Hi, i'm new to the forums but have found a great deal of info here. I just purchased a used 97 ford Sho w/ 132k. I had the dealer do a tune up on it before i purchased. Now my SES light came on and auto-zone ran a diagnostic and said the 6th cyl is misfiring. I took the car derictly to the dealer to fix. However, I am concerned about damage to the engine and possible future problems with the engine. Will or could this cause damage to the engine? The warranty is only for 90 days or 3000 miles. This was yesterday. Did I buy a lemon or am I just stressing out?
Thank you in advance

The '97 SHO has an individual coil mounted on each spark plug. I have a '98 with just over 80k and have had two coils go bad on me, so I don't think you bought a lemon. Of course we have no idea how many coils have been replaced up to now.

A misfire isn't likely to damage the engine if repaired soon. However, it can cause the O2 sensors to carbon up and it causes the catalysts to work extra hard to convert the extra unburned fuel to harmful gasses and water.

Are you relatively handy with tools? If so, you can replace this coil pack for much less than a dealer will charge. I can check my diagram tonight, but I believe cylinder #6 is one of the front cylinders on the car (1-4 are the rear I believe). You'll need the coil pack, possibly 8 spark plugs (and 5/8 spark plug socket), a 10mm socket, an 8mm socket, socket wrench, 6 or so inch extension for sockets, and a small flat blade screwdriver (to possibly release connector retainers).

You can get an OEM coil from O'Reilly Auto Parts for under $100. Around here (Cedar Rapids, Iowa) they keep them in stock. It will be in a Borg Warner box, when the part inside is a Motorcraft with the Motorcraft sticker and OEM part number right on it. The dealer will charge you around $250 for the part.

To replace the offending coil pack, remove the acorn nuts that hold the valve cover cover in place. Remove the oil fill cap. Lift the silver plastic cosmetic cover off of the valve cover. For cylinder #6 you will also need to remove the 10mm bolts that hold the intake manifold runner control box (IMRC) in place and unplug the electrical connection to it. Sit that box and connected cable out of the way. Remove the two 8mm (?) bolts that hold the #6 coil pack in and lift the coil out. You may need to twist it slightly to release the seal. Unplug the connector from the coil and replace, being sure to use some dielectric grease in the boot.

While you have the coil out, you may as well pull the plugs and see what condition they are in. If they look like they have 132k on them, replace them. The back 4 plugs are a bit more difficult to get to, but I can get the back four plugs out and the top of the engine back together now in exactly 1 hour, hood up to hood down, so they aren't as bad to replace as they appear they'd be.

The dealer will likely suggest you replace all 8 coils since the others may not be far behind, but at what they cost, I would not suggest it, unless you really want to be good for another 70k miles or so.

If you happen to be in the CR, IA area, I'd be more than happy to walk you through this process in person.

-Rod

Rod, thank you very much for the detailed info. This will come in very handy after the warranty is up lol. I am very glad that this will not cause real damage if taken care of quickly. I was really worried about that as this is the first used car I have ever bought off of a lot. Thanks again for your help.
Kevin

The cylinder location is shown at the following site:
http://www.v8sho.com/SHO/FiringOrderCylinderLocation.htm

Cylinder #6 is on the front of the engine, so it should be a quick and easy repair.

You may want to bookmark the site www.v8sho.com. Lots of good stuff there!

-Rod

The cylinder location is shown at the following site:
http://www.v8sho.com/SHO/FiringOrderCylinderLocation.htm

Cylinder #6 is on the front of the engine, so it should be a quick and easy repair.

You may want to bookmark the site www.v8sho.com. Lots of good stuff there!

-Rod
hope both of you guys have had your cams welded

hope both of you guys have had your cams welded

Ugh, I read a little about that. How would I find out? Take it to a mechanic? I bought this car used.

My plain 97 Taurus G came up with a cyl misfire code a while back (about 80,000 miles?) and all I did was replace the plugs and wires. I had the error code reset with my plug-on tool and that solved my problem. Since you indicate that the problem came up after a tune-up is it possible you have a faulty out-of-the-box plug or maybe it is gapped incorrectly?

My plain 97 Taurus G came up with a cyl misfire code a while back (about 80,000 miles?) and all I did was replace the plugs and wires. I had the error code reset with my plug-on tool and that solved my problem. Since you indicate that the problem came up after a tune-up is it possible you have a faulty out-of-the-box plug or maybe it is gapped incorrectly?

It ended up being a coil. The mechanic replaced that and the spark plug while he was at it. Thankfully the car is still under warranty. I will be picking it up today.
Would a carfax show if the cams have been welded?

Nope, about the easiest way to tell if the cams have been welded, besides asking previous owners, would be to remove the front valve cover and look for evidence of the cam being welded. The front one would be the easy one, so it wouldn't guarantee that the rear had been done, but I would think is someone knew what they were doing enough to know the cams should be welded, they would go ahead and do the rear one as well.

-Rod

-Rod

Nope, about the easiest way to tell if the cams have been welded, besides asking previous owners, would be to remove the front valve cover and look for evidence of the cam being welded. The front one would be the easy one, so it wouldn't guarantee that the rear had been done, but I would think is someone knew what they were doing enough to know the cams should be welded, they would go ahead and do the rear one as well.

-Rod

-Rod

Thank you again for the info Rod.

Kevin