Volvo MD11C oil pump not priming
 

On occasions on startup, the oil pump doesn't prime. This is most likely
when the motor has been running for a while, has been shut down, and
is restarted shortly thereafter.

The axial clearance of the pump's gears in the pump body is close to
midrange of Volvo's specification, as is the gear pair backlash.

The dipstick O ring seems OK, as does the fibre washer between the
dipstick housing and the block. The dipstick tube silver soldering into
its housing is OK. (On these engines the dipstick tube doubles as the
suction line for the oil pump.) The wire gauze suction filter is clean.

I'd much like to hear from anyone who has had this problem and fixed it.

(Antispam email address - please make country abbreviation applicable to
a land downunder if replying by email)

Since I have the same motor I am interested in your problem. Question: how
do you know the pump is not priming?
Gabriel
"Derek Weston" wrote in message
...
On occasions on startup, the oil pump doesn't prime. This is most likely
when the motor has been running for a while, has been shut down, and
is restarted shortly thereafter.

The axial clearance of the pump's gears in the pump body is close to
midrange of Volvo's specification, as is the gear pair backlash.

The dipstick O ring seems OK, as does the fibre washer between the
dipstick housing and the block. The dipstick tube silver soldering into
its housing is OK. (On these engines the dipstick tube doubles as the
suction line for the oil pump.) The wire gauze suction filter is clean.

I'd much like to hear from anyone who has had this problem and fixed it.

(Antispam email address - please make country abbreviation applicable to
a land downunder if replying by email)

Gabriel Latrémouille wrote:
Since I have the same motor I am interested in your problem. Question: how
do you know the pump is not priming?
Gabriel

The oil pressure alarm remains on, and no oil flows out if the oil
pressure warning switch is removed.

I have had a bad oil pressure sender. Its seal was blown and the contact was
coated with a thin film of oil. This shorted the sender hence the low oil
alarm would sound. After cleaning the contact the alarm stopped. Replacing
the sender was an easy solution.

Gabriel
"Derek Weston" wrote in message
...
Gabriel Latrémouille wrote:
Since I have the same motor I am interested in your problem. Question:
how
do you know the pump is not priming?
Gabriel

The oil pressure alarm remains on, and no oil flows out if the oil
pressure warning switch is removed.

I've had a similar problem with my MD2B (100hrs). The alarm would go off
intermittently at various rpm. After replacing the sending unit (at $28) it
still happened. I added a pressure gage and found the oil pressure was
normal and it was the alarm module (Volvo OEM). They want $140 for a new one
and I am going to add one that is after market for about $40. Right now I
have the alarm module disconnected.

Steve
s/v Good Intentions

Steve wrote:
I've had a similar problem with my MD2B (100hrs). The alarm would go off
intermittently at various rpm. After replacing the sending unit (at $28) it
still happened. I added a pressure gage and found the oil pressure was
normal and it was the alarm module (Volvo OEM). They want $140 for a new one
and I am going to add one that is after market for about $40. Right now I
have the alarm module disconnected.

Steve
s/v Good Intentions



Thanks for the info gentlemen. Unfortunately, my problem isn't the
pressure switch or the alarm module. I have replaced the switch, and if
I remove it on the occassions it indicates a problem, no oil flows from
its threaded hole in the block when the engine is turned over.