TD6 loss of power under heavy load

Evening all, my first time in this section, I'm normally in the Discovery section but am trying to help my Dad diagnose a problem with his L322 TD6 so hope you don't mind me popping in.

Ok the symptoms are under heavy acceleration, or putting some power down up a hill, it feels like it was struggling and had a lack of power. Today my mum used it and was overtaking on the dual carriageway when she lost power and it backed right off to 50mph max. Luckily she just made it passed the lorries and trundled on to her destination at 45-50mph.

No smoke from the exhaust.

It gets serviced once a year and has been done within the last 6 months I believe.

I've been searching here and elsewhere and the most common causes seem to be either the inline external fuel pump in the nearside rear wheel arch, or de-laminated boost hoses. Would you guys agree with that?

We left it running at their house earlier whilst doing something else, when I went back to it there was a definite resonating whine/hum coming from the external pump which then went away with a few blips of the throttle, so I'm leaning towards this being a very potential cause.

If I do go down this route, is this a 'genuine only' recommendation or are the bearmach etc aftermarket pumps any good?

Any advice welcome, cheers

Could be air getting in the fuel lines !

Blimey that was a quick reply thanks!

How does air get in? a break in the fuel line?

if the Fuel delivery system of the TD6 M57 is similar to the P38's M51, albeit the M51 isn't common rail....the spill pipes (leak off pipes) can split...

My thoughts are with the Secondary Pump mounted external to the Tank - this is a common fail item....

The HP Pump driven by the chain drive from the Crankshaft can deliver fuel at up to 1350bar which is a huge amount of pressure, it would be unlikely that air would get into the system at the point from HP pump to the fuel rail....but if the spill pipes split, this can put an air pocket in the injector itself which can cause a stutter.

I am fairly sure the TD6 HP Pump has a pressure sensor in there and if the line pressure from the Tank gets below a certain threshold it can trigger a Limp Home mode.

Would have to consult the TD6 System Operation and Description section in RAVE for a better understanding of the fuel delivery system to comment further or with more authority....

I trust as a seasoned LR owner you have the RAVE manuals...the later versions cover the 2002-2005 L322 Models!

Thanks for the response Saint.

I do have Rave, but at the moment it only goes up to the P38. Need to get the newer version that covers the L322. I did download the L322 workshop manual last night though and had a good read through, couldn't quite believe the pressure of the HP pump!

I think the secondary pump has to be a good place to start, especially with the whiring/whining noise I could hear from that area. Looks a fairly easy job too.

So what do people think about genuine vs aftermarket pumps?

And does the L322 have a self purge procedure to get rid of the air in the system after fitting? (I should probably consult rave on that shouldn't it)

I'll also leave it running on some wet tarmac for a while and see if I spot any leaks underneath anywhere

Easy job to change the secondary pump and does bleed itself , normally when the secondary pump goes you get intermittent starting but if it's noisy change it they aren't that much, after that might be worth leak doing a leak off check on the injectors

Cheers Birchy. As far as I know starting hasn't been a problem (well apart from a battery drain issue that I'm also addressing, hopefully a new Final Resistor switch will fix).

As it's a nice easy place to start, and making a noise I think I'll start with the pump. I'm certainly not confident that will fix it but will see.

Might as well replace his crankcase breather filter whilst I'm fiddling with it, seems another common issue that's cheap to remedy.

Its overboosting because for whatever reason the turbo variable vanes are not able to control boost pressure.More common on TD4 Freelanders,but its the same ****ty VNT system instead of a wastegate that you can fix with a hammer and WD40....

Hmm. I hadn't thought of overboosting. When my D2 was overboosting it was like hitting a rev limiter, bouncey. These symptoms are more like power being sapped slowly. But perhaps that's because if the difference in turbo systems I dunno?

Well that was a waste of time. Changed the secondary fuel pump today. Took It out for a test drive, put my foot down, turbo squealed and plooms of white smoke.

I guess it was the turbo dying then.

Orch said:

Well that was a waste of time. Changed the secondary fuel pump today. Took It out for a test drive, put my foot down, turbo squealed and plooms of white smoke.

I guess it was the turbo dying then.

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Sure it's not a turbo hose off? they are known for poping off.

Got to admit I didn't check, just assumed it was knackered and parked up. Would a hose popping off cause all that smoke and a squeak from the turbo?

Orch said:

Got to admit I didn't check, just assumed it was knackered and parked up. Would a hose popping off cause all that smoke and a squeak from the turbo?

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High pressure air escaping from a displaced hose can certainly cause a squeek, think stretching the neck of a ballon when you were a kid.
Smoke if it's overfuelling due to lack of air, the MAF would still be indicating the air quantity as normal.

Went back out for a look, couldn't see anything. Checked the oil and it was below the minimum :/

Orch said:

Went back out for a look, couldn't see anything. Checked the oil and it was below the minimum :/

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Look at the one actually on the turbo outlet, it can move under pressure.

Oh yeh sorry forgot to say, I've read about crankcase pressure and I had already purchased a new crankcase filter. I pulled the dipstick up a little bit and oil spurted out. Was I being stupid doing so or would oil not normal spurt out? Ie. Does this mean it is over pressurised?

Orch said:

Oh yeh sorry forgot to say, I've read about crankcase pressure and I had already purchased a new crankcase filter. I pulled the dipstick up a little bit and oil spurted out. Was I being stupid doing so or would oil not normal spurt out? Ie. Does this mean it is over pressurised?

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If it's spurting out with the engine running that means you have excessive pressure in the crankcase / ie a blocked crankcase filter !

Get the cyclone upgrade part and change it ASAP before your turbo dies !

Do you think perhaps it's not too late for the turbo then?

I've got a replacement filter to fit after reading about it just this week.

Can anyone explain how the crankcase pressure, the squeaking turbo and the white smoke are all linked? I can't get it right in my head!

I'm not very clued up but I think the High crankcase pressure puts stress on the turbo causing the oil lubricated bearings in the turbo to give up !

Smoke from the exhaust is an early sign of crankcase breather issues