Low compression and knock on #8 cyl 4.7liter
ok so i bought this 2001 jeep grand cherokee with the 4.7 v8, upon driving it home it overheated on me so i shut it off got a tow and let it cool off overnight.
Next day i figured out cooling issue and did a comp test to see if anything was terminally damaged, 130 psi-135 across the board except #8 was only 75, plug was wet with fuel but obviously not firing. coolant is clean and oil is clean. has a noticeable tick at idle and when driving it around 2500 rpm it starts to knock fairly loudly, but does not knock when throttling up when parked only when under load. other than the knock and the slightly lumpy idle you wouldnt know anything was wrong, id really appreciate any help, i will pull valve cover off if i have to but it looks like a huge mission, as its buried under ac lines, wiring harnesses etc.
P.S apparently this is a crate motor with only 10 000 k on it, at least this is what the guy told me. Needless to say he probably lied since it didnt even get me home the night i bought it.