Your Oil Recomendation

bgred2 said:
My 1989 MJ with a 4.0 has 95,000 miles on it. I am a little afraid of starting to use synthetic oil at this point for fear developing oil leaks. What would be the best NON-synthetic to use?

Try it and if it does leak, switch back!! :wave1:

:cheers:
 
crystalship1 said:
Try it and if it does leak, switch back!! :wave1:

:cheers:

ROFL.. the biggest reason why leaks start to develop after switching is the amount of detergents in synthetic oil vs conventional. It "cleans" all the crud around your seals etc keeping your engine from leaking oil. MY OPINION is that its a good time to replace those seals and run leak free with synthetic. (as i do now). If your too lazy (and again the "lazy" comment is my opinion) to replace the old ass seals in your Jeep then stick to conventional oil. If you go to synthetic and leaks develop, they will still be there after switching back. At that point its best to just stick to synthetic since you are now forced to replace all your old crappy seals anyway.
 
I've started to use Mobil Delvac 1300 Super 15W-40, which contains a higher level of ZDDP. I just installed a larger Mobil M1 oil filter with an oil filter relocation kit. The Delvac is under $9 per gallon at Wal-Mart.
 
xjohnnyc said:
I've started to use Mobil Delvac 1300 Super 15W-40, which contains a higher level of ZDDP. I just installed a larger Mobil M1 oil filter with an oil filter relocation kit. The Delvac is under $9 per gallon at Wal-Mart.

You warm weather pukes get away with murder too out there, 15W dino will about test the limits of your battery and starter out here in the north east winters....
 
:D It was a beautiful 75 degrees today.
 
RichP said:
You warm weather pukes get away with murder too out there, 15W dino will about test the limits of your battery and starter out here in the north east winters....

I hear you, not only that but you Americans drive me crazy with your $9 gallons. Mobil 1 high mileage is on sale up here right now for $38 per gallon! Regular price is $48 per gallon!!! No justice I say. But I love you guys.
 
Well I put in Mobil 1 High Mileage 10w40 and a mopar filter today. Still got the lifter or something clicking but ive only driven like 15 miles so i didnt expect anything to happen yet, may never go away when cold. Oil pressure stays around 45-55 at idle, higher than before. Im just knockin on wood that it doesnt start leaking, didnt have any before but front and back of the oil pan were lightly oil covered before filling.
 
Keep in mind the injectors also click.
 
Ya I will check back on this thread in every few weeks for a while, however the engine will only run better when spring rolls around but then again leaks are more prone due to warmth maybe.
 
Muad'Dib said:
ROFL.. the biggest reason why leaks start to develop after switching is the amount of detergents in synthetic oil vs conventional. It "cleans" all the crud around your seals etc keeping your engine from leaking oil. MY OPINION is that its a good time to replace those seals and run leak free with synthetic. (as i do now). If your too lazy (and again the "lazy" comment is my opinion) to replace the old ass seals in your Jeep then stick to conventional oil. If you go to synthetic and leaks develop, they will still be there after switching back. At that point its best to just stick to synthetic since you are now forced to replace all your old crappy seals anyway.

Nahh.... Myth!!! :laugh:

[FONT=Arial, Helvetica, sans-serif]Myth #2 debunked[/FONT]
[FONT=Arial, Helvetica, sans-serif]Synthetic oil causing oil leaks is another commonly spread myth. The truth of the matter is that if all your engine seals and gaskets are in good condition, synthetic oil will NOT leak in your engine. The myth started because on occasion, an engine will leak with synthetic oil, but not dino oil. The reason for this is that the smaller molecules of the synthetic are able to get past very small crevices, where the larger molecules of dino oil cannot. But this does not mean that the synthetic oil has caused the leak, it simply has "discovered" an infant leak, and regardless of what oil you are running, this infant leak will eventually grow to a size that will allow dino oil to occupy and pass also. Synthetic oil has not been shown to deteriorate engine seals or gaskets. It is not some evil solvent that will break down sealant, or anything like that. Like was said earlier, it is just a man-made base stock, that is uniform and smaller in molecule size than dino oil. Nothing more, nothing less.[/FONT][FONT=Arial, Helvetica, sans-serif]
[/FONT]
[FONT=Arial, Helvetica, sans-serif]From: http://aircooled.net/gnrlsite/resource/articles/synthoil.htm[/FONT]

[FONT=Arial, Helvetica, sans-serif]:cheers: [/FONT][FONT=Arial, Helvetica, sans-serif]
[/FONT]
 
OK Crystal, I will give you that synthetic oil does not CAUSE oil leaks. But if it tends to CREATE puddles of oil under your 20 year old Jeep, can we at least call it an EFFECT?

I don't think anyone is saying synthetic oil is bad stuff. It's just that some us want what is best for our Jeeps without spending our lives changing seals.
 
Wow, anyone tried that ZDDP Plus stuff on Ebay? Looks pretty concentrated....

Or is it just snake oil? I guess you'd have to check your UOA after using it huh?
 
bgred2 said:
OK Crystal, I will give you that synthetic oil does not CAUSE oil leaks. But if it tends to CREATE puddles of oil under your 20 year old Jeep, can we at least call it an EFFECT?

I don't think anyone is saying synthetic oil is bad stuff. It's just that some us want what is best for our Jeeps without spending our lives changing seals.

As I stated before, Try synthetic and if it leaks, switch back to dino.. Since the root cause for the leaking is the size of the molecule and not some kind of attack on the seals, no one need change seals if they don't wish to. :peace:

Here... this guy gave synthetic a try and had leaking problems. He switched back to dino. rather than replace seals and that was that. :

http://www.jeepforum.com/forum/showpost.php?p=4825979&postcount=6

:cheers:
 
Last edited:
crystalship1 said:
Nahh.... Myth!!! :laugh:

[FONT=Arial, Helvetica, sans-serif]Myth #2 debunked[/FONT]
[FONT=Arial, Helvetica, sans-serif]Synthetic oil causing oil leaks is another commonly spread myth. The truth of the matter is that if all your engine seals and gaskets are in good condition, synthetic oil will NOT leak in your engine. The myth started because on occasion, an engine will leak with synthetic oil, but not dino oil. The reason for this is that the smaller molecules of the synthetic are able to get past very small crevices, where the larger molecules of dino oil cannot. But this does not mean that the synthetic oil has caused the leak, it simply has "discovered" an infant leak, and regardless of what oil you are running, this infant leak will eventually grow to a size that will allow dino oil to occupy and pass also. Synthetic oil has not been shown to deteriorate engine seals or gaskets. It is not some evil solvent that will break down sealant, or anything like that. Like was said earlier, it is just a man-made base stock, that is uniform and smaller in molecule size than dino oil. Nothing more, nothing less.[/FONT][FONT=Arial, Helvetica, sans-serif]
[/FONT]
[FONT=Arial, Helvetica, sans-serif]From: http://aircooled.net/gnrlsite/resource/articles/synthoil.htm[/FONT]

[FONT=Arial, Helvetica, sans-serif]:cheers: [/FONT][FONT=Arial, Helvetica, sans-serif]
[/FONT]


Umm..... that's exactly what he posted. You just linked an article. His post was in regards to an earlier post stating that the person didn't use synthetics becuase they cause leaks.....
 
Stumpalump said:
I just called Mobil on behalf of NAXJA. It got me to the top that way. I told the engineer what we do,what engine we use and our concerned about our flat tappet cams. He was very clear and consise on recomendations for us and this is what I got from him with a backing from his team members: ZDDP levels are highest in these 4 oils:

15W-50 extended drain 1300-1400 ppm ZDDP. best oil and their 1st choice.

15W-50 regular mobil 1 Thats the good old stuff they brought back with the red top and has same ZDDP.

Turbo 5-40 but only if you are constantly below zero. He said use 15W50 for me in Colorado winters.

Moble delvac 15w40 is also above 1000 ppm ZDDP and will work.

Anything else will have less than 1000 ppm ZDDP and is not recomended by them!

I have a similar call into Royal Purple and left a detailed message as to what they have and recomend for us. I'll post up when they call back. Mobil 1 is nice because you get it at walmart but remember to look for the red cap 15W50 or 15W50 extended drain unless you are in a frozen below zero climate and then use the turbo 5W40.
Use the oil that Mobil recomended to us. If you insist on thin then add a few quarts of turbo to the Extended Performance to thin it or run straight turbo oil. Those are the only (and they were very specific) 4 oils they said were OK to use in our Jeep engines. They insisted that I run the 15W50 in Colorado winters. All sythetics flow well. They perfected synthetics for the Alaskan pipeline workers so they could start cold trucks and still have protection when they got hot. Smoky Yunic the famous Indy car engine builder said in the 60"s " even at $25 bucks a quart synthetic is a bargan."
Synthetic oil leaks more period! Everthing I ever put it in developed a seep or slight leak. It's worth it. The synthetic is smaller particles and creep out. It also contains more detergents so you can use it longer. If you put it in an old neglegted fithy sludged up moter then you may lossen sludge that was holding some oil in. Butyl rubber is effeted by synthetics. It swells and softens the rubber. Most engines have no butyl rubber but my rubicon front air locked axel did. It swelled the internal air line and it poped off. I switched to vacume line but maybe some engines in the past used that kind of rubber in gaskets and they had big problems like I had.
 
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