texascadillac42
New member
- Joined
- Sep 17, 2008
- Messages
- 362
Customer brought an 05 CR (auction truck he just got) to the shop the other day, missing on 1 or 2 cylinders, odd chugging sound out of the exhaust, metallic tapping from somewhere in the motor and some whitish smoke out of the oil fill cap.
Was throwing codes for Cyl 5 and 6 not firing, as well as a few other unrelated codes. Codes were cleared and they came back immediately, before the truck was even started. Valve cover was pulled and the first thing I noticed was that all the plastic under the valve cover was melted. Crankcase breather assembly, plastic retaining rings for the rocker arms, plastic clips for injector wiring harnesses, all melted into blobs or totally missing.
Ran it with the valve cover off for a few minutes and noticed some coolant bubbles coming out of the headgasket right between exhaust ports 3 and 4, also noticed that several rockers had a ton of valve lash (like 1/16th inch or more)
Decided to pull the head figuring that some valve seats may have dropped. As I took the valve cover base off, I saw that the injector wiring harness for cyl 5 and 6 were melted together into one blob (that explains those codes... :bang)
Valve stem height all seemed to be the same, and after pulling the head this was confirmed. No visual evidence of valve, valve seat or piston damage.
Cylinder walls all have vertical marks on them, not enough to catch your nail on but some fairly significant scuffing, and the pistons all have quite a bit of side to side play, both parallel and perpendicular to the piston pin.
Cutting the oil filter apart showed some small metal chunks in the filter, and the thermostat and cooling passages were all covered in an oily slime.
Obviously the motor has seen a rough life and should come completely apart, I was just curious if anyone had seen a motor get hot enough, for long enough to melt all the plastic and injector wiring harnesses together?
Was throwing codes for Cyl 5 and 6 not firing, as well as a few other unrelated codes. Codes were cleared and they came back immediately, before the truck was even started. Valve cover was pulled and the first thing I noticed was that all the plastic under the valve cover was melted. Crankcase breather assembly, plastic retaining rings for the rocker arms, plastic clips for injector wiring harnesses, all melted into blobs or totally missing.
Ran it with the valve cover off for a few minutes and noticed some coolant bubbles coming out of the headgasket right between exhaust ports 3 and 4, also noticed that several rockers had a ton of valve lash (like 1/16th inch or more)
Decided to pull the head figuring that some valve seats may have dropped. As I took the valve cover base off, I saw that the injector wiring harness for cyl 5 and 6 were melted together into one blob (that explains those codes... :bang)
Valve stem height all seemed to be the same, and after pulling the head this was confirmed. No visual evidence of valve, valve seat or piston damage.
Cylinder walls all have vertical marks on them, not enough to catch your nail on but some fairly significant scuffing, and the pistons all have quite a bit of side to side play, both parallel and perpendicular to the piston pin.
Cutting the oil filter apart showed some small metal chunks in the filter, and the thermostat and cooling passages were all covered in an oily slime.
Obviously the motor has seen a rough life and should come completely apart, I was just curious if anyone had seen a motor get hot enough, for long enough to melt all the plastic and injector wiring harnesses together?
