ASE T1 Gasoline Engines (Medium/Heavy Truck) case studies
ASE T1 Gasoline Engines (Medium/Heavy Truck) · Put your knowledge to work in context.
ASE T1, Gasoline Engines (Medium/Heavy Truck), is one of the specialty credentials in the ASE Medium/Heavy Truck technician certification series. It is aimed at technicians who diagnose, service, and overhaul gasoline engines in trucks, buses, and commercial chassis rather than light-duty pickups. The ASE T1 Gasoline Engines (Medium/Heavy Truck) case studies are 5 cases and about 2,804 words.
1Low Oil Pressure After Overhaul on a Fleet ISX
A shop rebuilt a 15 L diesel six and reinstalled it in a highway tractor. At first start the mechanical gauge reads 55 psi at high idle cold, but after 20 minutes at operating temperature (coolant 195 F, oil 230 F) pressure falls to 12 psi at 1800 rpm and the dash warning triggers at hot idle.
619 words, about 3 min2Misfire That Only Appears Under Load
A 2016 Class 7 truck with a spark-ignition CNG engine arrives with a complaint of a flashing check engine lamp and power loss when climbing grades loaded. At idle and light cruise the engine runs smoothly.
524 words, about 3 min3Overheating Only With the A/C On and Trailer Loaded
A 2012 highway tractor with a 13 L diesel overheats only when pulling a loaded trailer up long grades with the A/C on. Coolant temperature climbs from 195 F to 225 F over about four minutes of hard pull, then recovers on the downhill.
567 words, about 3 min4Camshaft and Valve Train Noise After Head Work
A shop replaced a cracked cylinder head on a 12 L diesel and reused the original camshaft, lifters, and pushrods. The engine starts and runs but has a rhythmic top-end tick that is loudest at idle and fades above 1500 rpm.
562 words, about 3 min5Crank No-Start With Good Compression and Spark
A 2014 medium-duty truck with a gasoline V8 cranks but will not start after a fuel pump replacement. The technician confirms strong spark at all coils with a spark tester, compression is 150 psi on all cylinders, and the engine will run briefly on starting fluid.
532 words, about 3 min