Breaking Camshaft Bolts...HELP

[aljam]

Hi All
Looking for advice on a little but becoming more and more (and more) expensive problem with a 2003 110 TD5
Just completed a head upgrade on a TD5.
Replaced with New: AMC Head complete with new valves/gaskets/head bolts/rocker gear bolts and asstd seals etc
I Reused: existing camshaft and sprocket and bolts/timing chain/timing chain guides and rocker screws/lash adjusters/followers and injectors - all of which were in very good order.
Full job done by the book.
On initial start up vehicle ran - for about 5 minutes at idle before slowly loading up - then stopped. Checked all the usual suspects which appeared normal. I found I could turn over by starter but not by hand - really tight.
Pulled it all down again checked all valves etc , nothing bent or damaged, no metal shavings etc. but found the camshaft bolts had become loose. Cleaned very slight bruising on thread with die and chased through threads in camshaft with tap. Everything looked (and felt) 100% OK.
Also - (on second occasion) following advice from a head shop, I ensured lash adjusters were compressible before re-installation.
I was also a bit suspect on the timing chain tensioner as when I removed and cleaned it, it seems to only compress about 10mm at most - is this normal??
This time I used loctite 243 on camshaft bolts.
Re start. Ran well at idle for about 10 minutes.
Noted a "tinny" sound - like loose tappets - which progressively got worse. Shut it down.
Removed front camshaft cover to find one camshaft sprocket bolt head had sheered off completely - the others no doubt will be loose. Camshaft sprocket slightly twisted off its seat on camshaft.
Guessing now there will be lots of damage to crankshaft timing gear sprocket and probably everything timing chain wise.....sigh..
At this stage (after throwing a few things around) I have "walked away" for some deep breathing and contemplated adding my vehicle to some artificial reef somewhere....
Calm brain says: Plan to: drain oil, drop sump to find bolt head, clean what needs cleaning, inspect, remove broken bolt from cam shaft. Replace what needs replacing....(spend even more money....) new camshaft sprocket, bolts chain etc etc...and add loctite again.
Can anyone offer me any advice on why these bolts would come loose, or sheer in the first place? Is there some "greater" problem I may be missing which would cause such???
Can anyone see any issues or something I am totally missing here?
Appreciate any advice anyone can give.
Cheers

[donh54]

Haven't looked at RAVE yet, but I know that Rover has an affinity with "torque to yield" bolts. These are Necessarily a one use item, as the first use actually stretches the bolts, so you can never torque them up again successfully.
Just a thought, but I'll check in RAVE tonight.

[PhilipA]

Also - (on second occasion) following advice from a head shop, I ensured lash adjusters were compressible before re-installation.

I apologise in advance if it is a silly question, but did you set the injectors clearances at maximum lift then ease off one turn.

Setting them like tappets at minimum lift has been done before and reported on this forum.
Regards Philip A

[aljam]

I apologise in advance if it is a silly question, but did you set the injectors clearances at maximum lift then ease off one turn.

Setting them like tappets at minimum lift has been done before and reported on this forum.
Regards Philip A

Hi PhilipA: Yes did this ...twice to be sure..!
Previous response from donh54 is probably the issue....but i need to be sure ...before i make things any worse.. and i end up with a very expensive anchor..

[aljam]

Haven't looked at RAVE yet, but I know that Rover has an affinity with "torque to yield" bolts. These are Necessarily a one use item, as the first use actually stretches the bolts, so you can never torque them up again successfully.
Just a thought, but I'll check in RAVE tonight.

Hi donh54
I am thinking this is it.....
....usually around the $4.00 per camshaft to sprocket bolt
estimating its now around $400.00 per bolt.....
arrrggghhhh

[AK83]

I got curious and had to look it up.
Rave: page 12-1-93 says to remove sprocket bolts only(not to discard)

page 12-1-95 describes the fitment for sprocket, chain guide and pump sprocket.
Says nothing specific about torque for sprocket bolts, only describes torque for chain guide bolts M10 and M6 sized bolts.

Use Loctite 242 on the pump bolt and torque to 25Nm.

It then says fit top timing timing chain sprocket then bottom one, and then fit cover with sealant pre applied to mating face!

If you read page 12-1-44 describing the removal of the rocker shaft, it says remove the 6 bolts progressively, and discard the bolts .. implying these are torque to yield.
It also says to use new rocker shaft adjusting screws and locknuts AND rocker shaft(retaining) bolts @ 33Nm progressively.

on the cam sprocket tho, no torque values, no loctite, no special procedure.

You have to refer to the TD5 torque values to find the required specs tho(page 06-2)

Camshaft sprocket to camshaft bolts | 37 Nm | (27 lbf.ft)
i.e not really a lot of torque required.

Does the timing chain tensioner have a torque setting?(I'm guessing it's fully auto adjusting, ie. no initial torque setting)
timing chain tensioner could be a culprit to watch for.
Sorry I have very limited experience with TD5, but trying to keep informed for when my brother calls me out to the next problem! [bigrolf]

[discorevy]

What sealant did you use for cam carrier to head?. Remove the injector rocker shaft and then turn over by hand and see if it is turning over without excessive resistance then. Let me know , and we'll go further then