Hi, I'm new to the forum. I have done all the work needed on my vehicles in the past, have not taken them in for anything other than tire swaps/balances... I'm stumped at this point now.
4.0 liter, v6, 4x4, 166,000 miles. No previous engine problems.
I'm getting the dreaded chain rattle, or so I think it is, at 2600rpm and it disappears at 3,000rpm. It gets worse under any kind of load. I'm assuming it's the timing chain guide and I assume it's the rear one, of course. I'm just wondering if I should attempt to replace it or swap engines or just sell the ranger... I've taken transmissions out before, but this seems like it's a little over my head, especially without Ford's "special tools". Has anyone ever had this done at a shop? What can I expect for cost?

On a side note and something that makes me think swapping would be a better option, I am losing a lot of coolant. I fill my reservoir and 30 miles later, its bone dry. No visible leaks on or below the engine bay. I think I have a cracked head, probably in between my valves and I'm burning the coolant. I've sat with a flashlight, looking for leaks at idle, for 30 minutes and everything is dry. It seems to only take the coolant when I'm driving it around, under load. I have no codes... Truck drives and stays cool but I top the radiator off about once a month, because the coolant just doesn't stay in the reservoir (hoses are dry/no cracks in reservoir). Any advice on what I should do?

Thanks, Patrick

 

Welcome to the forum

The 4.0l SOHC engine, 2001-2011 Rangers, didn't have a cracking between valve seat issue, that was the 4.0l OHV engine, 1990-2000

The 2001-2003/4 did have the timing chain issue, what year is yours????

4.0l SOHC engines did have a thermostat housing issue, it would leak and coolant sits and evaporates on lower intake area, so no drips on the ground
Good read here with pictures: https://howtoreplacefordthermostathousing.com/


Look at the prices of used 4.0l SOHC engines, you want a 2004 or later model, and you should still replace BOTH long chain tensioners, and you should do this every 80k miles or so, IMO
These tensioners are what caused the original problems, not the guides or the chains, they were redesigned and used starting in 2003, so most 2004 and up 4.0l SOHC are OK

Then call local machine shops and find out what they would charge to do the timing chain fix, if you dropped off and picked up the engine

In either case YOU should pull the engine and reinstall, you can rent an engine lift and a u-haul pickup truck as needed
Bulk of the cost will be in the labor to pull and reinstall the engine, which will be about 14-16hours, so $1,400-$1,600 on top of the engine work or exchange

 

Thanks for the helpful response. I have a 2011 ranger... Sounds like I shouldn't be having these problems then, after what you said. I'll definitely look into that thermostat housing.
So if the guides are good, what is making the rattling sound? I assume my tensioners are okay, because there is no noise on startup, so springs should be okay and the oil pressure should take over after that. Think I should just replace them anyways?

As far as the coolant, your response makes sense. I'm not fooling out spark plugs or getting excessive exhaust fumes, like the coolant is being introduced directly into the cylinder. I'll read that article so I'm more informed on the problem.

Any advice is greatly appreciated!

 

Btw.... I just read that article. Very helpful and detailed. Thanks for the link!

 

If you hear the rattle, guides may already be broken
The tensioners use oil pressure after start up so one or both could have clogged passages, which is why I recommend replacing them every 80k miles or so

Video here on these and changing them:

You have to pull off the thermostat housing to change the front tensioner, but you can do the rear tensioner ASAP if thats where noise is
I would only use Motorcraft tensioners, they are more expensive