I own a 1999 Ford Ranger XLT 4.0L. It has just turned over 98,000 miles. MY problem is this. It seems that roughly every 6 month's my truck ends up cracking a spark plug. This occurs in the same cylinder every time. I am not sure of the cylinder number, but it would be on the driver side closest to the radiator. Whn I pull the plug everything looks good but the insulator is cracked. I replace with a new plug and the truck will run fine for 5 or 6 month's until it does it again. I have noticed that sometimes at idle the engine will be at about 900 RPM's and drop a few hundred RPM's for bit than return back to normal idle. This does not happen all the time as it is speratic. On some occasions when slowing down from crusing speed to idle the engine will run at about 1500-2000RPMS when at a complete stop than return to normal idle speed. This also occurs every now and than and is not consistant. I do no think that is normal for this vehicle. Please let me know what it may possibly be.
have the same problem?
Friday, October 26th, 2007 AT 8:02 PM