Last post on Dec 09, 2008 at 3:43 PM
You are in the Chevrolet Cobalt
What is this discussion about?
Chevrolet Cobalt, Oil, Coupe, Sedan
#17 of 23 Re: [poncho167]
Sep 09, 2008 (10:47 am)
I think your must be talking about the faulty anti-drainback valves that were found in some Fram filters a few years ago. I'm assuming they have corrected the problem, but I have nothing to back that up.
Anti-drainback valves allow oil to flow into the filter, but not back out of the filter. The only way oil is supposed to be able to leave the filter is through the center tube, after passing through the pleated filter paper that surrounds the center tube.
The purpose of the anit-drainback valve is to prevent the oil from draining out of the filter when the engine is shut off. If the filter were mounted vertically and right-side-up, then the anti-drainback valve would be unnecessary, but most filters are mounted horizontally, which means that without any pressure in the system, the oil would run back out of the filter to the crankcase.
The problem with letting the oil drain out of the filter when the engine is shut off is that the filter would have to fill up again when the engine is started before any oil would begin circulating to the moving parts. Those few seconds without oil flow at every start-up of the engine would have a cumulative effect in shortening engine life.
#18 of 23 Re: Question about oil? [harrisblack]
Oct 07, 2008 (7:50 am)
I have been using full synthetic for years and it is worth the extra money. There are many brands and as many arguments about who has the best. Regardless of which one you pick, Stick to it, don't change brands after you start. The 3,000 mile change rule should always apply. It will pay big dividends ten years down the road. Regarding oil filters, again draw a circle on the ground, take every brand and throw them up in the air, whichever lands in the circle use it. Is one better than another, (thought) is it worth the worry? Change every 3,000 with a new filter and the motor will stay clean and your rod and crank bearings will thank you for it.
Dec 04, 2008 (12:20 pm)
In the December 2008 issue of Road and Track, on page 73, there was an ad by Valvoline. It stated that there Synpower full synthetic oil is 4 times better that Mobil 1. Any comments?
#20 of 23 Re: Question about oil? [rweldon]
Dec 04, 2008 (12:49 pm)
I disagree with your assumption that all oil filters will perform equally.
The dirt holding capacity may not be much of a factor, if you are on a 3000 mile drain interval, but the quality of construction, the performance of the anti-drainback valve, and the amount of time the filter is in the by-pass mode (like on cold starts), are not necessarily going to be the same across the brands.
#21 of 23 Re: [harrisblack]
Dec 07, 2008 (7:07 am)
mobil 1 is the gm oil of choice. there is another forum here thet might help.
Dec 09, 2008 (11:22 am)
I seen the ad in other media. Walmart has it for $19.00 for a 5 qt jug, which is cheaper than Mobil 1.
#23 of 23 Re: [harrisblack]
Dec 09, 2008 (3:43 pm)
the maintenace and repair forum has a lot of info on oil quaulity that is worth reading. cost is not always a good measure of quaulity. mobil 1 is a proven performer. check out the other forum if you haven't yet it is way over my head but still has a lot of good info.