Service slants

Motor,  Mar 2003  by Savasta, Bob

• E-mail
• Print
• Link

Chrysler

Valvetrain noise. Some 1993-96 LH-cars (Concorde, Intrepid, Vision, LHS, New Yorker) with the 3.5L V6 may exhibit a heavy clicking or ticking noise at any temperature that increases in frequency with engine speed. According to Chrysler, this problem could be due to abnormal contact between the intake rocker arms and camshaft on either bank of the engine.

Before getting involved in complicated repairs, however, pull the dipstick and check the engine's oil level. A level that's either above the FULL mark or below the ADD mark can lead to oil aeration, which can cause similar symptoms. If necessary, adjust the oil to the proper level, then run the engine for up to an hour to see if the noise goes away.

If the noise is still present, remove the rocker assembly on the offending bank(s), then flip the assembly over and look for damage on each of the intake rocker arms at the side closest to the camshaft journal (see illustration). The damage will present itself as freshly shaved, bright aluminum rather than the oil-stained, dull-looking machined surface of a normal arm. Replace any damaged rockers, as well as the camshaft(s), with the revised parts listed below. If no abnormal contact is evident, inspect each lash adjuster on the rockers by attempting to compress it with normal finger pressure. Replace any rocker arm whose lash adjuster feels spongy or soft.

Note: During disassembly, Chrysler recommends inspecting and replacing the camshaft thrust plates) if wear is present. On reassembly, install new pedestal dowels and camshaft sprocket attaching bolts. After the repairs are completed, allow the engine to idle for up to an hour to eliminate trapped air from the valve system.

Here are the relevant parts and part numbers to complete the job:

Camshaft (left) ....4573925

Camshaft (right) ..........4573926

Thrust plate ..............4556518

Intake rocker arm (left) ...4573459

Intake rocker arm (right) . .4573460

Cam sprocket bolt (left) ...6502917

Cam sprocket bolt (right) ..6502916

Pedestal dowels .......... 4573379

Ford Truck

Engine noise, miss, rough idle. Some Ford trucks (full list on next page) with the 4.6L, 5.4L or 6.8L V8 may exhibit engine noise accompanied by a rough idle or miss after startup in temperatures below 10 deg F. According to Ford, the most likely cause is the business end of the roller rocker arms becoming dislodged from the hydraulic lash adjusters. New-design lash adjusters and rocker arm retaining clips are available to eliminate the problem.

Before installing the new parts, however, remove the valve covers and give the entire valvetrain a good once-over. If any rocker arm is dislodged, check it for chips or grooves. Also inspect its corresponding cam lobe, valve stem tip and valve guide for excessive wear or damage. Replace all worn parts as necessary.

If the problem is limited to dislodgement of the rockers, compress the valve springs and remove the rocker arms and lash adjusters. Replace all the old adjusters with the new design (Part No. YL3Z-6500-AA). Next, order up a set of new retaining clips (Part No. YL3Z-6A539-AA). Slide the clips onto the lash adjuster side of each rocker arm, install the rockers, then snap the clips into place over the adjusters to complete the repair. The following trucks are affected:

1997-9 F-250 LD

1997-2000 Econoline, Excursion, Expedition, F-150

1998-99 Lincoln Navigator

1999-2000 F Super Duty

Honda

Coolant gasket leak. In some 2000 Honda vehicles, engine coolant seeps from the bottom of the water passage near the EGR valve. The cause is usually a defective front water passage gasket. The affected models are: Four-door Accord V6s (VINs

1HGCG1...YA000001 through

1HGCG1...YA056930) Two-door Accord V6s (VINs

1HGCG2..YA000001 through

1HGCG2...YA027930)

2000 Odysseys (VINs 2HKRL1... YH500001 through 2HKRL1..YH567017)

Following normal service procedures, replace the front gasket using Part No. 19411-P8A-AO1. Then replace the rear water passage gasket with Part No. 19412-P8A-AO1. Also put in a new O-ring (Part No. 91314-PH7-003).

Ford Truck

Rough cold idle. Some 1997-99 F-250 LD, 1998-2000 Lincoln Navigator and 1997-2000 Econoline, Excursion, Expedition, F-150 and F Super Duty vehicles equipped with the 4.6, 5.4 or 6.8L engine may exhibit a rough idle or miss after starting in cold ambient temperatures (below 10 deg F).

First perform normal engine diagnostic routines before proceeding. If firing, compression and power output indicate the valvetrain is suspect, remove the valve cover.

The misfire may be caused by roller finger followers that run dislodged from the valves. (The problem may have resulted in damage to the camshaft!) Inspect and replace any worn or damaged engine valve components or camshaft, and install new retaining clips and lash adjusters as needed.

Using a valve spring compression tool, install service-only lash adjusters (Part No. YL3Z-6500-AA) and the attached retaining clips (Part No. YL3Z6A539-AA) by pushing the clips onto the lash adjuster. Note: The clip cannot be removed once it has been snapped into place. If the engine needs servicing at a later date, remove the follower by bending up the clip. Leave the adjuster in the engine with the clip while removing the follower. Then remove the adjuster from the head and cut the clip. Replace the removed unit with a new clip on the follower during reinstallation. After assembly, check valvetrain operation and reinstall the valve covers.