Thoughts About Changing the Spark Plugs

[willied]

So I've been having a problem with shuddering at highway speeds when accelerating slowly for around half a year now. It's clearly a misfire, but it generally won't set a code, however, it did set a code off once for a misfire on cylinder 6. I swapped coils, but I couldn't get it to set off another code. I then decided to go ahead and get a new coil, but that wasn't it. So today I changed the spark plug with an Autolite HT1. I went to drive it on the highway and it still shuddered on the on-ramp, though it didn't shudder anymore after that. So I'm not quite sure if the shuddering has been fixed, but whatever the case, should I just go ahead and replace all of the spark plugs? The plug I removed today was pretty hard to get out, but once I was able to crack it it came out easily enough. I've had these ones for about 53,000 miles or so. I can get new ones for about $6 each after rebate. Any thoughts?

 

[Explorer_PL]

Change them all. I had shuddering like yours and no light. After new sparkplugs, all is nice and smooth.

 

[willied]

I guess I'll go ahead and do that. I drove it again today and the problem is definitely still present. I wish these cars would set a code for a misfire a lot sooner. The guy in one video I was watching said it takes about 14,000 misfires to set a code. Oh, well...

 

[Explorer_PL]

Yep

When I had Tahoe it would set 300 or 30x right away.

The Explorer takes forever or never sets the code even when you feel like you're going to drop the engine on the street from shaking.

 

[Boomyal]

I guess I'll go ahead and do that. I drove it again today and the problem is definitely still present. I wish these cars would set a code for a misfire a lot sooner. The guy in one video I was watching said it takes about 14,000 misfires to set a code. Oh, well...

In case you are intersted, I just picked up a set of 8 MotorCraft SP514's off of ebay for $83.98 shipped. It's the best price I have found.

http://www.ebay.com/itm/26132740355...iewitem=&sspagename=ADME:L:OC:US:3160&vxp=mtr

 

[willied]

In case you are intersted, I just picked up a set of 8 MotorCraft SP514's off of ebay for $83.98 shipped. It's the best price I have found.

http://www.ebay.com/itm/26132740355...iewitem=&sspagename=ADME:L:OC:US:3160&vxp=mtr

Thanks for the link, but I can get a full set of Autolite HT1 plugs (same as the Motorcraft, just different branding) for about $48 after rebate.

 

[Boomyal]

Thanks for the link, but I can get a full set of Autolite HT1 plugs (same as the Motorcraft, just different branding) for about $48 after rebate.

Willied, I am not sure that the Autolite HT1 is the updated version, ie, the one with the nickel extension. All evidence I could find is that it was the original copper material.

I think that is why your are getting a 1/2 price rebate. I would rather get a good price on the updated nickel plugs than 1/2 price on the more problematic version of the plugs.

That being said, even the 'new and improved' version is a far cry from what Motorcraft or Autolite should have done and that was to make a one piece version of the plug with all the same durability attributes of two piece plugs.

 

[willied]

Willied, I am not sure that the Autolite HT1 is the updated version, ie, the one with the nickel extension. All evidence I could find is that it was the original copper material.

I think that is why your are getting a 1/2 price rebate. I would rather get a good price on the updated nickel plugs than 1/2 price on the more problematic version of the plugs.

That being said, even the 'new and improved' version is a far cry from what Motorcraft or Autolite should have done and that was to make a one piece version of the plug with all the same durability attributes of two piece plugs.

You could be right, but the one plug I've bought so far said it was updated, and honestly I'm not too worried about it at this point. I may eat my words in the future, but right now I feel okay about it.

 

[shucker1]

I had the same type of problem on my 98 5.0L a few years back. It was traced back to a bad plug wire. I finally brought it to the dealer since I was pulling my hair out! It never missed when you it it hard. Only during light acceleration.

The tech at the dealership explained it as an "On Demand" spark system which is tied back to the ECU.

During acceleration the ECU sends more spark voltage proportional to throttle input. Since the wire was going bad and not completely failed the problem would come and go.