Strange occurence when oil turns black

[metroplex]

Ok I know everyone says to NOT go by the oil's condition via the color of the oil.

Here's the situation:

1981 Ford T-bird, 302 V8, with 2-bbl 2150 carb (no sensors, not the VV) with the AOD.

Stock filter size is Motorcraft FL-1A, or SuperTech ST8A.

I installed thicker Hellwig anti-roll bars on the front and rear, but the front bar is so thick that I had to use the smaller FL-300 or ST16 designed for the late 80s/early 90s (pre 4.6) Crown Vics with the 5.8L V8 police option w/ the oil cooler (the story is that the oil filter adapter for the oil cooler lines was too thick, so they had to use a shorter oil filter - the FL-300).

Ok fast forward to my situation:
I use Pennzoil, or Quaker State dino 10W-40 in the 302 V8 frequently. Change interval is usually 3 months or 1000 miles whichever comes first.

With the FL-300/ST16, I'd notice that the oil turns black (considerably darker than when its new) at about 500 miles or 1.5-2 months. During this time, the car is harder to start and my gas mileage drops considerably!!!

I just changed to Chevron Supreme 10W-40 and squeezed in a FL-1A but only tightened it gingerly. I'm HOPING it will come off at the next change w/o tools (the bar leaves about 1/16" clearance between the filter and the bar, eliminating any chance of squeezing in a wrench.

Anyhow, the engine starts up really fast on cold starts - it just springs to life. gas mileage is also up considerably. After a few local errands my gas needle didn't move even when doing a few burnouts and high RPM runs. Usually the needle would have dropped about 2mm.
The oil is also "crystal" clear.

On the Ford 5.4L SOHC V8 and 4.6L SOHC V8 engines, the oil is still crystal clear on the dipstick after 3 months/1000 miles.

Can I assume that when my T-bird's oil gets darker, that its time to change the oil? Considering there MAY be a loss in oil pressure due to a clogged filter?? Or how else can you explain this? The 302 as with all of my engines, have been taken care of since day one. Frequent oil and filter changes, etc...

 

[turbochem]

quote:

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Ok I know everyone says to NOT go by the oil's condition via the color of the oil.

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Yet you choose to proceed......LOL....

Well, the only light I can shed is that when I took a sample of oil recently it looked and smelled dead.........I thought there was no possible way the oil could be any good.....

However, the analysis actually showed it was fine......

Unless, of course, there is some other characteristic of oil that does not show up on a UOA that is playing a part.....

 

[Steve S]

As an engine gets older more blowby occurs, so the oil should be changed more often. But how to tell is the question? oil analysis is the answer. Now the problem ,the cost is around $18.00 on up. At Costco Chevron Supreme is around $1.00 per quart Shopping around for sales maybe less ,pickup walmart oil filters or anything on sale and figure the cost and do what costs you less recycle the oil and filter as not to feel guilty about extra oil changes an let us all know your decision and why, this is a test.

If the smaller oil filter is a concern and there is room to add a high quality remote oil filter may be worth the pain in the elbow.

[ May 19, 2003, 11:54 PM: Message edited by: Steve S ]

 

[Spector]

quote:

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Originally posted by Steve S:
[QB] As an engine gets older more blowby occurs, so the oil should be changed more often. But how to tell is the question? oil analysis is the answer. /QB]

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I don't know if this is fact or opinion but sort of makes sense. However, as every engine is different at 100,000 miles I would not increase OCI simply because mileage is high. Further, you must have a trend of results to know what the numbers were at 50,000 as compared to 100,000 or 150,000 to recognize the blowby. I have kept the OCI interval the same for my 155,000 mile engine and analysis results are relatively consistent compared to when it had 40,000 miles on it.

Almost nothing can be stated as a 100% fact and must be done when it comes to engines, too many variables to deal with. Each case is individual.

 

[metroplex]

The T-bird was bought new in 1981 and up to now has 96,800 miles.

There is some blowby, it used to blow out a little blue smoke during hot starts (when you have the throttle down a bit to crank the engine), and I swapped out the valve stem seals. I think the rings are a little worn but I'm not getting so much blowby that my air filter is soaked with engine oil.

 

[3 Mad Ponchos]

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I'm HOPING it will come off at the next change w/o tools (the bar leaves about 1/16" clearance between the filter and the bar, eliminating any chance of squeezing in a wrench.

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Dude... buy a strap wrench, live happily ever after.

Cheers, 3MP

 

[dkcase]

If you are able to run the FL-1A, you may want to look at the K & N Filter. They have a 1" nut on the end for removal and won't need a wrench to fit around it.

I have one I got off eBay. With shipping it cost exactly what it would have at the store.

I'm going to use it next, between AutoRX applications. I have Motorcraft, Mobil 1, Supertech, Bosch Premium, and K & N in stock. 89 Ford CV.

 

[JonS]

Just a quick note about Chevron Supreme. I changed both my cars to it and the mileage went up from 22 to 30 mpg(1998 Nissan Altima with 5w-30) and 19 to 30 mpg(1995 Jeep Grand Ch. with 10w-30) This was all freeway 70mph.

 

[Pablo]

JonS wrote:

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Just a quick note about Chevron Supreme. I changed both my cars to it and the mileage went up from 22 to 30 mpg(1998 Nissan Altima with 5w-30) and 19 to 30 mpg(1995 Jeep Grand Ch. with 10w-30) This was all freeway 70mph.

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I'm sorry but I don't believe you. Well OK I believe you, ie your mileage did get better, but just because of the oil, seems HIGHLY UNLIKELY - that is a HUGE PERCENTAGE change. Did you change anything else? What kind of oil were you using before.

 

[Patman]

I agree with Pablo, there is no way oil alone caused that much of a jump. What probably happened is that he changed the oil right after the winter was over, so his MPG went up because the warm weather had arrived. Although even that's hard to believe, since my cars MPG only vary by about 10% at the absolute highest between winter and summer.

 

[JonS]

I can't explain it either. In both cars the previous oil was Havoline. I know it should be the same oil. I checked and double checked when i filled up. I could not believe how little gas i put in for the miles i drove. Maybe it is a good batch of gas. I have never got more than 19 mpg with the Jeep, and now a got 240 miles on half a tank (8 gallons) It doesn't seem possible i know.

 

[metroplex]

I just did quite a few more local errands which would have normally cost me 5-6 gallons already, but the gas needle didn't move. The 81 T-bird uses a "Real-time" gauge unlike the newer gas gauges where the needle position is updated every X seconds. I understand its not perfectly accurate but for the past 22 years its given me a very good idea of how much gas is left.

I drove the T-bird recently w/ other oils in similar ambient temperatures but never got such good gas mileage. I'm wondering if the ST16 was just going into bypass right away - it uses the 6 tiny holes in a plate style bypass valve.

 

[pedaltothemetal]

This is a good example to stick with the stock filter size. I would surmise the flow of oil thru your engine was so slow it got burned up a lot quicker, and the oil filter was the culprit.

Leo

 

[metroplex]

now what kind of oil filter tools could I use?? The problem is lack of clearance. Its something that is thin enough to slip through the crack between the anti-sway bar and the filter, or it has to be something that latches around the filter, and de-latches after you're done.

 

[dkcase]

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the flow of oil thru your engine was so slow it got burned up a lot quicker, and the oil filter was the culprit.

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