My 4.2 s/c gave a low coolant message the other day and when I looked the overflow tank was almost empty. Booked it into my local garage as I didn't want to drive 30 miles to my LR Indy with a coolant leak.

Local garage have diagnosed a pin hole in the pipe that goes from the thermostat housing to where they can't see. It goes under the supercharger.

They are suggesting, to fix will entail taking out the supercharger so a fairly long job. They freely admit they are not experts in the L322 so can anyone on here suggest firstly, what pipe this is and secondly, is there a work round to make the job easier.

Sorry I can't give more info. 2017 5.0 Autobiography Supercharged
2005 Merc SL350
2005 Disco HSE 2.7 oil burner

I've done this on a 2006, the pipe isn't easy and it's definitely at least an input plenum off job. My T-stat failed and left me with the pin hole The hose goes down the valley to the back of the engine, I was able to get access after I removed a load of stuff and fortunately the pin hole was right at the join.

I had enough play in the hose to cut it and get the front re-connected, this is a bodge of course and you have to be careful not to put the hose under too much tension. Fact is I didn't have a spare car and only had 1 day leave left from work so I had to get mobile again quickly. Formerly happymadison1978

Are there any options for silicone hoses on a 4.2? If it’s auch a pain to do it could be worth replacing with items that won’t perish.

Had the exact same on my 4.2SC and the Super Charger had to come off to replace the hose, probably not what you wanted to hear !

Thanks chaps.

Thankfully it won't be me losing knuckle skin as a trusted mechanic will be doing it over the next couple of months whilst I'm away.

Sounds like it's a fairly common problem. 2017 5.0 Autobiography Supercharged
2005 Merc SL350
2005 Disco HSE 2.7 oil burner

All sorted by my indy and pipe replaced. Also found the PCV was gummed up so a new one went on whilst they were in there.

Back to normal now. 2017 5.0 Autobiography Supercharged
2005 Merc SL350
2005 Disco HSE 2.7 oil burner

I’ve got the exact same problem. Would you mind me asking how much it cost to have it fixed? 2006MY 4.2 SC
BMW R1250 GSA Rallye TE
Triumph Tiger 1050 (sold)
1979 Pontiac Trans Am (sold)

Mulcher,

You'll be not pleased to hear it's a bit of a job so you won't get much change out of a grand, and that's at indy rates, not stealers. The pipe itself is nearly £300. They also found some other issues when they got in there to do with the PCV (on back order from LR) and throttle body gaskets. I believe the parts bill was over £350.

You'll obviously save a lot if you do it yourself but looking at the pictures of all the bits that came off, it looks a bit of a mission.

Not cheap running these old buses properly. 2017 5.0 Autobiography Supercharged
2005 Merc SL350
2005 Disco HSE 2.7 oil burner

Gulp, thanks V8Noise, looks like I’ll have to raid the kids piggy bank. 2006MY 4.2 SC
BMW R1250 GSA Rallye TE
Triumph Tiger 1050 (sold)
1979 Pontiac Trans Am (sold)

A bit late maybe, but for the record:

I had to replace this hose also. Yes, it is below the intake and the Workshop manual procedure is to remove the supercharger and intake.

This is what I did:

Used vacuum cleaner to suck a rope though the old hose from the back of the motor.
Used vacuum cleaner to suck same rope through new hose at the back of the engine.
Tied something to the end of the rope so it won't get pulled through the hose.
Smeared vaseline on the visible part of the old hose and new hose.
Pulled the rope and the old hose from the front of the engine, the new hose pushes the old one out.


I first tried to use a standard straight hose because of the cost of the original one, but there is one or more sharp bends that made the hose collapse after a few heat cycles so just get the original one. Be generous with the vaseline, I suspect there are some sharp edges under the intake and it take some force to pull the hoses through. 2006 Supercharged

Hello Ian928,

I know this is an old thread but just ran into what appears to be the same issue so thought I would reach out. Could you share the part number for the hose you replaced?

I would like to try your ingenious approach

Thanks for your assistance!

Hello, I did a search, the part number I ordered was LR006147, be aware that this is a whole set with hoses and pipes and unneccesary expensive for the one hose you need. Maybe it is possible to get the single hose now? In 2015 only the kit was available.

I also read up a old post in a Norwegian Land Rover forum where I stated that I did not remove the fan and shroud but that I sort of regretted that I did not remove those items so consider what you want to do. I removed the thermostat housing and ordered new bolts and O-rings. I pulled the hose from the back of the engine though to the front, about 10cm/4” further forward than it should be, then fitted the hose to the thermostat housing and then pulled the hose back when fitting the thermostat housing. 2006 Supercharged

I looked at doing this (preventative rather than an urgent job) but what concerns me is that the kit hose has 2 hoses that go under the supercharger from back to front and couldn’t work out how the rope method would work with 2 hoses.

Please update when/if you do this, if possible with pics 👍

I only changed the one hose. The other one I think you need to remove intake to change.

Edit: Found a video that show the process of removing the supercharger and changing both the hoses:
 2006 Supercharged

Thanks Ian928! It looks like the hoses are still just available as a set but there are decent prices for the set on eBay.

I think I'll try your method first and then refer to that video if that doesn't work out.

Thanks again