QUOTE (HCMQA @ Oct 17 2009, 08:08 AM)
My 07 SEL steams as well. Only in the morning and only when it is very humid and cool/raining. My 99 F-150 does it as well. Nothing is leaking it has to do with where you live and the climate.
I run my car approx 1000 miles a week. It has 110k on it already! Why on earth are you running premium fuel?
My F-150 will knock at start up with cheap filters because the filter is in a position that it can "Drain Back" into the engine. The filter on the 07 Vulcan points down just a bit so it should always have some oil in it so i don't think "Drain Back" is the issue.
It sounds more like an issue of initial flow just for a brief second or two. This is why you may not notice that the oil light comes on. 10w xx is a possible cause. The slower ignition of premium fuel at cold start up is a possible cause.
Also even though a Premium filter has a bypass with a 10w oil at cold start up it will take a brief second or two for the oil to push through a high quality bypass arrangement thus possibly causing a knock.
Lastly the reason that new 10 taurus is so nice is that it is basically a volvo.
Just some thoughts to ponder.[/b]
"The slower ignition of premium fuel at cold start up is a possible cause." doesn't make sense to me, for a few reasons:
1. premium fuel burns at the same rate that regular does. 92/93/94 octane fuel about resistance to *preignition*, and nothing else.
2. Even if we ignore point 1, an engine that spins over longer before it fires makes *more* oil pressure before things get movin', not less.
The startup knock (whatever the *reason*) is about how long it takes for the oil pressure to build. Oil pressure is partly about flow (5W30 flows better than 10W30 at low temps) but in this case I feel it's pretty safe to say the filter is to blame. Either the filter doesn't have an anti-drainback valve, or the one it has doesn't work very well.
As far as 10W30 taking substantially longer (as it long enough to cause startup knock), I can't say I agree but I won't belabor the point.
It's not about the filter having "some" oil in it, it's about the filter disallowing flow *backwards* from the *top* of the engine through the filter and back into the sump - the filter could be *full* and that wouldn't be all of the oil volume that is after the filter.
I think it's pretty clear. It's the filter. Why, I cannot say, and can only guess, but to me it's pretty clear.