Oil Question

[vrtillman]

I just want to know what I should expect here. When I bought my 98 it came with a stack of receipts. I'm just now going through them for something unrelated (he said the trans was rebuild within the last 2 years and its leaking like Exxon Valdez), but I'm also noticing that the shops he went to used oil weights from all over the spectrum in this 4.0.
So far I count 10W-30, 10W-40, 20W-50 and 0W-50 that he had records for. Other than a rear main seal I cant seem to get to seal up, I haven't noticed any other issues (i.e. flakes in the oil) and I get blackstone reports.

I guess my question is should I be worried?

 

[fourpointzero]

Probably nothing to worry about, if its running fine. 4.0 is a very resilient engine.

I highly suggest going with the manufacturers suggested oil @10w-30 You can debate oil types all day and night with just about anyone on this forum, or any forum for that matter. Im at almost 200k and use Valvoline classic, aka regular.

 

[cliffish]

Probably nothing to worry about, if its running fine. 4.0 is a very resilient engine.

I highly suggest going with the manufacturers suggested oil @10w-30 You can debate oil types all day and night with just about anyone on this forum, or any forum for that matter. Im at almost 200k and use Valvoline classic, aka regular.

yes I use high mileage conventional oil, not synthetic.

 

[Chris]

I wouldn’t worry about the different weights of oil they used.

 

[JEEPCJTJ]

This:

... I get blackstone reports.

should give you the answer to this:

I guess my question is should I be worried?

All I can say is use 10W30 conventional oil, "high mileage" if you've got any leaks.

 

[ParadoxD]

Probably nothing to worry about, if its running fine. 4.0 is a very resilient engine.

I highly suggest going with the manufacturers suggested oil @10w-30 You can debate oil types all day and night with just about anyone on this forum, or any forum for that matter. Im at almost 200k and use Valvoline classic, aka regular.

Resilient is an understatement. I bought a '95 XJ a few years back for $500 (score!) and when I brought it home to do my normal post-purchase freshening, I found it was 3qt low on oil, a qt low on everything else, the spark plugs were worn down to a nub, and it had about half a dozen vacuum leaks.

I replaced all the fluids, plugs, and fixed all the leaks and you know what? It didn't make a damn bit of difference. The thing ran just the same.

I run the same 10w-40 Castrol GTX I run in my compressor, dirt bike, yard tools, etc. because I have a bunch of it on hand at any given moment.

 

[Jerry Bransford]

All I can say is use 10W30 conventional oil, "high mileage" if you've got any leaks.

X2, a High Mileage CONVENTIONAL 10W-30 is likely to cure the leak. Synthetic engine oils can cause leaks at seals by leaching out what makes the seals compliant and able to seal. Switching my BMW from its original Castrol synthetic to High Mileage Mobil Super (a conventional) cured its huge rear-main seal leak within a week of daily driving.

 

[JMT]

Resilient is an understatement. I bought a '95 XJ a few years back for $500 (score!) and when I brought it home to do my normal post-purchase freshening, I found it was 3qt low on oil, a qt low on everything else, the spark plugs were worn down to a nub, and it had about half a dozen vacuum leaks.

I replaced all the fluids, plugs, and fixed all the leaks and you know what? It didn't make a damn bit of difference. The thing ran just the same.

I can attest to that experience in two other 4.0's. It's the damndest thing.

 

[vrtillman]

Cool. Ya nothing on the blackstone to indicate abnormal wear, I just wanted to make sure that having 0 weight mixed with 10 weight wasn't serious, but ill look into the high mileage stuff for sure. currently addressing trans/transfer case leaks lol

 

[ExitLeft]

All I can say is use 10W30 conventional oil, "high mileage" if you've got any leaks.

If you can find it. I've been looking all over for conventional motor oil and can't find any. Nevermind conventional High Mileage. Everything is synthetic or synthetic blend. I ordered some Mobile 10w-30 High Mileage conventional oil from Jegs and it's been on backorder for the past 3 months. Ordered it from Amazon and got sent Mobile 1 synthetic (so I sent it back).

 

[fourpointzero]

I'll never forget when I got rid of my NV3550 manual trans, it barely had any fluid, yet it ran 72 miles to its destination before it was extracted for good. Yah, it shifted a bit hard, but it ran low for God knows how long.

 

[MountaineerTom]

If you can find it. I've been looking all over for conventional motor oil and can't find any. Nevermind conventional High Mileage. Everything is synthetic or synthetic blend. I ordered some Mobile 10w-30 High Mileage conventional oil from Jegs and it's been on backorder for the past 3 months. Ordered it from Amazon and got sent Mobile 1 synthetic (so I sent it back).

Ive been running Valvoline Maxlife 10-30 in mine for 5 years, which I believe is a blend. I had an oil pan gasket leak when I got it. After replacing the pan gasket, not leaks since.

If I could find it local, I’d run a full conventional high mileage.

 

[cliffish]

If you can find it. I've been looking all over for conventional motor oil and can't find any. Nevermind conventional High Mileage. Everything is synthetic or synthetic blend. I ordered some Mobile 10w-30 High Mileage conventional oil from Jegs and it's been on backorder for the past 3 months. Ordered it from Amazon and got sent Mobile 1 synthetic (so I sent it back).

https://www.amazon.com/dp/B01M2YU3FH/?tag=wranglerorg-20

 

[ExitLeft]

https://www.amazon.com/dp/B01M2YU3FH/?tag=wranglerorg-20

Ask ask and ye shall receive. Thank you, @cliffish

 

[cliffish]

Ask ask and ye shall receive. Thank you, @cliffish

price is a little steeper than I remember paying....but what isn't (trying to resist a political comment)

 

[5632]

price is a little steeper than I remember paying....but what isn't (trying to resist a political comment)

Do you remember hourly wages being lower? It is all relative.

 

[chuck47]

price is a little steeper than I remember paying....but what isn't (trying to resist a political comment)

Looking at the price history on amazon, you are absolutely right. Price had been hovering right around $18 for a couple of months and just shot up recently. Still less than my local auto store but very possible that the price will bounce back down in the coming weeks.

 

[Fishtaco]

Magnatec 10w-40 I am sold on it for winter! going 20w 50 for summer.

20w 50 is fine for a TX summer anyone who says its not is well still using 10w 30 and never tried it lol

Dont be worried the difference to a TJ 4.0 is miniscule unless you need a thicker oil for wear or heat and that is where you notice the difference in a positive way!

Lucky you dont live in Australia! anyone without a high performance engine gets 15w40 Diesel oil from a 50 gallon drum.