Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Stu.C]

After reading up on timing belt changes, watching the OOF DVD a few times and gathering tools, I thought I was all set. Then I got to the step about locking the cams at TDC and things didn't seem to be adding up.    The crank locking tool was on and engaged against the water pump. Cams 3 and 4 were sort of nearly aligned, really just a smidge out. But cams 1 and 2 are out, seemingly a tooth out. The other thing I noticed was that as I turned the crank over, although the tensioner pulley was rotating, there was absolutely no movement of the tensioner itself, like I'd seen in the DVD.


Different to expected = step back and ask for help    Is it something like the old tensioner's stopped tensioning the belt, and it's jumped a tooth on just those left-hand cams? Is that a thing, as opposed to all four jumping? Or something else?


More importantly, what do I need to do now to sort it out ? I've left it as is and just closed the garage door for now... 




At least this seems much easier without a car in the way 



Cams 3 and 4 ...



Cams 1 and 2 ...

[LC0112G]

Looks to be a tooth out to me.

I'd stick a screwdriver down each spark plug hole in turn, rotate the crank till that cylinder is at TDC, and do a leak down test on that cylinder. Then rinse and repeat for the other 5.

If the leak down is Ok, then you've probably avoided any valve damage (which with only 1 tooth out is probably correct) so take the old belt off, and retime correctly on the new belt. Yo are going to have to remove the cam locks to wind the cams on 1&2 back a notch though.

Once it's back together do a compression test just to make sure. You can do that before the engine goes back in the car with a spare car battery and a screwdriver across the back of the starter solenoid . It'll make you jump at first, but you'll get used to it. 

[Nick W]

It's a tooth out on 1&2. That's probably too much to correct both banks back to timed without starting from scratch: wind the crank back 60°, remove the belt, set all four cams to spot-on, install their locks and turn the crank back so the crank lock fits. Then replace the pulleys with bearing, fit the new belt and follow the timing procedure as many times as necessary until everything is perfectly timed.


If you're not prepared, or able, to do the detail work this requires then you shouldn't be messing with timing belts on any engine

[GastronomicKleptomaniac]

Yeah, timing is off - are you fitting all new?

If so do as Nick describes and if you spin it over by hand enough times to be certain its right... Its right

[Stu.C]

Looks to be a tooth out to me.

Yo are going to have to remove the cam locks to wind the cams on 1&2 back a notch though.

Once it's back together do a compression test just to make sure. You can do that before the engine goes back in the car with a spare car battery and a screwdriver across the back of the starter solenoid . It'll make you jump at first, but you'll get used to it.

Hadn't even got as far as locking the cams - I rotated to TDC, saw it was different to expectations and came asking for help    I figured the cams could be wound back as you say, but didn't want to assume.


This is effectively a test engine, more complicated than the Pinto I've dealt with before, and something to learn on. The car went in the bin, but the engine survives - and runs completely standalone on its trolley.

[Stu.C]

It's a tooth out on 1&2. That's probably too much to correct both banks back to timed without starting from scratch: wind the crank back 60°, remove the belt, set all four cams to spot-on, install their locks and turn the crank back so the crank lock fits. Then replace the pulleys with bearing, fit the new belt and follow the timing procedure as many times as necessary until everything is perfectly timed.

Excellent, thanks    Way more succinctly put than the Haynes...

If you're not prepared, or able, to do the detail work this requires then you shouldn't be messing with timing belts on any engine

Couldn't agree more. That's what learning's all about. Maybe my initial wording was ambiguous, but I haven't changed anything yet - this is as I found it. The alignment checker tool is just there for reference - without it the perspective was weird in the pics.

[Stu.C]

Yeah, timing is off - are you fitting all new?

If so do as Nick describes and if you spin it over by hand enough times to be certain its right... Its right

Yep, there's a full Gates kit out of camera shot 


I figured what's been said would be the answer, but I second guessed myself while I was sat there pondering in the garage. It's way better to just stop and ask the simple questions to be sure, rather than miss a step that's "obvious" to the folks that have done it dozens of times before.

[biggriffin]

It's a tooth out on 1&2. That's probably too much to correct both banks back to timed without starting from scratch: wind the crank back 60°, remove the belt, set all four cams to spot-on, install their locks and turn the crank back so the crank lock fits. Then replace the pulleys with bearing, fit the new belt and follow the timing procedure as many times as necessary until everything is perfectly timed.


If you're not prepared, or able, to do the detail work this requires then you shouldn't be messing with timing belts on any engine

  THIS ^^^^^^^^^

  Words of wisdom, follow them

[Nick W]

I've just looked at your photos again, and have a few things to add:


align the flats on the water pump pulley with the sliding part of the crank lock as it's more secure that way.


a long handled ratchet is well worth having for timing belts, as you'll end up turning the engine over many times


it's probably out because the person who fitted the belt didn't turn the engine over enough times to align each bank and then the tensioner, but just bunged it on, set the tensioner and called it done.

[LC0112G]

Since it's a test engine, it's worth having a play with the rollers to see how they work and interact with each other.

The top and bottom rollers are eccentric, which means that if you loosen the center bolt you can rotate the center housing and it'll 'move' the roller in and out. This will change the tension in the belt, so to maintain that properly you'll probably have to move one in a bit and t'other out a bit. This changes the timing on the cams, so you have to continually tweak the settings untill the timing and tension are just right. However, I don't think there is enough adjustment to pull it back by a full tooth, so as others say, you are going to have to retime the left hand bank.

[Stu.C]

it's probably out because the person who fitted the belt didn't turn the engine over enough times to align each bank and then the tensioner, but just bunged it on, set the tensioner and called it done.

This   


Once I'd taken everyone's (much appreciated) feedback onboard and sat down to actually do the belt, further evidence came to light to suggest that the engine was previously worked on by a silverback gorilla with the delicate touch of a wrecking ball.


First I discovered why the tensioner cam wasn't rocking back & forth as you turned the crank, like I'd seen it do in the OOF video. The securing bolt was "nipped up" to about 187Nm    I'm amazed the pulley was still turning, it was that tight. And that was after I'd had the fun of delicately taking the timing cover off and realising that they'd done the middle bolt of the cable channel up so tight, they'd actually split the damn cover in half !  What did they use - a bloody ugga-dugga from the tyre bay...? 

[Stu.C]

As for changing the belt itself, it seemed no matter what I did, if I got the 3-4 cams bang on and rotated the crank through 720°, it then threw the 1-2 cams out. Line 1-2 up and it then threw 3-4 out. I played cat & mouse with the damn things all afternoon going back & forth, but just couldn't get them happy. It was only a smidge advanced, but in the real world a smidge is actually a couple of degrees and I just couldn't get it to go back. The belt was straight, but I'd obviously missed something.


So I left it till the next morning, stripped the belt off and went back to square one. Nick and LC's clear instructions heeded, and it only took a couple of tweaks of the rollers to have everything lined up.    Just to be sure, I then took the crank through a further 10 revolutions and this is how they lined up (which I was rather glad of, as I knew I'd have to report back here either way) ...

[GastronomicKleptomaniac]

Once I'd taken everyone's (much appreciated) feedback onboard and sat down to actually do the belt, further evidence came to light to suggest that the engine was previously worked on by a silverback gorilla with the delicate touch of a wrecking ball.

Someone call for me?

Outstanding work, the feeling of satisfaction when everything works as intended is brilliant isn't it!

[Nick W]

What you found is pretty typical of just bunging the belt on, setting the tensioner and calling it done.


Broken cover backing plates aren't unusual either. If you replace it, bear in mind there are two different types.


While you have the backing plate off is an excellent time to change the thermostat, as you don't need to split the housing from the transfer tube to get them off the engine  

[Andy H]

What you found is pretty typical of just bunging the belt on, setting the tensioner and calling it done.


Broken cover backing plates aren't unusual either. If you replace it, bear in mind there are two different types.


While you have the backing plate off is an excellent time to change the thermostat, as you don't need to split the housing from the transfer tube to get them off the engine

That isn't the (metal) backplate though. It is the (plastic) front cover & cable tray. My recollection is that the backplate doesn't come off until the cam sprockets are off

I think Darth Loony described the easiest way to release the thermostat:
- drain the coolant and remove the top hose from the transfer pipe
- plenum off and remove 2 bolts from thermostat housing.
- leave the bastard bolt in place for the moment
- use some BIG mole or vice grips on the body of the thermostat and keep working at it until it releases it's death grip on the transfer pipe.
- remove the bastard bolt and pull the transfer pipe out.