3.8 Liter V-6 Engine Checklight
New User
Joined: Apr 2002
Posts: 11
Likes: 0
From: Houston
3.8 Liter V-6 Engine Checklight
I have a 96 Windstar with a 3.8 litre V-6 that has an engine checklight on. My AutoTap diagnostic software indicates that the checklight was triggered by excessive missing of the #4 cylinder. No other cylinder misses are reported. The miss is noticable but intermittant. The engine does not seem to miss during cold startup but develops after the engine is warm.
I've replaced all the sparkplugs and also the sparkplug wires with no improvement. I just checked the compression and #4 reads 130 psi, the same as #5 and #6. I'd considered replacing the coil pack as I was out of electrical options. But then I learned that there are actually only three coils in the pack with each firing two cylinders. Since AutoTap does not report misses on other cylinders, I'm now assuming the coilpack is not the problem.
I'm now at a loss. Any suggestions?
I've replaced all the sparkplugs and also the sparkplug wires with no improvement. I just checked the compression and #4 reads 130 psi, the same as #5 and #6. I'd considered replacing the coil pack as I was out of electrical options. But then I learned that there are actually only three coils in the pack with each firing two cylinders. Since AutoTap does not report misses on other cylinders, I'm now assuming the coilpack is not the problem.
I'm now at a loss. Any suggestions?
New User
Joined: Jul 2002
Posts: 19
Likes: 0
3.8 Liter V-6 Engine Checklight
hi, i have a 4.2l v6 with the check eng. light on for a no.3 missfire which is PO303 code, and it was suggested to me to try replacing coil pac so i did and so far check eng. light is still out, just thought i would let you know because thats what i thought to if one was missfiring they both should but i was told it could still be just the one well its just a suggestion it worked for me.
Fleet Mechanic
Joined: Aug 2002
Posts: 1,899
Likes: 29
From: Raleigh USA
3.8 Liter V-6 Engine Checklight
Hello I work at a Ford Dealer and I see this all the time with 4.2 and 3.8 with the split port intake. You did not mention wether or not you have a split port so I'll give you the fix for both styles. On the split port 3.8 and all 4.2 the cause is a lean misfire on #4 b/c all the EGR gases are going to that cylinder. To repair you have to remove the upper intake manifold and clean out the EGR ports in the lower manifold with a pick. The EGR ports are at the top of the runners in the lower manifold and are round plugs with a hole in the middle. Use compressed air and blow through all the ports after you clean them out with the pick. As for the other cause, it does not matter what style 3.8 you have-the head gasket is blown. Ford extended the warranty on all 95-96 3.8s for defective head gaskets. To check pull the #4 plug and see if it has a greenish tint to it and pressure test the cooling system. Call your local Ford dealer and give them the VIN and the mileage and they will tell you if it is still covered. Hope this helps
