One dead Legnum (update: Fixed!)
- Thread starter Kaldek
- Start date
Kaldek
2 AYC Bars
- Location
- Melbourne
- First Name
- Ed
- Drive
- 2000 Legnum VR4 Manual, Ford Territory family runabout, BMW K1300R.
- Thread starter
- #22
Car is diagnosed. Short answer: it's all my fault.
Apparently, I overtightened the timing belt tensioner bracket bolt and it has suddenly snapped, causing the camshaft to jump a couple of teeth. What may have saved the motor is the fact that the tensioner bracket flies backwards and hits the alternator mount, leaving some tension on the belt (but not enough to stop teeth from skipping).
The possibly good news is that even though it sounds like a bag of spanners, it's running smoothly. We're going to fix up the issues and check it out, but if the valves are bent we're still planning to replace the motor.
I really don't know how I did that. I was careful as f*ck with all the torque specs but my torque wrench must be way out of adjustment, unless that bolt was weakened previously?
Apparently, I overtightened the timing belt tensioner bracket bolt and it has suddenly snapped, causing the camshaft to jump a couple of teeth. What may have saved the motor is the fact that the tensioner bracket flies backwards and hits the alternator mount, leaving some tension on the belt (but not enough to stop teeth from skipping).
The possibly good news is that even though it sounds like a bag of spanners, it's running smoothly. We're going to fix up the issues and check it out, but if the valves are bent we're still planning to replace the motor.
I really don't know how I did that. I was careful as f*ck with all the torque specs but my torque wrench must be way out of adjustment, unless that bolt was weakened previously?
naughtika
OzVR4 Stalker
I've read in several occasions that the timing belt tensioner bolt snaps and causes havoc.
are you going ot investigate how extensive the damage is or are you just gonna leave it as is?
are you going ot investigate how extensive the damage is or are you just gonna leave it as is?
Live an learn eh!
Ive done more cambelts than I can count on these cars and I've never had that bolt snap, never torqued to factory spec, just done up by feel. I'd say you just got unlucky and the bolt was fatigued somehow.
fingers crossed for you that it hasn't tagged any valves! but if its only a few teeth out you might, just might, get away with it.
Kaldek
2 AYC Bars
- Location
- Melbourne
- First Name
- Ed
- Drive
- 2000 Legnum VR4 Manual, Ford Territory family runabout, BMW K1300R.
- Thread starter
- #28
Thanks mate. That means a lot. Once when I was in the military as a 17 yr old I fucked up and lost a piece of kit in the bush. The Regimental Sergeant Major who was with me at the time could have chewed me a new one, but instead he just looked me in the eye and said "well you won't make that mistake again will you?". Hearing that turned a bigtime negative into a future positive, because by god I never made that mistake again.
Yeah. Since the car is running "smoothly" I'm assuming it means I either A) didn't tag any valves or B) only tagged one.
If I only did one, then the question is whether we fix it. Malcolm's opinion is not to pull the heads off but then he's not an engine builder.
What are your thoughts? Can the heads be safely removed and put back by your average engine guy without resulting in the car "never being quite the same"? And would it be cheaper than a new engine? And could it be done with the engine in the car?
Depends on how much you can pick a 6A up for in AUS. there are pretty cheap here in NZ
the work isn't overly complicated to change a head over. just the parts add up and its alot of work. you will need Head gasket, head bolts, turbo gaskets, thermostat gaskets, the head will need to be surfaced and the block throughly cleaned and checked for straightness.
most of the time its just easier to bung another 2nd hand motor in. but then you are taking a gamble on its condition and history. but Like I said it all depends how much thats going to cost you across the ditch!.
the work isn't overly complicated to change a head over. just the parts add up and its alot of work. you will need Head gasket, head bolts, turbo gaskets, thermostat gaskets, the head will need to be surfaced and the block throughly cleaned and checked for straightness.
most of the time its just easier to bung another 2nd hand motor in. but then you are taking a gamble on its condition and history. but Like I said it all depends how much thats going to cost you across the ditch!.
Kaldek
2 AYC Bars
- Location
- Melbourne
- First Name
- Ed
- Drive
- 2000 Legnum VR4 Manual, Ford Territory family runabout, BMW K1300R.
- Thread starter
- #30
Yeah. A bent valve would mean replace the motor but it also means I get the chance to create a forged build and go for 250+kw at the wheels with a solid engine.
whats_doing
QLD Events Manager
I bought all the parts for a head swap as I thought that I was going to have to do valve stem seals.
But I just dropped a new motor in instead. I was just fortunate I knew its history.
But I just dropped a new motor in instead. I was just fortunate I knew its history.
forge it, be rude not to
Kaldek
2 AYC Bars
- Location
- Melbourne
- First Name
- Ed
- Drive
- 2000 Legnum VR4 Manual, Ford Territory family runabout, BMW K1300R.
- Thread starter
- #33
So I've been to Malcolm's workshop yesterday and had a look. I have some pictures I've uploaded to Facebook which I'll push later.
Anyway the tensioner bolt sheared off right at the block, and the tensioner assembly only stayed in the car because it jammed against the alternator mount. This appears to have kept enough pressure on the belt to avoid it skipping more than a couple of teeth. The belt has friction burns on it too.
Malcolm is going to put the belts back on with a new bolt (duh) and start the car up briefly to see how she sounds. If bad, replace motor. If good, check compression.
Anyway the tensioner bolt sheared off right at the block, and the tensioner assembly only stayed in the car because it jammed against the alternator mount. This appears to have kept enough pressure on the belt to avoid it skipping more than a couple of teeth. The belt has friction burns on it too.
Malcolm is going to put the belts back on with a new bolt (duh) and start the car up briefly to see how she sounds. If bad, replace motor. If good, check compression.
- Location
- ormeau@gc.qld.au
- First Name
- Matt :)
- Drive
- 1963 Toyota Lite-Stout & 2007 Toyota Blade Master G
Sounds like you're going to get quite lucky 
Hasn't got the bill yet :-pSounds like you're going to get quite lucky
More news today?
Kaldek
2 AYC Bars
- Location
- Melbourne
- First Name
- Ed
- Drive
- 2000 Legnum VR4 Manual, Ford Territory family runabout, BMW K1300R.
- Thread starter
- #39
Status update - car won't get started until Wednesday. Malcolm was fully booked up and one of his guys was going on leave when I dropped the car off.
Worst case is it gets worked on next week.
Worst case is it gets worked on next week.
Kaldek
2 AYC Bars
- Location
- Melbourne
- First Name
- Ed
- Drive
- 2000 Legnum VR4 Manual, Ford Territory family runabout, BMW K1300R.
- Thread starter
- #40
Holy shit! The car is OK!
Just got off the phone with Malcolm and it's all been confirmed I didn't bend any valves. I cannot believe how lucky I am right now.
Picking up the car tomorrow. Awwww Yisss.
Just got off the phone with Malcolm and it's all been confirmed I didn't bend any valves. I cannot believe how lucky I am right now.
Picking up the car tomorrow. Awwww Yisss.
