Bought a 1986 GMC c30 350, with supposedly 160 k on it last thursday (day 1). Motor started up good - idle was rough - engaged in drive , idle really too low, when brakes where applied, it would backfire. Exhaust manifold gasket on left side was busted.
(day 2) Changed oil wich was really dark - oil filter too... changed spark plugs and wires. % 10 improvement... Engine lack power and vibrates but no more backfire (I set the idle a bit faster)
(day 4) Changed Cap and rotor - % 30 improvement - Obviously either badly maintained or the previous owner just let it go
(day 5) Got the manifold gasket replaced... The mechanic forgot to replug 3 spark plugs. Ran 3 miles and replugged the spark plugs wire... Same condition but silent...
(day 6) Changed coil in cap ... Changed fuel filter (had to cut the fuel feed pipe, was kinked, replace with flexible hose) % 60 improvement... The thing ran like new... Full power I started beliving again... Got full oil pressure 300 kpa - no valve noise
Ran 30 minutes on highway.... Valves started making noise especially on driver side... Engine lost lots of power, and vibrates a lot... doesnt heat up to much but oil pressure seems very low. made my trip
50 miles.... and leave it for a while(night 6) I cry
(day 7) Start up the thing, and even when cold and choke on, oil pressure not as good as in the beginning. Put kleen flow lifter treatment ... At idle in park the ticking stopped, a bit better while in drive... As soon has motor gets hots problem persists... At 60 miles per hour, motor doesnt run great but vibration acceptable... But while trying to accelerate valves are really noisy, vibrates a lot especially at mid speed revolution... Made my 50 miles trip back very slowly and stopping often to try not to burn the thing
(night 7) i cry again
What went wrong from better to worst PLEASE
(ONLY OIL PROBLEMS !)