Filled the Jeep with Mobil-1 now what?

CalicoKid

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2002 3.7L KJ , 45K miles. I just changed the oil and filter and put in Mobil-1 truck and SUV synthetic oil. I remember something about changing the filter again soon because of loosening deposits or something like that? Am I going to get leaks rattles or anything? My valvetrain seemed a little clattery (if that's a word) lately, will synthetic oil help that? 5w-30 sure seems thin going in and even thinner coming out! The oil I took out had only 2000miles on it but with lots of Wintertime idleing and it was almost water thin when drained warm.
 

Boomyal

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Re: Filled the Jeep with Mobil-1 now what?

2002 3.7L KJ , 45K miles. I just changed the oil and filter and put in Mobil-1 truck and SUV synthetic oil. I remember something about changing the filter again soon because of loosening deposits or something like that? Am I going to get leaks rattles or anything? My valvetrain seemed a little clattery (if that's a word) lately, will synthetic oil help that? 5w-30 sure seems thin going in and even thinner coming out! The oil I took out had only 2000miles on it but with lots of Wintertime idleing and it was almost water thin when drained warm.

What weight oil had you been using? The potential leaks are due to one of Synthetics ability to go where no oil has gone before. This could be both good and bad. Good for lubricating the engine and not so good if you have gaskets that do not seal well.

In the early days of synthetics, when our motor oil came in cardboard cans with metal lids, they had to package synthetics in full metal cans 'cause they would otherwise leak. With the advent of the plastic bottle, that problem was eliminated.

As for the viscosity appearance, once again, that is a positive attribute of a synthetic. It is thermally stable. In very cold climates dino oil turns to gel but synthetics will still pour. This is why they were developed, to lubricate the ice cold front end of a jet motor while still being able to lubricate the red hot rear end.

All that being said, some have had to switch back due to leaks. Otherwise the oil will get to your lifters and other internals quicker, stay longer when you shut down and due to it's slipperyness, just plain do a better job of lubricating your engine.
 

CalicoKid

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Re: Filled the Jeep with Mobil-1 now what?

The manual calls for 5w-30 in the 3.7 so that's what I've always had in it, Castrol GTX. It just looks so thin to me after running heavier oils in my previous VW and Porsche cars. Not too bad new but like I said the warm used oil drained out like water. We will see what this Mobil-1 looks like at the next change. The Mobil-1 is also 5w-30.

I'm assuming the call for light oil has more to do with gas mileage than anything else. My mileage is rotten with the lift and mudders etc. and I could care less as I drive this Jeep less than 5000 miles a year, previous owner put most of the miles on it. Would I be doing wrong if I ran a heavier oil in it? Would it do any good?
 

Boomyal

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Re: Filled the Jeep with Mobil-1 now what?

re Heavier oil. Wait and see if it uses any, if not stick with it. Not sure what weight ranges Mobil 1 makes, but by all measurements, synthetic is a better lubricant.

Lighter weight oil is an economy issue but also modern motors have better tolerances to deal with it. Tolerances that were not readily achievable in past years of mass production. Along with creating less resistance, the lighter oil also gets to critical points faster and carries heat away better.

You were right to change the oil. However, a cheaper way to have done it would have been to just add one quart of the synthetic and run it for the same amount of time. One quart will clean as well as a full crankcase.
 
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Skinnywater

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Re: Filled the Jeep with Mobil-1 now what?

Don't give it a second thought, you're just fine.

Today was a heavy service day, probably changed 20 gallons or more of that very same oil.
The most impressive vehicle today was a '04 CL55 AMG Supercharged a $140k vehicle. It took 8.5 quarts of that same oil.... your 3.7 will do fine on it.
 

rwise

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Re: Filled the Jeep with Mobil-1 now what?

Myself I have had bad luck with changing old engines over to synth oil. Each time the front and rear seals in the engine started leaking. The last one is on the engine stand now ready to go back in, (come on sunshine) all new gaskits and seals. The seals were crisp when pulled out and I even found some parts of them in the oil pickup screen. I will say that mine was just a bit older :rolleyes: good luck!
 

tommays

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Re: Filled the Jeep with Mobil-1 now what?

I have a GM with the oil life system and use GTX

Just to make you feel better every time we get a long cold spell it sets off the change oil light at less than 2000 miles

In warm weather will go over 5000 miles with the same oil without setting the oil change light

The only thing i every had leak was old motors with 2 piece rear mains


Tommays
 

CalicoKid

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Re: Filled the Jeep with Mobil-1 now what?

Thankyou for the input guys. I will drive it a few times a week and see what happens. I'm just wondering If I should go right into a normal change interval or start out with a short interval first or swap filters early or anything like that. If I don't get any leaks or anything I'll probably stick with the Mobil-1 it's really not too expensive in the 5 quart jugs. Since I change the oil in this Jeep pretty much twice a year I like the idea of having something more stabil in the crankcase. Thanks again, we'll see what happens :)
 

Solittle

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Re: Filled the Jeep with Mobil-1 now what?

For what it is worth I picked up almost 2 mpg after switching to Mobil 1 - 2001 Maxima.
 

Skinnywater

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Re: Filled the Jeep with Mobil-1 now what?

Thankyou for the input guys. I will drive it a few times a week and see what happens. I'm just wondering If I should go right into a normal change interval or start out with a short interval first or swap filters early or anything like that. If I don't get any leaks or anything I'll probably stick with the Mobil-1 it's really not too expensive in the 5 quart jugs. Since I change the oil in this Jeep pretty much twice a year I like the idea of having something more stabil in the crankcase. Thanks again, we'll see what happens :)

Your motor is not considered old and it isn't old technology, so the leaking and lighter weight isn't an issue.

I'd stay with the recommended service interval. The synthetic will only allow you to be a little more lax, as in, prolong the interval if you happen to be a little too busy to get the oil changed on time.
You won't need an early change because honestly, at 45k your motor should still be quite clean inside.

No AMG models today, only a few lowly C-classes an E and a S-class, Mobil1 in them all.
 

CalicoKid

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Re: Filled the Jeep with Mobil-1 now what?

Thankyou once again Skinnywater. That's the info I needed for confidence. I will probably not meet the mileage interval for oil changes as I don't drive it enough but will just change it in Spring and Fall. You see some beautiful cars btw! :)
 

jimr

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Re: Filled the Jeep with Mobil-1 now what?

I'd stay with the recommended service interval. The synthetic will only allow you to be a little more lax, as in, prolong the interval if you happen to be a little too busy to get the oil changed on time.

quote]

why would you switch to synthetic if you don't strech out the change interval? The possable increase in milage is not going to justify the price differance. I run Castrol GTX 10w30 in my truck and change it when the minder comes on (unless I tow alot) and run 4500-5500 miles on a change.If I ran Synthetic I would run to the reccommended interval and pull a sample on it and see what it comes up with then go from there.
 

Fishstick1962

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Re: Filled the Jeep with Mobil-1 now what?

I have a 2006 Chevy truck with all the computer junk in it. And it has a oil life indication. It came from the factory set to 7000 miles. Meaning that GM says you can go 7000mi. between oil changes. I run Mobile-1 and I pull a boat frequently, and my oil is never dirty when I change it. I swear by that oil! I bought a 97 GMC from my FIL and all he ever ran in it was Mobile-1 so continued to do the same. The truck had over 180K miles on it and ran like brand new, still had that "New truck pep".
I'm no ASE mechanic... but I swear by that oil and I run 7000 mi. between oil changes and never have burnt black nasty oil when I change it.
 

Skinnywater

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Re: Filled the Jeep with Mobil-1 now what?

I'd stay with the recommended service interval. The synthetic will only allow you to be a little more lax, as in, prolong the interval if you happen to be a little too busy to get the oil changed on time.

quote]

why would you switch to synthetic if you don't strech out the change interval? The possable increase in milage is not going to justify the price differance. I run Castrol GTX 10w30 in my truck and change it when the minder comes on (unless I tow alot) and run 4500-5500 miles on a change.If I ran Synthetic I would run to the reccommended interval and pull a sample on it and see what it comes up with then go from there.

Because todays recommended oil change intervals are extended intervals.
And as a professional it would be improper for me to recommend extending it out past what the manufacture recommends.
If people want to extend them farther than recommended by the manufacture they increase the possibility of sludging and coking at the rings.

The difference in cost over the course of several months both in oil and gas is minimal.
I use synthetic because it's a good product and I have so many vehicles (I use it in the lawn mower also) that it allows me to relax a little if I get behind on maintenance, it flows better on cold starts, it perfoms well in extremes and i feel good about it.

I use it our clients vehicles because it is the recommended oil.

Fact is, 99.9% of ANY motor oil on the shelf will work just fine for 99.9% of the people if you use the type/wieght that the manufacture recommends.
 
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