2_slow
New Member
Hello
My new to me lr3 4.4 with 140k is giving me trouble after new head gaskets and reassembly. Bought the lr3 sight unseen not knowing it had a small head gasket leak. It could idle all day and not over heat but once in motion it would over heat within 15 mins. No coolant mixing with oil and after new radiator and bypassing heater core we did a combustion leak test and confirmed it was getting combustion gasses in to the coolant. Took the heads off and got them resurfaced and completely gone through. New head gaskets new timing chains and guides. After reassembling I got the p0302 p0304 p0306 p0308 and also p0300 and p0316, I have been trying to figure out this misfire situation for a couple of months. I replaced all gaskets in intake manifold, all new spark plugs and coils, new injector orings ( did not replace injectors but did swap them around), new egr ( after smoke testing found out it was leaking),new cam positioning sensors, new knock sensors and new up stream O2 sensors. I smoke tested and found a slight leak at the oring on the hose that goes from the throttle body to the PCV valve? It runs great but can feel a slight miss at idle but has no problem when on the gas. Could the timing be slightly off? Or could it be just the vacuum leak? Is there a way to check the timing without taking everything apart?
Any advice is appreciated
Thank You
My new to me lr3 4.4 with 140k is giving me trouble after new head gaskets and reassembly. Bought the lr3 sight unseen not knowing it had a small head gasket leak. It could idle all day and not over heat but once in motion it would over heat within 15 mins. No coolant mixing with oil and after new radiator and bypassing heater core we did a combustion leak test and confirmed it was getting combustion gasses in to the coolant. Took the heads off and got them resurfaced and completely gone through. New head gaskets new timing chains and guides. After reassembling I got the p0302 p0304 p0306 p0308 and also p0300 and p0316, I have been trying to figure out this misfire situation for a couple of months. I replaced all gaskets in intake manifold, all new spark plugs and coils, new injector orings ( did not replace injectors but did swap them around), new egr ( after smoke testing found out it was leaking),new cam positioning sensors, new knock sensors and new up stream O2 sensors. I smoke tested and found a slight leak at the oring on the hose that goes from the throttle body to the PCV valve? It runs great but can feel a slight miss at idle but has no problem when on the gas. Could the timing be slightly off? Or could it be just the vacuum leak? Is there a way to check the timing without taking everything apart?
Any advice is appreciated
Thank You
