is this a good motor oil to use on a rebuild?

[43R1c26]

asked the guy at autozone which oil my whip uses he told me 10-40 so i got 10-40 from castrol syntec it's a full synthetic and i just rebuilt my top end.

port polished heads, new lifters, new rocker arm and tips and pushrods, so is 10w-40 a good oil to use

 

[Hartman]

Should be 5w-30. Whether your motor has been rebuilt or not means little.

 

[TedJ]

Ford recommends 5w-30 for the 4.0L v6, there are varying opinions with using synthetic for breaking in engine parts... maybe someone else can chime in about that.

 

[ErickSaint]

The oil question comes up all the time. I haven't switched to synthetic but I run 5-30 in the summer and winter mostly because that is what was being done by the previous owner. If you ask around most will tell you that it's not so much what weight oil you run as long as it's a decent quality.

 

[Blacksheep Josh]

i run full synthetic all the time now. but i always run 10w-30 in the summer, and 5w-30 in the winter. someone told me that with the heat, 10w-30 would act better, something about 5w-30 would thin with the heat?

anyways, that's what i do, and it works for me.

 

[43R1c26]

thanks you guys for all your input and being real friendly with the responses i think i'll go back and at least get a 5w-30 rather it be fully synthetic or nto i'll toss a coin up to it when i get back to the store. LOL

 

[Anime]

5W-30 is indeed the best for almost all temperatures in the 4.0 OHV. The only case in which you might want to use 10W30 is in hot, HOT weather, like where you can count on 90 degree temps EVERY day. 5W-30 doesn't thin with the heat, but the viscosity range makes 10W-30 more ideal for high temps. Anything like 10W-40 is probably a bad idea, both for mileage and the oil seals. On the first startup for a rebuilt engine, usually it's 20W-50 that's used to minimize wear, but then changed out for regular oil after it's broken in.

 

[jackieman402]

5W-30 is fine.

I would not use 20W-50 under any circumstances, and certainly not on a new or rebuilt motor, as that would be the worst possible viscosity to use in such a motor. With the 4.0, as with any modern motor, a thin oil will be better.

Use of heavy oils for break-in was once common -- and recommended -- but this hasn't been the case for many years now.

 

[manaen]

BTW I really wouldn't use fully synthetic oil for the first 1000 miles of a rebuilt motor, it can negatively effect the breaking process, not allowing the rings to seat properly. Stick with the dino oil, and change it out at 200, then 500, then at 1000 you can go to full synthetic

you only get one chance to properly break in a motor, and it does make a difference.

 

[43R1c26]

WHEW!! thanks for the advice it just so happens that i'm missing five bolts so i cant start up the whip anyways so i will go back to the store.

"stupid three thermostat housing bolts and the two stupid power steering pump bracket bolts i'm missing..... shucks"

 

[Essex4x4]

I use 5w-30 Mobile1 full synthetic.

 

[duke16]

I just had my engine rebuilt and was told to break it in with Valvoline Durablend, 5w30 of course. After the break in period he said it would be fine to go to a full synthetic, basically what manaen said.

 

[43R1c26]

man hope my ride comes pick me up today so i can get these last few bolts and get her up and running. and thanks for telling me what brand to at least think about cuz i'm sort of new to the looking into specs of a vehicle and i did not know what dyno oil was exactly

 

[manaen]

i did not know what dyno oil was exactly

sorry about that, I was referring to dinosaur oil, just plain regular oil, no blend, just the normal stuff that comes form the ground. The problem with synthetics on breakin is that you actually need a bit of friction for the rinds to seat properly, and you only have so much time before the cross hatchings on the cylinders will no longer work to seat the rings. and full synth is good at removing friction thus removing some of the effects of the breakin period.

You should look up proper breakin for an engine. here are some guidelines

1) don't keep the rpms at a steady rate for the first 500 miles IE don't drive down the higway and maintain a steady rpm and speed, drive back roads that you can really vary the rpms and speeds.
2) give the engine some load, but don't let it rev too high. Load(pressure) is what seats the rings. this can be tough on an automatic, since it is setup to rev the engine, this ring seating must occur in the first 50 miles of breakin. If you have a manual tranny it is much easier to break in the motor.
3) keep the motor under 3500 rpms for the first 500 miles
4) examine the oil for metal on the first few changes

 

[43R1c26]

thanks everyone for your help. the whip started up on it's second try tho i had a mishap with the oil filter the old seal from the first one was still on and i tried to screw the new one on. and oops three out of five quarts of oil slipped away LOL

now to research on why my car cuts off after idling for a few minutes. any ideas guys

 

[manaen]

did you check fuel pressure?

when it cuts off, does it just die, or sputter for a while and die?

 

[43R1c26]

at idle it runs strong for a minute then sputters for a sec then shuts off. it even shut off in the middle of drivimg but i think thats cuz it did nit have much gas in the tank

 

[atistang]

yep, synthetic is a no no on a fresh engine like stated, the rings will never seat properly

but he just had his top end rebuilt, that should just be the heads

so run synthetic if you want

 

[manaen]

yep, synthetic is a no no on a fresh engine like stated, the rings will never seat properly

but he just had his top end rebuilt, that should just be the heads

so run synthetic if you want

Good catch
Boy was my brain out to lunch