9n Loss Of Oil Pressure As Engine Warms Up.

Paul White · Jun 24, 2013

What could be causing this 9n tractor to lose oil pressure as the engine warms up. It carries 50 lbs. at start up idle. As it warms up it will drop to 20 lbs. at high idle and 5 lbs. low idle. Complete rebuild was just completed with the exception of a new camshaft and lifters. 30w non detergent oil. Is this normal Please help !!!!!!!!!!!!

36 Coupe · Jun 24, 2013

No cam shaft bearings in the 9N if I remember right.Dropping oil pressure says worn bearings.Hot oil thins out.Oil pressure at low idle dosent mean much.Whats the pressure at 1000 rpm.You could change to a 10/30 oil to see if pressure comes up.

W_B · Jun 24, 2013

Sounds normal to me. My 8N does the same thing, but more importantly, it runs in the 25-30 range at working throttle setting. Running 10w-30 oil and new guage, so it should be pretty accurate.

Lisa K · Jun 24, 2013

My 8n that was just rebuilt carries almost 50 pounds cold and 20-25 hot at low idle. I run Rotella 15-40 in mine

NOXJohn · Jun 24, 2013

That is not too bad for an N engine even a recently rebuilt one. You may try replacing the oil pressure spring, part#9N6654. That may help. You should consider getting it at New Holland. Also Ford recommended using 40w oil in the summer. I use 15w-40 year around and have had good results. My three 8Ns with about 125 hours/each on a rebuild carry 35-40 lbs when cold and 25-30 when hot.

teddy52food · Jun 24, 2013

Spring is ok if it comes up to 50 # cold. It has leakage from loose bearings or worn oil pump.

teddy52food · Jun 24, 2013

Was the crank ground & fitted with the right bearings?

souNdguy · Jun 24, 2013

ditto what teddy said.

oil spring is fine if it makes 50 at startup.

was the oil pump rebuilt during this rebuild?

cam inserts can be made if needed.

me personally? i like 15w40 oil.

as a rule of thumb, if it will make 6psi per 1000 rpm at hot 'idle' it won't self destruct. obviously more is better.

hapve you ever repalced the gauge to see if that is what you are really getting. a gauge that is 3 psi wrong means alot when you are looking at 5 psi or 8 psi

Dell (WA) · Jun 24, 2013

Paul........you do know that the 9N was originally designed for 30wt DETERGENT oil, don't you??? Ford also recommended 40wt DETERGENT oil while working in HOT climate.

You do know that oil THINS when it gitts HOT, don't you??? That is called viscosity factor. No matter how good yer oilpump is, it can NOT make high pressure outta thin oil.

I don't like 10-30wt oil as it is THIN 10wt oil with temperature sensitive additives. Me? I use 20-50wt detergent oil.

Iff'n yer low HOT temperature oil pressure bothers you, change to 50wt RACING oil. (and filter) Simple, eh? .........oily Dell

Dean · Jun 24, 2013

Classic symptom of excessive clearance in oil pump.

Installing a new kit in an oil pump with a worn housing will not cure this issue.

Most rebuilders do not replace the oil pump housing as it is integral with the front main bearing cap and replacement requires align boring of the block.

It will likely operate find for decades as is.

Dean

9n Loss Of Oil Pressure As Engine Warms Up.

Paul White

Member

36 Coupe

Well-known Member

W_B

Well-known Member

Lisa K

Member

NOXJohn

Member

teddy52food

Well-known Member

teddy52food

Well-known Member

souNdguy

Well-known Member

Dell (WA)

Well-known Member

Dean

Well-known Member

Similar threads