Timing / cam belt replacement on a 1990SE Esprit

[Mysterae]

It's time for me to tackle one of the jobs on the Esprit that I've dreaded the most - replacing the timing belt.

 

I need to remove the water pump as it looks like the seal at the bearings is goosed. The oil pump pulley needs to be moved a little for access to a bolt for the water pump which in turn means mucking about with the timing belt. As the timing belt hasn't been replaced in over 7 years (car has been stuck in my garage all that time) it needs replacing. 

 

So an opportunity to tackle both jobs . All belts and the cam belts tensioner's bearing will be replaced while I'm at it.

 

I've read many threads on the forum and studied the service notes, but all nuggets of info would be helpful! Expect a few noobie questions. Speaking of which:

 

1. The engine has to be at TDC before removing the old timing belt. I've checked the TDC from the clutch housing aperture and my engine is not at TDC:

 

 

To get the engine at TDC (and the cam sprockets lined up), do the spark plugs have to be removed so there is no compression? The service notes make no mention of this.

 

2. Do the cam sprockets have to be locked in position in any manner?

 

3. To remove the crankshaft pulley (aux drive pulley) means turning the bolt on it counter-clockwise, and I've read to never turn the engine in this direction - Travis (cause I'm sure you're reading this ) is that why you said to put the car in 5th gear and have someone press the brakes when loosening or tightening the aux drive pulley?

 

Expect a few more questions as I progress, such as the chosen method of measuring the tension of the timing belt, a frequently debated subject on the forum! Krikit, Burroughs, Clavis, Facom and even an smartphone app! 

 

Incidentaly, I measured the frequency of the currently fitted timing belt using an app on my iphone called "Carbon Drive" from Gates, and I consistently measured 95.9Hz at the recommended place of the belt to measure.

 

[cbclotus]

Good luck .i am sure you will be fine as you know your spanner work.i think I have the readings in my paper work I think it should be higher.i will check later..Mike

[jonwat]

Checkout this link on a can belt change:

http://lotusespritworld.com/EGuides/EMaintenance/TimingBelts.html

[910Esprit]

1. No, but its not a bad idea as its easier to turn

2.No

3.its a convenient way of locking the pulley while you undo the bolt

96hz is a little too slack - but did you remember to set the crank to the correct degrees before checking?

[Mysterae]

Good luck .i am sure you will be fine as you know your spanner work.i think I have the readings in my paper work I think it should be higher.i will check later..Mike

 

Cheers Mike, need a little confidence for this job. What ever figure you may have would be interesting.

 

Checkout this link on a can belt change:

http://lotusespritworld.com/EGuides/EMaintenance/TimingBelts.html

 

Cheers John, read that many times and sighed at the size and quality of the images . However, using the starter motor to release the nut on the triple v pulley is mental! I preferred Travis's method of 5th gear and brakes, worked a treat undoing the bolt, but I suspect the engine may have moved regardless , more on which later in this post.

 

 

1. No, but its not a bad idea as its easier to turn

2.No

3.its a convenient way of locking the pulley while you undo the bolt

96hz is a little too slack - but did you remember to set the crank to the correct degrees before checking?

 

Cheers Steve. I did manage to turn the engine at the crank with the spark plugs still in. It was a bit of a pain because the slightest movement at the crank equaled a big moved when viewed at the clutch viewing aperture - I'll admit I went round numerous times! The measurement of 96Hz was done on the existing belt and not at TDC. I was purely interested in testing the app.

 

So today was the usual fair of rusty jubilee clips and welded on pipework. Got the crank at TDC and the cams aligned.

 

 

Access was a big problem so opted to remove the alu pipe and alternator, much better!

 

 

The belt for the AC compressor was a pain to remove, even after completely removing it's tensioner from the engine, opting to cut the belt to get it off. That'll be fun putting back on.

 

Still at TDC at this point.

 

 

Auxiliary cam marked up for later.

 

 

And past the point of no backing down, timing belt off! Yeah, my cam covers need painting too

 

 

Various parts removed. The general recommendation is to replace the bearing in the timing belt tensioner which I shall do. The condition of the triple v pulley's key-way was good.

 

 

One problem, and slightly bricking it on this, is that between removing the timing belt the engine has gone slightly out of TDC. I don't have an image of it (I'll take one tomorrow), when viewed from the clutch aperture the marker is pointing to the middle of the D of TDC  . This possibly means the engine moved ever so slightly backwards. The cam sprockets don't seem to have moved from their aligned position, but of course small degrees are hard to see with the engine still in place. Should I be worried? Like, really really worried?

 

Other points where I haven't made it easy for myself are: I didn't take the pulley off the water pump when the belt was still on, and getting it off while it's spinning around is a pain; there's a bolt behind it that's being an arse. Also, I didn't loosen the aux cam sprocket while the belt was off. So those nuggets are waiting for me tomorrow.

 

My main concern is about the the slightly off TDC, despite constantly checking it.

[Shanesprit]

Hi

Normally you would choose to place the fly wheel at Its timing mark and then check the cam sprockets, more likely that the cam is not as aligned as you think.

Any way it's not a big concern, I have seen many engines running a tooth out.

However don't put it back like this, put all points at the correct timing marks, the distributor is the hardest to keep in line while getting the belt back on, and if the distributor pulley is out can always turn the distributor to correct it.

Just follow these very simple rules

always turn slowly

Never use force to turn

A minimum of 2 turns of the engine by hand before starting

Check the belt tension.

If you do this even if it won't run at least you won't damage anything.

[Shanesprit]

Sorry but Your mark on the auxiliary cam is useless as the flywheel is not at TDC.

You will have to follow the manual to align it all up, but don't worry.

[Mysterae]

Cheers Shane, allays my fears somewhat. I know it's a precision engine and that, but the tiniest movement at the crank meant a big movement when view from the clutch aperture. I'll set it up again before putting the belt back on and give the engine quite a few turns before starting.

 

When you mention the distributor, do mean the aux cam for the oil pump?

Sorry but Your mark on the auxiliary cam is useless as the flywheel is not at TDC.
You will have to follow the manual to align it all up, but don't worry.

 

No, that mark was made when at TDC, I checked it many times . It was only once the belt was off that the engine was no longer at TDC.

[Shanesprit]

Oh yes

I bet you don't have a really distributor?

I don't know the different models very well, but I do know about cars and engines.

If it's only driving a pump then it does not need a mark.

I have a carb model I long for fuel injection and modern ignition.

Mine is spread all over the shed awaiting parts delivery.

Using the starter to undue the crank nut has been done many times.

[Mysterae]

Your help is most welcome Shane.

 

The service notes said mark it so I marked it . It's a pain when your car is in bits. The hardest thing is remembering what you took off, where it came from and how it goes back in! The memory fades the longer you leave it. 

 

About the crank nut - it did take some undoing, using my longest torque wrench, but it did finally submit . I wasn't confident enough to use the starter motor, don't fancy that method at.

[lotus4s]

Your crankshaft being a little off TDC at this point is not a problem, just move it back when you put the belt back on. As a matter of fact, you could now rotate it backwards 90 degrees (90 degrees BTDC), and all of your pistons will be at their half way point and then you can rotate the cam pulleys at will without fear of valve contact with the pistons.

 

Now would also be a good time to check your valve clearances. If out of spec, that opens another can of worms but it will never be easier to check than with the belt off.

 

When you're ready to put the belt back on, rotate the cam pulleys to align the dots, move the crank forward to TDC and put the belt back on....

[910Esprit]

Alan - Good to see you getting stuck in! - Just a reminder that the tension is checked at 30 degree BTDC (not TDC) - but obviously leave all at TDC until you have the new one back on - As said above, just carefully check & realign all your 'dots' before fitting new belt.     

[Mysterae]

Your crankshaft being a little off TDC at this point is not a problem, just move it back when you put the belt back on. As a matter of fact, you could now rotate it backwards 90 degrees (90 degrees BTDC), and all of your pistons will be at their half way point and then you can rotate the cam pulleys at will without fear of valve contact with the pistons.

 

Now would also be a good time to check your valve clearances. If out of spec, that opens another can of worms but it will never be easier to check than with the belt off.

 

When you're ready to put the belt back on, rotate the cam pulleys to align the dots, move the crank forward to TDC and put the belt back on....

 

Thanks Jim, nice tip on the 90 degrees BTDC. I presume that's something that would have to be worked out at the crank as the flywheel isn't marked? I shouldn't need to move the cams as the dots lined up the last time I checked. I'll leave checking the valve clearances for another day, because I've have enough deviations getting this car back on the road . When I do another timing belt I'll do it then .

 

Alan - Good to see you getting stuck in! - Just a reminder that the tension is checked at 30 degree BTDC (not TDC) - but obviously leave all at TDC until you have the new one back on - As said above, just carefully check & realign all your 'dots' before fitting new belt.     

 

Thanks for the reminder Steve, I'll be following the service notes to the letter! Checking numerous times and turning the engine round by the crank numerous times too. Regarding tension, it's interesting that due to the nature of the tensioning bearing there's a finite level of adjustment. This is something I'll be paying close attention to .

 

Not much progress today with one unrelated thing and another. I did manage to remove the pulley from the water pump. To stop it turning I used an oil filter tool to hold it steady while undoing the bolts .

 

 

I'm currently stuck at removing the aux cam sprocket to get access to the last bolt of the water pump. I don't have a small enough puller and have been looking at cam sprocket removal tools. Anyone recommend one small enough to remove this cam sprocket? I've seen this one at Machine Mart. It's difficult to tell from the the picture if it'll fit in the confined space between the cam sprocket and the wall of the engine bay.

 

If there's another method to removing the cam sprocket I'd like to know about it . I've tried gentle leverage but no more, don't want to damage the sprocket. Then there's the putting it back on - thinking about heating the sprocket before putting it back on - any issues with that? 

[Sparky]

I bought that puller specifically for the aux sprocket!  Haven't used it yet though.  If you're anywhere near Watford you're welcome to borrow it.  You won't need to heat the sprocket to get it back on - you'll find it'll pop back quite easily and draw in if necessary with the bolt.

[Vulcan Grey]

Good job so far.

 

Should have loosened the oil pump pulley while the belt was on.  Oh well. 

You can use one of those strap wrenches to hold the pulley while un-doing the bolt.

 

Try some lube like penetrating oil on the pulley hub.  Then use small taps at the hub of the pulley, with a dowel of wood, alternating side to side to vibrate the pulley off.  DON'T pry on the outer rim, since it is aluminum.

 

It'll be much easier to get it back on with some anti-seize grease.

[Mysterae]

I bought that puller specifically for the aux sprocket!  Haven't used it yet though.  If you're anywhere near Watford you're welcome to borrow it.  You won't need to heat the sprocket to get it back on - you'll find it'll pop back quite easily and draw in if necessary with the bolt.

 

Good to know that it's the tool you are going to use . Unfortunately my local Machine Mart doesn't have it in stock and I'm quite a way from you, but thanks for the offer. I'm to going to see if a small 4" puller will fit instead, failing that it'll have to wait; I can get the same tool and an alternative sprocket tool for a lot less on the net. Doh, drawing the pulley back on with the bolt, of course it will (thanks for the tip)!

 

Good job so far.

 

Should have loosened the oil pump pulley while the belt was on.  Oh well. 

You can use one of those strap wrenches to hold the pulley while un-doing the bolt.

 

Try some lube like penetrating oil on the pulley hub.  Then use small taps at the hub of the pulley, with a dowel of wood, alternating side to side to vibrate the pulley off.  DON'T pry on the outer rim, since it is aluminum.

 

It'll be much easier to get it back on with some anti-seize grease.

 

Yeah Travis, should have loosened the bolts on the oil pump pulley and water pump while the belt was on. Learned that one well and truly . I managed to get the bolt of the oil pump pulley using the old belt to protect the pulley and a wooden wedge. As you say, a tool like this one would have made it much easier to hold the sprocket.

 

I've tried some gentle persuasion on the pulley but no joy. As mentioned before I'll try a smaller puller but failing that it'll have to wait until next weekend. Back to work on Monday .

[910Esprit]

As its an aluminium pulley on a steel shaft, may be worth seeing if it will pop off if you use thermal shock - e.g. by pouring boiling water on the pulley?

[Mysterae]

Hi Steve, I didn't try the thermal shock method, opted to try and get it off with the cam sprocket removal tool...

 

I changed my mind on the type of cam sprocket removal tool, thinking that the bolt would be short enough to fit - I was wrong!

 

 

It'll never come off at that angle! I had a few options - get a different tool, undo the engine mounts and raise the engine a little, modify the tool (make the bolt shorter) or cut some of the fibreglass to make way for the bolt. I decided on the last one, so used the dremel to cut space big enough for the bolt and spanner. I should have taken off more left and right to the bolt to allow the spanner more freedom.

 

 

The cam sprocket holding tool you see in the image above is a necessity to stop the cam from turning! The job would have been impossible without it. The removal tool is in place too, after a few scraped knuckles and a lot of forceful turning (I mean a lot, this cam was on solid) on the removal tool the cam is starting to move .

 

 

Finally it's off! Look at the state of that shaft. There is a key on the shaft but not shown in the image.

 

 

So I can finally get access to the last bolt of the water pump. I'll park this thread here until I've refurbed the water pump (details here) and refitted it, then it's time to put the cam back on and replace the timing belt.

 

 

 

[Mysterae]

The new cam belt is on

 

 

The aux cam sprocket went back on a lot easier than it came off. Some gentle tapping and driven home with the bolt and washer.

 

I wasn't convinced that the two cam pulleys were aligned so moved the crank to 90 degrees counterclock and spent an age setting them up, it's not easy to see even with a mirror. If the cams were marked with lines it would have been a damn sight easier to line up with a short rule! At one point I thought they were aligned, but with the crank at TDC the cam belt length from the crank to the lower cam sprocket was too flappy, so I considered this wrong and started again. In the end I've settled on what I think is right. I've turned the crank over many times and it feels about the same as before.

 

I've positioned the tensioner bearing correctly as per the service notes, tensioned and measured many times. The tension frequency is currently 104Hz which I will keep it at for the moment until I've turned the car over under it's own power, and adjust again if necessary. It was encouraging to witness the change in frequency as I altered the tension of the cam belt.

 

The rain has stopped play for the moment. Still to refit the a/c belt, the alternator, vac pump and top up coolant and bleed it. I need a workshop!

 

 

 

[cbclotus]

Good on you .looks scary.....Mike

[Mysterae]

Cheers Mike, the scary bit will be turning the key the first time...

[jonwat]

Well done Alan, have yourself a drink (or three) :-)

[Sparky]

Easy, mate.  No interference, belt correctly tensioned, it'll be a breeze!

[Mysterae]

Well done Alan, have yourself a drink (or three) :-)

 

John, next Saturday the car can have a drink of antifreeze and I'll have a JD or possibly more

 

Easy, mate.  No interference, belt correctly tensioned, it'll be a breeze!

 

Cheers Gary, from what you say I think my assumption of if the cam sprockets weren't right I wouldn't have been able to turn the crank without significant force, is right? As for a breeze, so far it's been a 6 on the Beaufort scale . 

[Mysterae]

So I was almost all done and set to put coolant in to the engine and turn it over, but I just wasn't happy with the positioning of the cam sprockets. They didn't quite line up as per the service notes. So out came the water pipe and the alternator and have another shot at setting it up.

 

This time I noticed that when I tensioned up the cam belt the engine would move out of TDC. After a lot of going back 90 degrees, inching the sprockets just that bit more, forward 90 degrees, belt on, tension, check, repeat etc, I feel I now have everything set up just right. I hope so cause I put it back together, filled up with coolant and gave it a stir!

 

And running well, although I do thing this 'ticking' at idle is more pronounced, perhaps because I have the boot lid off? I let it idle until the fans kicked in at 90C and no leaks .

 

I'd like some more advice please! - I tensioned the cam belt to an average of 109Hz at 10 degrees TDC (measured slightly lower than that when at TDC). After letting the engine idle while getting up to temperature, turning it off then measuring the tension again, it feels hell of a tight; it's off the scale on my app (>120Hz), - but I don't know at what position the cam is at. The belt at engine are obviously quite hot at this point and I'll measure again tomorrow when cold again. If it's still >120Hz when cold I'll adjust it down, but if it's 109Hz when cold, would this be normal? Obviously I check the TDC when measuring, both hot and cold. It looks to be a right pain to adjust the tension with it all together....