Patrol 4.8 Idle issues

[Strandblom]

Hi,

I have a 2003 4.8 GRX auto, my query is regarding the idling of my vehicle.

When the Patrol is cold, it idles perfect, even after warmup it if still fine, the problem is when I have driven a fair distance and I stop at a traffic light etc. As the Patrol idles, it seems to be missing a "beat" every 3 or 4 seconds, there is no distinct pattern, the revs just dip momentarily, goes back to normal and then misses a beat again. I would like to say that it mis-fires, but I don't know if this would be accurate. Even if I shift to neutral, it still happens

I suspect it might be the oxygen sensors, but just don't know. Perhaps even one of the coil packs, but it ildes fine when cold.

Has anyone every experienced something similar or know what this could be?

Any help will be much appreciated.

[Herrie]

I had a similar problem and when you keep the idling at 800rpm it was fine.

What I found was the the one sparkplug (no.2) was loose! Tighten it and the miss was gone.

[Strandblom]

Thanks Herrie, i'll definitely check that out. The plugs was changed about 2000km ago, as i'm going to have to remove the intakes, might as well change the plugs again while i'm at it!

Will let you know.

[Herrie]

The problem was a lot of carbon dust around to plugs that I had to clean out with the vacuum. Because of the dust - that you can't easely see because of the angle - it causes the plug to come loose because you think it is tight and as the dust move after a while , the plug come loose.

[Saltman]

Hallo Strandblom

Welcome!
Why would you want to replace plugs that were replaced 2000 km ago?
This takes me off on a different tangent regarding your problem - What plugs did you fit when they were replaced?
If they were the long life platinum plugs they should be great for 90 000 km according to Nissan.
If you fitted a standard plug that could potentially be part of your problem. I would follow Herrie's advice and check them all for tigtness when removing them. I would remove the plugs (all) and inspect them for burn patterns - did they burn normally as per standard plug charts or are there signs of fouling or running too lean etc.

Have alook at this thread for plug guidance: http://patrol4x4.co.za/viewtopic.php?f=44&t=976#p9682

Let us know!
Voorspoed
Herbie

[tour de frans]

Hi Daar
Ek stem saam met die ander manne,veral met die soort plug.Ook maak seker daar het nie n vacuumlek ontstaan met die ruil van die plugs nie.
Stupid vraag-dis nie dalk die aircon wat in en uit skop nie?Al is hy af sal hy werk met die agterste een aan,as jou kar agter een het.
Groete

[Strandblom]

Dankie vir al die inligting. Wel, die naweek het uiteindelik aangebreek, so moreoggend is dit vroeg uit die vere en onder die enjinkap. Ek sal laat weet wat die uitslag van die operasie was.

Groete

Jacques

[Tinus lotz]

ek stem saam frans myne maak ook so as die agter aircon aan is !!!!!