MY03 4lt V8 HSE engine pinging

[Ned Kelly]

Hello all, this is the first time I have used this forum and I am hoping someone can help. I am based in Australia and no one here or in the UK forum has been able to help.
I have an 03 Disco V8 HSE with all the bells and whistles. I allways use a petrol with RON98 rating. Once my enging gets to full operating temperature and after about 30 mins of driving I hear a pinging noise from the enging when it is under load going up a hill. You can induce this by squeazing on the throttle and once it drops gear the noise will pretty much go away in 1-2 seconds.
Has anyone experienced this problem? The engine only has 50,ooo km's on it. Sometimes this pinging is very loud and lasts fer a few seconds, sounding like someone is wrapping a tyre lever around in a milk churn. It may not be a "true" engine ping but certainly sounds like it. The dealer has told me all the knock sensors are working fine and no alarms have come up on their diagnostics computer. I have even had the front exhaust changed thinking it may have been a rattling catalytic converter but no luck. I am now wondering if it is a dicky oild pump or the pick-up rattling on the sump but I am getting desperate and clutching at straws now. Has anyone had this issue or have any suggestions on what it may be?

[Muddy Oval]

The knock sensors may work, but it sounds as if the computer isn't doing anything with the data. The Testbook or any decent scan gauge can be taken for a ride and you could watch to see if the timing is adapting to the load... sounds as if it isn't. Friggin dealers and their friggin "no code, no problem" keeeerap.

[Rovin4life]

And what throwing aftermarket parts at the problem at the customers expense until they are frustrated cause you didn't fix the problem is a better approach anyway,


of course in your case you can throw a million parts at the problem and then say,

Go to the dealer, They can fix your problem.

give me a break Muddy, Do this job as any dealer technician and see how this industry works.

Its great to sit on the sidelines and scream and yell about how bad dealers are when you work for an independant selling thousands of parts to solve all of their problems,

[6cuda6]

Ned, the first think i would do is change fuel brands....i have found that not all fuels work the same in a vehicle [ the same 94 octane fuel from different brands will make my car knock and others won't]. The other thing to try would be some sort of injector/combustion chamber cleaner as it's possible that the engine is all carboned up. If this fails to remedy the problem you'll have to find a shop that knows how to read spark plugs to see if you indeed have an ignition type problem [i have my doughts at this point as you do not have an "check engine light" on]. If this fails to remedy the issue you'll need a good mechanic to help you diag the noise.....and at least you will have removed some of the variables. Later, Dean

[Muddy Oval]

I didn't suggest putting a single part on that truck- just actually doing more than looking for a code like some friggin Rover Druid. You could park a truck with four flat tyres in front of many dealerships and they wouldn't know what to do because there's no code for a flat tyre.
Don't throw parts at it- get a real technician to examine it.

[02disco2]

(grabs a bag of popcorn) This is getting interesting!

[6cuda6]

Do i smell smoke????

[Ned Kelly]

Thanks for your replies guys. The dealers who have looked at this can't take a crap if the computer has not told them to.....
I've tried changing fuel, BP, Shell, Mobil, Caltex but the problem persists. I also only used RON98 as a standard and have tried a lower octane fuel just to see if it made the pinging more obvious and nothing at all happened apart from my fuel economy blowing out. I have also de-carboned the engine. I have also had the latest software downloaded, gearbox re-mapped to the engine etc.....
I am now concerned that it may be a sleeve in the cylinder block that has come loose? I just dont know I guess and LR don't seem too interested..........

[6cuda6]

Ned, this may sound like a funny question but have you made a visual check of everything that moves on your truck....start at the front, stuff like battery tight etc...than work your way back [so check stuff like hoses hitting the firewall etc] than underneath, than in the trunk [if you want to call it that]...your looking for anything that can hit the body....make a note of anything that looks suspicious....

Than if everything looks fine, grab the tire iron and check to see if all the wheels are tight [don't laugh, i have seen lug nuts come loose and the wheels move making noise]....

What you are doing here is covering all the basic stuff the tech will check anyways....

Can you duplicate the noise??? What do you need to do to make it happen??
Is it there all the time??? IF not when???
When do you think it started to happen??? When was the first time you heard it???
Have you changed anything recently???[ie; added a roof rack, changed the oil etc...]

These are all things a tech should be asking you.....the more info you have to present the easier it will be for the tech to hear the noise and make a diag or track the noise down.....

Later, Dean

[6cuda6]

Oh yah forgot..if you had a loose piston sleeve....lets not go there...lol...

[Ned Kelly]

G'day Dean,
I was hoping to go over it thoughroughly this morning to do just that but the wife has decided to go shopping with the car..........grrrrrrrr.
The noise has allways been there and only comes up when the engine in has reached its full operating temp after about 30mins or so. The sould comes on when you are going up a hill or accelerating so I guess this is best described as putting the engine "under load". It wont do it if the car is stationary. Its definately coming from the engine bay area. I have even changed the front 2 exhaust down pipes thinking it may have been a loose ceramic block in one of the cats but no difference, but that is the sort of sound it makes.
I am pulling my hair out over this.........

[6cuda6]

Ned, try to see if you can make the noise when the vehicle is stationary.....so get it up to operating temp [like you would to make the noise] then stop, hold the brake with one foot and try to accelerate with your foot on the brake [we call this stall testing] ....don't do it long, just enough to try to make the noise....[make sure nothing is in front of you just in case]...if no noise is heard i would suspect it is something moving that shouldn't be....

If the noise is there....look at stuff like engine components etc...

If no noise can be produced that would tell me that you have something that is vehicle pitch sensitive....so when the vehicle is in the accel posture something is hitting something or loose [so stuff like Ujoints etc....]...You may have to go as far asraising the truck up in the nose...

Dean

ps; you don't have a grease Zerk on the front drive shaft do you by chance???

[Ned Kelly]

all very good suggestions and I will do this when the wife gets back and takes all the new shoes out..... By the way, what is a grease Zerk on the front drive shaft?

[6cuda6]

A grease nipple or a grease fitting so you can put grease in the shaft.....

[Ned Kelly]

I am just about to get under it and will let you know. I havnt got a grease gun (I may have to buy one) but hopefully giving them a bit of a shake around would identify any issue?