Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 07-05-2009, 08:39   #1
Registered User
 
Beausoleil's Avatar

Join Date: Jul 2007
Location: Potomac Shores, VA USA
Boat: Formosa 51 Aft Cockpit Ketch - "Beausoleil"
Posts: 565
Images: 1
Genset - sudden jump in oil pressure?

What would cause a sudden jump in oil pressure - from about 45psi (normal) to about 110psi?

The last couple of times I ran my Westerbeke BTD-7.6 genset, after about an hour or so of runtime, I noticed that the oil pressure had spiked. The load on it at the times I noticed it was about 15A (1st) and 25A (2nd). Both times I was charging the batteries (125A and 75A chargers) while running the Spectra DC (14A max) watermaker, and running the electric hot water heater (120V 1500W). The chargers had tapered off, so the majority of the load was the HW heater. The genset powers two 30A legs on the AC side, with the 125A charger on one, and the 75A charger & HW on the other. I don't think the electric side of things is the cause - just putting it out here for completeness.

The genset's fairly new - 276 hours on it. I did recently change the oil, filter, and heat exchanger zinc. I double-checked to make sure I didn't overfill the oil sump. What else should I look at? I'm running the genset as I post this - 25 minutes and the oil pressure's normal - 45psi, load on it is currently 30A - 50%. As an FYI - I know the genset is typically under-loaded, but later this month I'll finally install the two A/C units (12k & 16k BTU).

Any ideas? The engine temp doesn't change, or the perceived loading on the engine (no noticeable change in sound). Could it just be a failing oil pressure sensor?
__________________

__________________
Cap'n Jon (KB1HTW)
S/V Beausoleil -1979 Formosa 51 Ketch
"If it's gonna happen, it's gonna happen out there." - Captain Ron
Beausoleil is offline   Reply With Quote
Old 07-05-2009, 10:22   #2
Senior Cruiser
 
skipmac's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: 29 49.16 N 82 25.82 W
Boat: Pearson 422
Posts: 12,376
I would check the sender first myself and also the gauge. Not a pro mechanic so not sure but I believe you can screw in a portable gauge or tester to verify the pressure. Also check the wiring going to the sensor and gauge to make sure nothing is loose. Otherwise I guess you would have to swap out the parts to confirm that part of the system is functional.

If you verify that the pressure is spiking I do not think that high a pressure would relate at all to load. I would focus on blockage or restriction in the oil system. Since you just changed oil and filters I would start there. Maybe put in another filter in case that one has a problem. Check to make sure you didn't lose a washer or o-ring into the system.
__________________

__________________
The water is always bluer on the other side of the ocean.
skipmac is offline   Reply With Quote
Old 07-05-2009, 11:04   #3
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,580
Images: 240
Quote:
Originally Posted by skipmac View Post
... I would focus on blockage or restriction in the oil system. Since you just changed oil and filters I would start there ...
Indeed.
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 07-05-2009, 11:10   #4
Registered User
 
Beausoleil's Avatar

Join Date: Jul 2007
Location: Potomac Shores, VA USA
Boat: Formosa 51 Aft Cockpit Ketch - "Beausoleil"
Posts: 565
Images: 1
Well, after speaking to a diesel tech at R. B. Grove down here in Florida, and he thinks it's the pressure sender. Since the oil filter mounts horizontally and has only a gasket near the outer edge (like normal), he's inclined to think it's the sender since he can't think how the gasket could have worked loose - plus I'd see oil leakage. He thinks the cause is the sender, since those seemingly have a higher failure rate in his experience. I have two which were included in the initial spares pack that came with the genset, so I'll check that first, once the genset cools down. I'll report the results back here later...
__________________
Cap'n Jon (KB1HTW)
S/V Beausoleil -1979 Formosa 51 Ketch
"If it's gonna happen, it's gonna happen out there." - Captain Ron
Beausoleil is offline   Reply With Quote
Old 07-05-2009, 14:04   #5
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,580
Images: 240
Test your gauge & sender, per this post:
Basic Engine Gauge Theory and Testing
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 07-05-2009, 14:52   #6
Registered User

Join Date: Dec 2008
Location: ontario canada
Boat: grampian 26
Posts: 1,743
oil pressure

If the guage and sender check out then it is probably the pressure relief valve that is sticking.
__________________
perchance is offline   Reply With Quote
Old 08-05-2009, 11:17   #7
Registered User
 
Beausoleil's Avatar

Join Date: Jul 2007
Location: Potomac Shores, VA USA
Boat: Formosa 51 Aft Cockpit Ketch - "Beausoleil"
Posts: 565
Images: 1
I re-terminated the sender wire at the sender end, and the problem hasn't re-occurred. I'll see what happens over the next couple of days.

Thanks for the info, Gord - both the new and old sender tested fine.
__________________

__________________
Cap'n Jon (KB1HTW)
S/V Beausoleil -1979 Formosa 51 Ketch
"If it's gonna happen, it's gonna happen out there." - Captain Ron
Beausoleil is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not 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 Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Oil Pressure drh1965 Engines and Propulsion Systems 18 07-07-2015 17:03
Oil Pressure on Volvo D1-30 nils Engines and Propulsion Systems 13 27-10-2008 08:13
Ruggerini low oil pressure Westie Engines and Propulsion Systems 6 18-03-2008 14:27
4.108 Oil Pressure cburger Engines and Propulsion Systems 14 01-02-2008 10:52
What is Normal Oil Pressure for ... Dave-Fethiye Engines and Propulsion Systems 17 06-10-2007 19:59



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 10:51.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.