My 06 Jag Super V8 has a head gasket leak, verified by combustion gasses in the coolant, causing excess pressure in the cooling system. After watching videos of the complicated head gasket replacement on You Tube, I decided to take the advice of our local independent Jag mechanic and try K-seal first. I found a K-seal product it calls Ultimate Head Gasket Repair, and added a bottle to the cooling system which did stop a radiator leak that had developed. K-Seal recommends removing the spark plugs from the cylinder or cylinders are leaking and doing several warm ups from cold to allow the product to “work its magic” without outward pressure from combustion.
I have performed dry and wet compression tests that did not immediately identify which cylinders might be leaking, so I am asking advice on anything else I might do to identify them.
Dry Compression test: Elevation 1400 feet, temperature 77 degrees F
All spark plugs out, engine cold, throttle closed, the engine cranked for 7 revolutions (twice for each cylinder to make sure I had the gage hose screwed in tight). I list the highest or average reading for each cylinder.
Left Bank Right Bank
#2 115 #1 130
#4 120 #3 125
#6 128 #5 128
#8 125 #7 120
Wet Compression test: Elevation 1400 feet, temperature 80 degrees F
All spark plugs out, engine cold, throttle open, the engine cranked for 7-8 revolutions
(For the wet compression test I used a small pump oil can with a plastic hose on it to pump 1/2 Oz of 2 cycle oil (7 pump strokes) into each cylinder, one at a time, and cranked the engine 8 compression strokes with the accelerator pressed. Readings might have been slightly higher on some cylinders (5 PSI?) due to some leak down in the time it took me to exit the car and read the compression gage.)
Left Bank Right Bank
#2 185 #1 175
#4 180 #3 175-180
#6 175-180 #5 185
#8 175 #7 175
Then about two hours later without adding any more oil I checked compression again with my wife cranking the engine 7-8 revolutions with the accelerator pressed and me watching the compression gage.
Left Bank Right Bank
#2 170 #1 170
#4 170 #3 170
#6 170 #5 170
#8 160 #7 165
I do not have a leak-down tester, but did observe a slow leak down from maximum pressure on my gage for most if not all cylinders, but I don’t know it is was within the cylinders or possibly the gage itself.
(sorry for the run-together readings; they looked separated until posted)
Any advice on further tests I might perform would be appreciated