Coolant Leak Numpty Questions!

[StewartIngram]

I've yet to find a Haynes manual useful at all! Nowhere near as good as they used to be many years ago, I threw mine away and got a Rover manual.

[vitesse]

Originally Posted by SD1too

It's far from ideal Joe because the ancillaries installation in a ZS is different.

Looking at my notes you'll need to:
1. Drain cooling system.
2. Remove battery & its box plus air cleaner.
3. Remove plastic manifold chamber.
4. Remove ignition equipment and fuel rail.
You will now be able to reach the manifold screws. Is it the LH or RH you are removing?

There's a lot to do, particularly disconnecting all the attachments to the plastic manifold chamber, so please be absolutely certain that the source of your coolant leak really is the inlet manifold gasket before starting. Note that it's very uncommon on the KV6.

I'd recommend that you get hold of a Haynes manual if you can. It will be very helpful.

Simon

I know of at least two cases, Norwegian May's ex-car and Kaiser who I believe coats the paper gaskets in rattle can silver spray to make them waterproof. To compound problems Lovel has suggested the gaskets settle or at least if I remember correctly recommends re-setting the inlet manifold bolts after a while.

I like the "Haynes" type simplicity "of you will now be able to reach the manifold screws" - I only wish they were so easily accessible.

I would suggest the OP replaces both gaskets, if one is leaking the other might not be that far behind. I'd also suggest lifting the inlet manifold as one piece and not disturbing the fuel lines. In the past I've chosen to disconnect the fuel line at the back of the battery box rather than disturb any O rings.

I've got paper versions of all the manuals, and a digital Rave disc somewhere but I prefer the paper world. Would the Rave disc be a better alternative to Haynes?

Keep well

[phenonix]

Thanks Simon
I have the Haynes and will go over that.
I'll replace both gaskets on the RH manifold.
Unsure of where else the leak could be coming for though.

[phenonix]

Is there any updated posts about removing the manifold?
https://the75andztclub.co.uk/forum/s...ad.php?t=71171
Or is there a way to recover the photos missing from Mr Edda post?

[vitesse]

Try this one: https://www.the75andztclub.co.uk/for...ad.php?t=73306

Regards

[SD1too]

Originally Posted by phenonix

I'll replace both gaskets on the RH manifold.

Both? The RH manifold has only one.

Regarding the fuel rail, I'd recommend disconnecting the supply pipe just after it rises from the tank into the engine bay. It's easier to separate than the joint over the LH bank which, according to some members' reports, is easily broken.
Also, I chose to lift the pipe off the injectors rather than removing the latter from the manifolds.

Originally Posted by phenonix

Unsure of where else the leak could be coming for though.

The most likely source is the 'O' ring on the thermostat housing base. Tracing leaks accurately is not easy and you'll be very demoralised if you go through all this work only to find that the manifold gasket wasn't leaking after all.

Simon

[phenonix]

Originally Posted by SD1too

Both? The RH manifold has only one.

Regarding the fuel rail, I'd recommend disconnecting the supply pipe just after it rises from the tank into the engine bay. It's easier to separate than the joint over the LH bank which, according to some members' reports, is easily broken.
Also, I chose to lift the pipe off the injectors rather than removing the latter from the manifolds.

The most likely source is the 'O' ring on the thermostat housing base. Tracing leaks accurately is not easy and you'll be very demoralised if you go through all this work only to find that the manifold gasket wasn't leaking after all.

Simon

Thanks Simon
Taking all your advice on board
I will be replacing the gaskets on both the inlets, do the inlet O rings need to be replaced also?

Getting used to being demoralised when trying repairs, never turns out exactly as i first think.

I'm basing my thoughts on the gaskets rather than the thermostat base as i can see a tiny stream of coolant traversing the V incline on the far left causing pooling, but there is no pooling near the thermostat area.
Where i can see, the V area has ribbing which creates small enclosures (hard to explain) so each enclosure fills up with coolant independently, the enclosure near the thermostat is still dry.

It could be where the thermostat pipe enters the engine block, that is the area that fills up first, but i can not see it dripping into that.

I would not be surprised if what i'm saying is incorrect.

I'll have another look before i start on the gaskets.

The other part that leads me to believe it may be the gasket is that the leak starts immediately i start the car, dripping onto the A/C pump, but the V are is dry at this stage, meaning its the flow into the engine that is where the leak is coming from?

If it was the thermostat base the V would fill up then drip down the front?

As you mentioned fluid mechanics is very hard to understand.

I there any other component i should look at that would explain the dripping down the front?

These descriptions/observations are all coming from a bloke who has never looked into an engine before
But happy and eager to learn.

[phenonix]

Bit of a video on Youtube of the leak if this helps.
https://youtu.be/b3CvnmDs-qs

[SD1too]

Hi Joe and thanks for the clarification. Funnily enough, I fully recognise your description of the small enclosures of coolant in the 'V'!

Originally Posted by phenonix

These descriptions/observations are all coming from a bloke who has never looked into an engine before
But happy and eager to learn.

Well you're certainly diving into the deep end!

Here are a few more things which hopefully will save you time.
You'll need to remove the plenum access panel to reach two screws securing the plastic inlet chamber support brackets to the RH camshaft cover. Allow plenty of time and several cups of tea for this tricky operation.
You will need a flat-bladed blunt tool to release the plastic inlet chamber from the manifolds, it's a very tight fit.
Remove the LH manifold first and refit it last (this is because the RH manifold rear lower screw is inaccessible otherwise).
Unless they're visibly damaged, the aluminium manifold to plastic inlet chamber seals can be re-used.
Make detailed notes as you go. There's a lot to do and you'll never remember it all when it comes to reassembling.

Simon

[vitesse]

I’ve done about five thermostat changes and whereas the first one was done as described by Simon I quickly learnt that the fuel line O rings do not enjoy being moved. By all means follow Simon’s advice on doing one section at a time but be prepared for possible grief afterwards. Or lift the two halves as one without disturbing the fuel lines other than disconnecting the long pipe up behind the battery box. By all means work on one section first and that will allow more access to the other as there is some give between the two.

I’d also like to point out that the plastic upper manifold is secured at the back by two L shaped brackets which are best accessed by removing the inspection plate on the bulkhead, although if it’s been off sometime previously then the brackets are often “lost” or broken. The manifold will not come off with these brackets in place, there is a convenient shoulder on the plastic manifold near where the throttle body sits which you can use to pry it loose rather than using chisels against the soft metal.

Regards