Possible bent valves?
Discussion
Bodgejob said:
So I was removing the camshaft bolt from an old 2.4L diesel engine and didn't realise the camshaft was not locked, broke the nut free with the valves pressing against the piston.... what are the chances I have bent something? Its an Andoria 2.4L TD
It's far from a given that you've done any damage. A lot depends on the angle of the valves in your engine. Some are vertical and hit the piston square, making them very difficult to bend. What car/engine is it?Its usually the power of the pistons smashing into the valves that causes the damage, so fingers crossed, the relatively light pressure from you cracking the camshaft bolt against them in comparison to the pistons smashing into them while running should be minor.
Can you run a compression or leak down test you will know for certain then.
Can you run a compression or leak down test you will know for certain then.
Bodgejob said:
Thanks for the reassurance! The engine is a Daewoo 4CT90 Andoria 2.4L TD from the Polish Lublin 2 van. The valves are indeed vertical in the cylinder head
It'll almost certainly be fine. I'd say I wouldn't worry about it but that would be a lie. I'd worry about it but then It'd be fine anyway 
. As suggested you could do a leakdown test but that's as that's not as easy in a diesel as a petrol and there's very little chance of any damage I'd just put it back together. In the unlikely event that there is a problem it would be no more effort to do it at that point.
Thanks again for the comments, it is certainly bothering me but I will find out tomorrow if it is alright. The valve cover which has the camshaft in it is cracked and I am using some metal epoxy to glue it back together, just waiting for that to cure and I will put it back together tomorrow. Will turn it over by hand a few times first and make sure it isn't sticking and there are no strange noises. If all is good then I should be fine to start it
Bodgejob said:
Thanks again for the comments, it is certainly bothering me but I will find out tomorrow if it is alright. The valve cover which has the camshaft in it is cracked and I am using some metal epoxy to glue it back together, just waiting for that to cure and I will put it back together tomorrow. Will turn it over by hand a few times first and make sure it isn't sticking and there are no strange noises. If all is good then I should be fine to start it
User name checks out 
TwinKam said:
User name checks out
Yep, needs must! Got the cover bolted down, timing belt fitted, turned it over by hand a few times and so far so good. Epoxy repair is holding the pressure of the springs pushing against the camshaft and I can't hear any strange noises so it is looking promising. Will hopefully have it running by the end of the dayBodgejob said:
TwinKam said:
User name checks out
Yep, needs must! Got the cover bolted down, timing belt fitted, turned it over by hand a few times and so far so good. Epoxy repair is holding the pressure of the springs pushing against the camshaft and I can't hear any strange noises so it is looking promising. Will hopefully have it running by the end of the dayE-bmw said:
But the springs don't push against the rocker cover, at least not in any engine I have ever seen.
In this engine the camshaft is installed inside the valve cover so the pressure of the springs push up on it. It was originally cracked because my friend tried tightening it down without setting the shaft to TDC so the pressure of the valve pressing against the piston in cylinder 4 as he bolted it down cracked the aluminum cover It's terminology confusion. There's a cam carrier that bolts to the top of the head. The rocker cover then bolts to that. Amounts to the same thing though, the part he's fitting carries the load from the valve springs.
Realistically so long as his crack doesn't go through an oilway he could get away with this. I probably wouldn't have used epoxy as it may hold the joint apart. Cast aluminium tends to crack without plastic deformation so some sealant in/over the new joint would likely be the best way.
Well, not best way but a serviceable and cheap fix.
Realistically so long as his crack doesn't go through an oilway he could get away with this. I probably wouldn't have used epoxy as it may hold the joint apart. Cast aluminium tends to crack without plastic deformation so some sealant in/over the new joint would likely be the best way.
Well, not best way but a serviceable and cheap fix.
stevieturbo said:
is it actually a load bearing cover of some sort ?
It has to withstand the pressure of the valve springs pressing against the camshaft, so far it is holding but we shall see when it is running if it is any good. He put some fiberglass mesh over the crack and coated the lot with a good dose of Bison metal epoxyRichard-D said:
It's terminology confusion. There's a cam carrier that bolts to the top of the head. The rocker cover then bolts to that.
Not in this engine, the rocker cover is actually the cam carrier also, the camshaft is inside the cover. I am not allowed to post links for photos as I am a new member or I would show youRichard-D said:
Realistically so long as his crack doesn't go through an oilway he could get away with this. I probably wouldn't have used epoxy as it may hold the joint apart.
The crack does not pass through any galleries, he also clamped it down to a piece of flat metal whilst it cured to ensure a flat surface where it contacts with the gasket. The only possible thing he may need to do is to re-adjust the valve clearances as they could have changed slightlyGassing Station | Engines & Drivetrain | Top of Page | What's New | My Stuff