Tech Tip: Heater Core Leak Repair
A classic sign of a heater core problem is when the inside of the vehicle’s windshield persistently keeps misting. Warm coolant is leaking out of the core into the vents and then condensing against the cooler surface of the windshield.
Tech Tip: Nissan Xterra Hesitates Upon Acceleration
The technician connected a scan tool and found code P0102 – Mass or Volume Air Flow “A” Circuit Low. He then performed an inspection of the mass airflow (MAF) sensor and related wiring harness, but found no obvious faults.
Tech Tip: Clogged Oil Line Leads To Chrysler/Dodge Turbocharger Failure
Extreme temperatures cause the oil circulating through the turbocharger oil feed line to burn. The coked oil buildup restricts oil flow, which leads to turbocharger failure. The oil line may appear fine externally.
Bringing Down The Bus: Battling A BMW No-Crank
I arrived at the shop and verified the no-crank condition. The dash lit up brightly, but no starter action was forthcoming. Beginning with the basics, I tested power supply at the ignition switch, behind the Car Access System (CAS). This is the module in which the key is inserted. Power and ground was intact; I tested at the starter and found actuation voltage unavailable for starting.
Head Gasket Q & A
One reason head gaskets fail is because of engine overheating. If the engine gets too hot, the cylinder head can swell to the point where it crushes the head gasket (usually between the cylinders because this is the thinnest point). The extruded material and/or cracked combustion armor then provides a leak path for coolant and/or combustion gases.
Diesel Injection Components: Coming To Terms With The Common Rail Diesel Injection System Is Not An Easy Task
For some time now, most of the development in diesel technology has been aimed toward making the engines environmentally friendly. But as diesel engines have become cleaner, the power levels have also increased. This is somewhat backward to what the country went through in the 1970s with gasoline engines.
Diagnosing Blown Fuses
Problems that occur based on temperature can be triggered with a test drive or a heat gun. A spray bottle can be utilized to simulate moisture. If the failure of the fuse is related to movement, a shake down test can be performed by slightly tugging on the wiring harnesses until the circuit breaker or PTC opens.
Customer States: Honda Soda Can Tab Fix
As I removed the timing belt and balance shaft belt, I noticed this soda can tab holding one of the crank sensors in place. Apparently, the customer knew of this from a year ago when the balance shaft belt broke but couldn’t afford the sensor or a new water pump.
Publisher’s Perspective: Changes
I’m also pleased to announce and introduce Andrew Markel who has been named editor of Underhood Service. Some of you may already recognize Andrew, who currently serves and will continue to serve as the editor of Brake & Front End and has contributed numerous technical features within past issues of Underhood Service and ImportCar.
ASE L1 Test Prep: BUS circuit testing on The Type 3 Composite Vehicle
The Advanced Engine
Plastic Engine Covers That Were Once Just For Looks Are Now Functional
Plastic engine covers are becoming a plague for technicians and it is only getting worse. Every year they get bigger and more difficult to remove. Once, they only cleaned up the engine bay, hiding unsightly wire harnesses, piping and intake manifolds. Now they have become barriers to technicians like the tamper-resistant screws on an iPhone.
ASE A2 Test Prep (Automatic Transmission/Transaxle Test Prep): Torque Converter Basics
The concept of using a torque converter, oil pump, planetary gear sets, clutches, bands and a computer-controlled hydraulic valve body to transmit torque and to change gear ratios is relatively simple.