15 second oil light on start up.

Ford4jack · Post by **Ford4jack** » September 21, 2007, 4:49 am

15 seconds is a long time Doc

Have you considered putting a mechanical oil pressure gauge in your truck?
That way you know where you stand on hot vs cold oil pressure, viscosity changes, rpm effect etc

Never have trusted a pressure light myself. Seems like to little to late info wise.

Yellardawg · Post by **Yellardawg** » September 21, 2007, 8:02 am

I'd attach an oil pressure gauge to give me a better understanding of what's going on. It could be something as simple as needing a new sending unit for the light or the 20-50 oil could have been disguising an issue with main bearings that the 10-40 doesn't.

FORDBOYpete · Post by **FORDBOYpete** » September 21, 2007, 8:13 am

A Sub Standard or Cheap Oil Filter, lacking the correct residual, anti Back Flow, Valving causes that problem by letting oil drain back and air to enter the system from the top. Every time you restart after sitting, the pump & system has to refill with oil B4 it creates PSI. The lighter the viscosity rating oil used, the more thorough the drainback will be hot, especially with an "I" configuration engine as opposed to a "V" configuration . . . . .

D'ya think Maybe there's a Motorcraft in your future. :hm:

FBp

Macon ACE · Post by **Macon ACE** » September 21, 2007, 8:37 am

A guy I used to work for had the same problem with his chebby. He just put a piece of black electrical tape over the oil light. You might try that.

Ford4jack · Post by **Ford4jack** » September 21, 2007, 10:00 am

Believe Pete got it covered Doc
A filter without a check valve is not good.

Just wondering has your light ever lit up or pulsed at idle?

Slick Fan · Post by **Slick Fan** » September 21, 2007, 11:25 am

Sounds like low oil pressure from here, Doc.

Macon ACE wrote:A guy I used to work for had the same problem with his chebby. He just put a piece of black electrical tape over the oil light. You might try that.

That's what I did with the ABS light on our '91 Exploder...works great! :thumright:

ICEMAN6166 · Post by **ICEMAN6166** » September 21, 2007, 11:59 am

15 seconds is an eterninty as far as the oil light being on.
also the light does not come on until pressure is below 8 psi which is very low. i do not hold a lot of trust in the electrical oil pressure units, either the light or gauge.a mechanical gauge provides a much more accurate reading.
i run sae 30 in my y block because there is a noticeable 5-7 psi more than with 10w30, and the consumption is less as well, 10w30 needs an added quart more often than 30w.

Ford4jack · Post by **Ford4jack** » September 21, 2007, 2:59 pm

Doc
The light coming on at idle is not good. Even if your idle is set way low it should still have enough pressure to keep the light off.
You might have a bad sender but I would suspect worn bearings, pump, or a stuck relief valve.
Since this happened when you switched a lower viscosity oil you might want to go back to a thicker oil.

Myself I would put in a mechanical gauge to check it.

My 300 has 20-25 lbs pressure hot at idle
Not sure but I believe a 240 should be the same on these pressure numbers.

Good luck hope its something simple.

O yea the filter is mounted horizontally on my 300 also
Guess I should add Im useing 15w40 oil in mine

Ford4jack · Post by **Ford4jack** » September 21, 2007, 7:07 pm

Hear ya doc I must have edited my last reply at least 154 times.
The hands not doing what the minds thinking here today.

cdherman · Post by **cdherman** » September 21, 2007, 9:35 pm

My old 240 fires right up to 75lb psi and the light goes out when I crank it. If I leave 10w30 in there in the summer, it will get down to perhaps 15 psi at idle, but only after the oil is blazing hot (like 30 miles at 70mph, with 90+ degree heat).

So I run 15w40 in summer and 10w30 in winter. I'd run 5w40 DEO year round, but those oils are synthetic or semisynthetic and I am afraid my slow leaks would become gushers.

Doc, get a good Wix or Baldwin filter. If that don't correct the problem, you better get a mechanical guage and see what's going on.

You have any idea what kind of miles are on that engine?

fmartin_gila · Post by **fmartin_gila** » September 22, 2007, 8:13 am

Doc,
The 10-40 iol should be OK, but get a good filter. Baldwin, Motorcraft, even a NAPA 1515 has a anti-drainback.
Fred

Phil · Post by **Phil** » September 22, 2007, 8:29 am

Everytime I fire up that greasy 429 and I see that gauge rise I feel like its a small miracle.

Gauges are good.

YukonCor55 · Post by **YukonCor55** » September 22, 2007, 3:43 pm

I run 4 qts of 10W40 and 1 qt of Lucas Oil Stabilizer in my ol' 55 with a 272 and my 62 4 x 4 with a 292. It's the best cocktail an old Y block will ever drink! I get good pressure as soon as the key is turned.

Yellardawg · Post by **Yellardawg** » September 23, 2007, 8:46 pm

I've always heard that if you overfill an engine with oil, you run the risk of blowing seals. Never tried it, don't know if it's true.

But, we do know that at startup, you had low oil pressure. After 15 seconds, pressure was sufficient to turn off the light, so, how much pressure do you have now after 15 seconds? Ever hook up a mechanical gauge to actually know what you're dealing with?

Ford4jack · Post by **Ford4jack** » September 23, 2007, 10:59 pm

Hope your joking about 16 quarts Doc.

But if overfilling helped it you might want to check out your oil pump pickup tube for a crack or something.
I would imagine there's a gasket or o ring where it bolts to the pump.
That could be a problem area also.(if you really put that much oil in it)

I know overfilling a hydraulic system on some things will find a cracked tube or a bad seal etc on the suction or return side. They will quit sucking air when this is done in some cases.

Phil · Post by **Phil** » September 25, 2007, 8:29 pm

The 460 guys bag on the consumer grade Fram as well.

I generally stick with Motorcraft and if I'm feeling rich I run a non bypass
Fram Race/KandN race.

I wiped a cam once and the bypass opened in a fram. It filled the engine with lots of metal

Johnny Canuck · Post by **Johnny Canuck** » September 25, 2007, 8:44 pm

I bet your filter was made in Canada. They knew you would buy it and purposely sabotaged the one you bought.

Ford4jack · Post by **Ford4jack** » September 25, 2007, 11:36 pm

Doc you still donating your used oil to the needy. :lol:

Slick Fan · Post by **Slick Fan** » September 26, 2007, 12:13 pm

Heavyhauler wrote:The 460 guys bag on the consumer grade Fram as well.

I bag on them as well, I wouldn't put a Fram on a car bound for the crusher next week. :evil:

It kills me when I see someone posts pics of their nice expensive freshly rebuilt engine, that they just sunk a few thousand bucks into & there's a friggin' $3 Fram screwed onto it.

BTW, I'm fairly certain that the same company that makes Frams also makes STP oil filters...along with a plethora of other cheap brands.
Wix, Hastings, Baldwin, Motorcraft & even AC filters are the only ones worth a damn. Maybe even K&N's filters, but I haven't seen one cut apart yet, nor have I seen a report on them.

fmartin_gila · Post by **fmartin_gila** » September 27, 2007, 7:35 am

The NAPA 1515 is Wix.
Fred