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[General] [VS-VY] How to change Crank Angle Sensor (CAS) with PICS

MadVk308

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Hi people,

I noticed there is not a how-to thread for replacing crank angle sensors on the ecotec, yet how popular CAS issues are, I thought I would write one up after recently replacing the CAS in my ute.

What you will need:

Socket set (make sure you have a 24mm for the harmonic balancer bolt)
Assorted tools (screwdrivers, breaker bar etc)
New crank angle sensor - Repco have these for about $70, genuine is about $130 from memory
Harmonic Balancer removal tool - pick one of these up from Supercheap, or repco, for about $20
1/2" unf bolts (as pictured below) these are used for removing the balancer as the bolts that come with the tool will not suffice.
Washers, as listed below
Silicone Sealant




Time taken

Approximately 60 mins

Why would you replace your cas?

If you are getting error code 47, random stalling, car wont start etc, there is a high possibility that you need a replacement CAS

Firstly, check the condition of your serpentine belt (fan belt) if it looks like any of the ribs are worn, or is starting to crack, you may as well replace it while you are at it. Secondly check your oil pressure switch, if its leaking you may want to replace it at the same time - they are very cheap!

Directions

Slide the power steering reservoir upwards, releasing it from its mount, tuck it behind the top radiator hose so it is out of the way. Take care to not damage any power steering lines.



un-clip the thermo fan wiring connector plug from the bottom of the power steering pump mounting bracket and un-clip.

Undo the 10mm bolt holding the power steering pump mount to the thermal fan assembly and remove.

Locate the 4 10mm bolts that are holding the thermo fan and shroud to the radiator and remove them.



Taking care not to damage the radiator, remove the thermo fan assembly from the car.



Using a 24mm socket, and a breaker bar, put the breaker bar onto the harmonic balancer, with the bar resting against the top of the passenger side chassis rail, this is very important you get this right, the motor spins in a clock wise direction. In order to loosen the harmonic balancer pulley bolt, you are going to crank the engine so that the breaker bar hits the chassis rail and therefore loosening the bolt. Ensuring that you have got this step correct, remove the EFI relay from the relay box inside the engine bay, and give the engine a couple of quick cranks. Ensure that the EFI relay is removed as you do not want the engine starting, potentially causing damage.



After a couple of cranks, check the harmonic balancer bolt, if it is loose, continue to the next step, crank another couple of times till it loosens up.

locate the second highest pully (tensioner) and using a 15mm socket, apply force in an anti-clockwise direction. The pulley is spring loaded, this will loosen the tensioner and enable you to remove the serpentine belt from it.





Remove the belt from the harmonic balancer.

Continue to remove the harmonic balancer bolt.

Using the washers, thread the 1/2" unf bolts through the washers and attach the bolts to the harmonic balancer. If you do not use the washers, then the bolts under tension will simply pull through the puller, possibly damaging the thread inside the harmonic balancer.



You should now be able to pull the harmonic balancer, using the removal tool (may take some elbow grease)







Remove the dust cover, there should be 3 locator pins that it is simply pressed onto, using a flat head screwdriver it is quite easy to remove.



Undo the CAS wiring connector

Remove the 2 bolts holding the crank angle sensor in place.



Install your new crank angle sensor and plug connector into loom.

Refit the dust cover onto the 3 locator pins

Slide the harmonic balancer back onto the shaft, note the key on the back of the puller, this has to match up with the key on the crank. Remove existing sealant from key/Key way and apply fresh sealant. turn the harmonic balancer on the shaft until you can feel it lock back into place.

Using a 24mm socket, tighten the harmonic balancer. You will notice that the balancer will not line up with the other pulleys initially, when tightening it will pull it closer to the block and you will see it eventually start to line up.

Additional Information regarding tightening harmonic balancer

Courtesy of Cheap6 (thanks mate) I have included the quotes below:

Cheap6 said:
270-325Nm is the tightening torque. Undoing it will require similar.

Few people have a torque wrench (that reads that high). Marking the bolt relative to the balancer before undoing it will at least allow you to get back to where you started from.

You will need to hold the engine to allow retensioning the bolt. I have posted on here previously with images of a couple of tools that allow using the slots in the front of the balancer to hold the engine against the chassis rail - which is why the slots are present. You don't have to get too elaborate. A couple of bolts, nuts, drill, steel plate and 20 min. should be enough.

Some people use an old drive belt looped around to lock the engine (you would have to search the forum for how to do that).

You need to clean and reseal the keyway on the crank nose to the balancer with RTV sealant.
Cheap6 said:
Doing it back up again to the same tension is often neglected :( . I made a couple of tools (for two different designs of balancer) which are lengths of steel bar (could be steel plate) with tabs, (design 1) or cut down bolts, (design 2) that fit in 2 of the slots in the balancer (that's why they are there) and rest against the chassis rail to stop the engine/balancer rotating. About 20mins with a drill, a hacksaw, angle grinder, some 6mm steel plate and 2 X 10mm nuts and bolts would produce something similar.

To get the crankshaft-balancer bolt back to the correct tension - it's not super critical but should be within the specified range - mark the initial position of the crankshaft bolt against the pulley. You can then tighten the bolt to match the marks back up.

If you were replacing the pulley as well as the CAS, you would loosen and undo the bolt, then retension it to somewhere less than the original torque. Ideally you would use a torque wrench set to an arbitrary value but a calibrated elbow will get you close (enough) - the actual torque value you use isn't important. Then note the angular difference between the marks on the bolt and the balancer. Retorque/retension the bolt to the same value and tighten by the angular difference between the marks previously measured.
Cheap6 said:
There are (3) slots in the balancer that, with an appropriate tool, allow the balancer to be locked/held against the chassis rail.

Making a suitable tool is possible with basic hand tools - drill and hacksaw (another contributor to this forum has done it - I've made a couple myself but they are welded. it's another "How To" I haven't got to yet).

Two ~75mm X ~8mm bolts and 4 X nuts through a steel bar (eg. ~600mm length of 50mm x 6mm) would do. Cut the heads off the bolts to leave the plain shank to go into the balancer slots and secure the bolts to the steel bar through holes spaced to match the balancer slots, with the nuts on the threaded end of the bolts.
I had a piece of 10mm box about 500mm long, with 2 holes that lined up with the holes in the balancer however I did not get any pics of this. I have also done it with an old belt in the past and 5 years later everything is still fine.



Fit the sepentine belt back onto the pulleys as per the picture below. Remember to use the tensioner.



Retighten the harmonic balancer bolt using a 24mm socket.

install the thermal fan assembly, power steering mount bracket, power steering reservoir and EFI relay back to the car.

Retighten the harmonic balancer bolt using a 24mm socket.

check you have removed all tools from the engine bay and start the car.

Cheers Mick
 
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VS_Pete

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Good writeup and pics thanks.
 

Cheap6

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About time someone did a write up of it. Well done.

A couple of extra things:

The key/keyway has sealant applied to it to prevent a leak path. That should be removed and fresh sealant applied.

It doesn't hurt to apply some oil onto the lip of the front oil seal and/or the balancer sealing surface.

I really don't like doing up the crank pulley bolt without being able to hold the pulley and stop the crank from rotating. It doesn't take long to make a simple tool that will fit into the slots in the centre of the pulley (that's what they are there for) and hold the pulley against the chassis rail. I think there is a description of how to do that in one of the non-genuine workshop manuals but the application of basic common sense and a brief description should be enough to work something out:

You need a length of ~6 or 8mm x ~75mm flat bar and two (8mm?) bolts that fit in two of the slots in the balancer and 4 nuts to suit them.

The proper tool looks something like this:

https://forums.justcommodores.com.au/threads/locking-the-engine-on-a-vp-auto.164515/post-1820706

If you mark the bolt and balancer pully before removing the bolt you can at least match the bolt tension as it was before removal.

Also:

https://forums.justcommodores.com.au/threads/changing-crank-angle-sensor.187966/post-2097431

https://forums.justcommodores.com.au/threads/engine-crank-sensor.117556/post-1340743

https://forums.justcommodores.com.au/threads/crank-angle-sensor-vp-calais.72609/post-764621
 
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MadVk308

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Cheers for the info cheap 6, appears I missed the sealant part, I just used some sealant as you mentioned, I will add it in.

I have also added your quotes as reference for extra information, thanks mate.

Mick
 
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trav27

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Great write up! I might attempt to replace my harmonic balancer within the next week or so, although ive never done anything like this so i'm a bit concerned but it doesn't seem to complicated. Just a few questions though, sorry if they sound silly haha. But what is a keyway? And when fitting the new HB, is there any other way to stop the crank move while tightening it up? I'm no where near handy enough to make a tool!
 

KTM mad

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hi guys. just puting my 2 cents in! firstly, thankyou shitloads to madvk308 for the write up! gave me the confidence to give this project a crack!

my HB on my 99 VT SII wagon needed to be changed, sdo i oredered a powerbond one from MACE.

just finished fitting it, no drama's.
just a couple of pointers that might help someone else.

firstly, in my VT i had heaps of room to work on the HB and CAS without having to remove the thermo fans. not sure if there is lees room on a VS, but i was fine.

i took the fuel pump relay out and started it a few times, to make sure it wouldn't run wheni put the breaker bar on the HB. so easy to crack the bolt!!

i bought a cheap puller kit from ebay, and the pointy little nub that goes on the end of the threaded push rod, was too big to pass throught the HB to the crankshaft. i found a 1/4 inch drive socket big enough to pass through the HB but not small enough to go into the crankshaft and damage the thread.

the dust cover behind the HB comes off easily enough, but i had to undo the wiring to the CAS to gt it off.( just in case you cant work out why it won't come off!)
to torgue the HB balancer to spec, i just threaded in two of the 1/4 UNC bolts used for te puller, into the HB and put reverse pressure on the HB with a tyre lever, and torqued it with a torque wrench.( this will reuire using two hands at the same time!lol)


all in all, pretty straight forward. took just over an hour, and now the annoying ticking noise is gone!!!!

woohoo!!
 

djvass

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Just a quick one on this. What were the nuts used for in the first pic under the washer pic?
 

KTM mad

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the nuts arent used. the thread sizes are the ones used for the bolts though. makes it handy when buying the bolts.


just to throw in an update to my two cents worth, i had to retorque the HB. it turns out, i didn;t get it tight enough by just putting the screw driver between the bolts and putting opposite force on. the HB started squeaking the other day! lol.

so today, i put the HB puller back on with two bolts, but mounted it the opposite way round, so that i could still get to the crankshaft nut. then i put a piece of chain from that to the chassis rail, and that locked the HB in place so i could tighten it properly!

hope that helps
 

djvass

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can some show me where the sealent needs to go?
Thanks
 

benmo29

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can some show me where the sealent needs to go?
Thanks

When you say the key has to match up what do you mean? I had a dodgy mechanic come out and removed the balancer from my ute. He told me the balancer was stuffed, only to find out from another mechanic that there is nothing wrong with the balancer. So due to the fact I have no idea when key is where, how do I go about refitting the balancer?

I hope you understand my lack of Mechanical knowledge.

Thanks
 
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