Hello everybody! I have just traded for my first ever Volvo; a 1989 740 GL that runs well but unfortunately has the oil pressure light illuminated. I've read some other posts and it looks like it could be a blocked screen, seals on the transfer tube or the oil pump itself. The light appears very dim when the car is started (runs great oddly enough) but as it warms up, the light gets brighter. Would anyone have any advice on where the problem would most likely be?
It has 240,000 miles on it and I've only got a grand into it, so I'm also looking for any advice on what I can look at to determine if it's a good vehicle to hold onto as a fun weekend beater worth putting a few bucks into, or if I should sell it to someone looking for a project who could devote the time and energy to it that it may need. Are there any things I should look out for that are Volvo specific problems; like how old Cadillacs need the timing chain replaced or they tend to blow, or how old Lincolns and Mercurys need a solid vacuum system otherwise it's a fortune to replace? Any advice is appreciated, thanks!

 

How's the oil? When I got my car the oil hadn't been changed in over a year and it had an oil light at idle after it warmed up. Also you can check the wiring for the pressure sensor. Could be shorting on something.

 

Cwazywazy: Thanks for the reply! The oil looks nice and clean and looks fairly new, but I will do an oil change anyway just to be on the safe side. I'll check the wire as well, from what I've read I believe the gauge sensor is near the oil filter so I'll check that when I do the oil change. I've read 10-W30 is recommended for these engines, is that still true for when they have excessive mileage, or should I move up to a thicker viscosity? In my classic cars I tend to run 20W-50 to make sure everything is properly lubricated when they warm up, should I do the same for a Volvo?

 

10w30 is fine, I have 15w40 in my engine because it was cheap. The sensor is next to the filter and I don't know if you have biodegradable wiring, but if you do the insulation will probably be flaky/gone like mine was.

 

The light seems to be acting consistent with low pressure. Still, check the wiring to the sensor--shouldn't be a problem in an '89 but oil may have contaminated it. Then take an oil pressure reading to see what it actually is. If the pressure is indeed low, the oil pump would be the prime suspect. As an interim cure you may try a little heavier weight oil.

 

Pulled the sensor and the light went off immediately so the sensor seems to be in good working order. When I get back from my honeymoon I'll go get a gauge for the oil (I've read that I need a special adaptor to get it to work with the engine) and do an oil change. Thanks for the replys everyone!