2003 GM 6.0 LQ4 Oil Pan/Rear Main Leak, which oil

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388
hey guys, i have a 2003 GM 6.0 LQ4 in my truck, its been on synthetic 5w30 its whole life essentially, it used to be always on castrol 5w30 dexos but then ive regularly just been switching between amsoil pennzoil mobil/ whatever full synthetic is on sale. It developed a oil pan or real main leak, its very slight leak, it just drips very slowly. Over the course of 5000km the oil will drop from full to about minimum so its not leaking that much. By the time it gets low on the dipstick its already time for another change. What do you guys recommend i run in it? owners manual says 5w30 all the time, soon we are going to be seeing temperatures between 32 f to about 90 f , and then in the summer between 77f and 95 f. however our winters get cold cold so i probably have to stay as a 5w30 or a 0w30 in winter because we are always ranging between -4 f and -40 f. i mostly drive city short distances, and then occasional trip on the highway. I am not planning on getting the leak fixed until it gets much worse because its about $1200 in labor just to take everything out and replace whichever seal is leaking. i heard high mileage oils are good for this type but do they even come in full synthetic? in canada they seem harder to find. what do u think i should run? thx
 
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6,318
Location
Suburban Washington DC
Originally Posted by apollo18
I am not planning on getting the leak fixed until it gets much worse because its about $1200 in labor just to take everything out and replace whichever seal is leaking.
Why would you fix it at all? So it's now costing you maybe an extra $5 for a quart of oil between changes. If it got twice as bad, you would be spending $10 between 5,000km changes and over an average 20K km a year that's $40. You would have to drive it 30 years just to break even on that repair. Thing will be rusted out long before that.
 
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2,333
Location
South Carolina
A HM oil will not fix a pan gasket leak. It's a 50/50 chance it will slow or stop a seeping rear main seal leak. Mobil1 HM 10w-30 eliminated a rear seal seep on my 1993 F150. Guess I was lucky?
 

jalikaria24

Thread starter
Messages
388
Originally Posted by atikovi
Originally Posted by apollo18
I am not planning on getting the leak fixed until it gets much worse because its about $1200 in labor just to take everything out and replace whichever seal is leaking.
Why would you fix it at all? So it's now costing you maybe an extra $5 for a quart of oil between changes. If it got twice as bad, you would be spending $10 between 5,000km changes and over an average 20K km a year that's $40. You would have to drive it 30 years just to break even on that repair. Thing will be rusted out long before that.
oh ya i completely agree, i meant i wont change the pan gasket or rear main or whatever it is until its literally oozing out ahaha
 
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4,473
Location
N.C.
Originally Posted by FordCapriDriver
Valvoline Maxlife
I went with the 10w30 flavor of Maxlife on my 5.3. It stopped a rear seal leak for me.
 
For what is worth, last summer I ran 5w40 in my 2008 6.0.I found the oil pressure to be to be slightly higher but not a lot, so no big deal. You could try a 5w30 HM to see if it helps and if you wanted to try a higher viscosity use a 5w40 after that. 2cents
 
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684
Location
FL
I was trying maxlife 5w 30 to fix my 5.3 rear main seal leak, didnt work Just went to maxlife 10w 30 still leaks after 2000 miles. I will keep tring 1 more oul change than will move to a thicker mobil 1 hm. Mobil 1 5w 30 hm is thicker then valvoline10w 30.
 
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