telstar timing belt alignmet

[jan99]

Hi
I got the Telstar 2.2 l 1989 which had stopped and won't start. Appears the engine has no compression.
Could anyone advise how to check if the timing belt had slipped; in particular how to check the the alignement of the timing belt.
Thanks
Jan

[wesso]

Hi Jan,
I don't know the 2.2L '89 Telstar but I doubt that the timing belt would have slipped since they are designed to be as accurate as any chain drive. I think that even if the belt had snapped you would still have some compression since the valves wouldn't be opening and closing. This would in most cases also lead to at least a couple of valves being bent or broken due to the pistons hitting those that were open at the time the cam stopped turning. I think that would probably be the worst case scenario.
The only other things that I know of that causes an engine to loose compression is holes burnt in the top of the pistons or blown head gasket. I would be checking the head gasket first by getting a compression test done on each cylinder.

Sorry... that probably wasn't much help, but don't give up as it can sometimes take a week or two to get a really good answer. Check back regularly...

Cheers

Wayne

[jan99]

Wayne
Thank you.
I will look at the head gasket... indeed I noted that water had gone from the radiator.

However, since I have the timing belt cover opened already I would still want to check that the belt is in write position - can you help how to do that?

Appreciate
Jan

[wesso]

Arghhh Yes!!! The water going down is one sign that the head gasket could have blown. You may also find that when you check the oil that it is a greyish colour too. A blown head gasket will usually allow water to get into the oil.

As for checking the timing belt... I am very sorry, but without being familiar with the engine I couldn't accurately tell you as I have only ever worked with engines that have push rods or timing chains.

There is bound to be someone in this forum who can tell you exactly what you need to know though.

Cheers

Wayne

[jan99]

Wayne
Hmm... all this sounds serious.
It appears there is no compression on any of the cylinder and this is the reason I wanted to check the belt alignment.
But I will pursue the check of the gasket and look for signs of water in the oil.

Thanks again
Jan

[wesso]

No worries... I hope it isn't anything too serious, but loss of compression across all cylinders could mean otherwise. I'm just trying to think what can go wrong and cause that.

I'll get back to you on that one...

Cheers

Wayne

[jan99]

Hi
Checked today the oil and this looks OK without water...
But had another look at the timing belt and noted that when the belt pulley is at TDC mark, none of the pistons is in top top?
The only explanation would be that the key on which the pulley if fited to crank shaft is sheered off...... do thing like this happen.
Or is there something else I am missing?
Please comment.

jan

[smally289]

Timing belt has either jumped quite a few teeth or broken altogether. Pull the dissy cap off and crank the engine over. If the rotor doesn't turn, the belt is broken. Pretty sure the 2.2 is an interferance engine, so you will have bent some valves too.

[wesso]

Jan there are people in this forum who are a lot more qualified to help you with this than I am. However, until somebody else steps up to help you I will help as much as I can.

That is a good sign if the oil is clean, but I don't think you can completely rule out the possibility of a blown head gasket. Lets get back to the timing belt issue...

Yes it is possible to sheer a key off, but to do that there would have to be another pretty big problem somewhere to cause this to happen.
Again as I said yesterday... I am not familiar with your engine so I am only making guesses. I know that chain driven cams have a key on the bottom sprocket and the top sprocket, so if the belt has a similar setup there should probably be a key at both the top and the bottom pulleys and to check if the key has sheered off you should only need to remove the bolt in the center of the pully that holds it on the shaft and you may be ablt to see from there if the key way in the pulley and the shaft is in alignment.
Be very careful not to disturb the location of the pulley on the shaft though. If the key is still ok and aligned you don't want the pulley to be coming off unless you have the correct information for setting up the timing again.
I'm actually thinking now that it may be more likely that the belt has jumped a couple of teeth rather than sheered a key off. At the same time I would be trying to find out what may have caused that to happen if that is the case. Because if you reset the timing belt and the pulleys to where they should be, there is nothing stopping the same problem from happening again if you know what I mean.
I'm really sorry that not much of this is good news for you, but I will say that at least you are willing to have a go at repairing this problem and that's pretty gutsy in my books.
Ok I just had another thought... it may be another wild goose chase, but it could be worth a look anyway. Was there or is there any oil in the coolant that is left?

On another note... Have you had the tappet cover off at all? if you take the tappet cover off and turn the engine over by hand and check that each valve actually opens and closes in the prescribed firing order. Having an overhead cam may mean that this is going to be a bit more difficult to see especially if the valves run directly off the cam and not off rockers (AKA tappets). If your engine has rockers then you should be able to see that the valve stem is returning to the fully closed position after it has been opened thus making the rocker arm relatively tight except for a very slight gap. If you find that a valve is not completely closing then I would suggest that the valve stem is bent and that will definitely cause little or no compression because the port is open all the time.
This would also confirm that the timing belt has moved from it's correct position.

I'll leave it at that for now and see what your findings are from that.

Cheers
Wayne

[jan99]

Wayne
You have very logic and clear mind...., I do appreciate that and your help so far.

Now, in my mind, if the belt has jumpped this would had not altered the fixed relation between the first piston in top position and the matching of mark on the crank shaft sprocket lined against the TDC or TOC notch on the reference ruller. It is just pure consideration of logic - would you agree?


It might pay to consider sequence of events leading to the breakdown. Consider, in the first place my son took the car to tow a heavy loaded trailer and the car stalled on the road (never done this before). He restarted it however after few minutes and brought the staff home. Next day he took the car to work and all was OK. The break down occured the following day on travel without a load.
With this, I suspect the temperature (overheating) could be a factor.

OK, before taking the rocker cover off I will look at the sprocket key.
Probably in few days time.

Cheers
Thank you Wayne
Jan

[wesso]

Hehehe : I only wish I did have a clear mind... I just hope that the information that I am giving you is of some help and gets your car back on the road as soon as possible.

Yes to your question about the No.1 piston being TDC when the mark aligns with the incremental marker on the crank shaft pulley... That would never change unless the key has sheered off in the key way. If the mark on the bottom pulley (the one on the crank shaft) is not in line with the long mark or the zero mark on the "reference ruler" then it's a pretty good bet that the key has sheered off. Worst case scenario could also mean that there is a broken connector rod on the No.1 piston, but I doubt you are looking at anything that harsh and you would have know about it if you had dropped a con rod, so I'm pretty sure we can rule that out.

Mmmm I have just considered the events that you mentioned that led up to the problem occurring and I am getting some awful thoughts. The fact that the car performed ok for almost two days after the load stress makes me wonder what could have gone wrong :
I would be hoping for the least serious which would be a sheered key, but keep in mind that this would also mean that there should be at least a few bent valves because of the timing being so far out of whack. I would be inclined to carry out the following checks...

1. remove the distributor cap and check that the rotor button is turning when you turn the engine over (preferably by hand) You can also do a rough (estimated) check to see if the arm on the rotor button is anywhere near the pickup post for the No.1 cylinder when the timing mark is at or just before TDC.
2. You can also check for TDC of the No.1 piston by removing the spark plug and carefully inserting a pencil or something like a chop stick while the timing mark is at or just before TDC. This doesn't necessarily mean that it is on the firing stroke though.
3. If the timing marks do not align as they are supposed to then I would suggest the next step of removing the retaining bolt on the crank shaft sprocket and checking for a sheered key.

Lets just leave it at that for now so that we don't get lost and end up going around in circles. It will also give us a bit more time to see if anybody else may have a better idea of what the problem could be. I will also do a bit of searching to see what I can find out from my local mechanic.

Cheers
Wayne

[jan99]

Thanks a lot Wayne
Will report the outcome of the tests in couple days time.

Have a nice day.

Jan