jamie1234 Posted August 22, 2016 Share Posted August 22, 2016 I recently changed the oil and filter on my 05 350z (vq35de) i used magnatec 5w30 A5 and an K&N oil filter. After i had finished i started her up and she started revving low (under 500 revs) and the oil pressure gauge was reading 90, i let it run for about another minute or so and it shot very close to the 120psi mark at which point i switched off. had a little search about but havent come up with an answer thus far. Car seemed to be running fine before this, any ideas anyone?? Quote Link to comment Share on other sites More sharing options...
ZMANALEX Posted August 22, 2016 Share Posted August 22, 2016 How much oil did you put in ? Did you definitely fit the correct K&N filter ? What year, model and mileage ? Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted August 22, 2016 Share Posted August 22, 2016 Strange one, i have heard of some oil filters becoming partly blocked and raising oil pressure due to not having a relief valve in the filter, but cant see that being your problem, other than that i wonder if the pressure sensor/gauge has gone faulty, or perhaps the oil pump pressure relief valve is stuck, however it is normal for the oil pressure to get quite high in first cold start, and it should drop when fully warm. Quote Link to comment Share on other sites More sharing options...
jamie1234 Posted August 22, 2016 Author Share Posted August 22, 2016 How much oil did you put in ? Did you definitely fit the correct K&N filter ? What year, model and mileage ? 4.5 litres Ordered from euro car parts, i don't know the exact model but it was the one they had on their system, but from what i understood an oil filter couldn't cause over pressure. 350z GT, 05, 82k miles Quote Link to comment Share on other sites More sharing options...
ZMANALEX Posted August 22, 2016 Share Posted August 22, 2016 The wrong filter or faulty filter could cause under or over pressure. Pull the oil pressure switch and hook up an independent gauge direct to the block to get a true reading. 2 Quote Link to comment Share on other sites More sharing options...
Lewis_UK Posted August 22, 2016 Share Posted August 22, 2016 This is very interesting indeed, as I too recently fitted a K&N oil filter, but I use Castrol Edge 5w40 and mine had the opposite effect, the oil pressure was abit lower than with OEM filter :S 1 Quote Link to comment Share on other sites More sharing options...
jamie1234 Posted August 22, 2016 Author Share Posted August 22, 2016 Strange one, i have heard of some oil filters becoming partly blocked and raising oil pressure due to not having a relief valve in the filter, but cant see that being your problem, other than that i wonder if the pressure sensor/gauge has gone faulty, or perhaps the oil pump pressure relief valve is stuck, however it is normal for the oil pressure to get quite high in first cold start, and it should drop when fully warm. I did run for a little while but as i said the oil pressure only increased and nearly topped out the gauge, i didn't have the minerals to keep running any longer The wrong filter or faulty filter could cause under or over pressure. Pull the oil pressure switch and hook up an independent gauge direct to the block to get a true reading. I guess i'm going to have to get someone more qualled up to have a look at it! i just find it weird how changing the oil and filter has caused such a change Quote Link to comment Share on other sites More sharing options...
Ebized Posted August 22, 2016 Share Posted August 22, 2016 The oil you have used seems to have qualities recommended by Ford for their engines. Reading the description of the oil makes me wonder whether it is also suitable for the Zed engines from: http://www.opieoils....engine-oil.aspx "Up to 75% of engine wear happens while your engine warms up. When the engine stops oil drains off critical engine parts, however Castrol Magnatec’s intelligent molecules don’t. They cling to the engine like a magnet providing an extra layer of protection. Castrol Magnatec’s unique formulation protects from the moment you turn the key, dramatically reducing* engine wear. Now with ultra-refined molecules, for protection you can see, hear and feel. Castrol Magnatec. Instant protection from the moment you turn the key." Maybe the oil on start up is just too thick leading to the pressures you have seen? Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted August 22, 2016 Share Posted August 22, 2016 If the oil viscosity is 5w30 then it will meet the required spec, iit cannot change its viscosity, it deliberately thin on cold start up to make sure it can be pumped around all the oil galleries etc without being restricted, the fact that there is suddenly an increase in pressure implies a restriction in the circulation system, it could be a malfunctioning gauge/sensor, but as it rather sudden i would suspect a faulty oil filter, so i would first recommend changing this. Question for the OP did you happen to note cold oil pressure before the change? Quote Link to comment Share on other sites More sharing options...
jamie1234 Posted August 23, 2016 Author Share Posted August 23, 2016 If the oil viscosity is 5w30 then it will meet the required spec, iit cannot change its viscosity, it deliberately thin on cold start up to make sure it can be pumped around all the oil galleries etc without being restricted, the fact that there is suddenly an increase in pressure implies a restriction in the circulation system, it could be a malfunctioning gauge/sensor, but as it rather sudden i would suspect a faulty oil filter, so i would first recommend changing this. Question for the OP did you happen to note cold oil pressure before the change? Yeah cold oil pressure was sitting at around 30-40 ish before the change ill try changing the filter at the weekend see what happens.... thank you everyone for your help! Quote Link to comment Share on other sites More sharing options...
ZMANALEX Posted August 23, 2016 Share Posted August 23, 2016 (edited) Yeah cold oil pressure was sitting at around 30-40 ish before the change That is to low for cold start. edit: "Best to fit a genuine Nissan oil filter": Edited August 23, 2016 by ZMANALEX Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted August 23, 2016 Share Posted August 23, 2016 My thoughts too.......how often is the oil changed? Quote Link to comment Share on other sites More sharing options...
Richf Posted August 23, 2016 Share Posted August 23, 2016 Pop up to H-Dev , they keep the oem filters in stock and no doubt will take a quick look for you Quote Link to comment Share on other sites More sharing options...
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