Questions and Answers

Ford Windstar DTC P0304 Q. Mr. Ciulla, I am sending this message having read one other one that sounded similar to our problem. We have a 1998 Ford Windstar van with the 3.8 liter engine. A few weeks back my wife noticed that the check engine light came on. On the suggestion of her father I took the vehicle to a local Auto Zone to have the code read.

The print out said it was a P0304 and identified the #4 cylinder as having had a misfire. The suggestion by the Auto Zone person was that the cause was either spark plugs or plug wires. I went ahead and bought new parts and even bought a new PCV valve, too. Since the engine is so conveniently placed under the hood I had to have a professional do the replacement work. I opted to go with a dealership.

After having the work done the dealership tech pointed out that the check engine light was still on. He recommended going back to Auto Zone as Ford would charge around $75 to do a diagnostic check. I did and the same code came up. The person reset the computer and the light stayed off until just a few days ago.

I can't say for sure if there have been any particular symptoms or noticeable things about the van when driving it when the light has either been on or when it comes on other than it does seem to run a little rough at times. The only other thing I have noticed on a couple of occasions is that the light came on when the fuel was low (1/8 of a tank) and the low fuel light had not yet come on. Filling the van back up seemed to make the check engine light go away for awhile.

One suggestion that my wife's father found was that perhaps a heater hose is leaking. It, too, is conveniently located on the side of the engine as were the PCV valve and plugs for #2, 4, and 6. He also suggested that the distributor cap might be cracked. I have not checked either of these two ideas as of the time of this message to you.

One final thought with this issue is that we still have about 11 months left on a Ford issued extended warranty that we bought at the time we purchased the used van (despite the $50.00 deductible, it has probably saved us money ... I am fearful of what we might be in store for once the warranty expires!!!). Would you think that this problem would be better serviced by a dealership?

To answer the other questions you requested be answered in any message to you, the transmission is automatic, approximately 78,000 miles, fuel injection, ABS brakes, P/S, A/C, and cruise control. I don't know about the rack and pinion steering but I would hazard a guess that the answer is "no".

Thank you,
David

A. There was a TSB issued on this problem.

Article No.: 98-25-5

Date: 12/21/98

• Malfunction Indicator Lamp (MIL) - MIL Lamp Illuminated - Diagnostic Trouble Codes (DTCs) P0300 Through P0306 - Comprehensive Diagnostic Procedures - 3.8 Liter Engine
• Lamp - Malfunction Indicator Lamp (MIL) Illuminated - Diagnostic Trouble Codes (DTCs) P0300 Through P0306 - Comprehensive Diagnostic Procedures - 3.8 Liter Engine

Light Truck: 1996-98 Windstar

This TSB article is being republished in its entirety to update the Calibrations, and add a symptom to the Issue.

Calibration: 6-62J-R00, 6-62J-R10, 6-62J-R11, 6-62S-R00, 6-62S-R10, 6-62S-R11, 8-62J-R11, 8-62J-R12, 8-62J-R17, 8-62J-R18, 8-62J-R21, 8-62K-R11, 8-62K-R12, 8-62K-R17, 8-62K-R18, 8-62K-R21, 8-62P-R05, 8-62P-R17, 8-62P-R18, 8-62Q-R05, 8-620-R17, 8-620-R18, 8-62S-R11, 8-62T-R11

WARNING: This modification is authorized only for the listed engine(s). Performing this modification on other engine calibrations is unauthorized and could create liability under applicable federal or local laws.

Issue: The Malfunction Indicator Lamp (MIL) may illuminate and Diagnostic Trouble Codes (DTCs) P0300 through P0306 may be stored in memory. This may be caused by any of the following conditions:

• Fouled, cracked or incorrectly gapped spark plugs and/or wires.
• Low compression.
• Vacuum leak.
• Faulty injector.
• Powertrain Control Module (PCM) calibration.
• Plugged EGR orifice(s) in each primary port of the lower intake manifold.
• Leaking intake manifold gasket)s).

If everything checks out good, there is new software that Ford can reprogram your PCM with.