D3 EMS amber fault light

[dobbo321]

Hello All
Bought a 2006 4.4 V8 D3 several months ago, very impressed and a vast improvement over my ever reliable TD5 D2.
On the way back to Perth from Albany several weeks ago the dash chimed and displayed "reduced engine performance" while I was using minimal throttle on a downhill section into Williams. Display cleared after 5 seconds or so and all was fine until this am on way to Dawn Service.
Same chime and display with minimal throttle on short downhill section. Then slight, but noticable, surging at 60kmh for the next 5 km, then stalled at roundabout. restarted OK but with the EMS light now lit. Light has remained lit (not flashing) but engine performs fine, is smooth and idles well. I know i will have to get it checked out early next week, but was wondering if anyone else has had a similar problem and knows of a likely fix.
Cheers
S

[Epic pooh]

How many Km's has it done ? What fuel are you using ? How's your coolant level and is the engine running within a normal temperature range ?

Bang out your air filter, clean the MAF sensor and throttle body would be my starting points. But since it idles smoothly (? - no hunting at all with A/C on or off - ?) may be unrelated to the fuel system - but I would do what I have mentioned to any misbehaving V8 as a starting point.

Sorry not helpful, but to effectively diagnose, you will need to see the logged faults (if any) to get a steer in the right direction.

[dobbo321]

Thanks Epic
funny thing the light didn't illuminate when it was used today, will give the filter and sensor a clean tomorrow after work, coolant level are fine. Has 150K on the clock.
Due for a service soon so will get the faults checked out as well and go from there.
Thanks again for your advice, The D3 petrol is newish to me, still have my trusty TD5 D2 which is very familiar mechanically to me after many years working/servicing it.
Rgds
S

[Epic pooh]

No worries, hope you get to the bottom of it quickly ! Light being on then off the on may be indicative of a dirty sensor that the ECU is now ignoring (I could be wrong, but mine has done this).

At that mileage you should check out if the plugs have been changed and if the coolant has been done (both due around that mileage). When I did my coolant recently I'd been having mysterious coolant loss (very slight over several years) and discovered that one of the bleeders was leaking slightly onto the throttle body - so I changed the bleeder, the thermostat, thermostat housing, sensor and coolant (see pics of parts) - has made a big difference to running temperature and slight fuel economy improvement. So when you've got the engine cover off, take a look at the condition of the bleeder.

Here's a link to the service manual online (Land Rover Workshop Manuals > LR3/Disco 3 > General Service Information (http://workshop-manuals.com/landrover/lr3/general_service_information/)) which will point you to the relevant sensors etc !

Cheers,
Mick

[dobbo321]

An update for anyone experiencing the same problem.
Went to the previous owners mechanic who specialises in 4WD and speciffically LR. He checked the faults, cleared them and then advised he thought the MAS was possibly dirty. He cleaned this and checked a few other areas during the 150K service. All OK for next 4 days then the intermitent surging returned.
Booked into Southern Landrover in Cannington after return of this fault.
Left it for 1/2 day, diagnosed a sticking throttle, cost $170 for a throttle body clean. No problems during the last 3 weeks and appx 1200km.
I know not everyone is keen on LR dealers but in this case I feel they had the proper tools/knowledge to diagnose the problem quickly and repair it for a reasonable cost.

[Epic pooh]

Glad to hear that got sorted. Agree with your comment about a good LR dealers, excepting for their hourly rate !

[Rich84]

For petrol engines the MAF, oxygen sensor, spark plugs and EGT sensor (if it has one) are very good first points of call for surging. Checking the system for air leaks is another one.