KV6 Stat replacement - fuel rail(s) removal

[Rover600]

Hi Gents,

Seems like I might have a lot of questions coming up – after starting to strip things down to get to the clutch I have discovered the V full of coolant.
Reading through a few threads on here I now have the gist of what needs to be done and started stripping everything apart to get to the stat and pipes.
I’m now at the stage of removing the lower (metal) intake manifolds to gain access but have a couple of queries before I proceed.


First question:
I assume the injector fuel rails have got to come out.

My initial thought was to leave them attached to the injectors and still in the manifold and just separate the two banks.
However, I understand it is best not to disturb the link pipe between the two rails as this can cause lots of issues with leaks.

It seems my other options are to either try and remove both manifolds simultaneously complete with the injector rails still attached, which seems a recipe for disaster.

Alternatively separate both rails from the injectors and carefully remove both linked rails together prior to removing the manifolds individually with the injectors still in situ.

Have I missed anything?
Which is the preferred method with the minimum chance of damaging or having to replace anything?
Do any of the O rings need to be replaced?

Second question:

I removed the metal pipe that supplies the front injector rail from the tank/pump.

This was carefully extracted from the rail leaving the o rings, seals and spring clip still in the end of the injector rail and nothing on the end of the metal pipe.

Now I assumed this was how it was supposed to come apart as this is how the other end came out of the hose connector going to the tank end.
However, in the threads I’ve been reading on here it seems like this is a source of a lot of issues and the pictures members have posted shows the stack of o rings and seals complete with metal clip all mounted on the end of the metal pipe instead.

Which is correct? Do I need to dig these out of the injector rail prior to reassembly or can the metal pipe just be pushed back in?


Sorry if this is covering old ground, but I’m trying to wrap my head around this before making any potentially costly silly mistakes!

[Matt_75]

Have a look at this video, it's on a ZS but still applies. About 4 minutes 15 seconds in is where he starts to remove the fuel rail. Hopefully it'll help answer some questions.

https://youtu.be/0W7Gu3dPXaE?si=iKyCz18PtoepGEM_

When I did mine, I removed the U-shaped rail and the injectors as a complete assembly. Getting the injectors to pop out if the manifolds was a bit tricky. The seals had become almost glued in place.

[vitesse]

I removed the injectors, and separated the fuel lines the first time I did a thermostat and swore never again. I had to source new seals and O rings locally which wasn't that easy.

I've since done about six thermostats and lived up to my promise - instead preferring to lift both inlet manifolds at the same time without disturbing the fuel rails. I separate the incoming fuel pipe at the connection behind the battery.

Good luck

[Rover600]

Thanks for the replies.

Originally Posted by Matt_75

When I did mine, I removed the U-shaped rail and the injectors as a complete assembly. Getting the injectors to pop out if the manifolds was a bit tricky. The seals had become almost glued in place.

Funnily enough I did watch that earlier - so you remove the injectors and leave them attached to the rail? No problems with damaged O rings?

I'm sure I read a thread by somebody who left the injectors in the manifold and pulled the clips so that the rail lifted off the top of the injectors.
I assume this was done to avoid any problems with the injectors being stuck and damaging the o rings on the way out.

Originally Posted by vitesse

I've since done about six thermostats and lived up to my promise - instead preferring to lift both inlet manifolds at the same time without disturbing the fuel rails. I separate the incoming fuel pipe at the connection behind the battery.

I was considering doing this but worried that trying to handle two heavy lumps of aluminium connected together via one small pipe and some plastic might end up in disaster.
Is there a trick to it to avoid snapped anything? How difficult is it to fit them back when trying to position everything with new gaskets?

This does sound preferable to avoid disturbing too much.

[SD1too]

Originally Posted by Rover600

First question:
I assume the injector fuel rails have got to come out.

My initial thought was to leave them attached to the injectors and still in the manifold and just separate the two banks.
However, I understand it is best not to disturb the link pipe between the two rails as this can cause lots of issues with leaks.

Originally Posted by Rover600

It seems my other options are to either try and remove both manifolds simultaneously complete with the injector rails still attached, which seems a recipe for disaster.
Alternatively separate both rails from the injectors and carefully remove both linked rails together prior to removing the manifolds individually with the injectors still in situ.

In the past I've always separated the linked fuel rails from the injectors but the tray clips are very fiddly to remove and refit, particularly on the R.H. bank. The injectors were very firmly seated and I didn't want to disturb them. So on the KV6 I'm currently repairing I've removed both manifolds with the rail still attached which worked well. I've yet to discover any problems refitting!

Originally Posted by Rover600

Which is the preferred method with the minimum chance of damaging or having to replace anything?
Do any of the O rings need to be replaced?

I'd say that the method with the lowest risk of damage is removing both manifolds complete with fuel rail, including the long supply pipe.
When I previously removed the fuel rails from the injectors, the 'O' rings did not need replacing provided that the rails were aligned perfectly level with the injectors and pressed home firmly and carefully. They should be lubricated first though (I used petroleum jelly).

Originally Posted by Rover600

Second question:
I removed the metal pipe that supplies the front injector rail from the tank/pump.
This was carefully extracted from the rail leaving the o rings, seals and spring clip still in the end of the injector rail and nothing on the end of the metal pipe ...
Do I need to dig these out of the injector rail prior to reassembly or can the metal pipe just be pushed back in?

It can just be pushed back in.

Simon

[vitesse]

Originally Posted by Rover600

Thanks for the replies.

I was considering doing this but worried that trying to handle two heavy lumps of aluminium connected together via one small pipe and some plastic might end up in disaster.
Is there a trick to it to avoid snapped anything? How difficult is it to fit them back when trying to position everything with new gaskets?

This does sound preferable to avoid disturbing too much.

Two heavy lumps of aluminium? - not at all heavy just a bit unwieldy, I manage it on my own but an extra pair of hands would help even more.

Refitting is a bit difficult not because of the set-up but the new gaskets tend to slide but I use smears of hylomar with a couple of bolts to keep the gaskets in place.

Good luck

[Rover600]

Thanks chaps,

I think I will try removing both manifolds together, it seems the easiest route.

Originally Posted by vitesse

Two heavy lumps of aluminium? - not at all heavy just a bit unwieldy

I was thinking more in terms of relative to them hanging off each other by a small metal pipe and a couple of clips into a plastic rail – which was what was worrying me.

Obviously I'd be trying to support everything together to stop any stress being placed on it - but I can also see how the awkwardness of manoeuvring them together could easily end up with the weight of one hanging from the rail of the other - which I assume would not end well.

Hopefully it turns out easier than it looks!

[Matt_75]

Originally Posted by Rover600

Funnily enough I did watch that earlier - so you remove the injectors and leave them attached to the rail? No problems with damaged O rings?

I'm sure I read a thread by somebody who left the injectors in the manifold and pulled the clips so that the rail lifted off the top of the injectors.
I assume this was done to avoid any problems with the injectors being stuck and damaging the o rings on the way out.

I've done this on two different engines and the first gave no trouble at all, the injectors popped out the manifolds relatively easily. The second did put up a fight (as mentioned previously) but ultimately came out without damage to the o-rings. In hindsight though, I'd probably buy two inlet manifold gaskets and remove both manifolds, injectors and fuel rail as an assembly if its an engine where the injectors haven't been disturbed recently and are likely to be stuck.

By the way, I got chatting to someone at the weekend who'd recently done a clutch slave cylinder on a ZT V6. The engine also needed belts, thermostat etc. so he removed the engine and gearbox from the car and felt that this was a worthwhile exercise. He did it the same way I did though, front end removal leaving the subframe in situ.

[Rover600]

I got a chance to crack on yesterday evening and removing the manifolds was easier than I expected - in terms of just grabbing hold of them to support them as a piece.

However, getting to the bolts was a royal pain, and I can't imagine torqueing them back up accurately will be very successful given the array of universal joints, extensions and spanners which were required to remove them - I can see it being slightly easier if the rails were not in the way but not by much.

The biggest issue was having to jiggle the manifold out around the bracket for the alternator and raised castings on the heads - basically having to partly slide it out.
Not a problem for removal, but I can see a lot of challenges trying to slide it back in with gaskets in place without damaging them, knocking them out of place, or smearing any sealant all over the place.

V is filled with about a quarter of an inch of coolant although no obvious leak apart from some white "salt" staining around the seam of the stat. However, I'll be swapping the lot now I'm this far in.
I'll investigate further later but the pipes showed no signs of budging so I think I may have to break them out of the block in pieces.

It is begging for some sort of metal pipe or spigot and silicone hose conversion - daft unnecessary design in the first place really.

I've worked on quite a few engines, Rover and others, and the deeper I get into my first KV6 experience, the more I'm left with the impression this was more "organically" put together than designed.

Frustrating so far, but still progress of a sorts.

[Rover600]

Originally Posted by Matt_75

By the way, I got chatting to someone at the weekend who'd recently done a clutch slave cylinder on a ZT V6. The engine also needed belts, thermostat etc. so he removed the engine and gearbox from the car and felt that this was a worthwhile exercise. He did it the same way I did though, front end removal leaving the subframe in situ.

That's interesting, I've got slightly distracted chasing down this coolant leak, but still debating whether to pull the engine and box out or not.
Did he happens to mention what he did with the A/C? That's really the only thing that is putting me off. It is fully gassed and working flawlessly so I'd rather not pull it apart if possible.