What brand and kind of oil do you run in your 4.0?

[97grntjsahara]

I am coming up on an oil change and i have been hearing alot about putting synthetic into the 4.0. I used to run full syn. in my VW GTI's but have been sticking with reg. 10w30 oil. I have about 116,xxx or so miles right now. What do you recommend and what are your experiences with both types of oil..thanks in advance!

[MossMan]

I use vegetable oil :shrug:

[SMOR YJ]

DON'T DO IT!! I did in mine and had close to the same miles on mine and it made my engine knock. I don't know why I draned it back out and put normal oil in and it stopped. I talked to the guy at the parts store and he said unless it is a new engine or freshly rebuilt that sythetic was not a good choice, so I would not use it.

[desmo888]

Originally Posted by SMOR YJ

I talked to the guy at the parts store and he said unless it is a new engine or freshly rebuilt that sythetic was not a good choice, so I would not use it.

Yeah - that's a good source, some dipshit making $6/hour at Pep Boys. Probably never bought a quart of synthetic oil in his freaking life!

Having said that, synthetic oil is better, no question. The problem lies in the trade off - i.e. oil leaks. My high mileage 4.0's have developed oils leaks after changing to synthetics. They don't leak a lot but it looks like a lot and spots your garage or driveway.

My current 4.0 is not leaking at 104k but it started on synthetic at 68k. Give it a try and see what happens, it certainly can't hurt.

[sw99]

if you do switch over to full syn, do it over a few oil changes.

[Keith Strong]

Only the good shit

[SMOR YJ]

Okay we have our first dumbass in the discussion now, The dipshit was and ASE certified mechanic for the department of Trans. and knew what he was talking about . as stated above we first blended the oils and did it the correct was the is almost a 100k between your vehical and mine and his if you switch earlier the better but at least you were correct that it won't hurt anything just you pockets for 30 for the syntetic oil.

[supernatural]

i use baby oil

[SMOR YJ]

baby oil works too! hell just dont run any oil it adds weight

[1RUSTYRIG]

I can't believe I have to post this again...you guys should really start searching!
It's all about the Bacon Grease. Not only is it viscous, but when you park in your drive way it cools down and self-seals from leaks. Not to mention you can cook with it in a pinch.

[SMOR YJ]

Bacon Grease.... I knew I forgot something!

[BlueAngel]

Originally Posted by 1RUSTYRIG

I can't believe I have to post this again...you guys should really start searching!
It's all about the Bacon Grease. Not only is it viscous, but when you park in your drive way it cools down and self-seals from leaks. Not to mention you can cook with it in a pinch.

Do they make synthetic bacon grease too?

[MC]

synthetic oil is NOT good for a rig with a flat tappet camshaft. If you run synthetic your lifters can stop rotating causing a flat spot of the lifter and uneven wear and eventually a lobeless camshaft. Their are oils that lubricated many times better than conventional motor oil out there but their is a reason they are not used. More nad more cam mfg's are telling their customers to avoid synthetic oil unless the factory reccomends it for your motor.

[97grntjsahara]

thanks for the reply's and the smartass ones as well:oP i mena if i stay on reg. oil till the engine dies vs. synthetic. Is the engine life going to change by switching oils?.....

[95steel]

No, as long as you have changed your oil when you were supposed to in the past it will be fine. I wound up having to put rotella T 15-40 in my jeep to get me off the trail a few years back. That stuff will clean all the crap and sludge regular oil won't touch. I wound up leaving it in the jeep and have been using it ever since. I run the 10-30 visc in the winter and 5-40synthetic when I can afford it in the summer. Changing to synthetic will not harm your engine, synthetic oil will not cause oil leaks either, it just magnifies any leaks you already have. Putting synthetic oil in an engine with an oil leak is stupid, put cheap oil in it until you can fix the leak.

[97grntjsahara]

ok, thats all i needed. to know. I am just gonna stick wth what i have cause i haven't had any problems. Thanks for all the info. I appreciate it

[ItsaCJ6]

Just for an FYI there are only three types of motor oil. Parafin based oils, Ash based oils and synthetic oils. As far as I know GTX and Penzoil are the only ash based oils. Synthetics have wildly variable formulas, and Parfin oils are the kind that leave gook in the engine over time. Ash based oils are the better choice of the two non synthetics.

[deadmeat]

Here is a good read on oils.

Gear toward Motorcycles, but the info is still good.

[Geesh]

Funny, my friend's BMW motorcycle says specifically NO SYNTHETIC, while BMW autos endorse it . . .

[Rizon]

Royal Purple full synthetic and never looked back. i heard that inorder for an engine to properly " adjust" to a full synthetic you need to run a semi-synthetic first so i ran quaker 4x4 oil in it and that was good too, but my comanche knocks to shit anyways and nothing stopped that.

[jstandle]

I prefer using straight power punch. Cost's a little more to change the oil, but I've only had to do it once in the 80,000 miles I've put on it.

[95steel]

Originally Posted by ItsaCJ6

Just for an FYI there are only three types of motor oil. Parafin based oils, Ash based oils and synthetic oils. As far as I know GTX and Penzoil are the only ash based oils. Synthetics have wildly variable formulas, and Parfin oils are the kind that leave gook in the engine over time. Ash based oils are the better choice of the two non synthetics.

Almost all mass produced motor oils sold in the usa are parifin base stock. Mobil one is the only "mass produced" group 4 synthetic, (I do not know about royal purple and red line but because of the price I would assume they are group 4). Pennzoil, QS, Valvoline, Castrol synthetics are all group three base stock (comes out of the ground and is then refined and somewhat engeneered) and then labled as synthetic. What is interesting is that Mobil one has developed the tech. to go from gas to liquid in a lab. Haven't heard anything else about it though.
In all truth, govt regs require all motor oils to exceed what we think they can do. An engine sludging up 99.9999% of the time is caused by a problem with the engine (coolant leak etc...) not the oil.

[MC]

No, as long as you have changed your oil when you were supposed to in the past it will be fine. I wound up having to put rotella T 15-40 in my jeep to get me off the trail a few years back. That stuff will clean all the crap and sludge regular oil won't touch. I wound up leaving it in the jeep and have been using it ever since. I run the 10-30 visc in the winter and 5-40synthetic when I can afford it in the summer. Changing to synthetic will not harm your engine, synthetic oil will not cause oil leaks either, it just magnifies any leaks you already have. Putting synthetic oil in an engine with an oil leak is stupid, put cheap oil in it until you can fix the leak

Not entirely accurate, todays synthetics include esther which will eventually sweell the seal by replacing the natural oils in the seal and giving it its shape back if it isnt to worn away.

royal purple to my knowledge was a racing lube and had friciton modifiers in it, NOT GOOD FOR STREET MOTORS TO RUN FRICTION MODIFIERS. FM's cause alot of wear by having a unequal amount of larger sized molecules flowing around shear areas...do not use race oil in a streedt motor, your not doing yourself any favors

[MC]

Royal Purple full synthetic and never looked back. i heard that inorder for an engine to properly " adjust" to a full synthetic you need to run a semi-synthetic first so i ran quaker 4x4 oil in it and that was good too, but my comanche knocks to shit anyways and nothing stopped that.

Not true either, a synthetic oil only leaks for the first couple of oil changes and you do not need to break in any engine to run synthetic. Due to the additive (which is neutral) Esther, the seal will swell if not broken down too bad

[Mo]