'89 2.9 with about 40k on bottom end and less than 2k on top end. Blew a head gasket at 73k and Ford put a long block in (100k mile bumper to bumper warranty.)*1 Here's the issue: Got everything back together and drove it for roughly 1000 miles in mixed conditions. Starts fine, runs smooth and seems to have plenty of power around town. To date I have not attempted to tow anything heavy which use to be routine. On the expressway, past 55 or so, it has practically nothing left. Past 70 is like stepping in a hole. Lack of power is most evident when it will not stay in cruise while in overdrive, except on the flattest of pavements. Also, as you might imagine, it is sucking gas like there's no tomorrow. It was never thrifty, due to the towing package, but now gets between 10 and 15mpg. Compression in all cylinders is within norms. Since I can't see this issue at normal driving speeds I have been tempted to pay for a Dyno test so a possible cause might be found at the speeds where the problem arises. Also, my local Ford dealer has lots of issues diagnosing something on a vehicle over 5 years old.*2 *1) many 2.9 heads cast around '89 and later, though cast iron. exhibit issues once they have around 70k+ miles on them. The original castings were poorly made causing the valves to recede into the heads and/or causing the heads to warp just enough to blow into water jacket or across cylinders. I have had all 3 conditions on 3 separate sets of heads. Bear in mind this is Not the original block.The last time it happened I was able to find new recently cast heads and, hopefully, will not have this issue again. If I had not just rebuilt the tranny (Auto w/overdrive) I would have dropped something more substantial in the 2.9's place. *2) I had a bad vibration when I got the truck back together. They said it was the carrier bearing. I disagreed but replaced it anyway. The old one, which had probably 20k miles on it, was fine. Turns out new rear tires I had just bought were out of round and the Ranger is sensitive to that factor.
