Rattle when accelerating?? 2001 3.5 petrol

[01NMTAZ]

Looking for some knowledge from you guys.. when accelerating in my 2001 pajero 3.5petrol I can hear a rattle coming from engine bay.. No dip in power or any other issues just that. I'm hoping not timing chain if they have the chain..

Any suggestions? Cheers

[HomerJ]

Have you got any after market bash plates that may be loose?

[01NMTAZ]

No all stock.. would the tensioner pulley make a noise like this?

[RodMac]

Manual or Auto ?
If it is a manual you may be getting 'pinging' also called 'engine knocking' caused by the ignition timing advancing too far under heavy load or can be also caused by low octane fuel.
The spark plugs will fire too early before the compression is right and thus you hear the explosion 'rattle' going on inside the cylinder.
An auto would kick back a gear and probably not have this happen.

I once had a car that a mechanic tell my wife needed a new timing chain and when I checked it myself, it was the alternator rattling at certain revs, a quick tighten of the mounting bolts and the noise was gone.

Look for the simple stuff first.

[01NMTAZ]

Rodmac cheers.. might check the alternator and it's an auto.. does sound like a pinging / timing chain rattle kinda noise.. just using regular 91octane unleaded from Caltex.
Might throw some premium in it and see how it goes..and check timing..

[RUGGA]

I'm hoping not timing chain if they have the chain..

Any suggestions? Cheers

Petrol engines have timing belts, not chains,

[Roofchop]

Yup, timing belt, and you can't adjust the timing....


My aux belt pulleys X3 were rooted, regular knock at idle got louder with revs.


$90 ish to replace all 3.


Remove the belt and see if the noise goes away.


Cheers
Dave

[01NMTAZ]

It's only present under load. At idle it's quiet as a mouse.

[NMPajboy]

Hi,
Mine does this also, but only since changing engines and fitting extractors. Mine definitely sounds like an exhaust noise so I am in the process of going back to a stock system to see how that goes. Does yours have extractors?

[01NMTAZ]

Yes mine also has extractors.. seems to do it worse when car is warmed up after 10mins or more of driving.. what about urs??

[stumagoo]

funny you guys mention, I am combating Ping after about 10 minutes of driving - happens around 3000rpm and only under full load, I know what ha started this in mine (supercharger running 6psi) and I know that octane booster on top of 98 fuel stops it - I also know that after a couple of tanks with octane booster I can run for a tank with none (running it down until the fuel light comes on then refilling so no trace of octane booster effectively left in there). I cant remove it with extra fueling and I cant remove it by pulling timing. I believe I have a faulty injector(s) and the octane booster is cleaning or similar (some have fuel system cleaners) - the other thought I have had with a mate is a burnt valve (or 2) with carbon deposits that are getting hot - but I cant see the octane booster stopping that.

That said if you guys find another cause for your problems I would be happy to hear it