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Discussion Starter #1
What's the oil filter thread supposed to be on a 3.5? I just changed the oil in my company car today (there's a reason why I was changing the oil in a company car; company pays for oil change every 7K miles, but the last change in this car was done two users ago at a Jiffy Lube. I got that ancient crap out of there and replaced it with some Mobil 1. Normally 7K miles is only 4 months or so, but not in this case, because it sat around for a long time.) Anyway I had been thinking, if I could convince the shop that does our oil changes to go along with it, that I would put a CM filter on the car and pay him extra to keep using Mobil 1 because I'm going to need a decent car, and they often offer the cars to the people that have been driving them when the lease is up. Per CM's web site, the filter thread is 18mm (can't seem to access it right now, but it's linked from http://www.cmfilters.com/spin-on.cfm ) but both the filter I took off was stamped "13/16" The filter I just bought at Carquest was stamped similarly so I just shrugged and installed it. is that correct, or did I just install the wrong filter (for the second time?)

thanks

nate
 

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Discussion Starter #3
7K is nothing for most premium filters. Run a Bosch, M1, K&N, Purolator, AC delco, and call it a day..
I'm with ya... the reason I changed the oil myself was that that cheap Jiffy Screw oil had been in there almost a year and I still had 4K left to go before the company would pay for another oil change. I can't bring myself to abuse a poor defenseless car like that (actually taking it to JL in the first place probably qualifies... had to put a wrench on my wrench to get the drain plug loose)

I still am curious as to the correct thread but upon reflection if a 13/16 fits it can't be 18mm because 13/16 is 20mm plus a hair. I do recall reading somewhere that some filters could be fitted on the wrong stud but it would blow off under hard driving (maybe it was 13/16 on a 20mm stud?) but I looked up my application on Wix's web site and their listed filter is also 13/16 so unless I get leakage I won't worry about it.

I am still considering going to a CM filter simply because a) my old company car was about wore out when I turned it in (dino squeezins and whatever filter the garage used) and b) I will need a "new" car by the time the lease is up on this one, so I may as well take better care of it and buy it out...
 

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Might I suggest you do MEANINGFUL research before buying anything.

LOTS of things out there marketted as wonderful that are no so much.

M1 in LT1s is not worthwhile for instance, but everyone thinks M1 5w-30 is best for them because GM put it in the Vette.

Fram filters are arguably the WORST you can buy but still actually do the job if OCI is kept low.

Do you have ANY meaningful evidence that M1 or the filter you are looking at are useful in this application??
 

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Discussion Starter #5
No, I don't know for sure that M1 is really going to help... BUT... I figure with only a 4 qt. sump, 7K OCIs, and usage that definitely qualifies as "severe" that it can't hurt. Same theory with the CM filter. I agree with you re: Fram, as far as over the counter filters go I'm definitely sold on either Purolator or Wix. Used to have an old Dart (225 leaning tower of power) that was a demonstration of why Fram filters suck - oil pressure would take >5 sec to come up on a cold start with a Fram installed, but only a second or so with a Wix. ADBVs are there for a reason... (of course you could ask MoPar why they decided to mount the filter upside down as well...)
 

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we always go with the stock filter from gm,... the 2006 models ss v8, take a
different one ,2007 ss v8 and up, take same one pf-48... rkvette
 

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7,000 miles? What was the oil life percentage according to the DIC?
 

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Discussion Starter #8
I finally got a "full" oil change interval, and the DIC was reading 10% at 7K miles.

I've been paying the shop extra to use synthetic, they're using Havoline, although I have still not done anything about buying a better filter. I know that "modern" engines are supposed to be OK with extended OCIs but I really don't feel right using dino oils for that long especially with lots of stop and go, fast acceleration soon after a cold start (no stop light at exit from my office's parking lot) etc.
 
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