Looking for advice after purchase of 2003 4L Ranger in this thread. The truck has 193K+ miles on it and currently been using the recommended weight of 5W 30 Amsoil. With the relatively high mileage of the engine, I'm wondering it would be okay to switch to 10W 30 Amsoil and run it. Reason being that I'm running that weight of Amsoil in 2 other vehicles and it would simplify my maintenance to run 1 weight. No other reasons to do this, but concerned that a different than recommended oil use might cause harm to a good engine. TIA for useful and constructive replies!

 

I would hazard a guess and say depending how much your area's ambient temperatures fluctuate might tend to suggest one viscosity would be better but since your choice would be only 5 points different on the lower range it shouldn't make a huge difference.

Keep in mind this is just a guess, someone here might have another opinion or actual hands-on experience.

 

Thanks for your reply! I'm still "on the fence" though, concerned about cold starts. My research is has pointed out that once engine is up to operating temps, there is no difference between the two blends. Here in Eastern Oregon we have many below freezing (32*F) mornings in fall, winter and spring.

 

The manual says Ford "Recommends" 5W30 for this OHC engine. In years past they allowed 10W30 down to about 0F, but that was for Pushrod engines, not OHC engines.
I see your in eastern Oregon, so if it gets below 0F there when you'll be cold starting this puppy, you'll likely want the 5W30 in the crankcase, as OHC engines like plenty of oil in their top end without delay to be happy. So, if you choose to try the 10W30, let any untoward engine noise you hear on a cold start with a 10W30 in the crankcase be the guide to using a 5W30 in winter.
All that said, don't know which 10W30 recipe you'll be using, but looking at their XL 10W30 specs, with its -47F pour point, & CCA #, if it doesn't get below 0F where you are it might be ok, so again let the engine noise at cold soak starting be your guide.

Daughters 2014 Kia 2.4L OHC engine allows 10W30 down to 0F. While its been setting & not driven, I've randomly cold soaked started it down to 20F with 10W30 syn Havoline Lifelong in it over the past two winters here in SW Va without protest from the engine, but will put 5W30 in it soon for this winter oci, as we'll likely be driving it this winter & it'll be sitting outside 24/7, so all cold starts will be cold soak ones & I want lots of lube in its top end asap after all of its cold soak starts!!!. More thoughts for consideration, let us know what you try & how it goes.

 

Thanks for your reply! You bring up some good points. At this point with winter coming on and the mileage on this engine, I won't take the chance of the experiment. Next oil change, which will most likely be in warmer weather, I'll give the 10W30 a try. I hear what you're saying about engine noise at cold start. If this engine didn't have 193K miles on it, I might be a little braver. But at this point I want to be real gentle on it, at least until I've put some miles on it. Thanks again for your insight!

 

I like your cautious pre-thoughtful, "get the feel of it" approach on this new to you vehicle. 10W30 in summer would likely be fine, as its a 30 weight & that is what is specified for this puppy at operating temperature & the Winter viscosity figure isn't in play at warm temps as 10W & 5W are real close to each other at room temp up to 100F on a summer cold start, so no flow problems this time of year with either viscosity in the engine sump..

4.0L Ford pushrod & OHC engines never got a oil pump upgrade to be able to output enough Volume of the lower viscosity 5W20 at operating temp, so the 4.0L never was back specified for a 5W20, so we 4.0L owners shouldn't use 5W20!!!!

With the mileage on this puppy the timing chain & tensioners will likely be one of the first things to begin protesting, with a rattle that sounds like "marble noise" as it came to be called in the early days of this engine when it had tensioner design problems. The sound to my old ears was sorta like the click/clacking pool ***** make when striking each other when the front & or rear OHC chain tensioners began acting out & laying down on the job. As I remember about 02/03 was the timeframe the OHC Ranger got the tensioner upgrade that finally fixed the marble noise sounding timing chain slap the worn tensioners caused. Replacing them requires engine removal, so isn't something most owners are equipped to do & previous Ford Tech Makuloco has a good 4-part video on how it should be done here , & other good suggestions for how to keep this engine healthy with timely oil & filter changes & other useful maintenance input for this engine you may find useful. More thoughts that have come to mind thinking about the OHC 4.0L.

 

Thank you! I was warned about the chain tensioners by another 4.0L Ranger owner. This engine doesn't have the noise described (yet, right?...lol). But I'll have fun watching the videos and glean as much as I can from them.