[morton]

Have just bought a 02 4.8 patrol When starting up when cold , motor noisy for about 1-2 seconds and idle seems high on start up as well. Idles at 1100 once settled. Has any one else noticed noise on start up , maybe idle needs to be dropped down , how do i lower idle?

 

[Cornelius]

1100 seems high for an idle. My 4.8 of the same year idles around 750 rpm once the engine is warm , cold engine and the idle is a little higher. What kind of noise do you hear on start up ?

 

[MelloTB48]

u will need to take it back to nissan so they can put it on the computer and do a idle re-learn on takes a matter of minutes. as for noisy on start up is it only when cold??
the start up idle will be high to start off with as it will be in cold start mode and slowly get lower as the engine warms up.
hope this info helps

 

[morton]

its like a rattling noise i thought it might had something to do with oil pressure on start

 

[MelloTB48]

the rattling is probally caused by low oil pressure at start up. Wot type of oil do u use??

 

[4.2BeautUte]

Yeah your oil is either worn/dirty or the wrong viscosity. Quite common for Nissan petrol's to have a little rattle on startup if the oil is not right. My bluebird and maxima did it and the VL commos were renowned for it. My 4.8 has done it once or twice on a cold start when it was due for an oil change, change the oil and all good again.

As far as the high idle goes, on a cold start it should jump up to about 1500-1700rpms straight after start and then quickly drop down to about 1100rpms and then slowly slowly drop down to about 750rpms. You can also re-tune the idle without plugging it in to a computer if you follow the service manual instructions, but I've never had to do that to mine.

 

[GUIII4.8er]

Yeah I agree with above, it ides at 1500rpm or bit more for a bit when cold start but should idle at 750rpm when engine is warm. As for the noise, must be the oil.. Change it to correct viscosity if necessary.

All the best.

 

[patrol24]

I hear this sound too in my 02 4.8L when i start up the engine in the morning i mean when the engine is really cold

 

[brads4wdmad]

PM sent

 

[morton]

thanks for info wil be changing oil. as far as idle adjusting i dont have a manual ,can anyone help me out with this procedure.

 

[crusty351]

Hi Guys, What is the correct oil viscosity. I have just had the head reconditioned and had brian crower cams and valve springs and it rattles the timing chain at 2000rpm. it has new chain, guides and tensioner as well