Tech Tip: 1987-93 Jeep 4.0L: Head Gasket Leaks/Seepage Found in Engines – UnderhoodService

Tech Tip: 1987-93 Jeep 4.0L: Head Gasket Leaks/Seepage Found in Engines

Some vehicles equipped with a 4.0L engine, may experience engine oil leaks/seepage from the head gasket along the right-hand side (tappet rail) of the engine.

Models 1987-’92 (MJ) Comanche, (XJ) Cherokee, (YJ)  Wrangler; 1993 (ZJ) Grand Cherokee

Some vehicles equipped with a 4.0L engine, may experience engine oil leaks/seepage from the head gasket along the right-hand side (tappet rail) of the engine.

A new cylinder head gasket is now available. The new gasket has beaded silicone sealer on both sides to eliminate leakage/seepage.

Figure 1Diagnosis
Verify the oil leak/seepage is coming from the cylinder head gasket by visual inspection, or using fluorescent dye or by doing a low pressure leak test.

Repair Procedure

This repair involves replacement of the cylinder head gasket with a revised gasket using instructions outlined in the appropriate service manual using cylinder head gasket P/N 53020219 or equivalent.

Coat a new head gasket with suitable sealing compound and place it on the block. Most replacement gaskets will have the word TOP stamped on them.

Note: Apply sealing compound only to the cylinder head gasket. Do not allow sealing compound to enter the cylinder bore. The 1991-’98 cylinder head gaskets used on the 4.0L are a composition gasket. This gasket should be installed dry.

Do not use sealing compound.

Install the cylinder head and bolts. The threads of bolt No. 11 must be coated with Loctite 592 sealant before installation.

Tighten the bolts in three steps, using the correct sequence (see Figure 1):

1. Tighten all bolts to 22 ft.-lbs. (30 Nm).

   2. Tighten all bolts to 45 ft.-lbs. (61 Nm).

   3. Retighten all bolts to 45 ft.-lbs. (61 Nm).

   4. Tighten bolts 1 through 10 in sequence to 110 ft.-lbs. (150 Nm).

   5. Tighten bolt 11 to 100 ft.-lbs. (136 Nm)

   6. Tighten bolts 12 through 14 to 110 ft.-lbs. (150 Nm)

Note: Cylinder head bolts should be reused only once. Replace the head bolts that were previously used or are marked with paint. If head bolts are to be reused, mark each head bolt with paint for future reference. Head bolts should be installed using sealer.

Some or all of this information was provided by the Automotive Parts Remanufacturers Association (APRA). For more information on technical bulletins available through APRA, call 703-968-2772 or visit www.AutoBulletins.com.

You May Also Like

Battery Charging and Diagnostics

Here are six tips to use when diagnosing a vehicle with a dead battery. 

Remember the good old days of battery and alternator testing? With just a multimeter you could test if the alternator was charging and if the battery had a decent state of charge. On most late-model vehicles, the battery and alternator are managed together to minimize the load on the engine to boost fuel economy.

Oil and Carbon Deposits

Here’s how oil can influence carbon deposits.

10 Alternative Uses For A Smoke Machine

Don’t limit yourself to just checking emissions controls – use your smoke machine to check numerous vehicle systems.

Valve Lifter Technology

Hydraulic lifters are precision-fit assemblies.

Voltage Drop Testing

The measurement of voltage is like the speed of the traffic.

Other Posts

Cartridge Oil Filters

Mistakes made can result in costly comebacks.

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.

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.