Maybe it was just a coincidence but after reading the oil info article I changed my perfectly running GTE to 0-40 mobil 1 ( the only 0- oil I could find locally) and the car spun a rod bearing withing 100 miles with the oil pressure never dropping from normal. Before the change pressure was a bit less than I like in other engines, but always more than 10 psi per 1000 rpm. With a mechanical gauge I was getting about 10 at idle full hot, 20 to 25 slow cruse and 40 to 45 at 65 mph in 5th. Pressure never dropped, but fatal pecking noise quickly became loud rod knock and I shut her down. Any chance a worn engine did not like the 0 weight?
0-40 synthetic = rod knock
- Thread starter rustfarmer
- Start date
I dont see how it could cause a rod knock, it must have been coincidence unless it was a defective batch which is highly unlikely (just cant say impossible)
I have run that oil in my 7m, and im sure MANY others have without any effects.
I have run that oil in my 7m, and im sure MANY others have without any effects.
Heavy weight = higher pressures = more oil going through the oil cooling circuit, oil squirters, and the oil pump relief.
It was not the oil - that includes Mobil 1. What were you doing with the car after the oil change before the knock occurred? Any rapid accel/decel? High G turns? Did this motor have a HG failure in it's history, especially recent?
WELCOME to the club, rod knocking brother. This POS( Mobile 1 0-40) oil ruined 2 of my supras. Both rod nocked, one in about 1-2 weeks and the other coming out the drive way as soon as i changed the oil. Dont use Mobile 1 0-40 or you migh as well add your name to OUR list. 
---------- Post added at 11:06 PM ---------- Previous post was at 11:00 PM ----------
Is it mobile 1 0-40? I bought it cause it was on special for $30 dollars and i ran out of Gc that i had. Never again will i try another oil. GC is the way to go. Its almost as thick as a 40 w at operating temps. I was reading the data sheets and its thicker than Amsoil 0-30 by 2 points, Gc visc was 12.5 and amsoil 0-30 was 10.3 at operating temps.
---------- Post added at 11:06 PM ---------- Previous post was at 11:00 PM ----------
Is it mobile 1 0-40? I bought it cause it was on special for $30 dollars and i ran out of Gc that i had. Never again will i try another oil. GC is the way to go. Its almost as thick as a 40 w at operating temps. I was reading the data sheets and its thicker than Amsoil 0-30 by 2 points, Gc visc was 12.5 and amsoil 0-30 was 10.3 at operating temps.
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wardog;1611993 said:WELCOME to the club, rod knocking brother. This POS( Mobile 1 0-40) oil ruined 2 of my supras. Both rod nocked, one in about 1-2 weeks and the other coming out the drive way as soon as i changed the oil. Dont use Mobile 1 0-40 or you migh as well add your name to OUR list.
---------- Post added at 11:06 PM ---------- Previous post was at 11:00 PM ----------
Is it mobile 1 0-40? I bought it cause it was on special for $30 dollars and i ran out of Gc that i had. Never again will i try another oil. GC is the way to go. Its almost as thick as a 40 w at operating temps. I was reading the data sheets and its thicker than Amsoil 0-30 by 2 points, Gc visc was 12.5 and amsoil 0-30 was 10.3 at operating temps.
Are you absolutely and positively sure that a 0w40 oil ruined your motors? Did you send it out for oil analysis and you have proof that the oil broke down and rk your motor?
Well one was a fresh rebuild that was doing just fine pushing 430rwhp and 430rwtq all day and the other one was just a daily driver. It all happened with the same oil, it took about 2 weeks to kill the new rebuild and 15 feet still in 1st gear to kill the daily driver. So no more Mobil Crap for me, god damn special got me . I was so pissed off that i forgot were i put the freaken oil after the oil change. Im pretty sure there will be others joining the club cause of this oil i was waiting for them to pop up and i saw this post. Good luck OneJSUPRA
. I was so pissed off that i forgot were i put the freaken oil after the oil change. Im pretty sure there will be others joining the club cause of this oil i was waiting for them to pop up and i saw this post. Good luck OneJSUPRA
but mobil 1 says nascar on it! lol
just mobil 1 0-40 or all mobil 1 is sub-par?
why 0-anything?
10w-30 has never let me down in any brand.
just mobil 1 0-40 or all mobil 1 is sub-par?
why 0-anything?
10w-30 has never let me down in any brand.
Jdub says the 7MGTE was designed to use oil in the 10-12cSt range @ 100C. Mobil 1 0w40 is 14.3cSt @ 100C. Which is too thick for a stock 7MGTE. It is also thicker than most 5w30's when cold @ 80cST @ 40C. That is just more unnecessary wear. That's what happens when you "feel" that one oil is better for your engine than another. I base my oil decision on facts.
Wow now youve got me thinking. i used m1 on my supra a few blocks ago, same result. oil starvation. Ive been using castrol edge since and havent had a problem.
One more time:
ITS NOT THE OIL
Those bearings do look like a supply problem. Concerning the other guys blaming the oil, you'll meed to say what else has happened to the engine or under what conditions the knock occurred.
ITS NOT THE OIL
Those bearings do look like a supply problem. Concerning the other guys blaming the oil, you'll meed to say what else has happened to the engine or under what conditions the knock occurred.
san supra;1612205 said:
With multi weight oils the first number is cold operation temps and the second is hot. So with a 10w30 your bearings get starved more than with a 0w30. And castrol syntec 0w30 is closer to a 40w when hot so its basically the best of both worlds.
The book and the oil cap both call for 5w30 so why would you put 10w30? Thicker does not mean better and these are not the old skool hot rod days.