Inlet Manifold Replacement
How to replace the Inlet Manifold for a Rover 75.
This is not as difficult a job as it initially may seem.
Anyone who feels confident with a spanner can accomplish this task.
I ordered the replacement part from eBay and when it
arrived I discovered it came from XParts. Apparently if you are a paid up
member of the MGRover.org forum you may get additional discount. I didnít know
this until after I had made my purchase so I donít know what the comparison is
between the two prices. It may be worth finding out.
Delivery was very fast almost the next day depending on
what time of day your payment goes through. The following pictures show the new
The plastic bag covers the air inlet to keep it clean
during transport. There are also blank pipes ends in each of the vacuum breather
inlets etc to stop damage or ingress of dirt into delicate areas. Only remove
these after fitting and when you are about to fix the appropriate pipes etc.
This is the VIS motors on the left looking at the engine
compartment from the front.
These two sections circled in green are for fixing the
cable loom between the manifold and the bulkhead at the rear of the engine
compartment. I initially thought that they were part of the fastenings for the
inlet manifold to the engine but they only serve to hold the cables in place.
The one on the left in my car was broken off and looks like it may have been
like that for some time.
Now lets us start some dismantling. First take off the
front engine cover by removing the two bolts arrowed yellow.
Then undue the 4 finger screws. These seem to be quite
loose and only require a few turns and then pull them off, and remove the
soundproofing. The soundproofing should come off easily revealing a bulkhead
plate. There are two small bolts at the top holding this on, be careful not to
drop these into the engine compartment or the Plenum area. There is a large
slot that a rubber grommet fits into which a concertina pipe runs through. This
should just slide off quite easily.
Now systematically disconnect all the cables and pipes at
the following connections. Some of the cable connections require some dexterity
to remove. There are clips and levers that need pressing or squeezing to get
them to release. The pipes need the bright coloured collars depressing which
release the pipe from the holder. If your fingers are not nimble enough I found
a small slot screwdriver used to push the collar down while gently pulling on
This one below is hidden under the front VIS motor. The
pipe is very brittle and should be removed very gently otherwise if it gets
broken you may have some difficulty replacing it. I broke one and had to use
some strong rubber fuel pipe I had in the garage.
Most of these cable and pipe connections are unique to the
place that they fit so it would be very difficult to refit in the wrong place. I
took a photo of most of each connection just in case I needed to make sure which
fits where. You could just number them with a bright coloured text pen and then
replace them in reverse order.
To remove the air filter you have to undue the two screws
in the top near the battery cover and then gently praise apart the two clips at
the front revealing the air filter, this should pull out quite easy.
The one currently in mine was still quite clean and plenty
of life left in it so I reused it again after a good blow out and cleaning.
Below is the throttle box connection which has a small push on pipe on top and a
much larger one below. When I took these off they just slide off very easily. I
found some considerable oily deposit on the pipes below this assembly. I assume
that it had been leaking for some time and I think that it is this area that
some have made modifications to limit this oily residue.
I sprayed this area with degreaser and wiped with old rag.
I renewed the large cable tie used to hold the large hose on as the old one
seemed to have gone pasts its use by date.
Remove the battery and undue the 4 large screws holding the
battery casing in place. Depending on how dextrous your fingers are you maybe
able to leave the battery box in. I found it easier to remove it and also this
does the ďbattery disconnect and rebootĒ operation recommended now again to
reset the computer chips. My radio does not have a code and I donít have the
factory SatNav so saving codes etc wasnít an issue for me. Your situation may
Cable connectors located on the battery box make sure you
replace these so floppy cables waving about is reduced.
This shows where the battery box is fastened and what it
looks like underneath. I also found tucked underneath the manifold a loose
female electrical connector without anything connected in it. Apparently this
is normal and may have a use for a feature my car does not have. I think it
maybe something to do with cruise control.
In this picture you can clearly see the new Pollen filter I
replaced a couple of weeks earlier and the rubber grommet with concertina pipe
that slots into the removable bulkhead mentioned earlier.
This picture shows the two screws that hold the main cable
loom that runs across the top of the manifold. Down behind these (out of sight)
are the two bolts that hold the lower cable looms for the spark plugs. These
are very difficult to get to and in fact one was broken off. I was uncertain as
to how these held the manifold down but in fact they donít they are only for
holding the spark plug cables in place.
The broken oneÖ
Using wooden wedges to keep the manifold apart as you lever
it up. Underneath this are green rubber O rings that create a firm airtight
fix. I reused the original ones as replacements were not supplied. Apparently
you can get a full kit off eBay if you feel it is necessary. I found it easier
to disconnect the fuel line to get the manifold out, some suggest that this can
be left connected but I had no problems with it when reconnected.
Once I had got the old manifold out I was able to see where
one of the fixings had been broken off and may have been in this state for some
It requires some dexterity to manipulate the assembly so
that you can undue the screws holding the throttle box to the manifold. I left
the throttle cable attached to this as can be seen with it resting in the air
filter box below.
Now if you are inclined to change the rear spark plugs this
is what you are confronted with. I had bought new spark plugs but once I had
removed the manifold I was not expecting this view. To be honest I didnít know
what to do so I didnít attempt to change the spark plugs. I am afraid I will
have to leave that to my friendly mechanic. The front ones look simple enough
but I had never seen anything like this before so my thinking is if it ainít
broke donít fix it.