Wanted to share a positive experience i had with my car that i strongly recommend after
feeling the difference it made, and backing up the results via leak down test.
My car has worn valve guides, this i know for sure. I recently did a compression and leak down test with 10% and 12% leakage on two cylinders.
I work at an auto repair shop and we have a machine that runs a chemical thru the injectors which not only cleans them, but will remove carbon build-up on valves, pistons, and rings. It's called a POWER CLEAN 2000 and should be a fairly common tool at many shops.
The machine has it's own fuel pump, so the cars fuel pump gets disabled and then you hook into the supply and return lines at and near the fuel filter.
I did this service about 500 miles ago and have actually felt the difference in acceleration since. The improvement has been very noticeable. I redid the leak-down test a couple days ago and verified it also helped with cylinder leakage.
Here are the before and after numbers. ( 1st number is the before % followed by the after % )
CYL. #3 2% .... 1%-------- CYL #6 12% .... 7%
CYL. #2 2% .... 1/2%----- CYL #5 2% .... 2%
CYL #1 10% ....2%-------- CYL #4 2% .... 2%
Now, having the machine to myself i did perform the service twice. Takes about 1.5 hours each time so it took awhile but was certainly worth it. I believe it cleaned up the spray pattern of the injectors, along with helping those two cylinders seal better. My car is
AFAIK still an original 105K motor, so this may not be as big a benefit on a motor that has already been gone thru. But for the rest of us still running untouched engines i would definitely recommend finding a shop that has this machine and giving it a try.