Thread: camshaft carrier - camshaft TOO TIGHT !!

Originally Posted by trapaga7

hey all,


Land Rover Defender, 110, year: 2006

I redid my head, bought the head gasket, and all is good.

the problem comes when I torque the bolts


at 22, the engine rotates (camshaft as well)

at 48 lbs the engine rotates (camshaft as well)


after the 90 degrees, 180 degrees, the engine rotates, but NOT the camshaft.


what could be my problem?? .... anyone??

could the carrier be warped or.... loose, or should I install a small gasket ??



thanks for any help,


Antonio

TD5, or Puma? ( I'm not sure when they changed )

Td5 , nothing should rotate if you just doing top end bolts.

Sent from my GT-I9300 using AULRO mobile app

It depends on what you mean by not turning.

If you turn the crank the cam should turn unless you have the timing gear/chain disconnected assuming you have all of that connected then somethings come adrift in the timing setup. Dont try to start it or turn it over until you figure out what, bent valves and damaged pistons await you if you do.

Assuming you have the timing gear disconnected.

If you have the cam in the right position and the head bolted down it has a few positions it can sit in that will allow you to turn the crank over without the piston meeting the valves. Ditto for the crank if one of the pistons is up to high and you turn the cam the valve mechanically stops against the piston and locks out the cam.

If you have the crank positioned such that you can turn the cam and open the valves all the way without meeting the piston then you have other issues and these could include

1. a stuck valve
2. A stuck injector OR the bump clearance for the injector is 0 or less and the injector is stopping the cam
3. If the head has been machined and not done properly the alignment of the bearings will be out when the head is torqued down. this will be trying to bend the cam and its resistance to flexing will be stopping it from rotating by hand force.
4. you could have an oversized bearing configuration thats nipping the cam when you torque everything down.
5. if you have the cam gear on but not the chain on the gear might be fouling.
6. it sounds stupid but have you used a bolt as the timing pin and forgotten about it being in place?

Blknight.aus ok,

so to answer, yes it is a TD5,

If you turn the crank the cam should turn unless you have the timing gear/chain disconnected assuming you have all of that connected then somethings come adrift in the timing setup. Dont try to start it or turn it over until you figure out what, bent valves and damaged pistons await you if you do.

- timing is correct. I took apart the timing cover, and set everything on mark, TDC, no problem there. 100% sure.

- I am far from trying to start the car... no worries.



If you have the cam in the right position and the head bolted down it has a few positions it can sit in that will allow you to turn the crank over without the piston meeting the valves. Ditto for the crank if one of the pistons is up to high and you turn the cam the valve mechanically stops against the piston and locks out the cam.

- everything is in the correct position. positively sure on this.


1. a stuck valve
- nope, no stuck valves


2. A stuck injector OR the bump clearance for the injector is 0 or less and the injector is stopping the cam
- nope, injectors are at the correct position.


3. If the head has been machined and not done properly the alignment of the bearings will be out when the head is torqued down. this will be trying to bend the cam and its resistance to flexing will be stopping it from rotating by hand force.
- YES, it was machined prior to installation.
- why and how could the bearings be out of alignment??
- if this is the problem, do you think it can still be corrected? (re-machined or something??)
- I think THIS is the problem.... is it fixable??


4. you could have an oversized bearing configuration thats nipping the cam when you torque everything down.
- not sure I understand this part....
- the bearing is where the cam "sits", right??
- when I took apart my engine, everything was working fine (just overheating...)


5. if you have the cam gear on but not the chain on the gear might be fouling.
- not sure I understand this part either...
- I have tried to move the crank/damper WITH the sprocket + chain on the cam, and WILL NOT move. (nothing !)
- I undo the 3 bolts, and take the sprocket + chain OFF of the cam, and the engine DOES move (of course, only a bit left, and a bit right, because of the open valves....)


6. it sounds stupid but have you used a bolt as the timing pin and forgotten about it being in place?
- hahaha. trust me, that came to mind. I DID remove both pins (flywheel and cam)


so, I have done more research (for correct technical vocab), and from what I figure, the camshaft CARRIER is pressing down too much on the cam when I tighten the head bolts down. This even happens when I tighten the rocker shaft assembly bolts on to the head. (when the head is OUT of the car).


When these folks machined my head, could they have WARPED the carrier? could they have done something wrong?
Why would they have touched the bearing?


any input will help.

in my country, buying a new head is.... well.... impossible !! $$$$$

thanks!

TD5

reply below....

Originally Posted by trapaga7

Blknight.aus ok,

so to answer, yes it is a TD5,

If you turn the crank the cam should turn unless you have the timing gear/chain disconnected assuming you have all of that connected then somethings come adrift in the timing setup. Dont try to start it or turn it over until you figure out what, bent valves and damaged pistons await you if you do.

- timing is correct. I took apart the timing cover, and set everything on mark, TDC, no problem there. 100% sure.

- I am far from trying to start the car... no worries.



If you have the cam in the right position and the head bolted down it has a few positions it can sit in that will allow you to turn the crank over without the piston meeting the valves. Ditto for the crank if one of the pistons is up to high and you turn the cam the valve mechanically stops against the piston and locks out the cam.

- everything is in the correct position. positively sure on this.


1. a stuck valve
- nope, no stuck valves


2. A stuck injector OR the bump clearance for the injector is 0 or less and the injector is stopping the cam
- nope, injectors are at the correct position.


3. If the head has been machined and not done properly the alignment of the bearings will be out when the head is torqued down. this will be trying to bend the cam and its resistance to flexing will be stopping it from rotating by hand force.
- YES, it was machined prior to installation.
- why and how could the bearings be out of alignment??
- if this is the problem, do you think it can still be corrected? (re-machined or something??)
- I think THIS is the problem.... is it fixable??


4. you could have an oversized bearing configuration thats nipping the cam when you torque everything down.
- not sure I understand this part....
- the bearing is where the cam "sits", right??
- when I took apart my engine, everything was working fine (just overheating...)


5. if you have the cam gear on but not the chain on the gear might be fouling.
- not sure I understand this part either...
- I have tried to move the crank/damper WITH the sprocket + chain on the cam, and WILL NOT move. (nothing !)
- I undo the 3 bolts, and take the sprocket + chain OFF of the cam, and the engine DOES move (of course, only a bit left, and a bit right, because of the open valves....)


6. it sounds stupid but have you used a bolt as the timing pin and forgotten about it being in place?
- hahaha. trust me, that came to mind. I DID remove both pins (flywheel and cam)


so, I have done more research (for correct technical vocab), and from what I figure, the camshaft CARRIER is pressing down too much on the cam when I tighten the head bolts down. This even happens when I tighten the rocker shaft assembly bolts on to the head. (when the head is OUT of the car).


When these folks machined my head, could they have WARPED the carrier? could they have done something wrong?
Why would they have touched the bearing?


any input will help.

in my country, buying a new head is.... well.... impossible !! $$$$$

thanks!

ok now Im on net with the problem.


I suspect that the most likely cause is the cam fouling, if the head has been over heated and not relieved properly when the head comes off it bends a little bit, when they clamp it and machine it they take this "bend" out of the head by simply removing it as part of the machining proces.. At this point your cam journal is straight(ish) when you put the head on and torque it down the head "flexes" as you tighten the head down which puts a bend in the alignment for the cam journals. This is very common on the TDI engines (but less obvious due to the push rod and rocker arangement) and yours will (if it turns out to be the case) be in the handful that I've head of on the TD5 that this has occured on (usually a td5 head lets go in an unrecoverable manner so I suspect there is more occurances out there but they go un noticed as the head fails after the initial machine up)

it is in theory possible to rebore the cam journals so they align again and the rebearing it However I suspect that it will turn out cheaper and more reliable to replace it with a fresh rebuild head from a reputable supplier. there was a couple of places that were redoing the bearing surfaces for the cam by line boring them over size then fitting a "fatter" bearing and then undersizing the surface of the cam, occasionally if the bearing was too fat it would nip up the cam.

Its a significant pain to do it but you may need to drop the chain off of the drive gear and put the drive gear onto the cam so you can establish if the cam is free to move or if its something else.


As for not being able to get a head somewhere, I call bollocks. I reckon with about a 2 month lead time and the resources to spend I could get a td5 head to anywhere on the planet you cared to stick a pin in a map and say "there please"


Dont forget you're not supposed to re-use td5 head bolts and the head gasket is a one use item. While you're fault finding go a head and reuse them (but be very careful if you go all of the torquing steps you will swear if you snap one) but once you have the problem nailed fit a new head gasket and bolts.

Good luck.

Originally Posted by trapaga7

reply below....

Try running a straight edge along the cam saddles, did you mark the cam saddle caps so they went back in the same position they were removed from.
Also put a straight edge on the bearing journals of the cam shaft, did you check the length on the valve springs to make sure they are not binding and jambing the camshaft.
If the cam bearing saddles are out of alignment, you can have the caps machined and a new cam bore align bored.
If the TD5 has no combustion chamber in the head and has only a flat surface, then depending on how much was machined from the head surface the valves seats and valves may need to be recessed to clear the piston, a good machine shop would/should have done that as normal procedure, Regards Frank.