Multics Posted December 4, 2009 Share Posted December 4, 2009 The engine is a 100k miles RB25DET on which I change the oil and filter every 3k miles, I use Silkolene Pro-S 5w40, the engine generates around 320bhp atf. I have an aftermarket oil pressure gauge, sensor is attached to a sandwich plate on the block. Recently I noticed a weird noise when I cold start the car and the oil pressure fluctuates between 4bar and 7bar on idle. Before it used to sit at 7bar on idle until it got a bit warmer. The noise is definitely related to the oil pressure fluctuation. It goes back to normal behaviour after a minute and sits at 6bar on idle. Oil and filter have been changed less than 1000 miles ago. Any ideas of what it could be? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 4, 2009 Share Posted December 4, 2009 Probably a sticky oil pressure relief valve. Is it a stock Nissan pump? If so you need to drop the sump to get at the valve. I wouldn't worry about it, it may settle down. There are a few tricks like adding ATF to the enegine oil and idling it for an hour or two, then draining and refilling. ATF has solvents in it to remove varnish like deposits. Quote Link to comment Share on other sites More sharing options...
Multics Posted December 4, 2009 Author Share Posted December 4, 2009 Thanks Chris, I'll do the ATF trick and see how it goes. Quote Link to comment Share on other sites More sharing options...
Andy Blyth Posted December 14, 2009 Share Posted December 14, 2009 There are a few tricks like adding ATF to the enegine oil and idling it for an hour or two, then draining and refilling. ATF has solvents in it to remove varnish like deposits. How much ATF would you add when doing this? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 14, 2009 Share Posted December 14, 2009 50/50, but idle it only, no driving. Then drain fully, change filter and fill with normal oil. Quote Link to comment Share on other sites More sharing options...
Multics Posted December 14, 2009 Author Share Posted December 14, 2009 Update: I've changed the oil and filter during the weekend and the problem seems to have gone. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.