Help! have I bent my valves?

[Adzsy]

OK so I fixed an oil leak to the oil feed on the turbo and completely forgot I had the timing belt off. The inlet cam is in but the exhaust cam is out. I spun the motor on the starter to check for the oil leak! With the inlet cam in its natural position I.e not fully compressed any spring do you think I could have bent a valve or two?

I have read some people have snapped a belt at low speeds and been lucky.

I was waiting for a spare lifter to arrive hence why it was in peices. I can't believe I did it but it was late dark cold and I was rushing! What a dick!

[dukey]

Well 2 good ways to find out. 1 take it apart and check 2 put it back together and check. I'd go with 1. I'd have to check before going any further.

You could be luck but I'd rather know for sure.

[Maff_1991]

Let me know if you have bent any, I has spares

[Adzsy]

Let me know if you have bent any, I has spares

Cheers. I think I'll throw it back together when the spare lifter arrives and do a compression test. I'll let you know.

[Adzsy]

I am pinning all hopes that as it can only be the inlet valves at risk which have a lesser lift and duration I may have got lucky

Optimistic I know.

[pointz]

As long as you are 100% certain it was in a neutral position all valves would be closed. Put it back together then turn it by hand to make sure there is no interference.
Then compression test it then you will know if anything is bent.

Also could take the plugs out and look in the bores with pistons at the bottom you should be able to see any marks on the piston crowns!

[skyshack]

Did it come to a sudden halt or spin over freely?

If it stopped then it definitely whacked a pair of valves. The possibly of bending increases depending on how long a run up it got. Mid stroke to TDC not so bad, a full turn and a bit more then its more likely to bend valves.

As long as you are 100% certain it was in a neutral position all valves would be closed. Put it back together then turn it by hand to make sure there is no interference.

At least 2 pairs of inlet valves will be at part lift. One opening, the other closing.

Then compression test it then you will know if anything is bent.

Also could take the plugs out and look in the bores with pistons at the bottom you should be able to see any marks on the piston crowns!

Yes. A Borescope would make this much easier. About £10 for 7mm or 5.5mm on E-bay.

[Adzsy]

Hopefully this lifter will arrive today. So I will reassemble and do a compression test. I can get a boroscope from work so will try that if needs be. It seemed to spin freely although much slower than normal. I guess because there was compression on multiple cylinders and the cams weren't moving the valves.

[pointz]

I would probably get the boroscope and inspect 1st tbh just for piece of mind!

[Adzsy]

UPDATE:

I have assembled it all back together. I have checked the piston tops with no signs of impact.

Now...with it all timed up properly i.e. all markers correct, counting teeth between cam markers and crank marker etc, there is zero compression on all four cylinders. no reading whatsoever.

With no cams in so all valves are closed I get 1 bar across all four. I would expect this as there is no air being drawn in. But why would I get zero compression with it all timed up? I even pulled it apart and started again just to make sure! Surely If I had made contact between piston and valve it would only have been one?

Any ideas? I have turned it over with no rocker covers on and can see it all working correctly.

[R3K1355]

1 bar?

You want 10 bar on a relatively healthy engine, minimum 100 psi but you want no more than 10% difference between all 4 cylinders.

[Adzsy]

But if all valves are closed continuously, then wouldn't you just pull a vacuum and compress what you already have? I hear what your saying but I can't understand why I would get zero with it all running correctly across all four cylinders?

I am thinking that IF I did make contact between piston and valve it could only be a couple of valves based on my first post. Surely I should get some compression on at least 1 or two cylinders?

I think I am going to have to take the head off again, but I would like to understand these odd readings first, and just make sure I am not doing anything retarded!

[autosri]

Is there any way your 180 degrees out on the crank ?

[Adzsy]

All the timing marks are aligned as per workshop manual... so I don't think so..

[pointz]

And you have 39teeth between dots on cam pulleys and 48 between dot on exh cam pulley and crank pulley? You holding throttle wide open?

If the correct amount of spacing between timing dots on pulleys and dots are near the marks on the cam backplate and oilpump housing then being 180degree out should not matter.

May be worth checking that tdc mark on oilpump housing/crankpulley is true!

And check comp tester is working correctly by testing on another car.

[Adzsy]

Yep, 39 and 48 teeth and WOT.

Can I even be 180 degrees out? surely if you are on the marks then your set?

Tried second compression tester, same.....

[pointz]

I wonder if it is possible to see the valves with a boreoscope by feeding it through the tb or by removing the tb and feeding it down the runners!

I hate to say it but its not looking too good

Also if you put the cams in a neutral position get one of those telescopic magnet pens and see if the lifters have any up/down movement indicating that a valve is slightly open.

[Dastardly]

I think you may as well remove the head and have a look. With compression that low it's going to be an obvious problem. Having a look costs nothing too.

[Adzsy]

I have just been out for a ponder. Having played around a bit I have noticed that by tightening the Cam down the valves/lifters that should be closed are pushed down about 1.5-2mm. Does this sound right? I would have thought these should not be pushed at all until the cam is in the correct position.

[Adzsy]

I think you may as well remove the head and have a look. With compression that low it's going to be an obvious problem. Having a look costs nothing too.

If the readings were just low and different across the cylinders I would no doubt take the head off. But having zero across all four just doesn't seem to add up for me. I would like to explore other options before having it all in pieces again.