Matra Enthusiasts Club UK
FAQ's: Frequently Asked Questions
- I need a new battery for my Murena. What type do I want?
The correct battery for a Murena (and a Bagheera) is an '049' battery.
This code denotes the physical dimensions, the types and positions of the
terminals (as on the right here)
the clamping arrangements, and possibly the power level. However, it is not very
common judging by the number of stockists that keep it 'on the shelf'. The '048'
(lower image) in fact tends to be much more common and more likely stocked. The
only difference between the 048 and 049 is that the positive and negative
terminals are reversed, so it will not fit without some modifications.
If you are prepared to do these modifications, you will have access to more
batteries, as the MX5 used to fit an 048 and there are many of those around!
The batteries are also slightly more powerful these days. The original battery
was rated at 265 CCA (cold cranking amps) and 35-40 Ahr whilst the newer ones are
up to 330 CCA (commonly 300 CCA) and 40-45 AHr within the same physical size case.
This physical size is important. The Murena needs a battery that is no wider than
135 mm. Most common batteries are 175 mm wide and if you fit one of those you will
not be able to fit the tools back in their designated place. To fit the '048'
battery you will have to make up, or have made, a slightly longer earth lead and
replace the original. Then simply shorten the positive lead and fit the 048
battery. Whilst shortening the positive lead you can eliminate that terminal for
the lead to the circuit board and get rid of one potential problem area too.
Other possibilities are the 053 or 154 battery, which are very similar to the 048
but do not have the hold down strips along the base of the casing, which the
original hold-down brackets clamp on. As these batteries do not have these ridges
so you will need to devise another method to secure them. One suggestion is the
'L' shaped strip along the top edge and two hooked rods to clamp it, like you
see on some other cars. You can often buy these parts as a kit from parts
suppliers. Batteries should always be clamped as it reduces the wear from
the heavy battery moving around and helps improve their life. The other possible
difference are the terminals which may be the smaller Japanese terminal posts so
you will need the converters to bring them up to the standard size.
Finally, if you don't mind paying more for a superior battery, you could go for
an A.G.M. battery. The only one I know of in the U.K. that will fit is an Optima
'yellow top' YTS 2.7 coil cell design battery which has an even higher spec. and
should last much longer as well as hold its charge far better. It is rated at
460 CCA and 38 AHr but will cost around GBP130 (in 2019).
- My Murena 2.2 sump gasket is leaking. How do I change it?
The sump gasket is special on the Murena 2.2 and MUST have metal spacers in the
gasket. So the gaskets are expensive for a reason. There are many incorrect ones
listed so beware that even manufacturers often list the wrong type. e.g. BGA
list the Tagora gasket for the Murena - WRONG.
Do NOT fit any 180/2-litre/Tagora gasket as it will not last any time at all, and
since it is such a big job to change usually involving the engine out, you do not
want to do this a second time because you used the wrong one!
First of all, if you examine the installation, the engine is mounted, not on the
block like most cars, but on the sump and the gearbox. So think about it - since
the engine is mounted on the sump not the block, the engine MUST be rigid with
the sump, especially since the gasket is cork. If you only have a soft gasket
(whatever type) it will soon get damaged by the power unit movement, and it will
be leaking again in no time. So don't try to use the Chrysler 180/2-litre/Tagora
sump gasket. If the engine is rigid with the sump, they will move together and
preserve the seal between them.
You can't simply drop the sump off to replace the gasket, like a conventionally
mounted engine, without making alternative arrangements to suspend the engine!
Since the long (RH) driveshaft runs in a bearing held in a non-removable sump
casting, it has to be slid out which involves removing the RH trailing arm. If
you decided to do the job, leaving the engine in and suspending it, before you
drop the sump, you MUST remove the oil level sensor otherwise it is going to
get damaged, and they are no longer available.
However, I have usually found that not only is the sump gasket leaking, but the
timing case seal is often leaking too. Taking off the lower timing case involves
removing the water pump and crankshaft pulley, and the sump mounting normally
gets it the way of the latter, but as you are removing the sump, you might think
this is now the time to do it. But removing the water pump means tilting the
engine away from the RH inner wing, which is more difficult when you have the
engine suspended. You have to release the gearbox mounting and lower that end,
and what you now have suspended is no longer just the engine, but the complete
powertrain! And you must remove the original air box on a Prep 142 or S, if
still fitted, otherwise it will foul the fuel tank. Finally, removing the
crankshaft pulley and the lower timing case whilst the engine is temporarily
suspended in the engine bay, is not particularly easy either. Also, while you
are fixing oil leaks from the engine, you need to check and make sure it is not
leaking from the rear seal behind the flywheel. This is not a lip type seal as
with more modern engines, but a cord type seal set into a rear block housing cap;
with a reverse scroll and thrower on the crankshaft to deflect oil away from it.
(This is similar to old BMC engines if you have ever worked on them.) If you do
have an excess leak at this point, then you have to remove the crankshaft to fit
new cord seal halves, so you can see the job becomes one where removing the
engine is definitely the easier option!
This is why I normally recommend you take the complete unit out. Yes, it becomes
an even bigger job, but not by much, and you will be able to work on it much
more easily, and you will be able to see ALL the things that need doing, and do
them in one complete job.
The bolts are torqued up on the metal spacers, and the gasket forms the seal but
does not take the load. This is why the sump gasket is special to our car and
costs a little more. When the original supply of Murena 2.2 sump gaskets ran out,
I had some more made up by Cooper-Payne but without the spacers - just the holes
to take the spacers. You simply transfer them across from the old gasket to the
new one. This is why my gaskets cost much less than others. Mine cost around 35
Euro plus post and packing, where I think you will find others cost much more,
possibly twice as much. Please check them out. The choice is yours.
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This was last updated 31st March '19