oil pressure

[joeh]

hi i am new to this thread.
i have a volvo MD 6A on my 28 yr old sloop.
the oil pressure alarm lit n sound off over the weekend but a check of oil level n leaks yield nothing unusual.
any ideas n suggestions as to possible problem most welcome.
thank you.

 

[spannerman]

In view of the age of the motor I would suspect the oil pressure sender unit first, only a few quid to change if you buy from an auto factor, if poss I would put a manual pressure gauge on just to confirm the actual pressure is OK. If its low then when did you last change the oil filter? If recently then it looks like you are going to have to pull the motor to investigate it further.

 

[vyv_cox]

Low oil pressure might be an indication that the level in the sump is low but what it is really telling you is that there is leakage between the oil pump and various bearings in the engine. The "leakage" would be air in the system if the sump level was low, but since this is not the case the cause is something else. It could be wear of the pump, wear of the bearings, a failed seal or gasket in the supply system, or a faulty indicator. On the basis that checking the cheapest option first makes sense, try replacing the switch with one that works on another engine, or a new one. As suggested above, installing a temporary gauge gives you far more information than just a switch so it's worth doing. If the low pressure is genuine it is probably an indication that your engine is ready for some reconditioning.

 

[joeh]

if i could use a manual pressure gauge what should the reading be ?

 

[spannerman]

Not sure of the exact readings for this engine but would expect around 20 psi at idle with warm engine, rising with speed to 40 ish.

 

[joeh]

thank you all.