202 Holden Air Leak Issue

[MONARQ]

Hey Guys,
Just to keep you informed... I have just picked my car up from the mechanics & he has diagnosed the issue has a 'Manifold Air Leak' but was unable to fine it.
So next step is to remove manifold, get it machined & replace with new gaskets, & cross my fingers!

Once again though, very hard to understand how replacing a cam shaft & cause an manifold air leak!?

I will let you if this solves the issue.....

 

[EYY]

Does it have extractors? Or the standard dual outlet cast exhaust manifold?

I wouldn't waste money machining the inlet manifold btw.

 

[Big-Al]

Hey Guys,
Just to keep you informed... I have just picked my car up from the mechanics & he has diagnosed the issue has a 'Manifold Air Leak' but was unable to fine it.
So next step is to remove manifold, get it machined & replace with new gaskets, & cross my fingers!

Once again though, very hard to understand how replacing a cam shaft & cause an manifold air leak!?

I will let you if this solves the issue.....

Sorry but your mechanic sounds like he doen't know a piston head from his sister's titty. Get a second opinion.

 

[Not_An_Abba_Fan]

It would have to be a substantial leak to cause your issue, in which case it would be very easy to find.

Is the vac line hooked up to the modulator on the transmission?

 

[MONARQ]

Does it have extractors? Or the standard dual outlet cast exhaust manifold?

I wouldn't waste money machining the inlet manifold btw.

No, I don't have extractors, it is the original intake manifold & exhaust.

 

[MONARQ]

It would have to be a substantial leak to cause your issue, in which case it would be very easy to find.

Is the vac line hooked up to the modulator on the transmission?

That's what I said to the mechanic!
Before I took it there, I carried out tests on the manifold (e.g. listen with hose, spray manifold gasket with ether etc...) & could not find any leak. The mechanic said it will most likely be on the under side on the manifold.

Yes, trans vacuum line is connected (this has been checked).

 

[Big-Al]

you do have a leak, a leaking valve. Eventually when you listen to me, your issues will be solved.

 

[Not_An_Abba_Fan]

Have you done a compression test?

 

[EYY]

1) check compression- a bent valve as Al suggested would cause the symptoms you mention, although it's not incredibly common. Most people are lucky when their fibre gears strip and there is no interference.

2) make sure ignition timing is properly set (I.e. Make sure balancer hasn't slipped and initial timing is at 6 degrees btdc.)

3) make sure there are no manifold leaks - the hose method will confirm this. If you find it difficult to hear, take the fan belt off just for the hose test. Don't let it run for more than a couple of minutes without the fan/water pump spinning. And make sure all vacuum lines are connected properly and are in good condition. The only vacuum source you would have touched when doing the cam gear should have been the vacuum advance for the distributor

4) if none of this works, take the car to somebody who has experience with cars - 202's are one of the most simple engines to work on, and if a mechanic can't get one to run properly then you should run far, far away and never go back there.

 

[delcowizzid]

It's hard to bend valves in stock 202.s I've had the gears strip at idle and at high rpm never bent a valve.burnt valves on the other hand been there done that lol.Carby will be the issue I just converted one with a small cam from varajet to efi all the no idling and no downlow power was instantly fixed quadrajet was the cause no amount of messing withthe carb would make it run nice