Thread: So the PUMA goes back to the garage again tomorrow

Sounds pretty much the same as my car, at the same time too. We have some cold wet mornings coming over here soon, I'll have to start recording my morning drive.

Cheers,

Tim

PS I must say I make strange noises when I'm woken up in the morning, perhaps it's just coming out in sympathy??

we had another recording too..Ian records every morning now but we really need to do it with a camera...problem with the mobile phone is i think there video and sound recording pick up to much ambient noise.

the idea is all recordings have date so we can prove how much it does it.

well the dealer covered the cost of the filter replacement, then said i could just pay the insurance excess on the hire car, ouch i messed up there by misunderstanding the cost. the car was $27 or $35 if i was to reduce the excess, damn the $35 was the excess reduction and did not include the car hire, so if they had not covered that it would have been $62 for a single days rental, now thats an expensive way to get to work and home for one day, guess its back to the train and wasteing more of my time getting too and from the dealer.

on another note the dealer is in talks with landrover and has said fault codes were logged and they have been supplied to landrover, first i had heard of it, but asked for the codes and should have them tomorrow. hopefully some one on here will help diciffer them.
ian

Next time my one does it I'll scan it straight away, hopefully there is some sort of common fault.

Cheers,

Tim

I know that sound.......

thats the injection timing wandering and throwing it into diesel knock. (injecting too early and knocking like a petrol engine pings when the spark timing is advanced too far)

the wrx motor can do it too..

theres literally a dozen causes for it and my favorite one is "bad earth connection"

other things that can help it along are

poor connections to
boost pressure sensor
knock sensor

noise on the cam/crank angle sensor line
injector crack pressure set too low
timing gear/chain lash (for mechanically actuated injectors
restriction in the injector pump spill port
fuel cetane rating too low
hot spots in the combustion chamber (usually only on precombustion diesels)


I can quote the chapter and verse on it for the old school mechanical diesels, some of those are best guess for whats the electronic equivalent of a mechanical part. Suggest it to the dealer, see what they think.

To my untrained ears it sounded like timing too

After Dave's excellent response I was going to add solar flare as a possible cause but apparently there isn't much of that happening either.

In all seriousness it sounds like something electrical that changes state as it transitions. ECU's use temperature as a trimming factor in their mapping. I wonder if it's a glitch in the map that happens as the car moves through a temp. Temperature senders aren't perfectly accurate. I wonder if that explains its intermittent nature.

It would be interesting if someone could tap the temperature sensor on one that does it and see if it happens at the same value (temp) each day. If you could prove it was at the same value on one car then you could test it on another. That would be a big find.

A mate of mine designs engine ecu's and control software .. I'll run this past him.

Thanks Dave, one of the fault codes I've had appearing in the past has been due to the inlet (boost) pressure out of range. Could be a problem with the MAPT sensor, or like you said a bad earth. Could even be a problem with moisture affecting the MAPT sensor, which would explain why it only happens when the engine is cold.
Hopefully LR will figure it out soon and come up with a fix, (fingers crossed!).

Cheers,

Tim

Originally Posted by Captain_Rightfoot

<snip>
It would be interesting if someone could tap the temperature sensor on one that does it and see if it happens at the same value (temp) each day. If you could prove it was at the same value on one car then you could test it on another. That would be a big find. <snip>

I'll keep an eye on my scan gauge, as its permanatly mounted on the steering collum (sp?) displaying the MAP (boost) value, the inlet air temp, and the water temp. Hopefully there is some sort of pattern.

Cheers,

Tim