Tech Tip: Jeep Cherokee and Wrangler Multiple Cylinder Misfire
The customer may experience an incident of engine misfire during certain vehicle operating conditions. The misfire may occur when the vehicle is operated between 50-70 mph and under light loading conditions, e.g. slight uphill road grades. This condition may occur at all ambient conditions, but is more noticeable when ambient conditions are less than 0° C (32° F).
Tech Tip: The Case of the Warbling Volvo
Each year, Robert and his family enjoy driving their 1998 Volvo C70 through the New England states to see the brilliant fall colors. This year was a little different than previous vacations though. After an unusually warm October day, the engine began to make a "warbling" noise any time the car was running. When Robert called the shop, we discovered that the timing belt had recently been replaced. One of my technicians recalled that the timing belt tensioner adjustment can be problematic if the procedure isn’t followed exactly.
Tech Tip: Special Timing Chain and Belt Tools
Before you replace a timing belt, chain or gear set on some engines, you will have to look up the timing reference marks. Some engines have multiple timing marks that can cause confusion if you don’t know which ones to use or how to line them up. Many engines also require special tools when changing a timing belt or chain. At the very least, you should have a belt tension gauge to make sure the tension on a timing belt is correct.
Tech Feature: Understanding the Metallurgy in Today’s Engines
Cast iron is like an old familiar friend to most of our readers because it’s been around forever. Vehicle manufacturers like cast iron because it’s cheap compared to most other metals, it is strong and durable, and it can be easily cast and machined to make engine blocks, cylinder heads, crankshafts, connecting rods and other engine parts. But as automotive technology continues to move forward, other metals have been replacing ordinary cast iron in many applications.
Power Your Profits with Performance Mods
The sport compact car market is certainly a good place to be these days. One of the advantages of doing import performance modifications and upgrades is that you don’t have to wait for cars to break to get business. The people who drive these cars spend money on performance modifications regardless of the age, mileage
Diagnostic Solutions: Transmission Electronics…Contined Refinement of Electronically Controlled Transmissions Shifts Fuel Efficiency into High Gear
Electronic automatic transmissions have gained popularity in recent years because of the flexibility that on-board electronics can provide in the area of powertrain management. Electronic transmission controls, for example, have done away with the rough, imprecise shifting patterns inherent in early mechanically controlled transmissions. With the continued refinement of electronically controlled automatic transmissions, an automatic
Kansas Machine Shop Manager Wins the 2007 MAHLE Clevite Machinist of the Year Award
MAHLE Clevite Inc. recently announced that Kenny Burns, machine shop manager for Harry’s Machine Works, Inc., has won the 2007 MAHLE Clevite Machinist of the Year Award. Harry’s Machine Works is located in Dodge City, KS.
Tech Tip: Don’t Turn Away Clutch Replacements
Clutch replacement does not have the prestige of driveability diagnostics, but at times, it pays better. Some shops turn away clutch replacements in fear of comebacks and lost productivity. But, clutch replacement offers the shop opportunities to sell additional services that might slip past the bottom line.
Tech Tip: Understanding How the Ignition System Works is the First Step in Diagnosing a Problem
All gasoline engines have a spark ignition system to ignite the air/fuel mixture in the cylinders. The spark is created by a high-voltage surge from an ignition coil. The coil is triggered by an ignition module and/or the PCM using a signal from a distributor pickup or crankshaft position sensor. If the engine has a distributor, a single coil is used on most engines to supply high voltage to all the spark plugs. If the engine has a “distributorless ignition system“ (DIS), each spark plug has its own separate coil.
Current Trends for Ignition Systems
As automotive technology moves forward, ignition systems are becoming more and more entangled with other systems on the engine. The current generation Nissan Maxima 3.5L V6, which was introduced in 2004, has a fairly conventional coil-on-plug (COP) ignition system. The individual coils are driven by the powertrain control module (PCM) using the input signal from