Its been ages since I posted here...bought a house moved etc etc...been pluggin away at the beast when I have time.. Since my dynafflow self rebuilt ...it works great drove to new house :TU: Anyhow been tryin to align windows to put door panels on and dual exhaust... The idiot light is all I have for oil water gen...I bought digital gauges for all 3 waiting on oil psi to get here.. I should note.....I pulled motor a cpl yrs ago to repaint it and pulled oil pan and valve covers to clean the sediment from leaded fuel...I took rocker assys apart to clean re lubed and instlled... Did trans while at it I posted thread in juice box..anyhow.... My problem is idiot light for oil comes on b ut dims when engine is revved up...that's why I got digital gauge to get a number... I was going to take to shop b out 10 miles bto get muffler adapters put on so I don't deaffen town when I take from garfage to yard to tinker with... but ab out 3 miles or so from house the light wouldn't dim wbhen gassed so I puttered home afraid I had a problem..well I took breather caps off valve covers and can't feel oil on the rocker arm but have only put like 12 miles on car since I cleaned them..sso I don't know how much oil I'm sposed to be seeing... I put new sending unit on when repainting but I seen there are 2 different ssending units and thought maybe put wrong one in so I got light on? I read about an oil plate or ssomething and gasket kit to redo pump but ?? Can I pull oil pan and put this in without pulling eng again? Is tbhere anything I can do before gauge gets here to see if I have something going on? Like a head start? Also I did change oil and filter with eng out. Stp filter I think... Hopefully someone has ideas or something as I'm lost where to start or do in mean time. Thanks everyone in advance for the help. Trikeman
BELIEVE THE IDIOT LIGHTS...... dont run the engine any more than you absolutely have to.....mechanics hated them , but they do work.... Are the lifters pumped and working ???? are you getting oil up to the rocker arms ???? The usual cause of low oil pressure is worn out cam bearings/main bearings/rod bearings..... I have never seen a oil pump completely fail.... very carefully check this problem out before driving the car anywhere,,, you can destroy the engine....
thanks doc nice to see ya again bro!! I havent pulled the valve covers off and checked anything yet. but i hear no valve noise or ticking etc engine "sounds" strong. mileage is low on motor id have to check odo to be sure im thinking 24 or 54 butagain i have to look. just cant imagine bearings are worn out etc. i was thinking it was the pump needing rebuilt or something but wasnt sure....figured to post here and see where to go from here. i got her back in the garage so i can work on finding the issue b4 driving anymore... i cant frikin remember if i had the oil light deal before i pulled motor to repaint so thats why im thinking it has something to do with when i did the rocker assemblies.. i read somewhere about the only way oil gets up to rockers is thru one side of arm has a larger hole..??? i cant believe i did it but could i have put the rockers etc on the arm with it backwards if that makes sense?? oil is new ( clean) so its hard to see thru the fill holes on both covers but i stuck my finger back in there far as i could rubbing the arm and didnt get anything on my finger.. so im going to say no i dont think it is oiling rocker arms?? but will pull covers off and ??? start it and look or will oil be flyin all over the place or???
You should always check the simple things first. Grounding the lead to the oil pressure switch turns the light on. Although unlikely, you should check the wire insulation for a short to ground.
I wouldn't freak out until you actually install the gauge and get an accurate oil pressure reading. The sensor could be bad, and like Larry noted the wire could be shorting out. It's easy to pinch a wire when re-stalling an engine. Once you get the gauge installed, you need about 1psi per 100rpms. On cold start-up, you should see close to 40psi. Hot in gear, around 15psi is not uncommon.
Yep,,, check out the simple stuff first,,,, first put a mechanical gage on the oil pressure port and see if you actually have pressure,,, both at cold start up and at a hot idle..... like they said , it could be a shorted wire, defective sending unit ect..... the hot idle pressure will tell the tale,,,, then check out your rocker arm assemblies.....
Too late already freakin out :-( I did get another send unt didn't install yet wanted to get my digital oil gauge so I clian put a fitting in to use the light and gauge too.. Apparently they send my gauge via michael cuz he's rowing the boat ashore from china they had to send me oil psi not temp so of course they screwed that up so now I'm watin as winter looms. if sender is bad or wrong one I should still be able to get oil on my finger when I feel around in fill hole on rocker covers tho right? Just seems awefully still clean in there even tho I havnt ran eng much at all... Oh yeah 54k is mileage And I think my new tstat is sticking or rad cap is stuck??? Because the top hose was hard as a rock and no antifreeze went into my overflow can...thought stuck tstat or/and original cap is stuck wwont let the fluid out the hose? Anywyas that's another problem or issue. More worried bout this oil light.... Thanks for the help all....I may justwait til digital gauge gets here that way I can hook up all three gauges and be sure whatg. Volts/water temp/oil psi is so I have a starft point... I'm hoping its a simple fix since everything is original maybe its a bad plug or something beccause I'm getting an intermittent gen light that goes out on rev up too so ill keep ya posted..
It's not abnormal for no coolant to enter the overflow. You would need to get the coolant hot enough for the pressure in the radiator to exceed the pressure rating of the cap for this to occur. With a 16lb cap, I don't start loosing coolant to the overflow until I hit 190-200*, and that's cold filled right to the top of the radiator. You can check that coolant is circulating by removing the cap before you start the engine, and then let engine idle until it comes up to the temp rating of the thermostat. It'll be blatantly obvious when it opens, if it's working correctly. In regards to the GEN light, again it's not uncommon for the generator to not charge sufficiently at idle, thus illuminating the light in the dash.
Just had an intermittant gen light - was the two wire connector at the back of the alternator - needed the terminals cleaned.
can you, under the rules,,,, install a toggle switch to cut the field out when you charge down the strip ????
Ok got the new gauge and went and got a nipple and T fitting to attach both sending units. Will post soon as I can what I get for psi on cold start up Some oil ran out of the hole when I pulled sending unit so I guess that's a good thing. And when I pulled car over to garage to work on it the light would be on but blink completly out when I gassed it so hopefully this turns out good.. Bill ---------- Post added at 07:43 AM ---------- Previous post was at 07:37 AM ---------- Thanks rhett ill check it out once I get the oil psi conffirmed. I'm thinking terminals may be an issue since all is original under hood and car sits a lot specially before I got er. 54k isn't much mileage IMO for a car that's over 50 right Doc.....I got no clue bro figure the toggle question was for rhett givin his avatar ---------- Post added at 09:16 AM ---------- Previous post was at 07:43 AM ---------- I'm goin to put a 160 tstat in I like running cooler than 190 just seems too hot idk. Anyone got a pic showing how you ran both sending units for water temp on a 401? Don't look like I have near the room I do for oil psi fittings.. Thx again Headin out for oil install and start up will post soon
On the back of the driver side head, there is another port you can use for a water temp sending unit. It should currently have a pipe plug installed. A 1/2in ratchet should fit the square cutout. You might have to use a little heat to get it to loosen up, since they have a tendency to seize up. I'm running a 160* t-stat, and it has a tendency too cool in the fall/spring months. If it is 50-60* outsde, running at 160-170* is not uncommon. If you planning on driving it during the cooler months you might be better suited with a 180* t-stat.
UPDATE::::: Installed ddigital gauge and origilal sensor for oil... Start up at idle is 36.....I don't have temp sending unit in yet so didn't know how hot coolant was but id say 5 or 10 min tops Still at 35-36 and I don't have a tach so kinda guessing my rpm but id say if it idles at 1000 then I was at 2000-2500 And gauge shows 39-40 Apparently 40 is cut out on the orig sending unit because it flickers @39 and is out @40 I see oil on rocker arm where the rocker is on arm on RH cover when I take out fill cap. Arrm is wet clear over to other arm I can barely see thru hole. Id like to think I'm good but want to get temp number so I know op temp before any travels with it Question.... is this good bad ?? Send unit bad too high cut out for the 401 ??? Etc. Also....I'm working on temp sendikng unit...... Is it ok to put original one where it goes on front right of eng normally and take the plug out on the left rear corner and get adapter to go from that huge hole to the smaller fine threaded sending unit for temp gauge or??? I wanna keep original if I can but want an accurate read on my digital water temp gauge tbho???? Please advise so I can run to town ffor fittings Thanks again evryone Bill ---------- Post added at 02:17 PM ---------- Previous post was at 02:07 PM ---------- So I shoulda read before I posted lol thanks andy Ill put digital one on rear of eng to leave original wiring goin to front like it is. I don't plan to drive it much either route but I see my leak is at the tstat gasket so ill swap while in there..more of a seap I guess but anyhhow... When car cools down or I let pressure out of rad.....I can smush the top rad hose and feel like coolant is moving around....but man when. I had car warming up the pressure in top hose makes top hose like a rock with little if any smush and I can't feel any fluid movement...didn't look in rad to verify flow yet but I really think AZone gave me a dud for a tstat....no way it wasn't up to temp when I drove it like 1t miles last week and had oil light issues.... Ill put temp sender in tbhis evening... Anyone have thoughts on the oil pressure numbers I. Posted plz let me know Thanks again everyone!
I'd chalk it up to a faulty oil pressure sensor. 35-36psi is plenty at idle, and topping out at 40psi is the norm. Just make sure you've got good oil pressure at hot idle in gear, and you should be good to go.
yep,,what Andy says..... sounds like you are idling just a tad low... and that is causing your blink on the oil lite.... 190 deg. aint bad for a nailhead,,, up north you need that much for the heater to work good.... in the spring change to 180 deg.... or less..... yep the toggle question was for Rowdy Rhett.....
A temp sending unit in the rear of the head won't be too accurate as it is only measuring temp of coolant after it goes thru the block but before it flows thru the heads. .... Coolant in a Nailhead enters the front of the block, flows thru block and enters the heads at the rear. Then it flows thru the heads from back to front and into the water manifold. You could drill and tap the water manifold (under the thermostat) and install a sender there.
yep,,,,drill and tap the water manifold,,,,carefully ,,, or the other front side of the head.....study the internal water passages carefully before drilling....
I've experienced minimal temperature difference between the two ports. The factory sensor turns the cold light off at 110*, which is what my gauge reads when it flickers out. The factory sensor illuminates the hot light at 248*, for which my gauge read 245* during the one experience I had getting it hot. There might be a slight difference, but its certainly not drastic.
What you say is true, but bear in mind that from the factory, the early Nailheads took the coolant temperature reading off the back of the left cylinder head.
