My belt is 10 years old (58k), so It is way overdue!

Sh1t Bradley !! Definitely need to have this done asap. The belt takes an enormous load and that is why they snap without any pre-indication. It happened to me with my previous car .... the service history had documented a garage belt change but it snapped on me at around 60k miles. I don't know if it was ever really done or poorly fitted or crap quality parts. That was an expensive top-end rebuild.

But like you my belt on the camper is due for a change too. I was wondering about the question of tensioning the belt. The Haynes manual quotes a deflection figure and says a firm thumb pressure is ok for initial setting but to have the tension checked at a Renault garage once the job is completed. Does anyone who fits these at home use any kind of tension gauge and has there ever been problems of the belt slipping a tooth or two in the ensuing years or does the spring tensioner take care of everything? Let us hear the advice.

 

Oh BOY, this could be a fun thread LOL




RW, Have never used a tensioner myself, and dont want to think how many belts I have changed over the years..
( Must be at least 3,,,,,, wink )
People tend to over tension the belt, this tucks them up.
Rule of thumb, if no auto tensioner, using the longest length, the belt can turn between 45 degrees, and 90 degrees . ( 8 Valve engines here )
Anywhere between and your good to go ..
To tight, it pulls on the teeth of the belt, but where the teeth actually is bonded ( as such ) to the belt, . this then rips them away. also it puts too much strain on the bearings in the tensioner, and idle pulley
Not come across a 16 valve thats not auto tension for a long time now.. or with a pointer on it for the tensioner



Bradders, got go do a bit, sure someone will answer this for you

 

You don't time these to marks, you need a set of timing tools.
Basically a pin that goes in from the side of the engine and into the crankshaft web, there is a hole there for that purpose.
Cam(s) also have a lock pin or a lock plate, depends on engine and I am not sure which you have.
Basic is set engine to TDC, staw or BBQ skewer through spark plug hole nd turn engine to ensure pin goes in.... .do this before undoing anything.
DO NOT use the pin to lock engine when undoing or tightening, check only with it.
Top engine mount off as you have just been doing with your manifold job.
Release tensioner on aux belt and remove
Undo crankshaft main pulley and tensioner and remove belt
Now put in lock pins and camshaft locks.... I think twin cam uses plates at gearbox end but would need to look.
Once the belt is off, do not rotate engine or cams
Remove and replace tensioners, pulleys and water pump. Pulleys etc for aux belt as well as timing.
Fit new belt...cam sprockets may have sliding plates to be loosened and then reset after belt on.
Torque up the main pulley. Lock pin out for this.
Adjust tensioner, which is basically pinch it, then twist adjust till finger gets to right position then lock it.
Lock pins out then two complete turns of engine and recheck timing
Fit new aux belt, covers engine mount and brumm brumm, good to go.

You will need to be jacking engine up and down for access.
You will find a clatter gun (impact driver) makes undoing main pulley so much easier.
You may need someone with a large screwdriver through TDC hole jamming the starter flywheel.
Marks on old belt and pulleys transferred to new belt can be used as guides when refitting... timing tools are main though.
Torque on the main pulley is FT.... dunno exact but someone will, just 'effing tight so be warned.

 

Basic is set engine to TDC, staw or BBQ skewer through spark plug hole nd turn engine to ensure pin goes in.... .do this before undoing anything.

In addition to the above I would also advise to remove the top engine cover first so you can see the valve gear and watch the valves open & close so you are certain you have the cylinder at TDC on the ignition stroke with both valves closed and not at TDC on the exhaust stroke with the exhaust valve open.

 

Get some torx sockets- the screw covering the crankshaft hole needs one. And if you don't have it, the Haynes book. The torque setting for the pulley bolt is in there, but as advised, ...ing tight will do.
There are timing sets on ebay for about £15 with a locking bracket for the camshaft sprockets- getting the belt round them is tricky. If you get stuck, come back here.
My own particular odyssey- Lag2- is here- it's a K4M so it might help you.

Laguna 2 1.6 K4M Cambelt Change **Sorted**

I'm biting the bullet and changing the timing belt/water pump so we don't get stuck in France profonde this autumn- can some kind person help me out with the pulley bolt size so I can order a proper socket and not have to use mine which seem to be made out of biscuits these days? I hear 18mm...

www.renaultforums.co.uk

 

People like Sealey produce the timing tools.
Though others are available or you can simply use the butt end of a drill or a bit of steel rod.
They also provide detailed instructions for use which are readily available and judging by the ones for the 1.5dci, well detailed.
You may want to talk to them and see if any are available for your engine.

Sealey

Sealey is one of the UK’s leading suppliers of workshop tools and equipment.

www.sealey.co.uk

 

I'd like to thank everyone for their reply.

After reading the information, and through doing countless hours of my own research, it's hard to admit that I still don't know what I'm doing.

I imagined that all you do is turn the crankshaft until the cam shaft lines up with some kind of marking, then lock the cam pulley (or pulleys) with a fastener. Then release the tensioner and fit a new belt.

I know it's not as simple as this. There's also the locking tools that fit inside the caps on the right side of the engine, and somehow, you need to lock the crankshaft. I don't know how to lock it, and how removing the crankshaft pulley could effect this, or when to even lock the crankshaft. Lock it against some kind of marking? If the crank pulley starts spinning when you try and remove it, and the cam is locked, they'll be out of sync with each other right?

I could do with someone showing me. I don't have a problem removing everything,.... It's just how to lock everything and when to lock everything and how to keep everything in sync. That's the issue I believe.

Thank you.

 

I imagined that all you do is turn the crankshaft until the cam shaft lines up with some kind of marking, then lock the cam pulley (or pulleys) with a fastener. Then release the tensioner and fit a new belt.

You are describing my Kia there, don't have to lock anything though you can get the tools.
If there was decent access would be a 30 minute job.
But there isn't and book time is 7 hours IIRC... needed all that and more.
Havng done it once, would probably shave some off the book time but when you get things like pulleys being held by a torx and only 1" clearance, it is a pain (Torx bit and 10mm ratchet spanner and screwdriver/fingernail to keep bit located)
But that digresses, it isn't a difficult job on the Renault but one you have to get right so what Ourkid has suggested, easy steps and you will not go wrong.

 

First thing you need to do is lock the crank shaft so it cannot spin..
IGNORE everything else until you have mastered this
Take the spark plug out of the cylinder closest to the timing belt ( Nu 4)
Put a screwdriver in the hole where the plug has come out,
Turn the engine clockwise, .. with either a socket and ratchet, or a spanner
You are waiting for the screwdriver to raise here,. as high as it will go
Once the screwdriver starts to go back down, then stop, Turn crank slightly back, place your hand on the screwdriver handle and gently rock backwards and forwards on the crank pulley bolt head ,
spanner needed here, you will feel the screwdriver rock as such ( Go up and down ), ..
The sump bolts to the engine block, follow the sump back towards the gearbox, about 3 inches from the gearbox with your hand on the sump follow it up to the engine, there you will find either a size 10 or size 12 E torx bolt head.
This needs undoing, IT WILL be tight, and as its not easy to get at, make sure its the correct E tork you are using.
Always work up on E torx so try the 10 first, It is a real good fit on all E torx when you have the correct size .
Careful here, this is where the hands can get cut/knocked..

Get this bolt out, now slide the locking pin in , at the same time rock the crank pulley, you will feel the pin Enter The Webbing on the crank.
IF you have this right, the crank will not turn either way..
If you have this wrong, the crank will turn counter clockwise.. NOW with some paint/tipex mark the crankpulley to the sump,
Thats it..
Build it all back up. Go have a brew,


Once you have mastered that, AND happy, then come back on..

(DONT FORGET to mark crankpulley to sump , Otherwise you will have to do all the above on again on the big day)

 

First thing you need to do is lock the crank shaft so it cannot spin..
IGNORE everything else until you have mastered this
Take the spark plug out of the cylinder closest to the timing belt ( Nu 4)
Put a screwdriver in the hole where the plug has come out,
Turn the engine clockwise, .. with either a socket and ratchet, or a spanner
You are waiting for the screwdriver to raise here,. as high as it will go

I take it you mean to follow these steps once the old belt has been slipped off ?

 

I've read each post carefully and things are making sense.

It would be best for me to practice raising and lowering the engine. Afterwards, I'll find TDC and lock the crankshaft, then mark it.

If successful, I'll have good experience and I can tackle the job properly another day. Sure, it's more work, but I'll feel more comfortable.

Does this sound like a decent idea?

Cheers folks.

 

Does this sound like a decent idea?

Damn sight more reasonable and sensible then jumping in on a Saturday morning and having a pile of bits by lunchtime.
Ready to try by Sunday and calling the scrapman on Monday.

Just don't dither on it, if you are right that it is an original, 10yo belt, yum on borrowed time.
Considering weather at the moment and not sure if you will be in garage or on drive, may be an idea to phone around and get some prices.
I know you want to DIY but it may be the quicker option

 

I'll be in the garage, so no problem there. You agree it's a good idea to practice then? I share your concern in terms of the belt's age, but she'll hold. If practice is successful, I'll order the parts next week.

 

I share your concern in terms of the belt's age, but she'll hold.

Famous last words. Now you've gone and put the curse of sodas law on ya self Bradders. :d

 

Making sure that you know what you are doing and practicing the initial steps to make sure you are comfortable with them, nay worries and IMO a decent idea.
I am not beyond jacking a motor up to give it a decent coating of looking at before embarking on a job.

 

Well I'll give the practise a go and this will tell me if I'm ready for the job. And I'll have a marker set for crank if I'm successful.

You guys all seem confident that I can do this with some guidance so that is a great boost.

Better give this belt a few revs for good measure

 

Better give this belt a few revs for good measure

And buy a bus pass.

 

Well I was feeling optimistic about doing this myself, but with recent advice, not so much. A local Renault garage (not dealer) quote £400 parts labour and Vat. All Renault OE.

 

No one is saying don't DIY.
We are saying weigh up the pros and cons especially with a belt that is living on borrowed time.
Parts will cost £!50 to £250 depending on what make and where from. (full kit, belts, pulleys, tensioner, water pump)
Decent make like Gates, SKF et al call it £180.
£400 all in seems a little high to me but shop about and check.
Balance that against your desire to learn and DIY.
When I was younger, there was no balance, I couldn't afford to pay someone else to fix my cars.
But there wasn't tinternet for advice either.

 

I get what you mean. I just see it as the final achievement. It means a lot to me. I'd settle for a garage to do it if they let me get involved. Perhaps wishful thinking. It's a shame you guys don't live closer. Would pay for your time.

 

Its a time consuming job.
And only time consuming because its your first one ( Best not put attempt here, sounds to negative )
Reason its time consuming is because you are double sometimes treble checking everything.
400 Squid is not really far off the mark, you will need coolant, new aux belt, new kit plus water pump..
Most garages are at least 50 squid a hour , and will still be best part of 4 and a bit hours so around the 200 squid labour
( No idea how long it takes, I just book the car in for a day, so never really care about a time scale,, and depending how much I like them is what I charge Wink )

 

I don't mind if it takes me a few days. It's just all down to getting the timing correct. Finding TDC sounds simple enough now.

How would one set the timing for the cam shaft? I guess they become set when the crank is set, so you just lock the cams with the special tool. Again, just a guess.

Is it a garage you have Ours?

 

How would one set the timing for the cam shaft? I guess they become set when the crank is set, so you just lock the cams with the special tool. Again, just a guess.

That is the size of it when changing a belt.
Everything is in the right place before you start so as long as you keep them there, should be when you finish.

 

It no longer sounds too difficult to be honest. Time consuming of course. But it really does sound doable. I've gone from having zero understanding to feeling confident.

If the crank and cam became out of sync, how do you adjust? I guess first you find TDC to lock the crank.

I wonder, can't you just lock it all as it is, seen as everything is already in sync?

 

I wonder, can't you just lock it all as it is, seen as everything is already in sync?

I really think that is what we have said Bradders.

As long as you put crank to TDC and lock cams, then don't rotate nuffink, all is sweet

 

No I mean lock it without finding TDC, but I've just realised you can't lock crank without TDC as the pin won't go in and stop it all from turning.

If by mistake the cam moved with the belt off, and it was out of sync, how do you adjust it so it's all good to go again? And how tight should I reinstall my spark plug. Torque from new is 28nm.

Cheers.

 

You cant rotate a cam when the crank is locked at TDC... at least not more then a couple of teeth as a valve will smack on a piston.
And they take a little effort to rotate, cams are not free spinning so you are not going to turn it topsy turvy by catching it with your sleeve.
Plus the sensible person has made marks, has stuck in the timing locks and doesn't play with the thing to find out if they can rotate it. Photos even.

Different matter if starting from scratch, say if the belt has snapped and timing is lost.
And I'm not even trying to write that up at this time of night.... once I wake up and got a couple of coffees down my neck maybe.
BTDC Bottom Top Dead Centre is another way of saying that the piston is at the top but on the end of exhaust stroke/beginning of suck stroke.
Remember the 4 stroke cycle, suck squeeze bang blow.
And the firing sequence which is embedded in my mind for Fords 1342 and I think the same for 4 pot Reanults.
From those two facts plus that the crank does 2 rotations for one rotation of the cams, you have all you need.
Oh, and don't forget that the valves will clash with pistons so have to allow for that to get the initial positions, then fine tune.

 

With the crank locked at TDC, the cams can turn a few teeth, as valves will hit pistons. If this happens, how do you rectify?

You say valves will hit pistons, so I'm to allow for this to get initial positions, then fine turn. Can you explain this more?

Don't know how easy it is to do on your engine but it makes it easier to rotate the engine by hand once ALL the spark plugs have been removed and also the engine won't accidentally kick past the timing marks you are trying to align spot on caused by another cylinder moving over on its compression stroke.

Why is it easier to rotate by hand with all plugs removed?

Bit more on this.
@RW...Before TDC (AIUI) refers to valve or ignition timing.... ie how far before TDC does the spark fire.
Which is all dynamic and driven from the ECU these days but in the days of dizzies and rotor arms, critical to know.
Nice bit was you could see.... so you turned the crank towards the TDC mark and often had a little scale showing degrees BTDC so would stop say on 10 degrees, then drop in the dizzy and rotate so the points just opening on relevant pot... usually No1 but could check against valves/cam position, lock it then plug in a strobe light for fine tuning.

Right, some basics for Bradders.
Suck squeeze bang blow... or if starting from Bang...blow, suck, squeeze.
That is what each cylinder does as the crank rotates, twice for the full sequence.
Compare that to the valves/cams for any pot.
Bang... at the start and as the piston goes down, being pushed by the fuel burning/expansion, both inlet and exhaust valves closed and stay that way, nominally for the first half rotation.
Blow... piston starting to come up, exhaust valves open, inlet valves still closed. exhaust gasses are pushed out.
Suck... piston has now come back to TDC, exhaust valve closed, inlet valve opens, as piston goes down, fuel/air mix is sucked in.
Squeeze.... piston coming back up, exhaust and inlet valves both closed, fuel mix compressed....
Back to TDC and repeat from bang.
Opening and closing isn't at TDC, exactly where depends on engine, design, valve timing but it gives an idea.

Next is the firing order.... 1342
So 1 is at TDC just about to go bang... valves are all shut.
3 is next to go bang so is at bottom of stroke and just about to squeeze, inlet valve just closed, exhaust valves closed.
4 is at TDC at end of blow, exhaust valve just closed, inlet opening.
2 has just gone bang so at bottom of stroke about to blow... inlet closed, exhaust just opening.

You can see all that happening if you rotate the engine when belt all on and can use it to set from scratch.
At least nominally. For exact set up you really need to be sure of dwell angles and when opening/closing happens plus measuring kit.....

BUT.....
Makers help us here.
By putting on marks or similar for timing.
Renault AFAIK on all their 16v petrol burners have a slot at the gearbox end of the camshaft, this is what the cam locking tool goes into. Off centre and IIRC, when cams are set correctly for crank at TDC, horizontal and below centre.
From that you really don't need to worry on first principles, just set the slots and all should be well.
On my KIA was dimples on the (keyed) sprockets that faced each other, one at 9 O Clock one at 3 when set correctly.
Renault Diesels (the 1.5dci at least) has location holes in the sprockets and back plate for a location pin
Just need to know what the specific engine has.

You can take off the covers and have a look while you are practicing locking the crank.
Lock them as well and paint on some marks on cam sprockets, belt and back plate for easy reference when changing.

So at TDC, locked, piston 1 will be set to bang (and all valves closed). Is that why we set TDC, and not BTDC?

Regarding crank locking, you said "off centre, when cams are set correctly for crank at TDC, horizontal and below centre". What does this mean and is it something I should check?

If the crank and TDC are perfectly set, how can you double check it? I heard the crank pulley won't be able to rotate at all, clockwise or anti clockwise, when the crank pin is inserted. If the pin is inserted and the pulley can still turn anti clockwise, the crank and TDC is not properly set. Right?

I watched a clio belt change video. The mechanic put crank lock pin in, rotated crank until it wouldn't turn anymore, then he declared this at TDC and locked the cams before removing the belt. Surely that's not correct?

Thank you.

 

BTDC = Before Top Dead Centre or Bottom Top Dead Centre (depending on the workshop manual instructions you are reading at the time)

 

Don't know how easy it is to do on your engine but it makes it easier to rotate the engine by hand once ALL the spark plugs have been removed and also the engine won't accidentally kick past the timing marks you are trying to align spot on caused by another cylinder moving over on its compression stroke.

 

Bit more on this.
@RW...Before TDC (AIUI) refers to valve or ignition timing.... ie how far before TDC does the spark fire.
Which is all dynamic and driven from the ECU these days but in the days of dizzies and rotor arms, critical to know.
Nice bit was you could see.... so you turned the crank towards the TDC mark and often had a little scale showing degrees BTDC so would stop say on 10 degrees, then drop in the dizzy and rotate so the points just opening on relevant pot... usually No1 but could check against valves/cam position, lock it then plug in a strobe light for fine tuning.

Right, some basics for Bradders.
Suck squeeze bang blow... or if starting from Bang...blow, suck, squeeze.
That is what each cylinder does as the crank rotates, twice for the full sequence.
Compare that to the valves/cams for any pot.
Bang... at the start and as the piston goes down, being pushed by the fuel burning/expansion, both inlet and exhaust valves closed and stay that way, nominally for the first half rotation.
Blow... piston starting to come up, exhaust valves open, inlet valves still closed. exhaust gasses are pushed out.
Suck... piston has now come back to TDC, exhaust valve closed, inlet valve opens, as piston goes down, fuel/air mix is sucked in.
Squeeze.... piston coming back up, exhaust and inlet valves both closed, fuel mix compressed....
Back to TDC and repeat from bang.
Opening and closing isn't at TDC, exactly where depends on engine, design, valve timing but it gives an idea.

Next is the firing order.... 1342
So 1 is at TDC just about to go bang... valves are all shut.
3 is next to go bang so is at bottom of stroke and just about to squeeze, inlet valve just closed, exhaust valves closed.
4 is at TDC at end of blow, exhaust valve just closed, inlet opening.
2 has just gone bang so at bottom of stroke about to blow... inlet closed, exhaust just opening.

You can see all that happening if you rotate the engine when belt all on and can use it to set from scratch.
At least nominally. For exact set up you really need to be sure of dwell angles and when opening/closing happens plus measuring kit.....

BUT.....
Makers help us here.
By putting on marks or similar for timing.
Renault AFAIK on all their 16v petrol burners have a slot at the gearbox end of the camshaft, this is what the cam locking tool goes into. Off centre and IIRC, when cams are set correctly for crank at TDC, horizontal and below centre.
From that you really don't need to worry on first principles, just set the slots and all should be well.
On my KIA was dimples on the (keyed) sprockets that faced each other, one at 9 O Clock one at 3 when set correctly.
Renault Diesels (the 1.5dci at least) has location holes in the sprockets and back plate for a location pin
Just need to know what the specific engine has.

You can take off the covers and have a look while you are practicing locking the crank.
Lock them as well and paint on some marks on cam sprockets, belt and back plate for easy reference when changing.

 

Less compression, so less resistance when turning by hand.

I've watched a few timing videos for the K4M and plenty of mechanics just turn the crank until the CAM shaft markers (right side of engine, behind the CAM caps) align vertically. Afterwards, they use the special lock tool to lock them both together, then shove the crank timing pin into the bottom of the engine. Is this a good way to get TDC? Cheers.

 

You got it.
Actually no compression so a lot less resistance.
You can turn an engine with the plugs in but it is hard.

 

Makes sense. I just need to remember to install the plugs back with 1/3 of torque.

The mechanics in these videos put the crank pin in, turn crank until it won't turn, lock cams with tool fitted to right side of engine and the lines seem to line up for them.

 

Is the video the right engine?
Principles will be same but there may be slight differences.
Looking at the manual I have here.....
1.6 K4J and K4M the length of the locking pin is critical as a flat on the crankweb abuts to this... will only lock the crank in one direction.
1.6 F4P and F4R engines, there is a slot across the crankweb that the pin engages with...will lock the crank in both directions.