Ive got a 1998 ford ranger 4x4 with the 4.0 engine 114k . i just put MC 5-20W synthetic blend in it . I know it calls for 5-30w but i didnt think it would matter- that is till i did some reading on this site.Now i dont know what to do.how much harm would it do if i ran it for 5k then put 5-30 back in . or should i drain it out now and take the loss.

 

I'd drain it, that oil is too thin for that motor

 

Probably best to drain it...
It would be cheaper for you to be right and drain the oil anyways, then for you to be wrong and wind up with a locked up motor...
what like 30 bucks in oil tops compared to a possible 3k rebuild... Ill take the 30 bucks everyday...

 

well,I guess I will drain it out,gonna be hard to get under the truck now with those donkey ears.Thanks for the replies.

 

It could destroy the engine. Either change the oil or change the engine.

 

That's sucks, were you trying to save fuel? If so, I understand. Just like everyone else said, this isn't the motor to do it in.

 

I'd change the oil to the specified 5w-30, as the oil pump on our 4.0L engine isn't designed to meet the engines flow volume needs, with a hot 20 weights viscosity.

Don't forget to drain the filter too, as it holds about 1 qt!!!!

Your engine isn't likely to instantly self destruct, but I sure wouldn't consider trying to run this lube 5K miles.

Just get it done soon, before you do any high speed, lugging, or tugging type driving.

 

No i wasnt trying to save fuel its just that my other two late model Fords call for 5-20w, just wanted to buy and use the same oil in all of my vehicles+ walmart where I live sells only MC 5-20w + MC15-40 in the 5 qt jugs which is cheaper& more convenient than individual MC5-30w quarts.Heck even my wife noticed the weight discrepancy on the jug when we were walking out of walmart, i laughed at her and told her it didnt matter,needless to say she was standing there snickering with her arms folded, while i was draining it out.

 

Explain to her that you were just doing a 100K mile detergent rinse, sorta like her washing machine does, to get the detergent with all the dirt it's removed from the clothes, out of the machine!!!!

Anyway good to hear your 4.0L has the correct viscosity lube in it & is now all fresh & clean inside!!!!

BTW did you remember to drain the oil filter too????!!!!

 

Is there a warning in the owners' manual that says not to use anything less than 5w30 or it will destroy your engine? What made his engine all clean and fresh inside? Would a heavier than recommended viscosity such as 10w30 be just as detrimental to his engine? The owners' manual with my truck "recommends" 5w20 (5.4) but I can't find in there anywhere that any other viscosity will destroy my engine. I'm just curious as to where you all get your information from.

 

I don't think it would damage the motor in my opinion, but maybe someone who knows these motors might chime in?

 

+1. The truck will be fine with 20 weight. The only exception would be if the truck is used in heavy duty applications, and if that is the case, 30 weight wouldn't be thick enough. Not to worry, your truck will be fine.jd

 

A 10w-30 weight oil at operating temp isn't heavier than a 5W-30, or a straight 30wt for that matter, as their all rated as 30wt, within the 30wt viscosity range, at hot operating temps.
Only at cold temps is their a meaningful difference in viscosity, with the 5W being less viscous than a 10W, or a straght 30wt.
The 5W will flow faster/easier on a cold start, where we're told most engine wear occurs, so the faster a lube will flow on a cold, high rev start, the better it is for our engines.

Ford has a TSB lube specification, listing engines that can use 5W-20 & those that are to use 5W-30. 02-1-9***ENGINE - ENGINE OIL - RECOMMENDED APPLICATIONS FOR SAE 5W-20 AND SAE 5W-30 MOTOR OILS - GASOLINE AND FLEXIBLE FUEL VEHICLES ONLY

The 4.0L engine is to use 5W-30, beause it's oil pump hasn't been upgraded to be able to provide the engines flow/volume needs, at hot operating temps, with a 20wt's lower viscosity. You can dig this oil pump info out of a Ford Q&A warranty policy manual to Dealers, but you'll have to scroll down about 5 times to find the oil pump part. Lots of other good
info there though, so it's worth reading through the whole document.
http://www.dantheoilman.com/fordoilfaq.doc

 

Well I guess a better question to this would be how does the typical 4.0 ranger owner know that a lower viscosity oil would be so detrimental to their engine. Manufacturers always recommend a certain oil for their engines but there typically is a lot of others that would also work just fine in them. Ford has actually backpedalled on their recommendation of some engines that were originally to use 5w30 oil but can now use 5w20.

 

Well all we really need to know is what Ford recommends for our 4.0L.

If we want to mess around with a lower viscosity crankase lube for our particular type of driving, we could incur the costs of regular UOA's & see how the wear metals & the oils viscosity, ect, is doing & get an idea if the change works for our engine, driving conditions & drive cycle, ect, but any vehicle warranty is out the window!!!!

For instance, going from a 5W-30, to a 5W-20 for mpg reasons, is good for only something like 0.5 mpg, so why the heck take the risk of using a unspecified viscosity lube, void our warranty, risk excessive engine wear, for 1/2 a mile per gallon increase in fuel economy?????

My 94 Taurus 3.8L originally was specified for 5W-30, but now is back specified by Ford to use 5W-20 if I want to use it.

For instance, I choose to run energy conserving Havoline 5W-30, which has a hot viscosity figure thats low on the 30wt scale, such that it's just about in the upper vscosity range of a thick 5W-20.

Some 5w-30 lubes have a hot viscosity figure that approaches a 40 weight lube & an ash number about 20-30% higher than one on the low end of the 5w-30 viscosity scale.
So if an engine consumes some oil between changes, that lube will produce more engine deposits & the engine will have more pumping losses trying to move the ticker lube around.

Using a better quality base oil, can enable a lube manufacturer to build an oil with a lower viscosity figure, use fewer aditives, have a lower ash number to limit engine deposits & still provide the needed protection.

So unless we want to spend some money on UOA's to see how a particular lube is holding up in a particular engine, for a particular driving style & driving cycle, just follow the OEM's lube sugestions, as it covers a worst case scenario & the maufacturer has already done all the wear tests for us!!!! lol

The manufacturer isn't going to specify any crankcase lube thats likely to increase his warranty repair exposure, because that 3/36 bumper to bumper warrantys cost, thats hidden in the prce of the new vehicle, that we just paid big bucks for, is gravy money for the manufacturer, so he doesn't want excessive warranty costs eating away at his bottom line gravy money!!!!

Now if he's managed to sucker us in for an extended warranty, he sure wants to protect that gravy money too, so now he has to think longer term about engine protection.

So protecting all that gravy money he's just extracted from us, calls for him being careful about what he specifies for us to use as an engine lube, because he now has to make sure what he specifies will cause that engine to last at least 8 years, with low probability of failure.

So knowing all that, we can save a bunch of bucks by betting with him, that if we use what he recommends as a crankcase lube, the engne will likely last at least 8 years with a very low probability of failure, if thats so, we don't need his extended warranty, or to incur a bunch of UOA costs trying to second guess him on what crankcase lube is best to use!!!!

A bunch more thoughts for pondering!!!!!