Another oil question.. 5-40 not many selections

[candymancan]

Its winter now and with the cold temps ny engine is chattering on startup. Right now i have 10-30 synthetic blend in it but with a bottle of STP for the added zinc and thickening combo.. My oil pressute on hot idle is 10-15 psi with a 30 weight oil and if i use 40 its more around 25 psi.

With the stp bottle the winter viscosity of 10 is probably like 15 or more who knows and the engine isnt liking this with temps in the 20-30s.

So i want to try a 5-40 oil straight up. But i cant find any.. All i can find are 5-30s and the only 5-40 i saw was the t6 rotella. But it isnt SN or SM certified anymore and i also read it uses magnesium for a cleaner and not much calcium.. Gasoline engines need calcium to neutralizs acids.. So i dont think i want to use the t6 stuff that everyone swares by.. If i want more ZINC ill just use rislones ZDDP.

So i checked walmart but i havent gone to vatozone and advanced yet.. Do they even make 5-40 gasoline oils ? Or am i stuck with 10-40 ( dont think i even saw 10-40 either) or 5-30 10-30

[nograin]

T6 was reformulated about a year ago. I was only using the 5W-40 because my old engine was really worn. With the fresh engine I'm back to 30 wt oils.
If you're getting 15 psi hot with a 30, that's fine as long as it climbs with the rpms. At highway speeds it will level off somewhere between 50 and 70 psi depending on the bearings and oil temperature.

IIRC Mobile and some others have (had?) 5W-40. Whether they too only have the Diesel rating now, I don't know.
The grades are a ball park indicator of viscosity, but you can search out the spec sheets from most manufacturers for the specific oil's viscosity. You might do fine with a 0W-30 or 5W-30 synthetic that has a good high temperature viscosity. I may have some graphs.

[440sixpack]

It doesn't matter what the certifications are the only oils made today for your engine are specialty ones like Joe Gibbs or Brad Penn. I run only Brad Penn in flat tappet engines myself.

Your engine was made to run 10-30 or 10-40 so why not use it. 10-15 lbs at idle works.

[nograin]

T6 was reformulated about a year ago. I was only using the 5W-40 because my old engine was really worn. With the fresh engine I'm back to 30 wt oils.
If you're getting 15 psi hot with a 30, that's fine as long as it climbs with the rpms. At highway speeds it will level off somewhere between 50 and 70 psi depending on the bearings and oil temperature.

The grades are a ball park indicator of viscosity, but you can search out the spec sheets from most manufacturers for the specific oil's viscosity. You might do fine with a 0W-30 or 5W-30 synthetic that has a good high temperature viscosity. I may have some graphs.

IIRC Mobile and some others have (had?) 5W-40. Whether they too only have the Diesel rating now, I don't know. Amsoil, Scheaffer are a couple of others to google. With a stock cam and valve train, shouldn't need anything crazy in terms of zinc/phos. 900 - 1200 ppm is probably fine. Too much is definately bad. IIRC that 1400 or 1500 and up. A little moly is nice too if your looking for proven anti-wear components.

[candymancan]

Oil oressure is at 50-60 when i drive the second i tap on gas itll shoot up to that. and about 30-40 when in park with that higher idle.

[Stuka]

If it’s tapping only at startup and it’s being driven regularly, it’s most likely your oil filter’s anti-drain back valve not working. What filter are you using? May also want to skip out on the thicken additive and just use an oil with zinc added.

[nograin]

Here's some graphs:
Start up, warm up and operating temperatures. This viscosities here came from the manufacturer spec sheets.
Viscosities are ridiculously high until the engine is warmed up. Pressure at the pump will be high but the volume will not be flowing well because its thick. Also a bunch will be going out the bypass valve and into the pan.
For really cold starting temperatures, also check the Pour Point.

Viscosityfromminus20C.png

The next one is viscosity around the operating temperature. These are general SAE viscosities for the oil grades in the '85 service manual.
If the assumes oil temperature was 200- 212*F it looks like the target viscosity was 10 to 15 centiStokes.
If an engine is hot running (say pulling a load for hours) it will need the 40 wt to get the same viscosity as an engine with oil temperatures in the 200 to 212 F range.

Jeep-Viscosity-140-284F-blank.jpg

[candymancan]

If it’s tapping only at startup and it’s being driven regularly, it’s most likely your oil filter’s anti-drain back valve not working. What filter are you using? May also want to skip out on the thicken additive and just use an oil with zinc added.

Using a Nappa gold classic. i drive it daily. Besides driving my 5.9 zj to work. my wagoneer is my daily. The noise didnt start until it started getting to the 30s-40s out. which is why i think its too thick with the stp in it.

Main reason i used stp was because ive been using the rislone oil suppliment which is a engine cleaner. Not quite as harsh as a flush like motor medic but still a cleaner and its very watery so i used stp to thicken the oil back up. But i think its way too thick on cold startups..

like he said abive oil pressure builds up but flow sucks.. Which is why i was thinking of doing 5-40. It just sucks there is no 5-40 besides diesel oil at least from what ive seen in person.

This is the 2nd time ive used the cleaner in my engine. Also used motor medic before i drained it last time. Reason is because when i had my valve cover off i had a little sludge i could scoop with my fingers in some spots. Oil pan had some on the bottom too.

But i think Ill flush it with motor nedic one last time. Then i guess ill try some 5-30 since i cant find 5-40.. And maybe out in rislone ZDDP

[Stuka]

Ah ok, I think you are on the right path. Good filter, so it isn’t the issue (unless it is plugged).

5-30 is pretty thin for an AMC V8, and 20’s aren’t that low. How does it act with 10-30 without the thickener?

[candymancan]

10-30 Well last year when i used 10-30 it didnt chatter really. This is the first time ive heard it. I just figured since i read the viscosity difference on startup in temps between 5-10 is better i would look for 5-40. That and 30-40 the engine has better hot oil pressure with 40 then 30. Not sure im comfortable seeing the needle on the last line at 10-15 psi with the 30 vs 20-25 using a 40

I've had the pan off and took 3 bearing caps off on 7-8 and 6 i believe, along with the main bearing when i did the real main seal, and the rod bearings looked brand new had no wear at all, still silverish/cloudy color and the crank i couldnt feel scratchs on it with my nail. It looked a bit scratched though but i figured that looked normal. I dunno, lemme find the picture i took earlier thsi year and you tell me if the crank looks bad or good. I took pics of the bearings but my phone had issues in the past and used to take pics but they didnt show up. Kinda pissed at that.

But they looked brand new i have new bearings and there was no wear on the old ones.

[SJTD]

Wow, you've got a real chemical soup going. If that cleaner is doing anything maybe just changing the filter will help.

I'm using Mobil 1 TDT in my 4.2 CJ since rebuilding it based on the following:

I've got two '98 Diesels. VW with over 350k, most of that using Mobil 1 TDT, that looks like new inside and a Dodge with 200k on Valvoline Premium Blue 15-40. It had a thin black film on the inside of the valve cover that could be wiped away. No sludge.

My conclusion was that "C" oils are pretty good at keeping the engine clean.

I've switched to M1 on the Dodge to see if it removes the film.

[Stuka]

Wow, you've got a real chemical soup going. If that cleaner is doing anything maybe just changing the filter will help.

I'm using Mobil 1 TDT in my 4.2 CJ since rebuilding it based on the following:

I've got two '98 Diesels. VW with over 350k, most of that using Mobil 1 TDT, that looks like new inside and a Dodge with 200k on Valvoline Premium Blue 15-40. It had a thin black film on the inside of the valve cover that could be wiped away. No sludge.

My conclusion was that "C" oils are pretty good at keeping the engine clean.

I've switched to M1 on the Dodge to see if it removes the film.

Unless Mobile 1 TDT has both C and S specifications, I would NOT use it in a gas engine. Without the S designation, it lacks additives to deal with gasoline combustion byproducts, and may not have enough anti-foaming additives, as gasoline engines typically run at much higher RPM than a diesel engine.

This is from Amsoil:

Pay attention to oil specifications

The American Petroleum Institute (API) publishes its “C” category of specification for diesel oil (currently CJ-4) and its “S” category for gasoline motor oil (currently SN). It’s common for today’s diesel engine oils to carry both the API CJ-4 and API SN specifications. Though they’re truly designed for diesel applications, they can be used in gasoline applications for motorists who want to use one oil in all applications. If the diesel oil carries both specs, the oil is safe to use in diesel and gasoline applications. If the diesel oil does not carry the “S” category, AMSOIL strongly recommends against using it in gasoline applications.

[SJTD]

I thought the main difference was the S oils were eliminating some of the additives like ZDDP which killed the cats on gas engines which is another reason I was running it in a old flat tappet motor.

Maybe a moot point now that Diesels have cats and is why they can have the S rating too.

Anyhoo, I checked and M1TDT meets SN.

[Stuka]

Anyhoo, I checked and M1TDT meets SN.

Good to go then

[candymancan]

I thought the main difference was the S oils were eliminating some of the additives like ZDDP which killed the cats on gas engines which is another reason I was running it in a old flat tappet motor.

Maybe a moot point now that Diesels have cats and is why they can have the S rating too.

Anyhoo, I checked and M1TDT meets SN.

Well i read the T6 shell oil lacks calcium and has more magnesium which is for diesels for like the soot or something. and calcium is for the acids gasoline causes. If thats true thrn people who have veen using t6 are only doing more harm then good imo.

Yea when i first got my wagoneer i was joking with my friend that i was Juicing it lol.. I poured stop leak in the transmission. power steering. engine ect because it leaked badly from all 3 spots.. which i fixed with new gaskets this year thank god it doesnt leak anymore lol Ill agree using stp and rislone engine cleaner at once us a lot but it hasnt had negative affects in summer and i wanted to clean this engine up. Onky thing i could do myself was clean the sludge on the oil pan and half of the pickup tube was covered in almost like a rock like substance thr old cork gasket turned into. Then clean uo the sludge in the valve covers.

cant reach anywhere else so i did flushes and rislone ect. Going to be taking the intake manifold off next year to address the coolant leaks from two rear bolts and oil leaks out if the rear gasket.

Anyway ima go oil shopping right now and see what i can find.


Btw how did my crank look ? bad good ?

[candymancan]

well i still voyldnt find any 5-40.. But i did find mobile one 0-40 for foreign cars lol.

I got that ima try it. See what happens.. Its pretty thin at 0 but well see what happens

[Stuka]

Btw how did my crank look ? bad good ?

Definitely has wear on it, hard to say how much from just a photo. Did it have any ridges that you could feel?

Any idea how many miles are on it?

[nograin]

A good 5W-30 is no thinner than a a typical 10W-30 at operating temperature. That can be seen in the second viscosity graph I posted above.
At cold start up - All oil is many times thicker than at operating temperature. That can be seen in the first graph I posted.

Bearings - can't help help you on the deep scratches. I'd be questioning that too. If you check again, get some plastigage. That will tell you the bearing clearances - and that's what will determine the need for higher viscosity.

Personally, I wouldn't keep dumping cleaners and thickners in. Let the detergents in your oil clean it up a little bit each time you change the oil.

Calcium is usual an indicator of detergent https://www.blackstone-labs.com/underst ... diesel.php

15 psi at idle isn't bad. 10 psi woul worry me too. I think 30 is high. BUT. The FSJ sending unit is right at the oil pump.
In any event the damage is going to be under load. So to really answer the question you need to know temperature, rpm as well as pressure.

Barring that, and if your set against 30 weights then for easier starting look at the synthetic 5W-40 and 10W-40 with low pour points.

Here's one of kendall's thats CK, Ck, CI and SN
https://s3.amazonaws.com/phillips-prod/ ... 1508336303

Rather different than Castrols GT1 TDT https://msdspds.castrol.com/bpglis/Fusi ... 9VX5VU.pdf

here's Shaeffer's http://www.schaefferoil.com/documents/244-9000-td.pdf

If you want to put those viscosities into a graph like I did in my earlier post:
http://www.widman.biz/English/Calculators/Graph.html
A real good overview of oils is the pdf on his corvair site
http://www.widman.biz/Corvair/English/Links/Oil.html

[candymancan]

Btw how did my crank look ? bad good ?

Definitely has wear on it, hard to say how much from just a photo. Did it have any ridges that you could feel?

Any idea how many miles are on it?

125k. No ridges felt with my finger nails. was pretty smooth.. And the bearing had 0 wear on em like i said smooth a silvery

[candymancan]

Also yea ive done 10-30 many times i just dont like the 10 psi i see when its hot. And a 40 makes it show 20.

Anyway i decided to buy that 0-40 from mobile 1 and a new oil filter. Drained it and refilled it and put in a bittle of ZDDP and oil pressure seems fine with it. drove it around for 40 min and hot is still 50 psi driving and 20 at idle in gear. and 30 idle in park.

Well see tomorrow when i cold start it how it sounds.

As for crank yea i thought those looked like scratches but i couldnt feel them by touch or with my nails and the bearings themselves looked brand new i was suprised. and i know the oik pan has never been off due to the hardended cork and sludge in the pan.

If its any evidence of the work ive done to the body of the vehicle inside and out. the engine was never taken care of either. When i first got it. it had a rusting fram filter on it.. Which tells me the oil wasntnchanged in years probably

Geeze 2 years almost time flies lol