Jump to content

Timing issue after full polo g40 engine rebuild


matthg40

Recommended Posts

I’ve had my g rebuilt and sadly it came back running like a sack of spuds.i recently discovered the car came back with the timing was a tooth and a half out.so I’ve had ago at putting it right myself as I’ve done it numerous times but as soon as I line my marks up and put the belt on and attempt to tighten the water pump the crank pulley mark moves.does anyone have an explanation as to what could be the problem and how I rectify it please.

Link to comment
Share on other sites

I usually account for the crank movement and off set the timing mark.

 

You could also use a rachet on the crank and cam and rotate them around eachother 1 full turn and then mark line them up.

Link to comment
Share on other sites

I usually  go off the crank which I don’t know if is correct but it’s keeps knocking it off about a tooth and abit everytime I go to tension the belt via tighting the water pump so don’t know what my next plan of attack is 

Link to comment
Share on other sites

Get the belt on and tight, tighten waterpump. Pull the belt off and then set the crank just past the markings before or after depending on what side you pull the cambelt. Put the belt onto the pulley just a slither on one side and the slowly move along pulling it on tooth by tooth. Its hard and youll need strong thumbs

Link to comment
Share on other sites

I forgot to say what you said about using rachets  on cam and crank turning 1 turn and then lining marks up that’s how I’ve been doing it so I’ll try your method tomorrow 

Link to comment
Share on other sites

Still having trouble cam mark lines up perfect but the when I like the 0 mark up and attempt to tighten the water pump it moves past the 0 mark even with the car in gear.tried moving it forward past the mark so when it moves it compensates for the movement and the belt is far to tight and just jumps way past the 0 mark I’m scratching my head now unsure of what to try next
Link to comment
Share on other sites

very  strange ive never struggled in the slighest doing them...keep trying i guess

 

in gear with a helper would stop the bottom end turning easily if you have a helper

Link to comment
Share on other sites

That’s why I don’t understand why the crank is spinning so freely if anyone has any further advice I’d be extremely greatful.ive never had problems before but sent it to a garage and it’s come back 10 times worse 

Link to comment
Share on other sites

your putting the belt on the bottom then pulling it snug along the front edge then fitting on the cam ? ...worst case get a breaker bar and jam it against the floor /trolley jack to hold it steady

Edited by steveo3002
Link to comment
Share on other sites

Some pics? 

 

I have had the occasion where ive spent 30 or so min guessing the swing of the crank when pulling the belt on so it lands spot on

 

What the garage got to say? They obviously had the same fun. Is the crank pulley on right and with no movement? 

 

Have you tried setting the cam tdc-1

Link to comment
Share on other sites

The garage sent it back a tooth out it was running like a bad a ****.he gave up ive set the cam perfect it’s tdc off cylinder no1 but as I say the crank is the problem it just won’t line up 

Link to comment
Share on other sites

It should, your too stressed at the mo

 

24" breaker bar with a 19mm on the crank wedged on the floor set to the mark. Make sure the cambely is tight on the bottom pulley teeth and waterpump and see how the teeth fit to the cam pulley, move the pulley a shade if needed. 

 

Is it a 128t round tooth belt? A 108 would be a problem

Edited by kiran_182
Link to comment
Share on other sites

not even sure if it would run but yeah check the teeth all match as theres early and late belt/pump 

 

 

Link to comment
Share on other sites

It has a notch on the back to fit the crank and a lump on the front that goes though a hole on the belt pulley, the pulley has notches on its endge 

Link to comment
Share on other sites

All this time I never knew that but saying that the engines in the car so can’t really see it If I’m honest.sorry to drag this topic out boys but there’s a simple explanation to this and I’m not sure what it is yet.

Link to comment
Share on other sites

With the crank pulley, it should only go on one way to make sure it can be timed

 

We need to see pics, maybe a vid of it running

Link to comment
Share on other sites

You will never overcome the half tooth problem without fitting a vernier sprocket to the camshaft, (or maybe by trying another belt, which could be exactly the same as the present one) but you should be able to compensate for a whole tooth out, by setting it on the next tooth to where you wish it to end up.

 

Use the two-to-one gear ratio between the crankshaft and camshaft to check the timing accuracy. For every degree that the CAMSHAFT is away from its mark, the CRANKSHAFT will be TWO degrees 'out' - So, setting the camshaft on its timing mark, any errors in timing will show up as TWICE the amount on the crankshaft.

 

Hope that there is some help there somewhere.

  • Like 1
Link to comment
Share on other sites

I’m going for a fiddle for an hour will

lwt you know of any progress I’m trying to figure out which is more important the crank or can timing mark 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. Terms of Use Privacy Policy Guidelines