I just did a oil change on my miata a few days back. Its a 91 with a 1.8 swap and a turbo. I used Rotella syn. 5w40 oil and a Purolator PL14610 filter (just a little longer than the PL14612). Today I was driving the car at ~60mph and I noticed that the oil pressure was fluctuating a little (~5psi) at constant rpm. Some where I read that the rotella has more dtergents and will clean the engine on first use. Could this be the reason its fluctuating, with all the crap floating around? I just bought the car and the previous owner said he used Mobile 1.

I am worried and wondering if I am damaging the engine. Any pointers?

Thanks.
-Raj

 

I have a 1.8l and mine fluctuates +- 5psi but only at idle, i use mobile 1.

 

how is your oil pressure sensor mounted? If its not pointing "down" then you could have air in the sensor.

 

It is mounted horizontally. I will check the connections tomorrow.


Thanks guys.
-Raj

 

Are you using the OEM OPG and sender?? If so a few things could be happening. First if you have knock the OEM sensor reacts to it as varying readings. The second thing is if the connector on the sender is dirty it causes strange readings. I've fixed many a "I have an oil pressure issue" by cleaning the tab on the sender with some emery cloth and spraying some tuner cleaner into the connector on the wire.

 

Yes, I am using the OEM OPG and sender. I have been driving the car for a few weeks now at about the same condition and did not notice any fluctuation before the oil change. I did try to remove the connector to the sender unit to move it out of the way when trying to remove the oil filter. I couldn't get it off, but I might have loosened it a bit. I will check it tomorrow.

Thanks.

 

Yeah, check the connector as been said. Also, how many miles since the oil change? I started using the Rotella in my Jeep a few months ago and changed only the filter after about 1500 miles because of the gunk that cleaned out of the engine and stuck in the filter. I'll do a complete oil change in it after another 2k miles or so. I also plan to start using Rotella in the Miata as well with the next oil change.

 

I have only driven about 100 miles since the oil change. Will check/clean the connector this evening.

Thanks.