Reduced Engine Performance - V8 d3

[PeterDisco3]

I've been getting this warning message on and off for about the past year on my 2006 8 D3. Had Alto LR suggest new battery would fix it, which didnt and they also replaced brake switch and fixed something there (probably just their normal code for no idea) then started going to Davis Landy's performance who reckoned 02 sensor, new filter, diagnostic job, etc, but again withn 2 days of this service it came back. On longer trips, say more than 1.5 hours, its accompanied with amber engine light. which goes after stopping for a while. Sometimes the engine just cuts out when say i stop at lights after the message but this only ever happens once during any trip and engine restarts without any issues. Strange thing is that the engine always runs like a gem and I cant detect any "engine performane issues, towing a big van or crusing along freeway.

Should I just ignore it or is it a ticking time-bomb.

[101RRS]

If the EML has been coming on there will be a code logged for this - have you had them read as they should either point directly to the issue or the general area.

Garry

[PeterDisco3]

Thanks Garry

Yes. Last service they were read and thats when the Guy at Davis Performance landy's said it was the O2 sensor but within 24 hours of that service, error message appeared again. Doesnt come on for short trips, just anything over 15 mins and usually always when you are coasting down a hill. The amber engine light only comes on after initial message when the trip has been more than say 45 mins. Do you think the engine stalling is related?

Thanks Garry

[SBD4]

Have a look at this thread on disco3 forum, I reckon it might have the answer for you:

DISCO3.CO.UK - View topic - 4.4 V8 engine surging & reduced engine performance

[PeterDisco3]

Thanks SBD4

Sounds exactly the same symptoms as mine. Anyone have any idea how much I'm up for with replacing throttle body

[SBD4]

4.4V8 - HOUSING - THROTTLE PLATE, L319 DISCOVERY 3 AND 4
4637031 upto VIN (V)6A999999

Superceded by:
LR006142 from VIN (V)7A000001

LR006142 | Throttle Body And Motor Assy

You may need associated hoses and gaskets - gives you an idea though.

See what your repairer thinks.

[PeterDisco3]

Thanks

Just rang Graeme Cooper parts and they quoted $700 for just the throttle boday. Sounding like an expensive problem. Do you think there would be any long term damage issues to other components in engine with putting off fix until next service in 4 months.

[101RRS]

Get these sort of parts from the UK - much cheaper.

Googling the above part description and number should show up plenty of suppliers.

[SBD4]

As Garry said , get the parts from UK, the link I provided shows it at 132GBP which is about 200AUD - you would then have plenty left for additional parts plus labour. Of course you would need to verify that the TB is indeed the problem before buying...

As far as long term(how long is long term) damage is concerned, I wouldn't know as I am no mechanic. There are others here that would be better placed to advise on that. I can't imagine that there would be much to speak of though.

[Mike_S]

Have a look at this thread on disco3 forum, I reckon it might have the answer for you:

DISCO3.CO.UK - View topic - 4.4 V8 engine surging & reduced engine performance

Blimey, 2 years ago ! That car is now here in Melbourne

It took us a while to resolve the problem, but it would be worth working through a couple of the cheap & easy fixes before replacing the throttle body. First off have a listen under the bonnet near the breather valve (black circular object visible on the left / drivers side of the engine cover). If it's whistling then change it, they're only about $20. If it fails again then there are other problems. The other thing to try is cleaning out the throttle butterfly shaft with carb cleaner, this is the cause of the failure on mine. A build up of fuel / oil vapours gums up the shaft, this over time stresses the TB motor so eventually it runs over rich / lean and sends the sensors mental. Should you need to replace the TB, it'll need calibrating by the dealer / someone with Land Rover software.

This turned out to be a known service problem with the V8's and was listed on GTR, but under the UAE section. Over there, the fuel quality was quite poor, so cleaning the TB was listed in a service bulletin to be done every 12000 miles. Took us ages to find that out !!