05’ Ford Explorer Sport trac 2 wheel drive... 140k miles and the front and rear timing chain guides and tensioners have just been replaced. Drove truck 250 miles and now it’s back doing the same exact thing... revs up at a cold start... check gauges light comes on and oil pressure gauge drops... after the cold start.. it doesn’t have an issue with the rev up or the oil pressure... this is 2x the guides and tensioners have been replaced and truck has only been driven 7000 miles in between these 2 replacements...

 

Did you have the cylinder heads off when the guides were replaced? Reason I ask is the driver side cylinder head has a nylon rod in the oil passage that feeds the timing chain tensioner. If it got removed, that tensioner would get less oil pressure at startup. Its also directly above the oil passage in the block that the oil pressure sensor is reading from.

 

Also answered here: https://www.ranger-forums.com/4-0l-o...sioner-161223/

 

Not sure if cylinder heads were removed when mechanic replaced the timing chain guides.... but I will find out... Thank you everyone for your help...this timing chain guides tensioners and starting rev up has really been a booger to get corrected...and I am so ready to have this thing fixed.