SonicGT

went into kragen and ask for help on the oil and told me to use 10x30 and so i got them. now im seeing that it uses 5w20? would it damage the engine? havent driven the car yet.

Eleanor Dreaming

My guess would be no. The thicker oil might make it harder to start if it were cold outside. Might rob a little horsepower. The only way I could see it being a problem is if the oiling parts have been designed for the thinner oil. IE pump pickup and flow. Might want to let it warm up a bit more before driving it.

adrenalin

My guess would have also been no, however, when you talk to FORD they do say using 10w30 will harm the engine. If you are not using the proper oil and have a problem I think you can kiss the warranty goodbye. However, I found this article to be very interesting

http://www.bestsyntheticoil.com/dealers/am...5w20-cafe.shtml

Firedude

You are ok. The only way the dealer would know is if you told him. Go buy some 5-20w synthetic and keep that receipt for your records. Then you will already have oil for your next change.

Scothew

Acctually, if you have premature engine failure, dealers can take the oil to have the viscosity tested and will find that it is an improper weight. Personally, i would drain it again for the proper oil, but thats just me. Thicker oil can put more strain on the engine parts and also makes the oiling system work harder trying to push a thicker oil through the journals in the crank and other key parts of the engine.

y22kc

Run it for 2k miles and change it. One oil change interval with 10w30 instead of 5w20 isn't going to harm the motor morethanlikely.

Firedude

They would also have to prove that the 10-30 did in the engine. It wont.

SonicGT

went back to the store and complained and got them to enchange it. thinking of changing it again on sunday when i have time. wouldnt want to risk it. im not a mechanic , so im just learning how to do the basics. i want to maintain the car myself. but yeah, should i leave it for awhile then change it or just simply change it again?

05stangkc

TAKE IT OUT NOW! I have seen The New Modular Engines throw a rod with too heavy an oil. Why Speculate Why Take a Chance. PUT THE CORRECT OIL IN NOW. BTMO!

kc

6505pony

It's just better to be safe than sorry. Doesnt cost much to change the oil. If the store exchanged it all the better. Drain it replace it and since they messed up replace the filter too.

No harm done then.

Firedude

You have got to be kidding.

Route 66

Your'e fine.

Cleveland

throw a rod, yeah right AND come on.

10w-30 isnt going to damage a thing.

0w-30 or 5w-30 is better for the overall health of the engine though. After I deplete the last 6 quarts of 5w-20 Amsoil Im moving over to 0w-30.

BTW...
This is all you need to know about oil.

-Dan

Gearhead

Hi Jose,
Since you are living in California, you probably are not getting colder than 45F. I would think you should be OK with the 10 base oil. If you were to drop colder than that, I would drain and switch to the 5 base oil. A 5W-20 oil behaves like a single viscosity 5 weight oil at 32F, and behaves like a 20 weight oil at 212F. Since you are above freezing, the 10 weight base number at 45F will be quite similar in viscosity when compared with the 5 weight viscosity at freezing, so your bearing number should be fine.
Brian.

SonicGT

thanks everyone for their inputs, but i think im going to play it safe and just change it tomorrow. since im putting headers next week and hopefully a tune, wouldnt want the oil to affect the tune in any way. thanks once again, feeling much better and obviously learned from my mistake

Hatchman

Really, you've seen cars throw a rod for having 10W-30 in them?

Hatchman

Another Amsoil user, cool!

SonicGT

one more question, should i replace the oil filter again?

6505pony

wouldn't hurt for such a low price. The 4-8 bucks I would just for peace of mind.

RRRoamer

Ok. I won't believe this one until I see the engine, the oil test, and the proof that the cause of the failure was having too heavy an oil in it.

Do a viscosity test on 5W-20 and 10W-30 oils at 0, 32, 100, and 212 degrees and you will find they overlap a LOT (meaning that 10W-30 oil has about the same viscosity at a higher temperature than the 5W-20 does at a lower temperature). Your vehicles spends a lot of time with cool (and even cold oil in winter) oil in it during winter driving following startup. No way in HADES would a 10W-30 CAUSE a rod failure. There was something else wrong to begin with.

Now, if you are talking about someone running 50W or 60W racing oil in one, then I could see it. That stuff is THICK when it is cool! I can see were the stock oil pump would have trouble getting that stuff to the oil passages in sufficent quantity to lubricate the bearings.

Keep one thing in mind: The oil pump doesn't pressurize the raceways at all (you wouldn't believe what the hydrolick pressures are between the bearing and the journal on your main and rod bearings. Heck, even the cam bearings!). It just pushes the oil TO the bearing where the motion between the the journal and the race pull the oil into the gap at very high pressures. That pump really only needs enough pressure to push sufficent volumn of oil to each of the bearings so they can each "draw" all the oil they need to do their job.