Hello guys

Before I start, I've thoroughly searched online, and have yet to find anybody with the identical issue (bar one)

So, I've recently bought a RRS, TDV8. Driving home I overtook a truck on the motorway which was on a long gradual gradient and the car went in to limp mode with "Engine system fault"

I have been able to replicate the exact circumstances to cause the fault. Basically, any long uphill stint that requires a good bit of throttle throws up the error, it also seems to do it at the exact point it tries to drop down from 5th to 4th. I managed to drive 200 miles by feathering the throttle, losing speed uphill so as not to endure limp mode. (First lane being overtaken by trucks basically)

My obvious question, can anybody shed some light on what it could be? It does it in any gear, but seems to do it less when operating the car in "command shift" however it will still throw the fault should I need to give it more throttle.

Any help would be really, really welcomed. The car drove fine on the test drive, and now the dealer is ignoring my calls and emails so I'm at your mercy!

edit: I've looked under the bonnet and cant see any visible splits in any hoses, however there is a thin (turbo?) hose on each side which leads nowhere. One is capped off and on the other bank it's just hanging down freely, but no vacuum or anything like that. Is this normal? They both look like they should be attached to something. I would assume if there was a hose that is left unattached on every RRS from factory I cant be the only person to have noticed it.

Edit: It also seems fine for power, it has the "get up and go" It just decides not to at anything above 50mph, it'll fly up any hill between 30-50mph
Thanks

Last edited by IggyIggins on Thu Jun 11 2020 7:17pm. Edited 1 time in total

I had similar on my TDV8. Turned out to be hairline cracks on drivers side inlet manifold causing loss of boost pressure. I identified mine by seeing light oil misting around the area as well as spraying a bit of water on and seeing bubbles with engine on. Could be several other things though such as turbo boost hoses, turbo actuator etc. if you see nothing obvious you'll need the codes reading.

Funny you mention it, the manifold on this side was replaced before the car was sold. It also threw up "manifold absolute pressure" on a code reader yesterday but not sure if that was historic or current, I'll have to check. I appreciate your help, I feel like such a mug right now

It does sound like a cracked manifold. It's a common problem.

Do smoke test and that should give you your answer. Kev

MY2014 L405 RR Vogue SE 4.4 SDV8 in Corris Grey
MY2010 L320 RRS HSE 3.0 TDV6 in Stornoway Grey

Sometimes you'll see the crack if you look carefully and spray some water on with engine on you might see bubbles. Failing that a pressure test or smoke test

The exact symptom and circumstance that I had.

Turned out to be the nearside inlet manifold had a hairline crack that was almost invisible even when it was removed from the car.
Replaced the manifold (and the various pipes that break) and everything's been well ever since.

I know you've opened the bonnet and checked the top intercooler hoses but my split was on the underside and when I did the same initial inspection it wasn't visible at all, even though the split was 2 inches in length.
Takes 5 mins to remove them so maybe worthwhile you doing this so you can inspect them fully and rule them out 100%.
I ordered a new set of both hoses for £40 which will be going on the car later today.

Thanks so much for the replies, guys.
I'm going to get some soapy water and have a look at the manifold, and I'll check the hoses too. Not an ideal situation but I'm glad it's not anything 'major'

A cracked manifold isn't the end of the world. I'll report back

derekmines wrote:

The exact symptom and circumstance that I had.

Turned out to be the nearside inlet manifold had a hairline crack that was almost invisible even when it was removed from the car.
Replaced the manifold (and the various pipes that break) and everything's been well ever since.

Did you replace it yourself? How easy is it? I've done rocker cover replacements on big BMW engines before but I'm not a mechanic, though if it's do-able I'd have a pop. LR indie want over £1000 to do it. I'm just concerned about the total lack of space under there. I have big hands

I have a friend who's a mobile mechanic and we did it together, it's fiddly and you will inevitably break a couple of the pipes that have to be removed (I'd read that that was likely so had already bought them, just in case) but it's a fairly straightforward replacement, access is limited in parts though, so if you really do have a couple of plates rather than hands you may have to draft in a small child to assist lol.

Cost wise, the parts were just over £300 and (slight mate's rates obviously) I think the labour charge was about £240