3.5 rover V8 pinging on normal unleaded

[chriso73]

G'day guys

My problem is my range rover 88 efi 3.5 V8 pings like there is no tomorrow when running on normal unleaded, as a result I run premium. I have checked the ignition timing and it is perfect 6 degrees BTDC. One mechanic said to me that the harmonic balancer could possibly slip on its rubber mount, and therefore showing an incorrect timming reading.
The engine has only done 160000km and in good nic

Any thoughts or information would be great
Cheers Chriso73 style_emoticons/<#EMO_DIR#>/smile.gif

[Rovernaut]

Try advancing the timing and see if it disappears.

[LandyAndy]

Advancing the timing should increase pinging.If the engine is running in top notch,the extra you pay for in premium should work out in a better mpg ,therfore actually more cost effective.
Andrew

[Rovernaut]

OOOPS! I should have said RETARD the Timing, and see what happens

[Hellspawn]

Don't think adjusting the base setting will do much. If it's EFI then I'm guessing the computer controls ignition too.

Had a mate's Magna doing a similar thing with the pinging so onto the rollers and found it was the computer. The part that controls ignition timing was if I could put it "dying" and the base setting would always stay exactly on the mark. Lift the revs with the timing light running on the markers, the crankshaft notch would wander all over the place instead of a "relatively" stable advance. So we swapped computers from a wreckers dunger that had a good motor. Back on the rollers, difference was mild though does not ping, even when he ran out of fuel and I only had two stroke which he used to get himself back into town (oil lowers the octane rating so increases the ping probability).

The only other thing than comes to mind that might make it ping is an air leak though you'd tell as it would "stumble" or be difficult to set an accurate and stable idle.

That said, my pre '86 engines ping unless premium is used. The Mazda pings on anything but optimax.... yep dun like Vortex (dunno why and haven't asked the question... just does) though I am yet to try the BP ultimate which is supposed to be as good as it gets for pump fuel. The rover only pings when its really hot weather and being worked hard, which is about when optimax gets tipped into the tank then will just keep going no matter how hot it gets.

[strange_rover1]

Gday,
Our family runs 2 3.5s and 1 3.9lt which all ping unless run on BP ultimate or Shell optimax. Dont know the reasons, we have just excepted it. The 3.9 is supercharged and has Motec engine management and still pings on anything otyher than premium.
Shano 8)

[shaunp]

They shouldn't ping at 6 if it has standard compression. Ignition on these engines is basic dissy with vac and mech advance. What you need to do is check the advance curve of the mech advance as the springs may have lost tension and bringing the advance in too early. Other things to look for are , spark plug heat range, carbon build up, lean mixture on load or full throttle, oil entering the combustion camber. I run my 3.9 Dico at 6-7 btdc no pinging at all, but the engine is good and has stock compression. Don't let it ping heaps, easy way to kill an engine. I broke the ring grooves out of 7 pistons in blown small block in a very short time from a little detonation.

[DEFENDERZOOK]

just retard the timing 1 degree at a time till the pinging stops. irrespective of the harmonic balancer possibly slipping.

it may have blocked injectors. faulty lambda sensor. or one of many other non serious problems causing it.

the fuel here is absolutely crap. to run octane booster costs around $10 per tank........not worth it unless you racing regularly.

if you have to retard the timing so much as to compromise performance
then you should find the problem and correct it.

i would say the problem is just bad fuel. we all gotta wear it

[Malibu9]

I have a 4.6 in my Rangie the low compression engine and it will ping on Unleaded. My girl friend has Feroza and it pings on unleaded aswell. If we use premium no more pinging. But lately I have been using regular unleaded with ethanol in both cars and no more pinging. People have had problems in the past with ethanol in fuel but now the ethanol has been stabilized and is good for the fuel.