URGENT oil pressure stop engine

[Pesky jones]

That kit will only work once the engine is timed up and using the starter/compression stroke to build compression..... by then you might aswell attempt starting it and seeing if it runs....

Which it wont (or wont run properly) as you will have valve damage..... these are interference engines... you cant turn the engine over with half the valves not moving without at least some of them making contact with a piston

Ok so when I turned it over by hand there will have been piston to valve contact? I wouldn't have been able to do that much damage by hand would I? Is it possible the valves have bent out the way of the stroke?

I was hoping that that the valves would have bent out the way, so the stroke can complete but lacking compression in some cylinders. Then after a compression test I would have an idea of how many valves have bent. Also, if it ran (even with misfires) then I would be able to see if the oil pressure warning is still there, with the new tensioner and correct timing.

I think at the end of the day I will have to take the head off at some point or another to find out whether I should send it off for repair or get a replacement cylinder head. It won't cost me anything to take the head off (fingers crossed) to find out.

[Dan_FR]

Damage would have been done when it snapped or from trying to restart it afterwards. End of day it doesn't matter how many valves are bent, the head would still have to come off to assess the damage and repair or replace. 

[Pesky jones]

Tbh removing it doesnt look too bad, apart from removing the cambelt.

[Paulo P]

Removing the cambelt and head should be easy compared to what you've already done, re-fitting is the harder part 

[Pesky jones]

Removing the cambelt and head should be easy compared to what you've already done, re-fitting is the harder part 

Ha oh really? What are the difficult bits of refitting?

I think I remember someone saying about the engine mount being a pain to remove @r5gtt or @dazza maybe?

[r5gtt]

Are we referring to the bracket on the engine side and if so yes it is.

[Paulo P]

Removing the cambelt and head should be easy compared to what you've already done, re-fitting is the harder part 

Ha oh really? What are the difficult bits of refitting?

I think I remember someone saying about the engine mount being a pain to remove @r5gtt or @dazza maybe?

Cambelt timing can scare people off but on VW engines that's easier because you've only got to line up one cam pulley. You've then got to make sure that everything is 100% clean between the head to block mounting faces and correctly torque the head down.

If you've got the time, tools and patience there's no reason why you can't do it, it just about confidence.

I had a cambelt snap 200 miles into a running in period on my old Integrale 16 valve after paying someone else to rebuild the engine. That suffered bent valves and I repaired it myself in the end and I'm no mechanic, all I did was towed it to a garage to fit a new cambelt because back then I was scared of cambelts having had 1 jump and destroy the engine and then another one snap

[Pesky jones]

Are we referring to the bracket on the engine side and if so yes it is.

Yay

Removing the cambelt and head should be easy compared to what you've already done, re-fitting is the harder part 

Ha oh really? What are the difficult bits of refitting?

I think I remember someone saying about the engine mount being a pain to remove @r5gtt or @dazza maybe?

Cambelt timing can scare people off but on VW engines that's easier because you've only got to line up one cam pulley. You've then got to make sure that everything is 100% clean between the head to block mounting faces and correctly torque the head down.

If you've got the time, tools and patience there's no reason why you can't do it, it just about confidence.

I had a cambelt snap 200 miles into a running in period on my old Integrale 16 valve after paying someone else to rebuild the engine. That suffered bent valves and I repaired it myself in the end and I'm no mechanic, all I did was towed it to a garage to fit a new cambelt because back then I was scared of cambelts having had 1 jump and destroy the engine and then another one snap

Ok. Ill keep telling myself I can do it then!

I’m sure im getting ahead of myself again but…

Say I remove head this weekend. Valves have bent and I decide to get a new cylinder head. I refit everything and all ready to go. I turn on engine and theres still an oil pressure warning light. I will have wasted a lot of time and money and probably would have been better off going for a new engine to begin with.

I’m praying that it is just a new cylinder head as I think I might be able to remove and refit myself, and it will just be the cost of the new head, bolts, gaskets, coolant etc.

Really I think Id need to eliminate the oil pump, but that will mean dropping the sump again, and trying to get the balance shaft unit off (something I can’t find much info for). As I’ve mentioned plenty of times if the tensioner had proved the reason for the oil pressure message I would be confident in just replacing the cylinder head. But then again I don’t know the order of events in which the chain snapped so cant definitively rule the tensioner being the root of the problem out.

Bit of a mental battle im having here 

[Paulo P]

I'd be very surprised if there's anything wrong with the oil pump, I think the warning came up due to the failed tensioner. In my opinion you only had one event happen inside your engine and that was the tensioner which led to the chain failing and possible valve damage.

If you are going down the route of removing the head and you're not timing it up first try compression testing the engine with the cams out before removing the head, it might give you an indication of what's going on inside the engine before you lift the head.

[Pesky jones]

I'd be very surprised if there's anything wrong with the oil pump, I think the warning came up due to the failed tensioner. In my opinion you only had one event happen inside your engine and that was the tensioner which led to the chain failing and possible valve damage.

If you are going down the route of removing the head and you're not timing it up first try compression testing the engine with the cams out before removing the head, it might give you an indication of what's going on inside the engine before you lift the head.

Ok although I don't know how or why the tensioner failed, I will work on the assumption that that was the reason for the oil pressure light. I was just worried about the fact that the warning message appeared for a considerable amount of time before the chain snapped. It looks like the tensioner was functional (thus no reason for pressure light) up until the chain snapped.

I don't really understand how compression testing with the cams out works, do you not need the cams in to keep the valves correctly timed to get an idea of compression?

[Paulo P]

with the cams removed all the valves should be shut, if any aren't it's because the valves are bent. Just remember to remove the plugs from the other cylinders if they aren't already out.

It's a dead simple test if you're already heading down that route, if it turns out that you have good compression you may not even have to remove the head.

[Pesky jones]

Ah I see, because the cam lobes aren't forcing the valves down against the springs, so they pop up.

So in terms of removing the camshafts – I would still need to remove the cambelt, as well as the exhaust cam adjustor, the inelt cam lobe on the cam chain end?

Then after camshafts are out, I would refit everything, and then compression test on each cylinder using the ignition and starter motor? Remove the other spark plugs im not testing so the pressure is released I assume?

[pudding]

You can just remove the cam girdle and they'll both come out without the need to remove the adjuster.  Just slip the belt off the pulley.   The bolts for the girdle are stretchers, so you'll need new ones.  There's 24 of them iirc.

[Paulo P]

Ah I see, because the cam lobes aren't forcing the valves down against the springs, so they pop up.

Correct, all valves (unbent) will be shut.

So in terms of removing the camshafts – I would still need to remove the cambelt, as well as the exhaust cam adjustor, the inelt cam lobe on the cam chain end?

I'm no expert on the tfsi engine, certainly the cambelt will have to be removed and you've already taken care of the chain.

Then after camshafts are out, I would refit everything, and then compression test on each cylinder using the ignition and starter motor? Remove the other spark plugs im not testing so the pressure is released I assume?

You shouldn't need to refit anything, I would personally remove the other plugs and crank it by hand just to be sure. I wouldn't bother cranking it with the starter motor because you've got no oil in there and valves could be bent and clip pistons, cranking by hand should be sufficient for what you need, it's just to give an indication.

If you find good compression across all 4 you've been lucky, I suspect that this won't be the case though, it would be better to find out now though rather than removing the head to find no valve damage.

[Pesky jones]

You can just remove the cam girdle and they'll both come out without the need to remove the adjuster.  Just slip the belt off the pulley.   The bolts for the girdle are stretchers, so you'll need new ones.  There's 24 of them iirc.

Right. So whats the cam girdle 

Do you mean slip the cambelt off the exhaust cam pulley? I take it I should mark it for reference when putting it back.

You shouldn't need to refit anything, I would personally remove the other plugs and crank it by hand just to be sure. I wouldn't bother cranking it with the starter motor because you've got no oil in there and valves could be bent and clip pistons, cranking by hand should be sufficient for what you need, it's just to give an indication.

If you find good compression across all 4 you've been lucky, I suspect that this won't be the case though, it would be better to find out now though rather than removing the head to find no valve damage.

Yeah I can see the advantage of finding out now. Ok sounds good. thanks Paulo