Need major help!!! Oil pressure drop on acceleration - Harley Davidson Forums: Harley Davidson Motorcycle Forum
  • 3 Post By noxcuse1973
LinkBack Thread Tools
Old 08-10-2019, 03:14 PM Thread Starter
Junior Member
Join Date: Aug 2019
Posts: 2
Angry Need major help!!! Oil pressure drop on acceleration

I have a 2009 StreetGlide with a 103ci on it. A couple of months ago I noticed my oil pressure gauge acting funny. Sitting in neutral and revving the bike the oil pressure goes up and down as normal, and cruising down the road it's steady as normal, but when I get on it and ride under acceleration (slow or fast) the oil pressure consistently goes down until about midways through acceleration and then it goes back up to normal. Almost as if the oil was pushed to the back of the pan on acceleration away from the sump, but as I understand the baffle and sump design that's considered to be impossible. Before making any suggestions here is a list of things I've done and tried.

New SE billet cam plate and HO oil pump assy.
Oil change with new HD filter and Mobil 1 V-twin that I've run since I bought the bike
New sending unit
Manual oil pressure gauge installed directly at the sending unit port

All my local sources and mechanics are stumped. I've taken all the possibility of electrical out of the equation with the manual gauge so it's got to be mechanical.

I've seen experiences with this from searching and researching, but it always turned out to be a gauge, sending unit, or pressure relief valve. And I've never found an occurrance of it happening under acceleration like this one.

It all of a sudden started happening so it's a new problem. I'm running out of ideas. Any help would def be appreciated.

And NO it's not making any abnormal "no oil pressure" noises.

Thanks in advance.
noxcuse1973 is offline  
Sponsored Links
Old 08-12-2019, 04:14 PM
Senior Member
Join Date: Nov 2011
Location: Costa Rica
Posts: 3,398
I'd bet the oil plunger is sticking, or has a piece of crap in it.
bobf is offline  
Old 09-23-2019, 08:54 PM Thread Starter
Junior Member
Join Date: Aug 2019
Posts: 2
Well guys here it is. I still don't believe it, but here was the fix. The previous mechanic's helper that installed the new motor on it pulled the pan to clean the trash on it (which was great btw), but upon reinstallation he used a 93-99 Evo gasket on the pan instead of the correct twin cam gasket. Refer to the pics and you'll see the absence of gasket around the pickup hole that mates to the trans. Essentially like drinking through a straw with a crack in it. I'm really surprised it had as good of oil pressure as it did and didn't eat or burn anything up. It's all back together and running great. At least I learned a lot about maintenance, repair, and assembly on my bike for future cases. Thanks again guys for all the input. Classic example of human error strikes again. For reference the correct gasket is on the left and incorrect on the right and the pics are of the pan as it came off the bike.
Attached Thumbnails
Click image for larger version

Name:	IMG_6759.PNG
Views:	13
Size:	3.60 MB
ID:	761845  

Click image for larger version

Name:	IMG_6757.jpg
Views:	14
Size:	518.8 KB
ID:	761847  

Click image for larger version

Name:	IMG_6756.jpg
Views:	14
Size:	792.3 KB
ID:	761849  

Click image for larger version

Name:	59051387470__2D80325A-DB6B-41A5-81D3-71CF6B5C81C7.JPG
Views:	14
Size:	474.7 KB
ID:	761851  

Kainam, candyman1340 and JLR like this.
noxcuse1973 is offline  
Old 09-24-2019, 06:51 AM
Proud Infidel
Alan S's Avatar
Join Date: Jan 2017
Location: Southcentral LA
Posts: 2,461
Well ain't that a b!tch. Glad you figured it out.

And thanks for updating us.

Sent from my SM-A102U using Tapatalk

What is freedom of expression? Without the freedom to offend, it ceases to exist.
Salman Rushdie
Alan S is online now  

Quick Reply

Register Now

In order to be able to post messages on the Harley Davidson Forums: Harley Davidson Motorcycle Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Thread Tools

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome