Scirocco Register

*cough* vac gauge *cough* ;)

Nate wrote:*cough* vac gauge *cough* ;)

Trying to learn something, rather than criticising your idea, what would the vac gauge tell him that the compression test hasn't already?

Doesn't the head need to come off anyway?

Oh god !!!!
Took the head off,could not believe how easy the manifolds came off,only took hour and a half.
Downside is the gasket looks fine,i mean new looking,all the metal is intact,does not look more than a couple of years old,i have had it 5 and never touched the head.
If anything,and i am picking hairs here,1 of the head bolts was a couple of pounds less torqued than the others,but only a couple of pounds,surely not enough to cause these readings ?
Been on the phone to an engine builders today,and he didn`t even have a clue what it is.
All components look really clean for 230 thou miles,even combustion chambers ,inside ports etc,valve seats.
Valves all open and snap shut nicely,so really stuck,going to clean the head up with some emery,and check if there are any visible cracks,also been told to check it`s straight with 2 metal rulers.
Re face will be £45 + vat,they can also crack test it for me
Will get a new cam belt,just in case it stretched,but would that not be taken up by the tensioner ? As it still ran the same after taking it off an re setting timing ?

Be careful using emery - don't get any of the grit inside your engine or it will chew everything up.

Ok scrap that then,will put a brass brush on the drill,give it a clean up,going to match the inlet and exhaust to the gaskets while it`s off,really stumped though

MikeH wrote:

Nate wrote:*cough* vac gauge *cough* ;)

Trying to learn something, rather than criticising your idea, what would the vac gauge tell him that the compression test hasn't already?

Doesn't the head need to come off anyway?

a compression test will tell you there is a problem, but not what the problem is. with a vac gauge you can accurately diagnose quite a few problems and the test is much quicker to perform. assuming you have neither gauge, they are both roughly the same price so will cost you the same to buy (judging by my own standards, where i buy tools not borrow or rent them. particularly if they're shiny. mmmm, shiny...) have a read thru the link i put up on the first page of this post, or google for vacuum gauge diagnostics. there are a few brilliant pages on it on a couple of american classic car sites, but still just as valid even with a brand new european motor.

i was introduced to them by an old guy from bradford. he trained as a mechanic with the raf during the 2nd world war, and now he is retired he works 2 days a week doing a "hometune" type service. i called him out after rebuilding a 2 litre passat and monumentally failing to get it to run right. it would start, just, and rev to nearly 1000rpm if you held your boot to the floor. static ignition timing appeared right, as did the cam timing. turned out i had the dizzy 180 degrees out as it had 2 marks on the timing belt pulley. he had a beautiful polished brass vac gauge that was from his apprenticeship and said he reaches for that before the diagnostic scanner every time.

looking at the pic, the valve to the far right (smaller, so exhaust if memory serves - but i have had a few) looks noticeably darker the others. is this the same cylinder that had higher compression? did it have a significantly different coloured plug? hard to tell from the pic. wondering now if this may infact be an injector problem

Cheers Nate,only reason i didn`t get a vac gauge is my mate had a comp tester i could borrow for free.
All plugs looked pretty much the same,one of the pistons has some blue ing on the crown,but only a little,the pistons have shiny bit`s around the edges in places,is that where the fuel was squirting ?
Been told i can do a sort of crack test if i fill each chamber with paraffin,if it leaks out there is a prob,never thought of doing that,suppose it will also tell if the valve seats are leaky too.I took it in for tuning last year,there are a few different sets of timing marks,maybe i have got it lined up with the wrong ones ? so it`s firing at the wrong time ?
Is it possible i stretched the timing belt ? I assume they have a set length,and a set number of teeth ? Would the slack not have been taken up by the tensioner,or would a stretched belt cause things to not be right,as it`s taking it too long to open and close the valves at the right time ?

It may be worth ringing round a bit on the topic of head skimming... A firm my way'll give it a soak in their vat of magic cleaning stuff and do a skim for £20 for cash... I've taken a couple down to them... (admittedly, a year or 2 since the last time) Same story every time... It's a shiny, surface ground finish too - not a dodgy looking fly cut.

Yeah,last time i had one done,place in Middlesbrough did it for £12,that is going back a few years.
Not many places round here that is my problem,mate is an engineer,and said that`s an ok price,as if he did he would need the mill for at least an hour,an would need the entire bed to set it up.
Will try a few other places,going to check with rulers to see if its warped,then try the paraffin trick,to see if it leaks..
And he did also say ground would be a lot better than cut :D
Don`t wanna be spending hardly anything on it,as i will be drawing from the pretty non existent engine building fund i have for the 9a.

Nate wrote:

MikeH wrote:

Nate wrote:*cough* vac gauge *cough* ;)

Trying to learn something, rather than criticising your idea, what would the vac gauge tell him that the compression test hasn't already?

Doesn't the head need to come off anyway?

a compression test will tell you there is a problem, but not what the problem is. with a vac gauge you can accurately diagnose quite a few problems and the test is much quicker to perform. assuming you have neither gauge, they are both roughly the same price so will cost you the same to buy (judging by my own standards, where i buy tools not borrow or rent them. particularly if they're shiny. mmmm, shiny...) have a read thru the link i put up on the first page of this post, or google for vacuum gauge diagnostics. there are a few brilliant pages on it on a couple of american classic car sites, but still just as valid even with a brand new european motor.

i was introduced to them by an old guy from bradford. he trained as a mechanic with the raf during the 2nd world war, and now he is retired he works 2 days a week doing a "hometune" type service. i called him out after rebuilding a 2 litre passat and monumentally failing to get it to run right. it would start, just, and rev to nearly 1000rpm if you held your boot to the floor. static ignition timing appeared right, as did the cam timing. turned out i had the dizzy 180 degrees out as it had 2 marks on the timing belt pulley. he had a beautiful polished brass vac gauge that was from his apprenticeship and said he reaches for that before the diagnostic scanner every time.

Thanks - I think I've even got one lying around. I assume you just connect them to one of the existing vac nipples on the throttle body or inlet manifold.

yup. there's 2 on the pipe that goes to the servo. i used one of these with a T piece so normal vacuum operations weren't disturbed

You get a very different vacuum pull from there, compared to the one on the throttle body. Try moving your MFA vac line between the two, and see how your 'mpg' figure changes. I guess it could still work with a vac gauge though.

Bargain,ordered this morn,will be here tomorrow,A.V.S if anyone is interested,spent a good 20 mins on the phone to him,trying to solve my issue,he thought possibly timing out 180 deg,or possibly a stem seal ?

1 x Quantum Synta 5-Litre (In Stock) (ZGB115QLB004) = £14.95
1 x W719/5 Oil Filter (In Stock) (W719/5) = £1.95
1 x #5016 Cambelt (In Stock) (5016) = £5.83
1 x 828.807 Head Gasket (In Stock) (828.807) = £9.95.

Going to port the head over the w/end,then take it it to be ground flat,and cross my fingers that i have not wasted time porting something that is busted,good practice i suppose

If the timing was 180 out, it wouldn't run at all.