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MG MGF Technical - Water Pump, Alternator and Camshaft Belt(s)

Hey, everyone,

I've spent a while perusing the archives, the RAVE CD and Tony/Dieter/Rob's sites for information on (a) changing the alternator belt and (b) replacing the water pump. (I've had an odd whistling noise at idle for some time now, thinking it's one or other of these things.)

Anyway, what I'm looking for is a bit of, er, encouragement that if I tackle these things myself, I'm not gonna create a total shambles :-O

We're talking a '97 VVC non-AirCon here btw...

o Alternator Belt

In the archives, there's a lot of discussion on whether it's strictly necessary to remove the rear o/s arch panel to gain access. Comments? Rob and Dieter made comments about electrolyitcal corrosion of a steel screw... is this easily replaced (if you manage to get the sheared old one out of the subframe)?

o Water Pump

It appears it's neccessary to drain the cooling system to change this baby, so I'm going to order Mike's aluminium pipes today, may as well do everything together.

Now, as if draining and refilling the coolant system doesn't put the fear of God into me enough....

Scarily, the RAVE CD says that it's necessary to remove and replace the camshaft timing belt if you're changing the water pump. Now, I had the timing belt done at 42K and I'm up to almost 70K, so I may as well do this too. Loads of questions here:

The CD groups the timing belt instructions for a VVC *and* vehicles with AirCon together. Can anyone confirm I'm gonna be working with the correct instructions?

From Dieter's site, it seems that my F (1997) has a manual cambelt tensioner. Can someone confirm this too?

Should I do the rear timing belt as well?

The CD makes mention of 'locking tools' to lock the camshaft gears (18G-1570 and 12-182 (rear)). Are these really necessary and if so, can they be purchased outside of MGR?

Many, many, many thanks,
Colin McIlwaine

Hi Colin,

Hopefully I can persuade you to take lots of photographs? :o)

Regarding the alternator belt and the cover screw, this typically shears off in my experience. The solution then is to drill the old one out and replace with a new self tapping screw. Unfortunately, the same problem with recurr with your replacement screw - any one got a better solution?

As for the water pump - Tim has done this job very recently on his MGF, so perhaps you can persuade him to fill us in on the details? But IIRC, he left the cam belt alone...
Rob Bell

LOL! Yeah, no problem with the photos, Rob. Ta for 'hosting' and updating the ARB debacle, btw!

Interesting about Tim... however, since it's been a while since the belt(s) were last done, I think I'll have a crack at it anyway... better to be safe than sorry ;-)

Since the orginal post, I've found out that (a) the locking tools are available everywhere and (b) yes, they should really be used ;-)

Colin McIlwaine

>> Regarding the alternator belt and the cover screw, this typically shears of in my experience<<

Which screw do you mean Rob???.

Replaced my alternator belt last week, screws in the cover had to be drilled out, and the 8mm?? adjustment screw for the alternator also sheared!.

When putting the cover back, removed the old plugs in the chassis, and fitted the cover back with some door poppers I had left over, they were a perfect fit into the existing holes!!, and easy to remove in the future!!.

Door poppers Mark? Do you have pix of these, I am being dense - I am not sure that I know what you mean - D'oh!!!

Colin - seems sensible to replace the belts to be honest. Good luck - have to confess that this isn't a job that I've done!
Rob Bell


When I removed the alternator cover parts of the old screws/plugs were left in the chassis, pulled them out with grips, and the hole left is exactly the same size as the ones in the frame of the door which you push the poppers into, which hold the door cards on!!.

In other words The plastic plugs on the back of the cards which hold it in place!!.

If that makes sense!!.

Ah! Yes it does now, thanks Mark - ingenious solution: is the trim panel held in place okay?
Rob Bell

Was still there last time I looked Rob!!. :o)

DCP4229 is the original *push in/screw off* rivet for the several liners to sheet metal at the MGF.
Wheel arch and fron bonnet cover i.e.
You can use any standard availiable 8mm plastic rivet with push in rod. Rod needs to be pushed out from the other side then, or drilled off.

Door cards poppers complete are EYC10042 (superseeded?)
EYC10046 the black *female*
EYC10047 the blue male part
I think as well it's a nice solution :)
Tiny image from old camera :(

I'd recommend a stainless steel self tapping screw or cut new M5 thread with M5 stainless screw.
Did this M5 thread cut at my old green and 4 years ago the same with my silver MGF and I wonder what will happen in next week with it due to Aluminum corrosion.


As Rob has already mentioned, I had to replace my water pump a couple of months ago and it's not rockt science just bloody awkward. A lot has to be done by sense of smell since you can't see a great deal.

A few things to consider:
Replace the cam belt tensioner (with a manual one)at the same time, the noise you hear may be a worn bearing.
Cam Belt removal
The hardest bit of the cam belt removal is getting the Enginge Mount bolt removed. A large breaker bar or impact wrench is essential.

Make sure you set the cams with the markers on the pulleys facing each other. Also put a reference mark on the crank pulley (the timing notch is on the BACK flange of the crank pulley don't be confused by the one on the front flange!)

You will need to use the breaker bar to undo the hex bolt holding the tensioner and a cranked 8mm ring spanner to remove the slider bolt.

Water Pump and pipes
All straight forward except remember the bolt at '10 O'clock on the water pump flange is removed from the opposite side.

The rubber hoses will be a bit of a pain to remove from the metal coolant pipes, be careful not to damage the rubber pipes.

Re-fitting the cam belt.
Leave the car in gear when re-fitting, you don't want to turn the crank!!!
Make sure you have enough tension on the 'driven side' of the belt (nearest the bukhead. Get the belt onto the exhaust pulley first, only push it on by 5mm or so.
It is likely that the cams have forced the pulleys apart a little, you need to ensure that the belt is not too slack (take note how tight the original belt was) It may be necessary to rotate the two cams towards each other with 17mm spanners (WITH CAM LOCKING TOOL IN PLACE)this can give you that important half tooth to get the belt on the inlet pulley.

Now just the waterpump and tensioner. From experience I have found that it is easier to place the belt around the waterpump and then fit the big tensioner bolt (if you fit the big bolt before getting the belt around the tensioner you'll make your life a lot harder) you can just about see what you're doing if you bend the metal wheel panel into the wheel arch (bend it back again afterwards.

Setting the tension is fun. use a LONG screw driver to push the slider up and use the 8mm setting bolt to hold it whilst doing up the big hex bolt with the breaker bar.

Bleeding coolant.
ensure you bleed ALL of the 3 main bleed points I found I had to apply a little air pressure to the expansion tank to bleed the engine bay point correctly.

Do a 'sanity check' and make sure there is nothing loose in the engine bay. REMOVE the cam locking tool and start the engine if you hear 'chirping' the tensioner is too tight, adjust it and try again. (Note: don't re-assemble every just yet incase you need to re-adjust.)

Sorry I can't help with the other VVC belt, I haven't done this before (shouldn't be too tricky if you can do the main belt).

Don't expect to do all of this in one day, it may be possible if you have done it before but not as a novice. It's not worth rushing.

These are not full and comprehensive notes but highlight a few of the main points you'll come across.

Good luck

tim woolcott

Thanks, Tim! All good stuff, thought it might be a multi-day job alright.

Annnnnywaaaay, the whistling/whirring noise was *very* noticeable at idle this morning, more than usual certainly, but drove to work anyway.

Needed to potter out at lunch, blipper wouldn't pop the central locking... looked in the cabin, no alarm led... opened her manually, key in ignition... nada ;-(

Lots of bad things went through my head until I realised I'd left the damn lights on ;-(

Never a dull one!
Colin McIlwaine

I had grinding rev-depending noise, which turned out to be the tentioner for the alternator belt.

Maybe you should check with a mecanic's stethoscope first, before changing the lot...


(I'll have to change it again, as i could only get a worn used one the last time...)
O Sander


If you opened the car with the key without the blipper the car will still be imobilised.

Your car will have come with an override imobiliser code. This is a series of numbers which corresponds to turning the key in one direction and then the other multiple times in the lock to de-imobilise. If the Blipper is dead or de-programmed the car will not start.

Have you tried your spare blipper....?

tim woolcott

Oskar, yep, since the alternator belt *seems* to be relatively straight-forward (compared with the timing belt), I'll have a crack it it first. Unfortunately, the timing belt change is due anyway... ;-(

Tim, first of all, 6am is *way* too early!

To clarify, it was the car battery that was dead (from the lights left on), there wasn't enough juice left to pop the central locking... though interesting, there was enough to sound the horn when I opened the bonnet to get at the battery... mind you, it only sounded like a very small animal with a bad case of farts ;-)

Happy Friday, everyone!
Colin McIlwaine

Oskar, presumably you mean the *tension* of the alternator belt, rather than a physical *tensioner*?
Colin McIlwaine


I started writing the first post at 5.20am :o

tim woolcott

Hi all,

as promised .. started works this morning.
On the list:
- belt
- tensioner
- alternator belt
- coolant swap to OAT
- swap broken thermostat to 82 with jiggle valve
- swap in new spark plugs
- oil change
- oil filter change
.... and some more
But got stuck with the belt change ...... :(((

Errrr !!! I've bought the small belt and the manual tensioner... and need the automatic tensioner with wider 26mm belt.
So urgent advise for other owners who have an MGF MPI made in 1999 .. don't believe the files, have a look behind the upper belt cover before you shop around. ;)

Works with all the above stuff including coolant swap to OAT went on without major troubles.
Thank You to the advises from Tim, Carl and all the other on this BBS :)))
- Air tool driver was used. And yes, I think that's the best solution for the crankshat nut.
- Engine got flushed from old coolant with connecting a hose to the jiggle valve connection in the head.

I just removed the RH small hose from the coolant canister and pushed on a garden waterhose to the loos hose. Let water poor in with low pressure until it leaks from all drain holes.
Close at the radiator, wait until lots of water escape through the waterrail drain hole and coolant canister.
Stop flushing. Drain at the lower coolant pipes as usual and repeat the whole sequence until the coolant doesn't shine yellow any more.
I think this is nuff.

The only very ugly trouble was the Thermostat change...
D*mn, did I SHOUT !!!!! Carl had written already 3 years ago:
This car is built *around* the Thermostat.


I would had given in just after removing the first bolt.
With the idea in mind:
"Oh guy, you maybe get the bolts off now in any way, but how in heaven will you put them back ?!?!!"

OK, Carl did it, hmmm ... I met him once, a quit normal looking Swedish engineer :)))) No witch, no myricals with him :))

So why should I give in ? ... ME went on !!

The engine side upper bolt is a real a*se !!
I sat in the boot, both arms inside the engine in any way. Small ratched with long enhencement and cardan knuckle did the job for this from above.
(Put it back later using mastics at the ratchet nut to prevent loosing the bolt.)

Then removing the broken Thermostat. Errrr... Sowhat of restricted space to get it off.
The friend from the garage (Hi Thilo) was so kind and did this from the right in any way while I pulled like mad from the left at the prior made loose water rail.
Good was that I had remove the waterpump before we tried to get hands on the Thermostat. Was able to release it from the housing through the waterpump hole.

Oh, and before I forget. THE waterpump... attachment ... no, nuff said for today ;)

Ahmm, btw. I took some images :)
Anyone curious to seeing them ?

Another about the broken Thermostat.
I found it _looking_ OK. So not always open. Spring isn't brocken. I can push it open with both thumbs with some pressure. Can't get why it doens't work what it should. I think I'll join the wifes new kitchen and boil some water to see what the mad part does under increasing temperature.

PS. nearly happy, with black fingers and scratched arms. Tommorow at 8am will fall the belt and tensioner. If it arrives in time from the supplier..

Uuups, please ignore the typos.
... and spelling ?

OK, me did the Thermostat !! LaLaLalaaLaaahhh ! :)

>> Errrr !!! I've bought the small belt and the manual tensioner... and need the automatic tensioner with wider 26mm belt. <<

The manual tensioner seems to be the one to go for - or at least that is what the Elise and Caterham guys are saying...
Rob Bell

Good fun eh Dieter??;-)) The auto belt tensioner is fitted to engine numbers from 18K4FJ31/32 on. The manual tensioner and belt cannot be fitted to the autotensioner head despite what the lotus guys say..unless you change the head.8-((


I've got one kit for sale now :)

>is fitted to engine numbers from 18K4FJ31/32 on
Thank You, will check other files to confirm.

>Good fun eh Dieter??;-))

Mike, I see your bright face more than smiling.
This seams definately a job 4 YOU.
would recommend MS for Thermostat repairs !!! HE likes this !!
Haahh!! .. and I'll get over as spectator and take images of *Mike-in-the-boot*

Back serious,
had investigated? (while wining about the hurt hands and arms) why does the broken? not work as it should.
- put in a cup of water
- placed in the Microwave oven
- let heat the water until it boiled
- get the cup out and ....
- .. it opens quick and closes slow as expected.
Err, it looks quite normal.

I can't get why the engine did heat up very slowly since I _boiled_ the Thermostat down in the Alps one year ago.

The only idea I currently have is:
May be the spring is to less force. The wax expansion body (spelling?) of the Thermostat seams OK.

Anyone with an idea about to test/verify the Thermostat spring force ?

Dieter <<< approved?? Thermostat changer ;)

PS. me's off now for a hot long lasting bath in the bathtub to heal wounds.

Yikes, you need to change the head to 'retrofit' a manual tensioner Mike? :o(

Dieter, the thermostat behaviour is odd. When it closes, is it sealing properly - i.e. is water tight?
Rob Bell

Yippiiiie !!

Got done the belt and automatic tensioner this morning !

Impressions after a short ride from the Garage where the works where carried out to my home.
I drove there yesterday and back today _without_ engine cover. So the ears quite near to the Engine.

Yeah ! What a difference !!!
No whistle anymore. I think the automatic tensioner was _on the brick_ of failing.
The kilometer 'idge recommendation from MGR for cam belt change after 100k km is far to much.
Even the 60k miles in the UK. I have daubts that is good.
I think I'll recommend cam belt change after latest 90k kilometers which comes quite near to the UK specs.

Anyway, off now for oil and spark plugs change.

Regarding the mad thermostat (problem?)
I still wonder what's going on with it.
May be additional my oil temperatur gauge and sender have any contact problem.
This combination of two faults, pre-damaged Thermostat and bad (to low) reading from the oil temperatur gauge may have resukted in this confusion.

I now have a 82° Thermostat and the accessed bleed process was absolutely usual this morning.
After 3/4 hours idle run, the front fan came off.
But the oil gauge showed less than 90° only. (80°)
I remember when I did my first coolant change three years ago, the oil temp was 120° when the front fan cut in.

At last again a reaööy big thank you to Mike and Tim and Will and ??? for the recommendation to turn both cam wheels slightly inwards whilst the cam lock tool is installed. I think I would have given in re-mounting the new belt without this hint.


Errr, can't read myself with this typo.
>This combination of two faults, pre-damaged Thermostat and bad (to low) reading from the oil temperatur gauge may have resukted in this confusion.

should mean:
This combination of two faults, the pre-damaged Thermostat and the bad (to low) reading from the oil temperatur gauge may have caused this confusion.


Ah ha! So it is the sensor playing up, not the thermostat?

Looking forward to seeing all the pix Dieter :o)
Rob Bell

>Looking forward to seeing all the pix Dieter :o)

Mate, unfortunately _me mad_ forgot the memory stick in the PC this morning. Got one lend 2 hours later when works nearly where finished :(
Only a few pictures available. Nothing from the wet floor and splashing water and coolant.

On the other hand neither me, or the friend from the Garage would have been able to taking pictures while mounting the belt and tensioner.
It seamed four hands had been to less for works and the space for taking images is also sowhat of restricted ;-)
The other "done that job"-friends will confirm.

Dieter <<-- approved Thermostat and Cambelt changer ... (LOL)
PS. now with big mouth. You should have seen me with shouts and daubts seven hours ago.

There is tons of usefull information in this thread now...

I must just add to my comment to check the tensioner for the alternator belt, this applies *only* to Air con models. (the rest adjust the tension with the alternator)

>>The CD groups the timing belt instructions for a VVC *and* vehicles with AirCon together. Can anyone confirm I'm gonna be working with the correct instructions?<<

I've noticed the same thing in the manual about this grouping. As I have a Air con 1.8i should this procedure be used?

Last thing, there has been mentioned to change Cam belt tensioner and cam bolts with the belt. Is this meaningfull for an 1.8i with manual tentioner?


(I'm happy to borrow your tool Carl, once I've built the confidence...)
O Sander

... just 4fun

Mpeg from yesterday about the automatic tensioner movement before it got changed this morning.

You get this movement if you pull the belt together with one hand above the crank pulley
Notice, 5Megs temporary upload only to another account

And this it what I _really like_ ;)
(please notice, how slim I got in the last years.
Fortunately the waistbelt holds the 4 years trousers in place) :)
And yes, I have two arms but they are below the inlet manifold anywhere.

Err, I know why I dropped that crap account years ago. Links don't work. May be later renamed without capitals.

Apology for the inconveniencs (again)

>> <<

I think that this picture deserves a caption competition!!! :oD
Rob Bell

Dawn reckons these cars cost an arm and a leg. There's proof.

Adrian Clifford

LOL... but it's fun, isn't it ;)


apology, late but not to late. Just read your quest.
At first see which edition of the _manual/file_ do you own.
(First or second page down on the right)

They are different, whyever.
Edition 3 is mainly manual and I now think it got introduced according to the upcoming change to the automatic tensioner.
Edition 8 and later include the almost greatest confusion. I've looked up myself yesterday night and the crap goes on in later until the current mgtf Edition.
There's no difference between VVC, MPI, TF 135/160 or what on the right hand long belt side, unless you have the engine on your workdesk ;)

If you have an MGF with Manual tensioner:
Use edition i.e. #3 including this BBS advise
There's nothing confusing included with dismanteling the whole engine butress, but unbolt the two big screws on top of the butress only.

Unbolt the both screws, and drop engine to get the belt into the RH engine housing that's it, and nothing else.

Aswell nothing with _install belt together with the tensioner_ (IMO)
I think this is possible, but only with the stripped engine direct on your workdesk !!

If you have an automatic tensioner.
Use Manual #3 and add the comments according to the tensioner installation from other editions.
This is different, of course.
It is impossible to install both the belt and tensioner *together*, unless you have the engine on the workdesk.

1. Never pull off the cam lock tool
(I admit, mine fell off this morning and the inlet cam jumped out of alignment (45 ?). I carefully turned it back inline with a 17mm spanner. Hope I didn't pre-damage anything.

May be it is useful to shorten the cam lock tool and cut off the thin grip part to get more space in front of the cam wheel housing. I didn't and had problems taking care on not loosing it while fiddeling the new belt through the gap between butress and butress upper mount. Well I lost ;)

2. turn the automatic tensioner arm to 9 o'clock, (90 left.)
You must have the largest clearance to get the belt over the tensioner wheel. Understand how it works with the spring and excentre part.
It comes clearer when you have the part in your hand.

The similar is I think with the manual tensioner. (Most availiable space required.)

The sequence of getting the belt in is mentioned already several times.
I did with help of a friend.

#1 below/beside the wheel house
feed belt 5mm on the crank wheel, direct upwards taut with the RH fingers whilst holding it to the cam wheel with the rest of the RH. (spelling?)

#2 from top of the engine
17mm spanner to the inlet cam and move that cam 1-2 degrees clockwise. This will remove the play between both cam wheels and the tool and it provides the later at the twnsioner missing 5mm.

Now #2 puts the belt 5mm on the outlet cam and pulls to the left and 5mm onto the inlet cam. Only holds all tight now talking about what he and the belt does, and over to guy #1.

#1 starts big shouts, cause the thingy neither gets 5mm over the tensioner or over the waterpump ;)

#1 moves it with the left hand 5mm over the waterpump.
Then change RH grip from crank wheel to LH.
Carefully push the belt bit by bit for 5mm over the tensioner wheel.
If you got this 5mm, you won. The other 20mm is more or less a game.

Congratulations Dieter!
I still cannot imagine how hard it is to get at the thermostat with the inlet manifold on (did mine without the head in situ and it was easy ;-)) )
If I am allowed to give some extra hints, I discovered it is a bit easier to fit both manual or automatic tensioners without the small bolt (used for adjusting on the manual and to hold the spring on the automatic) and then fit the belt because the tensioner will gain that bit of travel that allows the belt to slip in.
About the thermostat, it is a fairly common problem (not just Rover) to get a "sensitive" thermostat when they get old... the spring loses its nerve and the stat opens at lower temperatures and/or when the pump spins hard.

See you (in South Tyrol) soon

P.S. as I actually need a spare manual tensioner, I will happily buy it off your hands!

Hi Carlo,

great to see you.

I think this is worth a try with removing the upper RH bolt of the tensioner. At both, either at the manual or automatic. I didn't consider to according to the principals *Only bolt off what you can get back easy.

I remember another one to improve access to the parts and get an arm through between engine butress and inner wheel arch.
- Bend the sheetmetal above the brake disk outwards and bend it back when you have finished works.
This is aswell written to any of the several Workshop Manual Editions, and it works !

Update regarding Thermostat change procedure. (pic link above)
- the oil-filler assy needs to be removed to get enough space for the RH elbow.
After removing the screws, push in the red ring at the plastic filler parts lower end to seperate the oilstick pipe from the upper assy.

>See you (in South Tyrol) soon

Ehhyy, you will be there ?? That's really good news !
Lets exchange the Mobile Numbers. See Email.

PS just back from the home garage.
- changed spark plugs
- swapped in the uprated Fuel Pressure Valve

... webside under construction.
Looked up the archives and found useful....


The workshop manual editions produce aswell confusion about the fly wheel locking tool. (Not required usually, though)
Asked Will by Email, maybe he can clean the confusion about fly wheel tool 18G1571 or 18G1742

>> Anyway, what I'm looking for is a bit of, er, encouragement that if I tackle these things myself, I'm not gonna create a total shambles :-O <<

LOL! First of all, congratulations, Dieter, for achieving this with nothing more than sore hands ;-)

On reflection, though, I think I'll leave the timing belt to my MG mechanic. I *will* have a crack at the alt. belt though.

As always, a magnificent and helpful response from the BBS. Ta!

Colin McIlwaine

This thread was discussed between 18/05/2005 and 26/05/2005

MG MGF Technical index

This thread is from the archive. The Live MG MGF Technical BBS is active now.