Oil Pressure Light ON!!

BigSky

My 1937 Hudson 8cyl engine Oil pressure light came on the other week as I drove it to its new home. I was going 35mph when I saw it on so I slowed it down to 25 since I was a mile away and continued.



The light will not go off after starting it a couple different times. There's plenty of oil in the pan, per the dip stick. The wire in the engine compartment to the oil pump hasn't rubbed off on anything to cause a ground (at least in the engine compartment that is).



I would love some suggestions on how to continue to diagnose the pump/light problem. Right now I am hearing a deep knock or shall I say rattle and I dont want to loose the 8cyl engine, so let me know your thoughts.



Thanks,

Brian

Unknown

Assuming the 37's oil pump is similar to the 48-9's (pretty sure it is), test the pressure by loosening the nut on the line that from the oil pump goes to the front of the engine. Stick of section of clear tubing on the end and put the other end into a jar or something so you dont spill oil all over. Start the motor up and see if anything comes out. These pumps are not high pressure by any means, but you should get a descent flow out of it. If you dont, pull the pump first and check it on your bench by using same clear tubing and placing on end in a jar of oil and manually turning the pump gear. If it appears to be working fine, then you might have to check for other issues like a clogged pick up in the oil pan (or a line to the pump), or air might be getting sucked in to the system. I personally just learned the last part to be true with my own. Those lines to the pump must be clean, tight and snug. Hope that helps.. Good luck.

[Deleted User]

Brian- First disconnect the wire from the terminal on the sender on the pump. If the lite goes out do as Dennis said. If it stays on the wire to the lite must be groinded Norm

Unknown

I had a similar problem with my 39. I solved it by removing the oil line going to the pressure switch and filling an oil suction gun with motor oil and pumping the oil pump full. I replaced the line, started the car, and it seemed to fix the problem. I assume that with such a low pressure system, if the oil pump loses its prime, it is hard to get it working again. Hope this helps.

Oldpatt

BigSky

Thanks all, I will first try the wire then check the pump. Hopefully the rattle is just b/c of lack of oil or my over active hearing with the issue in hand, not damage to the engine. The 8cyl really makes that old car.



Once I get it fixed and assuming I haven't damaged the engine does anyone suggest an oil and/or viscosity to use in the old girl? I have been contiplating synthetic just for this type of a situation as I drive down the road.



Thanks!

Unknown

Brian ... you have plenty of 8 cylinder assistance right in Omaha. Check with Charlie Harris in Spring field ... has an 8 in his 52 Hollywood as well as his 46 pickup. Dr Jim Johnson is a Omaha native and another help... both can put you in touch with other club members who can give specific assistance for Hudson 8s.



Cheers ... former Omaha resident and member of the Nebraska Iowa Hudson chapter...

BigSky

Ken,



I was thinking of calling Charlie the other day when I was somewhat close to his place. I will have to call tomorrow. I dont think I know Dr. Jim Johnson but will ask Charlie on that as well.



Thanks for the note and I hope you make it to the nationals in Kearney this year!

Geoff

Don't on any account drive the car any further or run the motor until you have the problem fixed. It could be a stripped cam worm which meshes with the pump drive gear. I would disconnect the pipes to the front and rear and pump some oil in there manually to fill the troughs before you run the motor again. Having done that you can then run the engine for a short time to see if the pump is working, with one of the delivery pipes disconnected. You can unscrew the end cap off the pump to see if the plunger is oscillating. If it is you then have to check the suction side for air leaks. If it is not, then the gear is stripped. Good luck,

Geoff.

BigSky

Geoff,



When you say pump oil into the troughs, what exactly do you mean by troughs? upper tray? oil lines? I want to make sure I am on the same page with you.

Also, the delivery pipes? are you speaking of the copper pipes on each side of the pump? If so, would the line after the pump going up to the upper front side of the engine be the best to disconnect from the engine or just at the front side of the pump? Finally, when you say end cap, is that the cap on top of the oil pump? Would it be worth running a flexible wire or what not down each line away from the pump to make sure theres nothing clogging it or is this not necessary since the pan may need dropping soon? Do you also know if I can find an oil pressure gauge to put in the line permanantly which would read the low 4-5 lbs of pressure?



I appreciate your thoughts and everyone elses, for I feel like a father with a kid in the hospital with my hudson broke!

Geoff

I mean the upper tray, which is trough assembly for the connecting rods to dip into. One pipe goes to the front, and one to back, from the pump, and one to the centre, which is the intake side. You need to get oil into the front and back to fill the troughs. You will have to remove the pressure switch to get oil in the back, as there is a check valve in here which will not allow you to jut put oil in the pipe to get into the rear trough. Perhaps it would be better to remove the tappet cover and put a pint of oil in each end there. It will dribble down into the troughs through the drain holes. There is no need to run anything through these pipes, they will never clog up. the early Hudson and Essex models up to 1931 had lowpressure gauges for indicating the oil delivery, you may be able to find one of these somewhere, I don't know. the oil pump has a hexagonal cap on each end. You can take one of these off and crank the motor over on the starter and see if it oscillating. I doubt that it would be the seal around the intake flange, as this is unlikely to just suddenly fail. Good luck,

Geoff.