Be interesting to see how how has changed when they went from WD to ML....and I'm done hijacking!

 

Alright so changed my oil to T6 5w-40 with a six filter. and just replaced my sending unit again. And same issue. Maybe a hair better at idle, but 65 at 1500-2000rpm is at 20-25 oil pressure. Unless told otherwise I guess I will just run it till it dies? It does seem to be ticking more at higher rpms, but fairly quiet at idle. I would like to do more research on replacing the pump, everyone still agree it won’t do me any good?

FYI thanks for hijacking the thread, i got some good info out of it 👍🏼

 

Hey one last thing I don't think anyone mentioned and may be worth a shot trying to get the oil pressure reading higher is try and clean out the fitting the oil pressure sensor screws into with some pipe cleaners,zip ties or just rigging a hose and fitting up running it to a bucket and let it spit oil out for a few seconds.

here is the link on that. https://www.jeepforum.com/forum/f19/...fixed-1304679/

 

I would like to buy Rotella T6 5W-40 or 15W-40 for my 87 4.0 XJ.
As the PSI are low.

BUT we can't find it in Europe. As far as I can say.

Any alternative that would be as good ?
Or specifications I must track to find a similar oil ?

I live in Paris and drive to Corsica and Spain one a year (about 3000 Km to Spain)
5W-40 or 15W-40 or ?

 

I would think any good diesel oil would be a good option. I'd stay with 5w-40 if you can because 15w-40 gets like molasses in cold temperatures. I'm aware it snows sometimes in Paris. Rotella is quite expensive at $30 USD per gallon. Most diesel oils contain high levels of ZDDP (zinc) which is good for flat tappet engines and modern engines are using roller tappets more than flat ones today. Diesel oils are designed for heavy loads at high temperatures. Valvoline Maxlife High Mileage contains around 600 ppm zinc and is much cheaper than Rotella. I'm thinking 10w-40 would work using that. At one time I worked for Ashland oil and I know Valvoline is available worldwide. They sponsor racing teams in every motor sport in the world!

Valvoline has raised many questions now that they've started selling re-refined oil in some products. The chemistry is the same because it's purified by the cracking towers just like raw crude and is actually cheaper to produce since it's already been refined once. These product have the same additive package as new oils do anyway. BTW, this has been done for many years by many oil companies, but is now being used as a "green" marketing strategy.

Replacing the pump will help, but only slightly by reducing the clearances inside the pump, but it's not going to raise the pressure much because of worn bearings. I WILL say that a high volume pump is a waste of money. An oil cooler will do more to raise hot idle pressure than anything else. You can buy a bypass plate that sandwiches between the filter and adapter and uses 2 hoses to attach to a cooler.

 

600 ppm Zinc content isn't very much, a good diesel oil will have over 1200 ppm.

 

I have a new to me 1998 jeep Cherokee 190,000 and I've recently been noticing similar issues with fluctuating oil pressures. I started snooping around and have a few questions. My xj seems to have the oil filter attached straight to the block, but every video I look up shows them with the filter running off the adapter, and the oil pressure sending unit on top of said adapter. My oil pressure sending unit is towards the back of the engine block? Now it's always leaked oil, no new spots/increase in leaks.
Now cold start I have 40-50 pressure showing on the gauge, and after it warms up, it will drop to as low as 15 at a stop light. When light goes green I go back up to around 40 on the gauge. I'd like to change the sending unit at the same time as checking the pressure with a gauge. Anything else I should take into consideration? I'm new to jeeps, but I have low funds and one car for my family. I know the pump would be a serious job since it isn't lifted, and I need it for work so I'm willing to do what it takes.
I should point out that before the recent changes, I always registered around 20 on the gauges, and I recently changed the breather and ccv valve as I was planning on replacing the valve cover gasket to fix one of the oil leaks. Could this have any effect on the pressure reading? The other day we were breaking the stay at home order as a family and while waiting in park, the engine fan kicked on and the jeep made a loud whining noise and I noticed on the oil gauge had dropped to +/- 10. The whining continued for about 10 seconds and gave the family quite the scare. Not sure if those 2 are related.