Hey Everyone.
I need help to get this issue solve. 2007 MCS 98k miles on the car. I rebuild this spring top end of the engine, new chain, thermostat, HPFP, all gaskets, oil pan and clean the oil pump strainer. Car run absolutely fine.
The issue :
When car is cold and start everything fine but after short ride 15-20min trip and stop at intersection the light pop up on the dash. Is only happen on idle or low RPM after 15-20 minutes of driving the car and oil hot and liquid I guess, if you get more then 800 RPM light is gone.
I order and installed OEM oil filter, oil cover, valve cover and gaskets, valve cover cap, replaced oil pressure sensor.
My question should I get new oil like 15w40 or get replace oil pump chain kit. Where should I need to dig? I planing to get pressure measurements this weekend. Yes I forgot to tell you guys oil level is on the top mark.

 

It sounds to me like you are indeed loosing oil pressure. Another option would be the sending unit, but they usually fail to ground which creates max pressure reading as opposed to low pressure. You could verify by manually measuring oil pressure when warm. I’m assuming if you have the technical skill to do all the work you mentioned, you can do this too. In the meantime, limit your driving as there is likely not enough pressure to ensure proper lubrication to vital components.

 

Also, my guess would be that you missed some small but important item on the rebuild... could be one of many different items.

 

I’m sure if I get some mess with rebuild it will pop up right away not like 1/2 year later and thousands miles. No smoke or oils disappear , oil leak etc. All valves clean and adjust oil rings etc. 2 days ago I installed valve cover gasket and check the timing. Is no issue all marks the same.

 

Good point. I missed that the rebuild was in the Spring. Anyway, I would still start with manually verifying that the pressure is indeed low. Then maybe drop the pan? I would just do the simplest things first. There could be some gasket sealer blocking the pickup, maybe the pickup is too low or high and is struggling to get the oil... Either way, you are right to assume then that the rebuild was proper if you put on thousands of miles after it. Either way, going to a thicker oil would not really solve the problem.

 

Ok, my plan for now is check the pressure first and get oil pan down to check the strainer and chain at the oil pump. I let you know guys , I will get back as soon I will get this work done. Thank you

 

I have same issue on my R56 MCS with low oil pressure light after some driving on idle/low rpm, also I have issues with radiator fan that dont work properly and if I put climate control on max speed then fan starts to work(sometimes it dont and I need to play with settings to make it work), coolant temperature goes down and with that setup I dont get that low oil pressure light. I have no idea how this all works, need help also

p.s I removed oil pan, cleaned strainer, checked chain etc and it didn't help at all