zeshawn

Well im having an argument with a friend of mine whos saying his engine failed because of using Mobil 1 0w-40 supersynthetic in his Z.

1) His engine has zero oil pressure at idle, yet oil pressure would come up a bit with revs. Engine was replaced under warrantee. Its good to note however that this car had been driven hard, oil temperatures used to skyrocket to 120 degrees celcius during cross country high speed highway driving.

2) Another LS7 had a damaged lifter causing lower than ideal (not VERY low) oil pressure, problem went away after replacing the lifters, this engine also used the 0w-40 mobil 1. Engine also raced very hard.

3) Third engine dropped an exhaust valve, however this was a built motor and did not produce enough oil pressure with the conventional 5w-30 oil and we had to step up to maintain at least 10ish PSI per 1000rpms.

I personally like this oil, especially for people in our climate, car generated slightly more oil pressure and is more readily available compared to the 5w-30.

Question is: what are the odds that this oil is indeed one of the root causes of those engine failures?

thanks.

BSSN

It really depends on WHY these engines have low oil pressure and what happened to cause the failure.

Let me explain. This is similar to a patient dying of a coronary blockage and then someone asking: What is the cause of death?

A "heart attack" is one answer (pump/engine failure).

But the true cause may lie with a congenital defect-or diet choices-or genetic predisposition-or failure to adhere to prescribed medication-or a combination-or...

See what I mean? To simply blame the oil is a bit presumptuous and premature.

zeshawn

thats exactly what were arguing about (me and my friend), hes saying the root cause of the failures/low oil pressure, dropped valve is because of using 0w-40 Mobil 1, what are the odds thats true?

BSSN

Much like the CAD patient described in my first response, I don't think anyone can say without an autopsy and a history. An accurate E-diagnosis is hard to get when complex systems are involved. Vehicular or physiological.

Katech_Zach

Very well put.

songman3

GM actually recommends Mobil 1 0W40 for use in European C6 Z06 - it is the approved product.

Joe_Planet

your buddy must be loaded.. lol, that's a lot of engines
I doubt its due to the oil
what is the year of the blocks on those? there have been problems with blocks made prior to 2008

TonyC

Interesting fact from Songman. I also live in the UK and my 2006 Z06 was imported from the USA. I changed it onto Mobil 1 0W-40 two years and never had any issues whatsoever and my car is modified.

It sounds to me like the problems lie elsewhere.

MitchAlsup

The ability to avoid a failure is available right in the car. The oil temperature gauge can be used to help in the assessment. However, few drivers watch the gauge, and fewer still have a defined temperature in mind that would tell them to back it down and save the engine.

The GM oil (0W-30) is generally regarded as good up to about 250dF but by 265dF its time to think about saving the engine. And by this, I mean, that when the oil gets to 250dF start to think about saving the engine, don't just push on as if nothing can go wrong and hope for the best. Apparently this is what happenend in the OP. Touching 250dF is OK, driving for hours at 250dF is NOT OK.

{For me, any time my oil gets this hot, it gets changed.}

The 120dC mentioned above converts to 248dF so its right at the edge for the -30 oil for short periods of time, but not for continuous driving.

At this point instead of looking for a heavier oil such as 10W-40 one should be looking for an oil with a higher HTHS number and with a big dose of ZDDP (zinc or phosporous above 1100 ppm).

M1 00W-30 oil HTHS 2.99 low ZDDP
M1 05W-30 oil HTHS 3.07 low ZDDP
M1 10W-30 oil HTHS 3.14 low ZDDP
M1 00W-40 oil HTHS 3.7 good ZDDP
M1 05W-40 oil HTHS 3.9 real good ZDDP Turbo Diesel Truck
RL 10W-30 oil HTHS 3.8 real good ZDDP (RedLine)
RL 10W-40 oil HTHS 4.7 real good ZDDP

Thus, there are -30 oils which are as protective as the M1 0W-40 oil mentionied, and -40 oils that are a lot more protective at these temps than the stated M1.

DSOM Z06

I would be under the impression that in hotter climates, a car driven hard should have a better quality, thicker viscosity oil. At the very minimum a 10W-40, possibly a 15W-50 for hard driving would be my guess. For me its Redline 10W-40 all year round.

95jersey

Mobil 1 5-30 is good way past 265F. The breaking point is more like 300+. I use to hit 290F in my C5Z all day long during track events using 5-30. I was not necessarily happy with those temps (and since installed an oil cooler), but the oil will take 265F.

BSSN

Mobil 1 sucks, imho. I use only full group IV oils. 0-30GC burns 1qt per 4500mi in my LS1. 5-30 Mobil 1 did that every 2500. Mobil 1 shears badly/rapidly.

GMuffley

It isn't the oil.

TARANTULA

http://www.mobil1.lt/galery/_mobil1/...tte_mobil1.pdf

RUBYREDVET

Ha, ha, ha another oil thread where some people claim that "their" brand or weight oil is better than another persons brand and weight.
Because of this controversy, I run maple syrup in my LS7. But is has to be 100% pure maple syrup, No fake crap for me. Man what a sweet ride and the smell always reminds me of breakfast.

Dale1990

Maple syrup sucks. I only use pure bacon grease. There is a little lifter tick on cold mornings but when it warms up the smell is divine.

RUBYREDVET

Im interested, what brand of bacon???

FNBADAZ06

I find this comment and pictures very interesting.