Thread: Puma engine rattle under acceleration

Good luck with that Patclan. I hope they sort it for you & be interested to find out what they find.

If you do a search about Puma engine rattle you will find several threads people have posted with this problem. The extent ranges from mild (as in my case) to extreme (as in Dullbird's case where she had her entire engine replaced).

I had it in my MY07 Defender - usually in cold weather shortly after start-up. The dealer replaced the EGR then replaced the fuel common rail - still there. Software patch sometime in 2009 - hasn't happened since.

My 2010 started doing this too. Most noticeable when cold and under acceleration. Just had 20k service and told dealer about it. Got the standard answer that all is well and nothing wrong. However it's not there any more after service. Has not been as cold here but definitely less rattle now. So who knows. . If it comes back I'll just keep complaining until they fix it or I finally break it properly

Yes Solmanic
This is my second engine, but it's not the same rattle as prompted LR to replace the first one. The first one only rattled on very cold mornings on the first gear change, and they concluded oil jets under pistons not opening properly.

The current rattle is evident from any cold start until the engine is warm, and does it under load (even light load) or acceleration. So even after being parked for say 4 hrs, it will do it again until temperature is around 75C.

Mine's out of warranty now at 151,000km (68,000km on this engine), so I need to fix it.

Brid

To me it sounds as if the fuel rail pressure sensor is sending erroneous messages to the ECU when the engine is cold due to a sticking High Pressure rail control valve. This was supposed to have been cured through Service Action Number Q068 and really only applies in colder climes but you never know? Q068 happened to me and the clatter was very loud just before the rail pressure was dumped and the landy went into limp mode though the outside temp was -15C. They fixed the problem by fitting a complete new fuel rail (fuel rail pressure sensor and pressure limiting valve).





From the sound of your issues the first part of the explanation seems to marry up with your symptoms? Is your vehicle in the VIN range on the SAN?

When driving following a cold engine start where the engine coolant temperature is <5°C and accelerated with a throttle pedal input >35° and a gear change is made at an engine speed of >2000rpm there is a possibility that the High Pressure rail control valve can stick and cause high rail pressure.

Have you the means to monitor and record the fuel rail pressure? If so I would be curious as to the fuel rail pressure when the engine is cold and clattery compared to when it was warm. The Puma optimum pressure at the rail is a 1600 bar maximum (2320PSI) and the pressure limiting valve operates at 1800 bar (26106PSI) and will need replacing if it has operated as it is a one shot deal.



As to getting the MIL illuminated and entering Limp mode after unplugging the EGR, I had mine unplugged for about 6 months without it going into limp mode, did you do a DTC scan? if so can you post the DTC codes? I would expect to see P1402 and P1409 if the EGR plug is removed? But if there are any others they may be the cause of the limp mode, especially pending DTC's which in conjunction with the tested DTC's of the unplugged EGR may induce Limp mode, though limp mode is there to protect the engine from being damaged, something an unplugged EGR wont do!

P1402 Exhaust Gas Recirculation Metering Orifice Restricted
P1409 EGR Vacuum Regulator Solenoid Circuit

HTH Brian.

Originally Posted by Lorryman100

From the sound of your issues the first part of the explanation seems to marry up with your symptoms? Is your vehicle in the VIN range on the SAN?


HTH Brian.

OK stupid question time, in the SAN do you count the last 6 numbers in the VIN? if so I am in there..

Also if I remember rightly Mahn (oneiota) had a rattle at one stage and I'm sure he had moisture on one of his connector or sensors I cant exactly remember now..

I just remember him saying he disconnected something gave it a wipe put it back together and never had a drama after that