I am a little confused on this one. I have a Harley oil pressure gauge on my ride and at start up it is in the 30# area and at cruse up to 40#. But then it goes to 7-10# at idle and maybe 15-20# at cruse. I know as the oil heats up it will thin a bit but still?

This was with Harley synthetic that was changed at 1000 miles. So yesterday I threw a new filter and 3 qts of Aimsoil in her now at 4300 miles thinking it might be the oil/filter but still got the same results. The oil that came out looked great and no visable metal shavings or chunks.

Do these # sound normal? I am not really concerned and the idiot light is not coming on but just wondering if the numbers sound a little low. I asked the dealer and he tried telling me that 5# is common-LOL

 

I say its normal

 

It's normal. Keep your eyes off that gauge and just ride it.

 

Based on my experience with my '08 Heritage, your numbers sound low. At startup my gauge reads around 40- 42. After warm up, even on a hot Arizona day, I cruise at about 30 - 32 and my hot idle pressure is around 10-15. I don't have a Harley gauge. I have an Auto Meter gauge, Harley oil cooler, run synthetic oil, and a little over 26K miles. For a relatively fresh motor your numbers sound low across the board, especially your cruise pressure. If I were you, I would have a mechanic verify your oil pressure.

 

IMHO oil pressure gages on HD's is a giant distraction.

 

It's normal. I run straight fifty weight Dino oil in my Evo (what Harleys have run fine on for a hundred years, LOL) and these motors don't actually depend on much oil pressure except to oil the top end. And that doesn't take much pressure at all. The bottom end uses "oil volume" to lubricate the crankshaft bearings and the cylinders by virtue of the flywheel just physically throwing the oil around. If you want to see how well this works warm the bike to full operating temperature (so your oil pressure gauge is reading low at idle) and with the motor still running remove the timing hole plug. Oil will shoot out that hole like a frigging blowtorch!

Your oil pump also has a spring controlled check valve that directs more pressure to the top end when cold than when warm. That's more the reason the pressure eventually goes down rather than directly because the oil is thinning out. (BTW, that check valve not fully closing, and the bike left sitting for sometime, is what causes Harley motors to wet sump, which is simply too much oil collecting in the bottom of the cases.)

So an oil pressure gauge is only a distraction if you read it wrong. It's not the numbers that count as it's more for monitoring trending. Once you get used to how it reads on a normally operating motor you'll be quick to realize something is wrong when it suddenly differs.

 

OK, I guess it is normal. Thanks for the responses.

 

Well said and I agree.

 

That's why I don't have one! I have enough **** to worry about.

 

lot better than (0).