xfish 20 Posted November 20, 2017 Hey Guys, The 98 EL XR8 is having an oil pressure issue. Driving around suburbs is fine, but when i drive onto the freeway for a distance and hit the suburbs, i noticed the oil pressure drops (sometimes so low, the alarm is triggered). If i put a few revs on idle, the oil pressure rises. Then if I go back onto the freeway, the oil pressure rises and stabilizes. It appears i have the issue only after going for a drive on the freeway, and then the idle comes down while driving in the suburbs, then oil pressure gauge goes awkward. So, I already have replaced the oil switch and no success. Changed the oil, with no success. Currently have 10w - 40 oil in her. Would it be wise to go to a 20w - 50, or go to the trouble of ripping the sump off and changing the oil pump? Definitely no heating issues either.The motor is pushing 200,000. The idle is just over 800 rpm. Any ideas? Share this post Link to post Share on other sites
Outback Jack 6,352 Posted November 20, 2017 Sure its not just wiring problem? If not Id change pumps or you got a leak/ block in oil pickup.Did you change the oil filter... if clogged get those symptoms.Worst is oil pump change.Sent from my GT-S7583T using Tapatalk Share this post Link to post Share on other sites
deankxf 20,287 Posted November 21, 2017 i'd fit a separate oil pressure guage to make sure it's not an issue with the cluster one(unless you can try another cluster) before doing engine pull down. is that the right oil viscosity? i'd have no idea, but higher kms sometimes prefer thicker oil to some extent 1 Outback Jack reacted to this Share this post Link to post Share on other sites
Mr Polson 10,214 Posted November 21, 2017 What brand of oil?I'd probably try something like Penrite HPR15, which is a 15W60, with extra zincSent from my Pixel using Tapatalk Share this post Link to post Share on other sites
Valvebouncer 2,389 Posted November 21, 2017 i'd fit a separate oil pressure guage to make sure it's not an issue with the cluster one(unless you can try another cluster) before doing engine pull down. is that the right oil viscosity? i'd have no idea, but higher kms sometimes prefer thicker oil to some extent ^^ this.Does it burn much oil? What are the plugs like? Are they getting burnt oil ( barnacles) building up on the plugs? I’d do a compression test. No point putting a new pump in a stuffed motor.If the gauge is reading right then it sounds like you either have a relief valve problem or excessive clearances in the motor which would mean a rebuild. Share this post Link to post Share on other sites
bear351c 10,270 Posted November 21, 2017 Fuel Injectors can leak, and thin the oil down a notch or two. Try 20W-50, Cheaper than oil pump. Although it does sound like the pump is worn out. the thicker oil will help the pump clearances. Maybe bump the idle up to 900. Share this post Link to post Share on other sites
xfish 20 Posted November 21, 2017 Thanks for all the ideas. Yes, the oil filter is new. No burning oil. The engine oil doesn't feel diluted with petrol. Injector and rails are new. We'll try a separate oil pressure gauge, then a thicker oil. How is it possible to increase the idle? I thought it was all controlled via ECU.... Share this post Link to post Share on other sites