Misfire Possible Diagnostic Trouble Codes DTC’s P0301-P0308 – 2000-2005 Ford & Lincoln

FORD:	2002-2005 Thunderbird
LINCOLN:	2000-2005 LS

2000-2005 Lincoln LS and 2002-2005 Thunderbird vehicles equipped with the 3.9L engine and built through 5/1/2004, may exhibit a misfire condition and possible diagnostic trouble codes (DTCs) P0301-P0308.

This may be caused by water or moisture in the coil on plug (COP) and coil wells, due to water leaking past the foam seal of the cowl panel grill.

ACTION:

First verify water or moisture is present in the coil wells by removing the ignition coil covers.

If signs of water or moisture are present refer to the following Service Procedure. If there are no signs of water or moisture, perform normal diagnostics as outlined in the PC/ED Manual.

SERVICE PROCEDURE

1. Disconnect the eight (8) ignition coil electrical connectors.
2. Remove the eight (8) ignition coil bolts.

NOTE: WHEN REMOVING THE IGNITION COILS, A SLIGHT TWISTING MOTION WILL BREAK THE SEAL AND EASE REMOVAL.

3. Remove the ignition coil and inspect the boots for damage and replace as required.
4. Using shop air, blow (dry) out water from coils and coil wells.
5. Apply Silicone Brake Caliper Grease and dielectric compound (XG-3-A) or equivalent, to the inside of the ignition coil boot.
6. Reinstall ignition coils and tighten bolts to 44 lb-in (5 N-m).
7. Reconnect the ignition coil electrical connectors.
8. Install new ignition coil covers (XW4Z-12025-AD).

COWL PANEL GRILLE AND FOAM SEAL SERVICE

1. Remove the cowl panel grille.
2. Remove the foam seal and discard (Figure 1).
3. Clean foam-sealing area using Bug and Tar Remover (ZC-42
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   ) or equivalent.
4. Install a new foam seal (5W4Z-54021A46-A), centering the seal on the hole of the cowl panel grille (Figure 1).

Figure 1

5. Reinstall the cowl panel grille.
6. Clear all DTCs.
7. If misfire is still present perform normal diagnostics per the PC/ED Manual.

PART NUMBER	PART NAME
XW4Z-12025-AD	Coil Cover
5W4Z-54021A46-A	Foam Seal
XG-3-A Ford Genuine Ford Fluid XG-3-A Silicone Brake Caliper Grease and Dielectric Compound - 3 oz. Lubricates disc brake caliper slide pins High resistance to water and heat Provides high voltage seal to secondary ignition wires Suppresses voltage leaks by coating inner distributor cap surface Compatible with EPDM rubber $23.77 Buy on Amazon Price incl. tax, excl. shipping Last update on 2026-06-09 / Affiliate links / Images from Amazon Product Advertising API	Silicone Brake Caliper Grease
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