Servicing 4.6L And 5.4L Engines Found With Cylinder Head Oil Leak Or Weepage – UnderhoodService

Servicing 4.6L And 5.4L Engines Found With Cylinder Head Oil Leak Or Weepage

Some vehicles equipped with the Romeo 4.6L 2V engine or 5.4L 2V Windsor and 5.4L Supercharged engine may exhibit an oil leak or oil weepage from the cylinder head gasket at the right-hand rear or the left-hand front of the engine.

Oil weepage is not considered detrimental to this engine’s performance or durability. An oil leak may be caused by metal chip debris lodged between the head gasket and the block, chip debris between the cylinder head and the head gasket, or by damage to the cylinder head sealing surface that occurred during the manufacturing process.

Once an oil leak is verified with a black light test at the head gasket joint, replacement of the head gasket can be performed. If the head was damaged by chip contamination, the head should be replaced. A revised “service-only” gasket is now released for both of these cases.

Required for service are:

• A straightedge (machine flatness toleranced to 0.0002” per foot in length) that’s available from local tool dealers or as provided by Ford Motor Company;

• Motorcraft Silicone Gasket Remover (ZC-30);

• Metal Surface Prep (ZC-31); and

• Service-only gasket (3U7Z-6051-BA for driver’s side and/or 3U7Z-6051-AA for passenger’s side) with the new embossed area.

Repair Procedure

Cylinder heads damaged by brinnelling (depression marks from original gasket) of the head may still be reusable. The revised “service-only” gasket has a feature by which the embossed sealing area does not follow the same sealing path as the original gasket. This area is surrounding the High Pressure Oil Feed (HPOF) area. It’s triangular in shape and is found in the rear of the passenger’s side cylinder head, or in the front of the driver’s side cylinder head (see Figures 1 and 2).

If performing in vehicle service, the engine should be allowed to cool before removing the head or warpage may occur in deck flatness.

The cylinder head and block decks should be cleaned before performing a flatness check. Dark metal stains below the surface of the metal are normal. Do not attempt to polish off the stains with grinders or scrapers. Use a plastic scraper (or plastic ice scraper or equivalent) to pull away any residual silicone RTV with ZC-30 and ZC-31 applied in sequence.

The repair information and labor times have been updated for both cars and trucks using 4.6L 2V and 5.4L 2V and Supercharged 5.4L engines. These include instructions to remove the engine prior to removing the cylinder head. Labor times allow for extra time in engine removal and cylinder head deck leak repair out of the vehicle.

Cylinder head kits are available on most applications from Ford and include complete head assembly, with cam and valves; head bolts, service-only head gasket; both intake gaskets exhaust gasket; one rocker cover gasket; and one set of exhaust studs and nuts.

If it’s found that only one head is leaking, it’s not necessary to remove the other head. Repair only the side for which leakage occurs.

ALLDATA Technical Editor Eric Seifert is an ASE-certified Master Technician and Engine Machinist, with 20 years of independent shop and parts store experience.

Technical service bulletin courtesy of ALLDATA.

For additional information, visit www.alldata.com.

You May Also Like

How (And Why!) To Clean An Engine

Beauty is more than skin deep. Here are 11 steps to help clean any car’s engine compartment.

A well-kept car looks amazing when rolling down the street, and it drives better. But, more driving means exposing a car to pebbles, grime, greasy and oily residues, dirt and particles. This unwanted debris can also accumulate under a car’s hood.

For a car owner to enjoy the beauty of a clean car, it’s vital to address the cleanliness of the interior, exterior and under the hood — the engine.

Spark Plug Fouling

Understanding why spark plugs get dirty.

Aging Plastic Intake Components May Cause Leaks

BMW valve covers and intake manifolds made of plastic are susceptible to warpage and gasket failure.

Diagnosing Intercooler Boost Trouble Code P0299

The criteria for setting the code is very basic.

Understanding Coolants

All-season coolant used inorganic acid technology and worked great for almost 30 years.

Other Posts

Misfire Codes P0300, P0301-P0312 and P0313+P0314

The only way to clear the code is to use a crankshaft position relearn with a scan tool.

Belt-In-Oil Timing Systems

Oil contamination of the belt drive has been a death sentence, due to the rubber and fiber construction of the belt.

What Caused The Turbo To fail?

Up to 50% of turbocharger failures are due to oiling problems.

New Oil Specifications

Many 0W16 oils have a new donut certification mark on the bottle called API SN-PLUS and SN-PLUS Resource Conserving.