3200 GT cam/timing belt change

[jluis]

Maybe in the future we will have electromagnetic valves and get rid of chains and belts.
That way instead of worrying about chains or belts snapping and trashing the engine we will just need to worry about a software bug or ECU crash to destroy the engine

 

[safrane]

or a flat battery!

 

[Swedish Paul]

Ahh, a little like the 968 engine. That has a cam belt which drives the exhaust cam and a small chain linking the exhaust cam with the inlet cam. The chain is stretched with a oil driven solenoid which advances the inlet timing over 4000rpm. Whallah. VVC. Straight 4 so only two cams.

The chain guides are plastic, which wears, over time the chain can break and pistons meet valves. And not in a nice way.

 

[Alecci]

So, we started this little adventure today. Everything went fine up to the point where we have to remove the crank pulley. We tried all kinds of ways to hold it in place while attempting to remove the main bolt, but we only ended up in succeding to have the timing belt skip two teeth at the crank pulley.

Unless you have the special tool described in the workshop manual, how would one solve this? And even if we did, does the gearbox have to come off (since it's mounted to the flywheel)?

Some help would be very much appreciated.

 

[beau]

you remove the 4 x hex bolts and remove the pulley

 

[Alecci]

Hmm... So you mean that we don't need to remove the main/center bolt of the crank pulley, only the four minor hex bolts? Will the pulley then come off?

 

[beau]

Hmm... So you mean that we don't need to remove the main/center bolt of the crank pulley, only the four minor hex bolts? Will the pulley then come off?

yes if you undo the 4 bolts, the pulley will just pull off, maybe need a light tap with a rubber mallet

 

[Alecci]

I see... Cheers for that info mate, now there's a real possibility of seeing this to the end! This board is unbeatable when it comes to knowledgable and helpful people!

I will report back tomorrow with the progress (or perhaps lack thereof), the beer has sounded the bugle so we'll call it a day for now.

 

[jluis]

yes if you undo the 4 bolts, the pulley will just pull off, maybe need a light tap with a rubber mallet

Hold on the mallet!
The main big bolt needs to come out as well.

It should not have skipped tooths at the crank if tension is still applied.
If your gearbox is manual, just shift it into 6th with the parking brake applied and unbolt the main bolt.

If you have an autobox you might need an impact wrench to undo the bolt.

 

[davy83]

yes on the auto you need either a chain wrench on the pulley wheel or take the starter out and lock the flywheel there. I cant remember but i think there is a window below the gearbox, where you can get at the flywheel teeth, to lock it up. and yes big bolt must be removed, and yes it needs a lot of torque.

 

[jluis]

Regarding torque, if it's a manual and you can shift in gear all you need is a long pipe for leverage

 

[NickP]

If you email Mike Roberts, I am sure he can give you the real world instructions to change it. I know its not difficult but access is the issue.

I believe there is no locking tool used, I believe it is done with a dial gauge down the spark plug bore to get the piston to top dead centre (TDC)

When your indie does it, tell them they MUST remove the water radiator as the quick method is to unbolt it and pull it to one side.

This always stresses the pipe flanges and cracks them. If I had a pound for every time I have seen this happen I would be a rich man.

Mikes email is: mike@maseratished.co.uk

No need to remove the radiator when doing a cam belt change, plenty of room. Did mine in the summer and never touched the rad.

I used the info here to do mine http://www.sportsmaserati.com/showthread.php/8194-How-to-change-your-QP-IV-3-2-cambelt-with-pictures!

 

[beau]

Well it's 3 years since I done mine, I didn't use any special tools, and hadn't worked on an engine like this before and didn't really hit any trouble, so yeah maybe centre bolt does come out then.... I really can't remember

 

[beau]

Yeah I followed that guide, I remember now, not being able to get the pulley off because I didn't remove the centre bolt ha, so yeah sorry you should remove it, hopefully you see this before trying, you should get it off if you have a very long bar

 

[Alecci]

This confirms my initial suspicions then, and unfortunately it's nothing as easy as just loosening the four hex bolts.

We tried "locking" the crank pulley by putting the gear in reverse and applying the hand brake (it's a manual car), but we're still able to turn the engine. In my mind, selecting the gear that usually sends the most torque through the drivetrain ought to achieve the best lock, but perhaps we should try a forward gear instead.

Just to make certain, when facing the car you loosen the main bolt on the crank pulley by turning it counter-clockwise, correct?

 

[jluis]

i did mine shifting a 6th and it worked perfectly. The engine will still turn a bit but then it will lock
Yes, counter clockwise. Be sure to use a long pipe as a lever (I used my jack lever connected to a socket extender arm)

Can you elaborate how you skiped 2 teeth?
You should not even be able to see the interior crank pulley teeth with the cover on and the cover only comes out after the pulley is gone

 

[beau]

Hm I took my cover off with the pulley still on last week

 

[NickP]

I used my torque wrench on the main pulley bolt with it in a high gear, brake on, a few sharpish impacts and the bolt came loose no problem. Maybe try a little penetrating / lubricant on the bolt, if its not been off for 6 years it may have seized a little? Leave it for a while to do its work. The alternative I believe is to lock it via the gearbox inspection hole or the starter motor, i've done this on other cars but not the Mas. The starter motor is under the plenum, I'd look at the gearbox first.

 

[jluis]

Hm I took my cover off with the pulley still on last week

Mine would not come out with the pulley on.
Maybe I did not try hard enough

 

[NickP]

Mine would not come out with the pulley on.
Maybe I did not try hard enough

Mine neither, I don't think its supposed to?