truck and have gone above and beyond on maintenance so I’m hoping it’s nothing serious. I bought it new and have put every mile on it so I know this truck. Never had a CEL or anything. Noticed some hard starting, low RPM and ran the scan tool and got that P0230 code. I’ve changed the FPDM, checked the F27 fuse and checked the relay #8 in the power distribution box. My gut tells me my problems are stemming from the fuel pump. I’ve noticed the “miles to E” fluctuates a lot recently. I’ll park it on level ground and it will be 220 miles to E then start it later and it will show 320 miles to E. I’m also guilty of running the gas tank damn near empty before filling up (I know there’s debate on whether this is good or bad). Going back to the dealer next Friday so they can take a more in-depth look. I just happened to be going in today for the transmission recall and asked if they could take a glance. I’m keeping positive thoughts right now!
Relative compression test only shows a difference between cylinders, it is NOT an indicator of low compression on any one cylinder, in this case only that 1 is 5% less over all when compared to the other 7
Now lets say for example most cylinders are running around 150psi (not exact numbers just an example) and that one cylinder is 5% less that would mean it's running around 143psi give or take.
Any engine capable of producing 100psi is a good engine as far as compression goes.
With all that said if the truck is running normal and it sounds like it is, there's nothing to worry about. Tests like the one shown is a simple diagnostic procedure usually only run when the engine is actually running bad but is quick and easy enough to do so a lot of techs, myself included, will run it during diag.
What year is the engine and how many miles are on it?
.
Relative compression test only shows a difference between cylinders, it is NOT an indicator of low compression on any one cylinder, in this case only that 1 is 5% less over all when compared to the other 7
Now lets say for example most cylinders are running around 150psi (not exact numbers just an example) and that one cylinder is 5% less that would mean it's running around 143psi give or take.
Any engine capable of producing 100psi is a good engine as far as compression goes.
With all that said if the truck is running normal and it sounds like it is, there's nothing to worry about. Tests like the one shown is a simple diagnostic procedure usually only run when the engine is actually running bad but is quick and easy enough to do so a lot of techs, myself included, will run it during diag.
What year is the engine and how many miles are on it?
.
It a 2013 F150 XL with 5.0 V8. NOT used as a work truck. Never tows anything. I bought it brand new and my maintenance record is perfect. It just turned 140,000 miles. 80% of driving is highway driving. I’ve recently had some low idle issues and the truck feels like it is starved for fuel. Never had a CEL. I ran a scan tool and got code P0230. I have checked the F27 fuse. I have checked the #8 relay in the power distribution box. I have swapped out the fuel pump driver module with a brand new one. Brand new spark plugs within the last 20,000 miles. My gut is telling me that my issue is stemming from the fuel pump. Thoughts?
Low compression 5.0 V8
