my old slant in the valiant has started having the oil light stay on for several seconds on start up. i suspect the oil pressure sending switch, so I have one coming. its close to an oil change anyway so i can change it at the same time. is it worth while to spray it out somehow while its out? a can of brake clean or something through the hole while the oil drain plug is out to clear som gunk maybe? is that a bad idea?
i should mention that this motor owes me nothing and I could swap it for one of the spares in the garage if it grenades

It's far more likely the anti-drainback valve in the oil filter is leaking. Get a new, high quality filter and try it.

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Joshua

If you're going to change the sender, use your spray cleaner to spray around the sender before unscrewing it. As far as internal cleaning, focus on the other (front) end of the oil pump; whether or not you put in a new sender, it will be a good idea to service the oil pressure relief valve to make sure it's doing its job, as described in these two threads: thread 1, thread 2.

As Josh says, this issue may very well go away with a thoughtfully-chosen new oil filter. Try a Wix 51806, which has a built-in standpipe to hold more oil in the filter after engine shutdown.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

An easy check of the gauge and wiring if I recall correctly, is to ground the lead to the sending unit. If the gauge goes all the way to the high pressure reading, it's probably the filter as mentioned above or the sending unit.

i will also do that, thanks dan.

I have run the 51515 for several oil changes now. I feel like I might have a permanent stand pipe, but i might be remembering a different motor seeing as I have 4 slants now. if I dont, I will switch to the 51806 for the next oil change.

closing the loop:

I changed the oil, I used a napa gold 51515 equivalent, its made by Mann Hummel who is also making WIX filters now. This motor has a stand pipe on the oil pump. oil pump is from a later motor, its blue rather than redish orange of the block/head.
I forgot to change the switch in the process. I attempted to remove the oil pressure bypass, but discovered the motor mount in the way.

I have run it a few times since and the light goes out much quicker the same way it used to. I assume the problem was oil filter related.

I just performed this fix today on my 1966 Coronet Slant. I used a Standard Products #SP16 switch from O'Reilly for $12.99. I finally got myself the proper socket to change these (a Lisle #13200) from O'Reilly too for $10.99. My oil pressure warning light now works correctly though I may add a proper gauge later. By the way, I noticed in other threads on this topic mention is made of the pipe size that screws into the oil pump. It is 3/8" NPT on my 1966 225ci Slant. My switch screwed right into the pump with no reducers in between.

Every Slant 6 oil pump I have ever seen has been 3/8" NPT where the sender goes in. Thanks for posting that so others can benefit! Glad the switch swap worked well.

Lou

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Home of Slant6-powered fun machines since 1988

My latest build got a new pump with blind plug. So I had to take the "oil" light sender plug from the old one <= it came without sender hole. As well I have a '65 170 block where the sender was installed with 1/8" NPT theads on. Installed at the rear of the block oil channel. That outlet in the block is now for T3/4 turbo feed.

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1966 Dart. 170 cu.in. 200 rwhp.