Wrong Viscosity Oil=RIP Triton Modular V8!........

 

My question is why didn't you just wait until you could get your hands on some 5w-20 or 5w-30? I mean dont you think it would be better for your vehicle to go for just a few more miles than to put the wrong oil in? That would be like saying my truck was about out of gas but all i had was diesel so i just put that in there.

 

That 15W40 may cause real problems if the weather's cold. Can you say dry starts?

 

You may mess up your engine. Your fuel efficiency will suffer greatly from using 15w40 oil. I would get that oil out asap if I was you considering you live in the great state of Illinois. Obama . I lived briefly at Great lakes, and that was the most cold I experienced. During the winter only run 0w or 5w if you care for your engine.

 

I use to run Rotella 15-40 in my 4cyl Daytona Turbo (early 90's). Put over 100k on it using that oil. When she got totalled she was running as good if not better than the day I got her.

Just sayin'......

 

my dad runs syn. 15w50 in his 5.4 in the summer. he has about 20,000 miles of running time on that oil without any problems. not saying there wont be but so far so good. i do the same thing and never had a dry start or anything. even when my truck sat a week there wasnt any dry start.

 

Might as well add my thoughts:

I doubt you have to panic and change the oil "yesterday". But, since you are using a heavier than "spec" oil, it will not flow as easily on cold starts and will add more internal resistance (resulting in poorer gas mileage - maybe as much as 2mpg) as long as it's in there.

So, in the long term, you could increase engine wear and buy quite a bit more gas.

I advise changing it as soon as you get time to do it - maybe this weekend or the next? The filter will trap up to a quart of this oil I think. Probably, using the correct viscosity will dilute that and you won't have problems, but, why take the chance? As was pointed out, filters are not that expensive, so I'd change that too.

- Jack

 

Time for a reality check. 15w40 is not the best choice, but it's not going to do any damage or cause any problems. Can anyone explain how this oil causes a problem in a short period time?

Has anyone compared the viscosity of 15w40 at 32* with the viscosity of 5w20 at -30*. We have F-150 owners in Canada who say these trucks start at -40 with no problem.

I'll agree that it will start harder in January when the temp drops near 0*.

 

The point is, these Tritons have very tight clearances, and when it's cold, you need 5W to get the oil where it's supposed to go on a cold start. You are risking accelerated wear. Otherwise, you may be one of those who come back here later and complain about oil consumption.

 

The 15w-40 certainly isn't the oil of choice for your truck. Your biggest issue will be cold start up. I spoke with my nephew this evening, he lives outside of Chicago, and he said the temps are suppose to be in the low 20's in the AM. You will probably have lots of valve train wear on cold start up using an oil that thick. It just can't flow fast enough to get there when needed. As far as it being a 40 viscosity at temp, I would suggest avoiding any prolonged full throttle runs or you may end with valve covers full of oil and foam in the pan. I'd suggest changing it at the earliest opportunity. FWIW, an Xw-20 oil will flow faster at cold start up, absorb more heat at temp and get back to the pan to release the heat faster than any thicker viscosity fluid. The Triton engines rely on the oil for cooling as well as lubrication. Using a heavier oil buys you problems and solves none.

 

Ok, fine, I'll concede to the expert.

 

I run Rotella T 15W40 in the IROC, but thats a built Gen I small block, no where near the tight of tolerances of a Modular Motor such as ours. I couldnt dream of running that thick of oil through an engine with such tigh tolerances. . . on the other hand, the IROC loves it, big flat tappet cam and built loose. . . love $14 oil changes with it

 

Ford spec's the 5W20 strictly for CAFE reasons and not because it is a better oil than anything else...that is not to say everyone can start running 20W50 in your engines, climate plays a huge factor. Up here the mercury will drop well below zero for a couple of months so a 5W20 or 30 is definitely required.

I have seen stellar UOA's of guys running 5w20, 5W30, 10w30, 5W40, and 15W40 on these modulars. You "could" use the weights in order going from a cold to a hotter climate.....I find the 5W20 and 30 does more than enough in evey climate so it just means an easier choice for me.

 

I was at my local dealership 4 years ago getting an oil change, and there was a Ford Engineer flown onsite there to inspect a Mustang Cobra engine failure. I was picking his mind about a few things, including oil viscosity, and he told me this...

The tolerances between modulars that originally required 5W-30 and engines that were speced with 5W-20 are exactly the same, but after 5W-20 became widely available Ford switched to it.

Partly for improved fuel economy, but they also found thru testing that the engine lubricated better and improved long term reliability as well. That is why Ford back-speced it to older engines because it would benefit them.

So it makes sense to me. If it's strictly for CAFE reasons, they would not have back-speced older modulars to 5W-20. Why would Ford risk going to thinner oil on older engines if they didn't have to?

 

the hydraulic lash adjusters will not properly operate at high rpm with too thick of oil... so run what you want, but keep that in mind.