Thanks for all the advice guys, I ended up going with Mobil 1 Full Synthetic High Mileage Formula. I always make sure to change the oil at regular intervals, just to be sure. I used to work at a shop doing oil changes, and some customers would scare me with how long they would wait to have an oil change. One lady went 20 000kms and about 2 years without an oil change. Needless to say that oil was BLACK!

 

One guy on another thread recently was saying don't use synthetics in these magnums due to them having hydraulic lifters. Something about the synth fluid getting to thin and loud clackety noises starting in hot weather when pulling loads in the desert. Not my idea of fun.

 

I've been running Mobil 1 Synthetic since I rebuilt my engine and it is smooth as silk; therefore,

 

VW you need to change the name of that pic, DF doesnt like it.

 

Dont know about the other thread guy but when i bought my truck it had a knocl and ticking (reason for the rebuild). Having done 3 oil change's with amsoil full synthetic in the last year the knock has quieted down and the ticking is gone. Old man said its the synthetic cleaning everything out making it run smoother. I do know one thing when changing the first two the oil was black. The thirs wasnt as diirty so needless to say its helping this tired old engine.

 

Whatever dude. You're probably right and it never happened. It sounds as if your tech and logic is totally bullet proof though. Silk IS awfully smooth alrighty. I'm sold.

 

Mm that picture looks like the guy in your avatar.. I assume thats you ? Lol kinda funny. Anyway about the synthetic thing, i use a blend in the 4.0 and when i change the oil in my 5.9 i plan to put the same Valvoline blend in.

 

I'm saying his claiming Synthetic oil is incompatible with Magnum engines is a crock. There is something else going on and I bet he didn't even bother to perform a tear down to properly diagnose the issue.

It's like everyone on this board who claims running a 180º thermostat will make the engine run cooler. It's BS.

 

In case you were unaware of some of my posts on motor oils, I'd thought I'd share some information in attempt to help you choose the proper oil per application. Read on.

Synthetics are NOT designed to be run with hydraulic lifters and large tolerances in these vehicles for, these tolerances and clearances were designed / founded around the lubrication medium that they intended to be used which is DINO OIL- not synthetics. All the machined parts were, in part, spec'd around the material properties and performance of conventional (dino) motor oil.

It doesn't matter WHICH brand of synthetic you run either. I used to run AMSoil which is ten times the quality of M1, Penzoil, Valv and Castrol syths and, in every case regardless of brand, engines are coated with a nasty baked on crusty carbon deposit film that over time, flakes off and migrates into the lifter bore thus, either CLOGGING them or, JAMMING them up SOLID. When it jams up solid, one ends up with a bent push rod and, possibly a cracked, chipped or bent valve stem after the piston slams into the valve that's protruding.

The reason for debris is, there's no detergents in most synthetic oils and, over prolonged use, the engine becomes very dirty inside. This is just one of the issues with synthetic oils. The next issue associated with synths is what is known as oil thinning.

As synthetic motor oil heats up, it thins out more than conventional oil and weaps out of the lifters thus, lack of hydraulic pressure at startup and, in hotter weather, you can hear this more than during the winter months. Under hard use during summer months, the lifters can collapse due to oil thinning and loss of hydraulic pressure and, when you hear an occasional POP out the tailpipe or through the intake, that just may be due to a lifter collapsing.

Lifter clack at startup is the next issue. At night, the thinned /hot oil weeps out of the lifter and, upon startup, it makes a racket as if the top end of the engine were starved for oil.

With a high-quality dino-based motor oil such as Castrol GTX or Valvoline, this DOES NOT occur. It maintains lift / maintains pressure overnight so there's no lifter clack upon startup. When changing motor oil when hot, I've noted that synths are watery whereas, dino oil, it's much thicker. I've even run as high as 50 weight synthetic oil and, even at that weight, it still didn't work. I've tested 0-30, 5-30, 10-40 and 20-50 synths and, none of them worked nearly as good as 5-30 or 10-40 dino oil in my truck.

NOTE: lifter clack is not as noticeable (with synths) during the winter months

I've seen other engines that were torn down that had failures due to synthetics due to debris. Debris was everywhere and, it ended up clogging the oil passages thus starving bearing journals from oil.

I've seen another on this site report about just having a lifter go and, after asking him if he ran synthetics- the answer to that was YES. He was running M1. He tore the top down and found exactly what I had termed, Cajun BBQ Crust on everything down to inside the lifter to which is most likely - root cause for failure of a collapsed lifter.

Despite what anyone on this site tells you or claims about it being BS- it's not and, if I hadn't seen this many times on many different vehicles running hydraulic lifters, I'd probably think twice about what I was reading myself.

I've witnessed a brand new Vette motor (running M1 oil) that had lifter clack and suffered from lifter collapse at high rmp when jumping on it out in the So Cal heat.

WHY: the thermal loading on the oil induced oil thinning. This causes the oil to weap out of the lifters thus, full lift of the valve assy is not met. Under extreme conditions, the lifter would totally collapse (I've had this happen on my Dodge by the way)

The owner thought he'd blown a rod. We asked him which oil he was running and he told us it was OEM. OEM with Chevy is M1.

WHAT WAS DONE:

The problem was completely resolved by changing out that M1 synthetic material and replacing it with conventional motor oil (Valvoline SAE type). There was no mechanical problem. It was isolated to using synths in that application. It's not so much that the oil is bad- it's not and, that is not what I'm saying. It's just not suited for the application.

I do not recommend using ANY synths in your Dodge Magnum engine. It just doesn't work for the application properly and, over time, that engine is going to become so dirty and loaded with debris that, it's only a matter of time before some of it dislodges and takes out your lifters to which, you're looking at pulling the entire top end to clean all of that crap out of there. Worse, is if it blocks a crucial oil passage and ends up starving a bearing or journal.

If I wasn't out in NY and was back at my shop out west, I'd show you what my heads and valvetrain assy looked like after running synths for ten years solid. HUGE flakes on the valve assy, springs and rockers loaded with it. I've taken pics somewhere of the lifter valley and, it was a mess along with the timing chain etc etc. Others had posted their internal conditions and confirmed my findings on this site.

You will not see this crap when running HIGH QUALITY motor oil with top notch detergents and additives designed to keep your engine clean. If the oil is changed out PER MFRs recommendations- sludge and debris and ash content is a NON-ISSUE. Use a top quality filter such as WIX too.

So, do yourself a HUGE favor and get that M1 out of there and replace it with either Castrol GTX, High Mileage or Valvoline rated for both winter and summer for where you live. NOTE: Do pay attention to the W-rating in the winter along with using a SAE type in the summer.

I guarantee the motor will remain cleaner and your lifters will not clack or lose hydraulic pressure overnight thus, a smooth sounding engine at startup.

Debris is the enemy here and, remember now- most synths do not contain detergents because, they induce material breakdown thus, ruining the lubrication properties of the synthetic material. I called AMS and spoke to them about this to confirm what I was told. It is true and, this is why they do not have additives and why on some oil labels and tech support, it warns against using additives with their oil because of that very reason alone. It will not protect the engine when using detergents that were designed to be used with Dino oil. On some oil lables, it also warns against using Synths in engines that were running regular motor oil.

Here's another real world story of cause and affect.

I sold a guy a whole case of AMSoil after telling him he was going to have issues with his Chevy Silverado V8 after he put it in. He came back weeks later to my shop asking for a refund on the ones he didn't use. I already knew what the issue was but, I asked him what he experienced. He'd been towing up to the high desert (Palmdale, CA) and, he lost oil pressure and the motor was running rough and clacking like a diesel.

WHAT HAPPENED? high thermal loading in the hottest months induced oil thinning and, he lost pressure inside the lifters thus, the lifters were partially and sporadically collapsing thus throwing the timing out of whack.

ACTION ITEM: change oil out to Valvoline SAE 40.

RESULTS: engine was fine. No issues towing and, all was back to normal.

The thing I'm trying to convey here, is that, there's a problem running synths in this application vs. the material in discussion and, If someone hadn't made me aware of this, I'd never had found this out and would have kept running synths in my own Dodge.


Hope that may be of some help.

CM

 

Long post there, what do you think of the Valvoline Max Life, Synthetic blend ? Thats what i have been using for the past 2 oil changes and after 4k miles on the first change the oil was really thick and black. The bottle and online says it has extra cleansing agents to prevent clogs and sludge, conditions seals, and has anti wear agents and friction modifiers in it.

I havent used it in my 5.9 yet cause I bought it only 3 months ago only 2k miles so far and the dealership i got it from used Castrol GTX, but for my Jeep Inline 6 4.0 i've been using it and it seems to work good but i havent takin the engine apart so i dunno.

What dino oil do you recomend for a high mileage engine ?