Any 300tdi gurus out there

Discussion in 'REME' started by Didosdadsdogsdead, Apr 10, 2008.

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  1. Long story short, Had the cambelt replaced on my Disco 1 300tdi by a local workshop, the full kit was used along with the modified idler to prevent belt run-off.

    Fast foward 9000km and I'm driving to work and notice a cloud of white smoke behind me and the temperature gauge heading north so I pulls over and shut the engine down before it climbs into the red, had only travelled about 10 km at this stage.

    At this stage I'm thinking classic head gasket failure.

    Got the Disco transported to another workshop (this was just before Xmas and the original workshop was too busy to look at it)

    Anyhoo, the head is pulled off and the head gasket is fine however it's found that there has been valve strike on all four piston crowns from the inlet valves and the rocker shaft is snapped below a pedestal.
    The head was sent for crack testing and sure enough there is a crack inside No2 inlet port.

    Finally got hold of a new (generic) head and along with a self taught engineer we set about replacing the cylinder head, we removed the timing cover and found that although the injector timing was fine, the valve timing was out by one tooth.

    What I now would appreciate is confirmation from a VM or Tiffy to confirm my theory of the train of events being that when the cambelt was replaced the valve timing was either not checked or was incorrectly adjusted and over time with carbon build up this in turn placed strain on the rocker shaft eventually breaking it, at the same time this would have stresses on the rocker shaft pedestal which in turn caused the head to crack.

    Thanks in anticipation.
  2. Not sure what is wrong with it matey, but if you PM thenutstrangler he may be able to help you hes a landrover guru!
  3. sounds to me like a simple case of the timing belt jumping a tooth, what state was the belt in?
  4. Done a fair bit with LR and run a 300Tdi myself. I'd be inclined to suspect it jumped a tooth rather than it was out from the start... but I could be wrong. That does then beg the question - why did it jump? Incorrect tensioning of the belt?

    If correctly fitted (and assuming it was a new belt 9K ago when the kit was fitted) it should not have happened; I suppose irrespective of the exact cause it is probable (although not definate) that it is the fault of the fitter. I am probably seeing a bloke that will have a much better understanding on Sunday - will ask and post reply if I do.
  5. It does sound like the belt has skipped a tooth, its doubtful that it was fitted in the incorrect position as the engine would`ve run like a bag of shite and with some mechanical noise. I came across the same problem on a Transit albeit without the head gasket problem, turned out it had been over revved.
  6. "the full kit was used along with the modified idler to prevent belt run-off"
    The Cam Belt used to wear on early 300tdi, not because of the idler but because of the Injection Pump mounting bracket flexing, if you have the old type bracket and are in the habit of changing down then flooring the accelerator it is possable for the belt to jump on the cam sprocket. Also when you fit a new belt you have to go through the tensioning routine 3 times ,torque the adjuster each time turn engine over and do it again.
    Tip to check belt wear, remove the round cover in front of the pump (3 bolts) exposing the pump drive plate, cover hole with a clean white cloth, use hoover to suck debris out of timing cover housing. Any rubber and check the belt.
    .........300tdi is the most reliable diesel ever made......
  7. many thanks for the replies, keep em coming, am beginning to suspect a combination of errors here, the cam belt was in good nick when we took it off however we did find that the feck off big bolt at the end of the crankshaft wasn't very tight, in fact it came loose with a tap from a 4lb hammer on a short extension bar, that and the fact that 3 timing cover bolts were missing leads me to think the original work wasn't up to scratch.

    Thanks again.
  8. I don't like the sound of taps with a 4lb hammer as any sort of guide. If you'd used a torque wrench then it may have been a bit better to make a comment on - please don't get me wrong,I'm not criticising
    Were the three timing cover bolts there in the first place? Most garages replace what they have taken off but even then you would imagine / hope that they would have good sense to replace missing bolts. Again, following on from the above comments on the feck off big bolt - had they even bothered to tighten them at all?
    My money is on the belt having jumped a tooth thru not being tensioned correctly
    All of the above makes for a terribly difficult claim against a garage. Trading Standards may be able to help but I wouldn't hold out much hope.

    I'll stick to a 2.5DI :lol:
  9. After having my Isuzu Trooper serviced in a main dealer i noticed the aux drive belt squealing like a pig, upon investigating i found that the bolt that the alternator pivoted on was missing and it was only held on with the tensioning bolt. Took it back and they swore that they hadn't touched it until i asked them how they had managed to tension the belt without the alternator dropping off. Serves me right for buying jap crap :lol:
  10. Thanks for the replies, I think I now have a better understanding of what may have happened.

    I'm picking that the timing was out from the day of the belt change, I think I'm right to suspect the timing as being the cause of the valve strike and busted rocker shaft, it's possible the engine overheated the day before the breakdown but I'm sure I would have noticed that.

    I'm a pretty conservative driver and never rev the motor over 2500 rpm, just wondering if carbon build up played a part??

    Thanks again :)
  11. :?

    Gardners of Patricroft make those, not Landrover, IMO. Lovely!


    Wow, no danger of you wearing it out anytime soon. Driving that gently may cause carbon buildup on the wastegate, jamming it and causing associated power drop off, but I don't think it's likely to have contributed to the tooth jumping. To clear the carbon buildup you can either 1) dismantle the turbo and clean the wastegate manually(boring) or 2) take your motor to the nearest bit of straightish road that is flat or has a gentle incline, and thrash along it with around 3700-4000 rpm in top gear(fun-ish if rather noisy). If you do it at night you may see the naughty carbon deposits come out your exhaust in the form of sparks. :wink:
  12. Think I'll pass on that one, it would probably end up doing close to the ton and the Kiwi plod would rip me a new arrse :)
  13. The loose crank pulley bolt may well have contributed to it - the belt pulley may have been wandering about in there - check it and the woodruff key for damage as it doesnt take much to wreck those or in the worst case, the end of the crank itself. The bolt tension is critical - it should be 180 NM plus 90 degrees - not the paultry 80 NM quoted in the TUM/TUL XD AESP!

    My disco eats belts like its going out of fashion but changing them at 40K miles seems to have stopped it - must get a new FIP bracket fitted at some point really.

    My money is on them not having done up the crank bolt correctly and the pulley has then been able to move (usually by chomping action) and resulted in the valve strike leading to the rest of the damage......

    As an aside, if you've got a black plastic expansion tank fitted in the cooling system, bin it and get a gen part white one - they refuse to crack along the seams like the black ones do......... Just for anti-overheating peace of mind for the future with that loverly new heed......