How do you find TDC without visible reference markers..fixed

masood_ilyas · Unread post by **masood_ilyas** » 26 Apr 2011, 10:41

In my previous request for help following a cambelt change http://www.frenchcarforum.co.uk/forum/v ... hp?t=35158 the tractor noise was mentioned which was advised as the belt being a tooth out, somehow I managed to reduce it by one tooth and thought it was fixed, but on test runs it lacked power meaning I must have been more that a tooth out

As I was about to go on holidays I put the car away only to find that now I have forgotten the whole sequence!.
Is there any way of finding TDC on an automatic, there are no visible reference marks to lock its crankshaft other than the starter ring.
There is a plate with 4 holes where the flywheel would be but these are so far out that that I can feel the valves contacting the pistons when I rotate the pulley.
So how can I go about finding the correct timing position. I am assuming with the cam sprocket and fuel pump sprocket lined up against their respective holes all I need is piston 1 to be at TDC.
I have gone through the this cycle several times but still no way near its correct position,I am obviously missing something and need your help.

Would removing the preignition heaters help, will I be able to feel the piston rising if a coat hanger wire was inserted in its hole even though it seems at 45 degrees to the cylinder. I am tempted to flood the cylinder1 with diesel through the ignition heater hole and observe when it stops oozing out at TDC, then suck out the excess diesel.

Any advice received will be most appreciated.

spider · Unread post by **spider** » 26 Apr 2011, 11:19

Remove the starter and look for the timing hole. Not too sure on an auto but they must have something.

The petrol XU's had a hole in the crank pulley that fitted with a notch in the crankcasing, but the diesels rely on the flywheel hole. I assume the driveplate must have one too really ?

masood_ilyas · Unread post by **masood_ilyas** » 26 Apr 2011, 11:44

Thanks Spider.
Thats just it, it is an auto very different from the other manual versions, no fly wheel.
I did find that hole next to the starter and curiously there are four position you can feel there is some sort of hole in the plate behind, but unfortunately they are unrelated to crankshaft timing sequence.

Kind regards

Masood

Unread post by **DHallworth** » 26 Apr 2011, 11:59

Is it a Petrol or Diesel?

If you remove a spark plug on a petrol (might work for a glow plug on a diesel I don't know) and put a long, thin piece of fairly stiff wire down the hole it'll then touch the top of the piston.

If you swing the engine round the piece of wire will go futher in or will come out depending on where abouts the piston is.

You'll be able to find TDC that way as the wire will stop lifting momentarily as the piston starts to fall again.

Won't be as accurate as the timing holes are but it'll give you a good idea.

David.

Chlorate · Unread post by **Chlorate** » 26 Apr 2011, 12:15

From his other post it's an XUD, the glow plugs poke into the swirl chambers, you may be able to feel around carefully if the wire was bendy enough though.

Wish I had my BoL on me...I'd be able to look it up

Unread post by **citroenxm** » 26 Apr 2011, 12:56

Autos still have a TDC hole in the "Flywheel" Area...

Remove the starter as said above to clearly see the TDC hole in the block, then remove the locking bolts from the Cam and Injection Pump, turn the engine over whilt trying to inset a 6mm to 8mm rod into the TDC hole.. The TDC hole wont be far away if you have the Cam and Injection pump timed.

My advise would be put her in 5th gear.. and gently move the car fore and aft to locate the TDC hole..

Im sure theres a TDC hole in the autos "flywheel"....

You will NEVER feel or find the top of the Piston through EITHER the injector or Glow plug hole, and the prechamber they are in has a tiny outlet hole to the top of the piston.. So thats no where NEAR worth the route going down..

Paul

masood_ilyas · Unread post by **masood_ilyas** » 26 Apr 2011, 13:17

Thank you gentlemen.
It is a diesel as Cholrate mentioned.
By the way Chlorate, the BOL says nothing about automatics, it fails to spot that there is no flywheel to lock the crankshaft.
Citroen XM its an auto I can not rock it in 5th, though as you say there is a hole in the block next to the starter. Unfortunately there are 4 holes 90degrees apart in the plate behind. These are so far out that they cause valves to kiss the piston. I am sure I was not that that far out when I started, it is possible in order to move one tooth I may have mistimed the cam and pump sprocket. In which case now I need to retime the cam too. I am assuming the pump is easily timed with just the two bolts for its reference.
At the moment this car should be on the farm with its tractor noise.

Masood

Unread post by **citroenxm** » 26 Apr 2011, 13:20

Doh auto stupid me... No 5th.... The other clue after you have removed the crank pully is the crack keyway shouls be pointing DIRECTLY up at the cam shaft!!

Paul

Chlorate · Unread post by **Chlorate** » 26 Apr 2011, 13:40

Are all the holes in the automatic flywheel-esque the same size?
It may be the case that the timing hole is the only one that an 8mm rod will fit in snugly.

spider · Unread post by **spider** » 26 Apr 2011, 13:58

Hence me saying whip the starter out and look, hopefully there will still be a hole in the crankcase and a corresponding one in the driveplate (automatic transmission flywheel equivalent, well sort of)

If you disconnect the battery and undo the two or three bolts on the starter, it will move an inch to the left, there's usually no need to disconnect its wiring unless its strained, I never did on mine, just let it sit on the hoses with care.

I had to take mine out as although I had the proper (yes really) tool it did not fit due to a tiny engine bay on the 205 so could not swing the tool forward enough due to the radiator and the wrong starter motor (too big) as well.

But as several have posted, just whip the starter out and take a look.

masood_ilyas · Unread post by **masood_ilyas** » 26 Apr 2011, 20:15

I did have a look at the flywheel plate behind the starter, there are two holes in the flywheel plate which has the starter gear ring on its outer edge, one of these holes is pretty close to cam and pump sprocket marking so I am assuming this must be for TDC locking. The crank sprocket woodruff key slot also points towards the Camshaft at this position between 10 and 11 O'Clock approximately.
Using that as the ref and realigning the CAM and Fuel Pump sprocket the timing belt was laced up again. The noise now though a little less but still seems a tooth out.
I have done timing belt change on non auto xantia before never had so much hassle but with this one I am now confused

, the crankshaft is locked with the alignment hole through the hole near the starter, Cam and fuel pump sprockets are in line with their locking holes by using bolts yet it still appears in correctly timed, which was proven by a definite lack of power when I took it out for a quick check. What am i missing

I have not changed the timing belt tensioner is this having fun at my expense, could this be applying incorrect tension when every thing is running at normal rpm, The irony is it was all working fine untill I decided to put a new timing belt in. Reminds me of what my engineering supervisor used say, "if it works don't try to fix it" and that was over twenty five years ago.
Masood

citronut · Unread post by **citronut** » 27 Apr 2011, 08:05

im sure you laced it so all the slack was at the tensioner side/run,

if so was there any prob with engaging any of the belt teeth into the sprockets,

are the bolts you are useing a good fit in the sprocket holes, (8mm thread diamiter and 13mm spanner size???)

also you are aware you are ment to release the tensioner with timming pins still in place,

i usualy just add a slight bit of tension further that the spring tensioner put on,

also i lock the cam and pump then gentley rock the crank till the crank pin drops in, (crank pin= a length of kunifer brake pipe )

regards malcolm

masood_ilyas · Unread post by **masood_ilyas** » 28 Apr 2011, 09:09

Thanks Citronut Malcolm.
Yes I did find that when lacing up the belt it did not fit squarely between pump and cam, I did not think much of it at the time as it was very slightly out which required cam sprocket moving anticlockwise by quarter of a tooth spacing. Does that mean there is some slack between crank and pump or pump and cam are mistimed relative to crank?
I was unaware that you could apply slightly higher tension than the auto is calibrated for. I think I will put in new auto tensioner as the car is over 130K miles which will also remove doubts about the lazy tensioner and sticky pivoting.
Thanks again

Masood

citronut · Unread post by **citronut** » 28 Apr 2011, 23:10

the XUD tensioners very seldom give any trouble, the tension is created by a heavy spring inside a plundger,

ocasionaly the plundger gets stuck in the houseing, but once it is freed off,cleaned and greased it should be fine,

then all you need to do is feel the tensioner bearing to see if there is any sideways play or noise on spinning it,

regards malcolm

masood_ilyas · Unread post by **masood_ilyas** » 01 May 2011, 10:02

Thank you every one, with your help it is now sorted.
So what was the problem?
Firstly the crank timing hole, it was there amongst others on the flywheel plate just needed an 8mm pin to identify it. Secondly the auto tensioner was not applying the correct tension due to adjuster's pivot which was loosened a couple of turns only, I should have a done it properly to let the tensioner work back all the way. This was staring me in the face but I did not see it

Citronut Malcolm's handy tip of applying a slightly higher tension at the last staged worked like magic. Sounds much better now.

Now for some rest before I start on the head gasket of my second 1.9TD Auto Xantia which is leaking its engine oil and leaving it as evidence on the floor when its parked.