[royce]

OK for a while my Vitara has been a bit crappy power wise, you always need to wring its neck to get anywhere on highways and its sluggish in stop start traffic.

For ages I just put it down to the original exhaust being buggered, it used to make all sorts of strange noises and rattle and groans and had a few leaks.

So I finally fixed that, great nice new pipe, no real difference but it took some time to go right through cause I had to then replace the manifold, some flange gaskets (bugger me they are dear) and then the o2 sensor cause the thread had gone to shit. I spent plenty of time reseting the ECU, looking at the live data trying to figure if its a dodgy sensor

So still no difference, by then I am using near enough to 13l/100km (so 330 km was 38l of premium, this adds up rather quickly!

by now I had no power under 2500rpm, even above it was not flash, there was no using 5th gear under 100 and even then only on flat ground.

Yesterday I decided to stick some plugs in just incase and wind it over to see if TDC on the piston matched TDC on the timing marks, nope they were quite a few degrees apart, quite a lot really

I knew I had trouble, I knew I had the dreaded G16b flogged keyway

So expecting all kinds of nastiness and the likelihood I was going to be pulling the engine out to have the crank repaired I got stuck in early this morning and it was soon confirmed, the bottom pulley bolt was loose and the pulley would move around.

More digging ended up with this, one flogged key, one pissy little 30 cent bit of metal was cause of all this drama and power loss!

Close inspection revealed a small amount of wear on the crank keyway and timing pulley but not the worst I have seen thankfully so it went back together with a newly scabbed key from a G13a and some chemicals designed for dealing with such things

It's now like a new car, its actually nice to drive now and even a quick spin its back to where it should be fuel wise.

So when you are faced with something that doesnt seem right, remember to check your basics and be sure things like this are spot on before you go blaming ecu's and carbys and things like that, if you have a G16b in something, make sure that bottom pulley bolt is freaking tight!

[Scrawny]

You were lucky to get away with it! Flogged crank keyways are no fun

[jimbo_jones]

Lucky that was the only damage you had

[shandy92]

good to know royce thanks for that, do you know the torque for that bolt? because your "freaking tight" might be different to someone else's. are we talking 150lbft or more/less??

cheers

[alien]

150.976lbft mate.

[mnemonix]

shandy92 wrote:

good to know royce thanks for that, do you know the torque for that bolt? because your "freaking tight" might be different to someone else's. are we talking 150lbft or more/less??

cheers

54 ft-lb for the centre bolt.
11.5 ft-lb for the 5 outer bolts.

[Rusho]

[neofitou]

I had both the key and the keyway really worn,



I replaced the key,
and everyone have a cringe now: metal mended the keyway


Put it back together and forgot about it.

I was planning on putting in a new engine soon anyway.

Made HEAPS of difference.

[shandy92]

mnemonix wrote:

shandy92 wrote:

good to know royce thanks for that, do you know the torque for that bolt? because your "freaking tight" might be different to someone else's. are we talking 150lbft or more/less??

cheers

54 ft-lb for the centre bolt.
11.5 ft-lb for the 5 outer bolts.

thank you, after i posted that i thought 150 was a bit much, thought it would be at least 65 ft-lb.

[stocker]

Royce i'll be checking mine out on the weekend. (im hoping its just the 31's causing the ub3r lack of power) but its rough idling and very sluggish...

[Boneheimer]

I'm just putting the bottom pulley on at the moment and was wondering how much play there was in your pulley? Would be easier to check now rather than once everything is back together. Cheers guys.

[royce]

you really dont want any with the bolt loose and for sure none with it tight

when I pulled it off, I could twist it 3-4mm with teh bolt out

[Boneheimer]

Cheers Royce, I'll check it in the morning

[skyman]

Here in the US there was a TSB (technical service bulletin) put out on this. I believe they raised the torque setting over what was in the FSM,because they continued to have the keyway problem.

I will see if I can find the TSB in the next day or two. I am pretty sure 89% it is more than 54 ft-lb.

shandy92 wrote:

mnemonix wrote:

shandy92 wrote:

good to know royce thanks for that, do you know the torque for that bolt? because your "freaking tight" might be different to someone else's. are we talking 150lbft or more/less??

cheers

54 ft-lb for the centre bolt.
11.5 ft-lb for the 5 outer bolts.

thank you, after i posted that i thought 150 was a bit much, thought it would be at least 65 ft-lb.

[Boneheimer]

My FSM says 130Nm or 94lb/ft for the bottom pulley.

[shandy92]

Boneheimer wrote:

My FSM says 130Nm or 94lb/ft for the bottom pulley.

Yeah that sounds a lot more reasonable, was doing some bolts up today to 55 lb-ft and that wasnt tight, made me think about this. thanks mate

[squibby]

the cretin who designed that should be flogged.

[Scrawny]

squibby wrote:

the cretin who designed that should be flogged.

It's better than just a taper and no key way

[Fatzook]

Scrawn wrote:

squibby wrote:

the cretin who designed that should be flogged.

It's better than just a taper and no key way

Agreed.

I wonder if replacing the key is part of the 100,000km service list? Surely you would change this when doing the timing belt or crank seal? I'd wager that most of the damage in that area is caused by lack of maintenance or poor practice. (ie no loctite on crank bolt etc).

Still, every engine can be brought to ruin by a $2 part

[royce]

Fatzook wrote:

Scrawn wrote:

squibby wrote:

the cretin who designed that should be flogged.

It's better than just a taper and no key way

Agreed.

I wonder if replacing the key is part of the 100,000km service list? Surely you would change this when doing the timing belt or crank seal? I'd wager that most of the damage in that area is caused by lack of maintenance or poor practice. (ie no loctite on crank bolt etc).

Still, every engine can be brought to ruin by a $2 part

The key isnt supposed to transmit any drive, friction from the bolt being tight is and I think how the bottom pulley is held on sucks for keeping that level of friction intact

Ive never loctited a crank pulley in my life and this is the first time Ive had a problem, I wonder if the reason they are a drama mainly on G16B is driving aircon and power steer as well?

[jdk81]

royce wrote:

The key isnt supposed to transmit any drive, friction from the bolt being tight is and I think how the bottom pulley is held on sucks for keeping that level of friction intact

I disgree, the key is there is there to prevent independent rotation of each part, and to transmit torque.

It would appear there was insufficient torque on the bolt.

[royce]

jdk81 wrote:

royce wrote:

The key isnt supposed to transmit any drive, friction from the bolt being tight is and I think how the bottom pulley is held on sucks for keeping that level of friction intact

I disgree, the key is there is there to prevent independent rotation of each part, and to transmit torque.

It would appear there was insufficient torque on the bolt.

you've just contradicted yourself

why if the key transmits torque is the whole lot destroyed by the bolt being loose?

exactly the same as a wheel, the studs dont transmit drive, the friction between hub and wheel mounting face does

[Fatzook]

I've has a G13a crank bolt come loose. And I have found work keys on atleast 2 of the G16's I've owned over the years. Maybe its the grade of key steel

[royce]

did a full tank under usual driving conditions finally, 10.3l 100km