Service Slants

Motor,  Mar 2006  by Rosario, Tom

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Chrysler

Snapping noise from engine. Some 2001-04 Chrysler products with 2.0 and 2.4L engines (complete list below) may produce an irritating snapping sound from the engine bay. Chrysler says the noise is irregular in nature and most noticeable with the engine at normal operating temperature, the transmission in Park and the engine between idle and 1400 rpm. When you open the hood you'll probably find that the racket is emanating from the1 upper Iront portion of the engine. Improperly machined cam bearing caps is the most likely cause of the noise. Chamfering the two bore radius edges of each bearing cap with a file should help quiet the ruckus permanently. Here's how to go about it:

Begin, naturally, by removing the valve cover. Now look at the arrangement of the cam bearing caps. The left and right front caps are one piece. The left rear cap is larger than the rest of the individual cam bearing caps. These don't require filing, says Chrysler, but the rest do. Start by removing the No. 2 bearing cap on the left side. Now dig up a small, flat hand file. Using the illustration at right as a guide, file the bore radius edge of the cap so you create a 45° chamfer approximately 1 to 1.5mm wide. Flip the cap over and go at the edge on the opposite side of the cap. Repeat the drill for bearing caps 3, 4 and 5 on the left side of the cylinder head, and caps 2 through 6 on the right side.

Before putting everything back together, you'll want to clean all the bearing caps with solvent and a shop rag to remove metal filings. Once that's done, reinstall the No. 2 leftside cap and install the two retaining bolts finger-tight. While twisting the cap clockwise with your hand as far as it will go, torque the two bolts to 105 in.-lbs. Now repeat the drill for the rest of the caps on the left side, then the right. To complete the repair, reinstall the valve cover, adjust the oil level, then run the engine to make sure the snapping noise has been eliminated.

Vehicles that are susceptible to the problem and can benefit from the minor machining job are 2001-04 Sebring and Stratus models, Town & Country, Caravan and Voyager minivans and PT Cruisers, plus 2003-04 Neons.

GM Truck

MIL on, DTC stored in PCM memory. Some 2002-05 GM SUVs (full list below) may illuminate the MIL and store code P0526 in computer memory. One highly likely source of the trouble, says the General, is chafed wiring in the cooling fan harness. The wires get chafed because the harness pulls out of its plastic protective sleeve, exposing the wire insulation to the sharp edges of the sleeve. Replacing the harness with Part No. 89024920 and taping the wires to prevent movement within the sleeve should solve the problem.

Start the job by removing the cooling fan assembly and placing it on a workbench. Now disconnect the connector from the fan clutch and remove the harness from the plastic sleeve while feeding the wires out of the slot. Before installing the new harness, wrap the area of the wires that will go into the sleeve with electrical tape. Make sure the tape is positioned at least 1 in. from the connector so the wires can be fed completely into the slot in the sleeve. Next, feed the wires through the slot and install the harness completely into the plastic protective sleeve. To complete the repair, reconnect the electrical connector to the fan clutch, reinstall the fan assembly, clear the code and check for proper fan operation.

The following trucks are prone to the wire chafing problem and can benefit from the above fix:

2002-04 Olds Bravadas

2002-05 Chevy TrailBlazers & TrailBlazer EXTs and GMC Envoys & Envoy XLs

2004-05 Buick Rainiers and GMC Envoy XUVs

2005 GMC Envoy Denalis & Envoy XL Denalis

Ford Truck

Water in fuel. Owners of 1999-2006 F-350 pickups equipped with 6.0 and 7.3L diesel engines and 40-gal. rear fuel tanks may complain of hard starting and/or rough idling in colder temperatures. With a little detective work, you'll probably find that the fuel tank is loaded with water. How the stuff finds its way into the tank is pretty interesting.

According to Ford, the water typically starts out as snow or ice that gets thrown from the tires and ends up accumulating at the top of the fuel tank. As it starts to thaw, suction action causes the slushy mix to be drawn into the tank via the mushroom vent cap. Replacing the cap with a new vent line kit (Part No. 5C3Z-9S327-A) should solve the problem.

Start the parts swap by locating the existing mushroom cap at the tank's vent port. Remove and discard it. Now install the hose end of the new vent line kit over the port and secure it with a clamp. Guide the rest of the assembly toward the front of the truck, starting at the top of the tank, then moving to the No. 5 crossmember and finally under the fuel lines. secure the other end of the vent line to the large hole in the crossmember with the tie strap. To complete the fix, install a newdesign mushroom cap from the kit into the line, making sure it's positioned horizontally to prevent water from collecting in the cap.