Drove to the coast and back today (80 mi. each way) and on the way there I noticed the oil p. gauge fluctuating mucho. It has always been just above the mid (60 lbs.) mark when driving at highway speeds (50-70 mph), give or take. Today it mostly stayed just below 60 lbs. and would inexplicibly (sp?) drop to almost zero, would pause, and would rise again to just under 60. Other times it would drop slightly and stay for a little bit and rise again to somewhat normal. Seems like a faulty gauge but wanted to check with you all. Oil level normal. Engine Temp. consistent at perfect level. No smoke. No mods. Everything else electrical o.k. '84 gsl se. Thank you.

 

I had a similar problem with my car just after I purchased it. It's scary driving along, looking at your gauge and seeing low oil pressure. Mine would drop to near zero at idle.

Turns out it was the oil pressure sender unit. New one from Mazda fitted and now the gauge reads good all the time. I believe it is a common problem (on 2nd gen?) cars. The sender often gets oil spilled on it when changing the filter. Maybe check the connection first, make sure that it is not covered in oil and making bad contact.

Langa

 

Right. Thanks. I've since found some similar problems in my searches of previous threads and some similar remedies; the sender.

 

i was about to say check the sender...