• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Bennies of synthetic oil...

red91

red91

NAXJA Forum User
Location
exact location unknown
Just turned 100k on my 91. When I changed the Valve cover gasket, oil filter adapter rings, and my oil pan gasket ( what fun, its like Disneyland for Adults ) I noticed no biuld up of crap like you'd normally seem with, oh say PENZOIL ! At this point would it be ok to put in synthetic ? Heard that in older motors that havent used it it might loosen up and crap in there and cause problems. I currently have no oil / colling related problems and would like to know what the concensus is....

thanks in advance...
 
As long as you replaced all those gaskets you will be fine. The only reason you shouldn't put synthetic in an older motor is because it will clean up the gaskets, removing gunk that was otherwise plugging a hole.


BTW - Pennzoil is a very good oil, those who think it sludges up an engine don't have a clue what they're talking about...
 
ZmOz said:
BTW - Pennzoil is a very good oil, those who think it sludges up an engine don't have a clue what they're talking about...
Click to expand...
You know, I think you're only the second person (besides myself) that I've seen on here that actually LIKES Pennzoil...

Rob
 
Rob Mayercik said:
You know, I think you're only the second person (besides myself) that I've seen on here that actually LIKES Pennzoil...

Rob
Click to expand...

It's bizzare guys. When we get cars here at work and they have a bad motor and it gets torn apart. There is ALWAYS a huge amount of sludge followed by the 3-4 qrts of empty penzoil containers in the back. It could be that they don't change oil, but I NEVER see this with Castrol...
 
Take a look around this forum, and search for Pennzoil:
http://theoildrop.server101.com/cgi/ultimatebb.cgi
You will find very good oil analysis results - SCIENTIFIC PROOF that Pennzoil is good oil. Maybe in the '70s it was bad, (I believe that's where the myth started) but that is most certainly not the case anymore.


And for the original poster - I forgot to mention, if you switch to synthetic change the oil the first time sooner than usual, because it will clean out all the crap that is stuck in your motor.
 
Last edited:
red91inWA a.k.a. scott f. said:
Just turned 100k on my 91. When I changed the Valve cover gasket, oil filter adapter rings, and my oil pan gasket ( what fun, its like Disneyland for Adults ) I noticed no biuld up of crap like you'd normally seem with, oh say PENZOIL ! At this point would it be ok to put in synthetic ? Heard that in older motors that havent used it it might loosen up and crap in there and cause problems. I currently have no oil / colling related problems and would like to know what the concensus is....

thanks in advance...
Click to expand...

When you change it the first few times keep an eye on the color. Any sludge that is in there WILL get cleaned out and end up in the oil filter. When you cannot read the hash marks on the dipstick change the filter and add a quart. When the filter gets plugged a bypass cuts in and bypasses the filter so keep a clean filter on there. I run mobil-1 and have been for the last 190,000mi on my 98XJ, Mobil-1 in our 97 Oldsmobile that has a rebuilt jasper engine after the cooling system failed warping the heads, both our 2.5L 97TJ's are also running Mobil-1 and those TJ's had a tad over 125,000mi when we bought them, no leaks either.
When we pulled the Oldsmobiles bad motor to remove the valve covers and such the inside of that motor was immaculate but that one had been run since day one on Mobil-1....
 
Well now this is getting me worried. I've been using fully synthetic Pennzoil ever since I've got my engine rebuilt! (about 20k on her now)
 
Worried about what ??? Penzoil synthetic, provided it is 100% syn should be OK, I just have preference for Mobil...
 
FWIW.... I used Mobil 1 in my 94 Dakota from 20k miles to 115k miles when I sold it last month. When I pulled the intake to do the plenum it was beautiful inside. Don't worry about it, you will be fine! My thought Full Synth is full synth is full synth. I do plan to switch my 75k mile 98 Classic over to Mobil 1 on the next change.

:peace:

Travis
 
RichP said:
When you change it the first few times keep an eye on the color. Any sludge that is in there WILL get cleaned out and end up in the oil filter. When you cannot read the hash marks on the dipstick change the filter and add a quart. When the filter gets plugged a bypass cuts in and bypasses the filter so keep a clean filter on there. I run mobil-1 and have been for the last 190,000mi on my 98XJ, Mobil-1 in our 97 Oldsmobile that has a rebuilt jasper engine after the cooling system failed warping the heads, both our 2.5L 97TJ's are also running Mobil-1 and those TJ's had a tad over 125,000mi when we bought them, no leaks either.
When we pulled the Oldsmobiles bad motor to remove the valve covers and such the inside of that motor was immaculate but that one had been run since day one on Mobil-1....
Click to expand...

Do you run synth in your gear box or diffs?
 
red91inWA a.k.a. scott f. said:
Do you run synth in your gear box or diffs?
Click to expand...

I ran total synthetic Mobil-1 in everything till last week when the auburn went in. Auburn does not recommend synthetic lube for their rears. I run mobil-1 atf in the TC and mobil-1 gear oil in my AX15 even though it's not recommended. Still have mobil-1 in the front diff and use mobil-1 grease throughout the lube points.
Page two of my auburn manual says 'high quality non-synthetic 80W90 hypoid oils treated with GM or Ford Friction additives 3oz per quart of oil.

Ford part number C8A219B546A
Gm part number 1052358'

Which to me is pretty explicit....
 
well I'm not useing it currently, figured to star with the motor first. If / when I do the axles, should I also loook for the same as the engine. Getting dirty and changing it? or should I really even bother?

Primary benefit of changing it in the engine?
 
Runs cooler, less friction, much easier starts in the winter, less wear on moving parts. A few years ago Carnegie Mellon did a study with some ford Pintos or escorts and ran the snot out of them with about 8 different brands of oil. At that time mobil was pretty much the only game in town. When they disassembled them for measureing [they measured them before the test] there was NO measureable wear on the synthetic motors, NONE. No sludge build up and the engines looked like they were new inside.
 
red91inWA a.k.a. scott f. said:
Weight differences? Which do you use?
Click to expand...

10W30 in the engine though I did put 5W30 in this past winter for one cycle with no noticeable change so I went back to 10W30.
Mobil-1 ATF in the transfer case
Mobil-1 75W90 in the tranny and both diffs the rear diff has Kendall I think I saw on the 50gallon drum.
If you do change your diffs you might want to spend an extra 20 min, pop the axles out, pull the seals on the end of the axle shafts, smack in two new ones and put the axles back. Now that I helped do that I found out it's easy, you just need someone to push in on the end of the axle, or have lowland gorilla blood with the corresponding long arms, to get the C clips out and they fall into your hand. If the seals are at all worn the synthetic will go right thru them and lube your brake shoes, not a good thing.
I also use Mobil-1 grease on all my fittings and Mobil makes a spray oil in a can that I picked up, I use that on linkages around the tranny and TC. Need to find another source of the stuff, the store that carried it last year no longer does, It's not like a lithum based spray either.
 
You should break in the new engine with regular dino (petroleum motor oil) so that the rings will seat (0-15000). After that go to syn...forever
 
I've got 250,000+miles on my penzoil motor. still running like a champ.
redline 75w90ns in my ax-15, mobil-1 atf in the T/C, kendall in the axles.
 
I used to run Castrol Syntec 5w-50 in all three of the Jeeps. When I got my XJ it had been kinda abused and neglected. I took of the valve cover and scraped a ton of ash and deposits off it. The whole valve train was covered in sludge too. After the rebuild and running Syntec and now Mobil 1 my rocker arms are still shiney and there's no build up to be found 35k later. Dino oil is nice and cheap but the syn stuff is great. I still change out at 3k and I hear you can run the stuff for at least twice that but I like clean oil. :greensmok

Hey while were discussing it, I'm down if FL so it's not too cold (20 is about as low as it's ever got) but it's very warm in the summer. Now I'm running Mobil 1 10w30. Any benefit to going to another weight? I'd like to run the same oil in all 3 too, keeps it simple because sometimes I can be a :dunce:
 
You must log in or register to reply here.

Similar threads

C
New Jeep...new problems!
Replies
0
Views
286
CheapJerokee
C
C
New Jeep...new problems!
2 3
Replies
44
Views
3K
CheapJerokee
C
2
Steam around O2 sensor, engine whistle and a Cat-related engine code
Replies
5
Views
1K
89Mock
89Mock
M
Oil Pump Issues on 1990 XJ
Replies
2
Views
438
RCP Phx
R
G
Part number or source for Oil filter mount 1999 4.0 HO
Replies
7
Views
1K
Johnnie Walker
Johnnie Walker
Back
Top