CharlesY · Jan 3, 2012

offroadmad said:
its a 200 tdi - cambelt was done by myself less than 1000 miles ago - will not be checking timing ( i know i should ) but its a right bugger to get at - there must be a way of checking it hasn't slipped without taking it all apart again. - surely if the timing had slipped i would have more than one bent p/rod as the chances of only one valve meeting the piston if the belt slips is almost impossible - agreed ???? or am i completely wrong ?
The valves are all straight as if they were bent they would not close correctly - so i would be amazed if it's slipped a belt.
Dont get me wrong i'm not arguing - u guys blatantly know more than me but i'm not going through all that again to find out it has not slipped.

OK, 200 tdi or 300 tdi won't make a difference.

Sorry to say, but YES, if the timing is a tad out, it is quite likely that only ONE valve will get smacked by a piston, and mangle its push-rod.

The chances of ONE valve making contact are very high indeed, in fact, it's almost a certainty when the timing slips just the right (i.e. wrong) amount.

It IS possible to check the valve timing by fitting a protractor (a disc marked in degrees) to the crankshaft pulley, and then turn the engine over till the number one inlet valve starts to lift, but IN MY EXPERIENCE this has never been easy or accurate.

If you don't get the timing checked one way or another, you may be taking a big risk trying to fire the engine up.

Tuskenraider · Jan 3, 2012

The valves are inline with the pistons not angled like on a DOHC head and are much stronger than the pushrods so they wont bend unless hit really hard. You could put the new rod in and turn it over by hand to see if there is a clash but thats still not a 100% check as with full engine speed you increase the risk of a clash you might not see by turning over by hand.

CharlesY · Jan 3, 2012

Tuskenraider said:
The valves are inline with the pistons not angled like on a DOHC head and are much stronger than the pushrods so they wont bend unless hit really hard. You could put the new rod in and turn it over by hand to see if there is a clash but thats still not a 100% check as with full engine speed you increase the risk of a clash you might not see by turning over by hand.

Absolutely, and he MUST do that, but sadly this will not prove the timing is correct, or that the belt hasn't been damaged.

He never did say if the wading plug was in or out when he went playing U-Boats. The smallest pebble between belt and pulley can cause a timing slip, and once again, we must keep in mind, SOMETHING HAPPENED that buckled that pushrod. What was that something?

When timing SLIP happens, the engine moves forward of the valve and pump timing, and so the exhaust valve is LATE in closing ~ that is, the valve is still TOO FAR DOWN when the piston is the right amount up. Collision is inevitable if the slippage makes the valve closing late enough, and I can tell you, it doesn't take much.

offroadmad · Jan 3, 2012

My plan is to fit the pushrods i have which are strait - turn the engine over by hand & check all the pushrods are rising fully ( including the cylinder that bent the rod ) this will rule out cam follower problems. If the valves are hitting the pistons surely i would feel resistance when turning by hand & if this is not happening the timing must be fine ?
Im not really a technical guy or an engine builder that measures every tolerance & replaces every worn part - more someone that just wants a running vehicle as cheaply as possible -
I have very little funds right now & really cannot afford to buy gaskets & cambelts that may not be needed.
It may not be the correct way to do it & im aware i could do more damage but im going to risk fitting a rod, put it back together, set valve clearances, check by turning engine by hand and turn the key with crossed fingers
It will either run perfect or bend the rod again if it bends the rod then its head off & front off to diagnose & sort it when i have more funds.
I honestly appreciate all of your help & dont want to seem like im not listening but i only have what i have & ive got to do the best i can with it. This is my only option right now so wish me luck.

offroadmad · Jan 3, 2012

sorry charles still havent answered your question - i have a wading plug in the bell housing & filled the front one with silicone so nothing could of got in to the cambelt casing !

jamesmartin · Jan 3, 2012

good luck ,your only going to find out by trying ,you can check vale has enough clearance by adjusting tappet so theres no clearance and turning engine over carefully if it clears then it will run without the risk of touching once set right

offroadmad · Jan 3, 2012

cool cheers james - my only option m8

CharlesY · Jan 3, 2012

offroadmad said:
sorry charles still havent answered your question - i have a wading plug in the bell housing & filled the front one with silicone so nothing could have got in to the cambelt casing !

WHEW!

That's a big relief, and again, it is good news.

Back to the point - SOMETHING caused that problem!
If you are still lucky, the something may have gone in and back OUT.

I suggest you set all the valves with correct clearances and then rotate the engine by hand hopefully with no sensation of contact. This should prove it COULD be safe so AFTER that I suggest you do as James says, close the clearance of the rocker with the NEW pushrod to zero, and rotate again. If it clears, you don't have much choice - pray, set clearances to 8~10 thou, then FIRE HER UP!

offroadmad · Jan 3, 2012

Thats the plan - tmoz im going to put the str8 rods back in & check they all rise fully, if they dont then its front & top off. if they do il follow instructions & cross absolutely everything as i gingerly turn the key lol
Ordered a rod & rocker gasket - on theyre way !

CharlesY · Jan 3, 2012

offroadmad said:
That's the plan - tmoz I'm going to put the str8 rods back in & check they all rise fully, if they dont then it's front & top off. If they do I'll follow instructions & cross absolutely everything as I gingerly turn the key lol
Ordered a rod & rocker gasket - on their way !

I don't think turning the key "gingerly" will make much difference.
Be a MAN, and TURN THAT KEY!

Remember, when all the pushrods are OUT, all the valves should be SHUT tight, and you can turn the engine safely, even on the starter.

You SHOULD feel compression on all 4 cylinders if you make two full turns of the crankshaft by hand, or a regular thump thump thump thump if you turn it on the starter. If one cylinder isn't compressing for any reason, you will hear it by an irregular thumping when turning on the starter, or a hissing or NOTHING when turning by hand.

Remember to set it to TDC before putting the pushrods back. It's always good to start at TDC.

It's all very exciting and nail-biting!

offroadmad · Jan 3, 2012

may be exciting for you lol

Mr Noisy · Jan 3, 2012

offroadmad said:
may be exciting for you lol

i know, i'd be ****ting it too!

battenberg · Jan 3, 2012

can all this theory be tested by pinning the crank at TDC at the flywheel, then looking for alignment with a pump pin..?

CharlesY · Jan 3, 2012

battenberg said:
can all this theory be tested by pinning the crank at TDC at the flywheel, then looking for alignment with a pump pin..?

Can this be done on a 200tdi?
If so it would show the PUMP timing right or wrong, but would not quite guarantee the CAMSHAFT timing.

However, if the pump was right so too should be the camshaft.

Remember though, it buckled a pushrod. WHY?

jamesmartin · Jan 3, 2012

it can be done as there is inspection plate for pump as with 300 but as said doesnt prove cam timing,push rod can get bent through the brass follower jamming in worn slide not common but have seen it

battenberg · Jan 3, 2012

I would think Charlesy that if the crank was pinned at TDC then you would NOT be able to pin the pump (using the little service hatch) if indeed the belt had skipped at the crank pulley.

this could be done without dismantling the timing case, but would only prove that the relationship between the crank and the pump is in tact. not the relationship between the crank and the camshaft.

However for the sake of a set of drills as pins, and a 10mm socket, it would be a quick and easy test.

CharlesY · Jan 3, 2012

battenberg said:
I would think Charlesy that if the crank was pinned at TDC then you would NOT be able to pin the pump (using the little service hatch) if indeed the belt had skipped at the crank pulley.

this could be done without dismantling the timing case, but would only prove that the relationship between the crank and the pump is intact, not the relationship between the crank and the camshaft.

However for the sake of a set of drills as pins, and a 10mm socket, it would be a quick and easy test.

Agreed.
I think he should consider this.
The more things he can find that are GOOD, the better.

aviator · Jan 3, 2012

I have followed this thread with interest, I am so looking forward to a conclusion. Good luck Stu.

CharlesY · Jan 3, 2012

aviator said:
I have followed this thread with interest, I am so looking forward to a conclusion. Good luck Stu.

Perhaps we should run a book on the possible outcomes!

One thing we can all agree on - we wish Stu well, and hope it is fixed with the new pushrod!

offroadmad · Jan 3, 2012

love going away for a bit then returning for a look

- gonna try removing the fuel pump hatch & checking its in time - cheers for that battenburg
but convinced if any of the valves were bent i would of known when i removed the rockers (they all sprang to the closed position) if any were bent they would not be able to close fully also if it was out of time would it still start on the flick of the key as it always has ? - will know tmrw if followers are damaged or doing theyre thing, as always will keep ya all posted

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