How Do You Set Basic Timing After Cambelt Change?

[mmatthej1 1]

I recently had a head gasket failure and - as this job was too much for me - the 1.9 GTI went to a local garage for necessary repairs.

 

They seem to be quite competent (e.g.head has been skimmed, valve stems replaced, new stretch bolts used etc) but they are now struggling to get timing right, saying that there don't appear to be any reference marks visible, to use in setting up basic timing.

 

They are still working on the problem but can anyone out there give helpful guidance, please?

[chris-gti 14]

There's the diagram of timing marks, this is for the sliding tensioner type. pretty sure the marks are the same on both. A little concerned that the garage didn't check before they took the car apart. as a mechanic i always check for timing marks and if they are not obvious i make my own with my trusty tippex pen.

 

[glenwah 20]

Holes in crank and cam pulleys line up with holes in the block and head, stick drill bits or similar through the holes to hold the crank and cam in place.

[ORB 227 1 Cars]

What Glenwah said.

 

I thought this was the only way!

[mmatthej1 1]

Thanks for both responses! Yes, the only time that I removed a timing CHAIN (showing my age!) was from a Lotus Twin cam and I certainly made sure to Tippex mark lots of reference points!

 

Ah well, we are where we are - is there any text to further explain the diagram, Chris?

[ORB 227 1 Cars]

Seriously, cam pulley has a hole in it (about 7 o'clock) shove drill bit in to lock it to the head.

 

Hole in crank pulley, lock it to block (just off 11 o'clock)

 

Loosen cam belt tensioner.

 

Remove belt

 

Replace belt keeping it tight on the right hand side...

 

Take up slack and Tighten tensioner.

 

Done.

[welshpug 1,622]

how did they get it wrong? every garage has autodata which has the diagram posted above.

 

I would be taking it elsewhere..

[chris-gti 14]

Thanks for both responses! Yes, the only time that I removed a timing CHAIN (showing my age!) was from a Lotus Twin cam and I certainly made sure to Tippex mark lots of reference points!

 

Ah well, we are where we are - is there any text to further explain the diagram, Chris?

 

 

sorry i didn't add text but pretty much what everyone else has said, line up the holes in the crank pulley and the cam pulley with the holes in the block and the head. lock them with a suitable sized bolt or drill bit (parts 2 & 3)

 

turn the pulleys carefully, drop a long plastic rod down a plug hole and turn the engine on the crank pulley until the piston is at mid stroke (half way up the cylinder) then set the cam position to the timing mark. lock it in place then turn the crank gently to it's timing mark. if you feel resistance, back the crank pulley slightly and turn the cam pulley through 180 degrees, then carry on turning the crank to its timing position, then return the cam to its timing position if it was moved. The resistance i mentioned is the piston touching the valves, it is important not to force it as the valves/pistons will get damaged.

 

sorry if it sounds confusing but its just a case of getting the engine to its timing position without clipping valves against pistons.

 

The XU 8v engines are really simple to time up.

 

If they have had the bottom pulley off for any reason the bolt must be done up to the 110 nm as i beleive the oil pump on some of these engines is driven just by tension on that bolt not by a woodruf key. May be wrong though.

[mmatthej1 1]

Again, many thanx for responses, esp. the diagram & explanation.

 

I don't know if the garage already had 'autodata' (first time I've heard of it, as I'm outside that trade) but think all your info. should be enough for them now!

 

Cheers, indeed - I will post follow-up, to give (I hope) a happy ending to the story!

[ORB 227 1 Cars]

I hope they are not charging?

 

If they can't do a belt on a GTi then there is an issue!

[chris-gti 14]

I would recommend everyone has a copy of autodata it's brilliant.

 

If i wasn't so far away i'd come and time it up for you/them.

[dcc 855]

all of you have overlooked the possibility that this engine is fitted with a vernier pulley, which neither the owner or the garage might understand a, what it is, b, what it looks like, c how to time it up, d, how to wipe front to back.

[chris-gti 14]

You're right, i didn't think of that. just assumed it was an unmodified GTI

[ORB 227 1 Cars]

A garage that can't spot a vernier?

 

I'm a car salesman and I can!

[MikeC 10]

There's the diagram of timing marks, this is for the sliding tensioner type. pretty sure the marks are the same on both. A little concerned that the garage didn't check before they took the car apart. as a mechanic i always check for timing marks and if they are not obvious i make my own with my trusty tippex pen.

 

Anyone any part numbers for item No 7 (smaller cover) and Item No 8 in the drawing above, as i'm missing these.

Even better if anyone has any for sale, let me know

[Simes 248 2 Cars]

Anyone any part numbers for item No 7 (smaller cover) and Item No 8 in the drawing above, as i'm missing these.

Even better if anyone has any for sale, let me know

Try posting in your own wanted thread, you'll have more success.

[mmatthej1 1]

Just to clarify, the car is unmodified...............

[chris-gti 14]

Set it up as per pictures and description then.

 

 

keep us updated on progress with it.

[pug_ham 240 3 Cars]

The other thing that hasn't been mentioned yet, did the garage remove the dizzy & have they just refitted it way out of position?

 

I'm also fairly shocked a garage doesn't have at the very minimum paper copies of autodata which will show the timing pin locations or make marks for the timing prior to taking it apart & refers to it on a car they would rarely see.

 

TBH, the XU engine is probably the best engines for fixed timing positions I know about, although I'm not widely schooled on other manufacturers engines, I haven't seen any with such easily accessible, fool proof timing locking points that don't strictly need specific sized timing pins which you have to buy or be able to make.

 

Two 10mm bolts do the job perfectly on the 8v engines.

 

g

[chris-gti 14]

my 1600 will run pretty much wherever the dizzy is positioned, albeit very badly....

 

...unless it's upside down.

[mmatthej1 1]

Oh dear - the good news and the bad..........................

 

GOOD

Garage solved whatever the timing problem was, got it running sweetly, then took it for test drive...................

 

BAD

During test, they heard a mightly 'crash' noise, checked under bonnet and found that the two integral mounting lugs on block & head that hold engine mount had broken off!!!

 

This is real bad of course - they reckon bolts were properly torqued up, maybe the lug on the block had a prior hairline fracture (as some evidence of blackening on one side of threaded section) but they are treating it as something that happened 'on their watch', so have promised to fix it (somehow!).

 

Current thinking is to get a specialist aluminium welder in to re-attach the broken sections - they need to find such a man but do have concerns about effects of heat transfer (might it warp head??)

 

Any ideas out there, please? Has anyone had this happen? (I think I might start a new thread, specially on this aspect, ie. the repair of ali. parts)

[ORB 227 1 Cars]

Photos to explain a little clearer please!

[mmatthej1 1]

No fotos just now, 'cos still with garage.

 

As I saw it : the top engine mounting would normally be held, from the body, to the block/head, by 2Xbolts which go into the block/head.

 

 

In my son's car, both the block & head side of their ali. castings have broken 'in half', exposing the thread sections. (We still have the 'broken off' bits, so maybe could weld them back and (somehow) re-thread.)

 

 

Any clearer? Hope so!

[Miles 331 1 Cars]

It does happen, But there is no need to remove that mount when doing the cambelt. Welding is iffy as you will not know how well it will work, there's allot of head to warm up before the weld penetrates as it should, without that you may get some birds**t on the surface which will fail again

 

Hate to say it but most people change the head when that happens

[DamirGTI 325]

Ditto i'd avoid welding , especially aluminum welding - not so easy and needs an TIG machine + metal thermal stress ..

 

I would try "cold weld" , 2pack epoxy resin and aluminum powder , clean up the broken bolts stuff with the epoxy paste and once dry cut new threads for bolts .. if you do the bottom one good (on the block) the two on the head won't need to be so "perfectly strong" , one on the head and one on the block will do ..

 

I'm using this (for cracked blocks , stripped threads etc.) , it's really strong and durable stuff :

 

http://www.loctite.co.uk/cps/rde/xchg/henkel_uke/hs.xsl/fullproduct-list-loctite-4995.htm?countryCode=uke&BU=industrial&parentredDotUID=productfinder&redDotUID=1000000ICWQ

 

D

Edited March 21, 2013 by DamirGTI