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300TDI unwell


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Apologies if any of this has been asked before, but I've scoured the forum to no avail. Anyway, a mate and I bought a 1996 N Reg Defender 90 300tdi the other month, 146k miles on the clock. She's rough in the body, but chassis is sound enough and the intention is to do it up bit by bit until she's tidy. Before this all happened the engine was healthy and didn't smoke and there were no strange noises apart from the usual 300tdi squeaky aux belt.

As we were a bit tight for time, and the history of the vehicle is a little "uncertain" to say the least, we got a ful 28k service done on her about a fortnight ago from a local 4x4 specialist, along with a cam belt change (just to be sure). We got her back 3 days later, with a fresh MOT on her too.

All fine after the service, albeit start up was a bit smoky (white / grey smoke). This cleared after about 10 minutes. I'd put this down to the injection pump fuel demand screw being a bit out, and vowed to go back to the garage this week.

Anyway, it all went wrong last weekend.

Circa 150 miles after the service, whilst travelling at 45mph the engine cut out. Pulled over, as suspected the lead had come off the fuel stop solenoid (again!). Lead replaced, engine started and off we went. Made mental note to crimp the connector.

Approx 1 mile later, the engine started rattling like a bag of spanners and was very low on power. Couldn't get above 40mph, and was belching out black somke. Pulled over, switched off engine. Tried starting it a bit later, wouldn't even turn over. Gave it half an hour, and it started, albeit it sounded rough, and was smoking. Drove it up onto the back of a recovery truck and came home..

Three days later, got round to investigating further. Fuel system ok, bled through but no air. Fuel in tank, and is going to injectors. Engine cranked (sounding rough), but wouldn't fire.

Then just checked oil. Dipstick not showing any oil. No sign of oil contamination on the air filter, coolant looked OK and no nasty sludge in header tank. Added 2.5l of oil, and oil registered on the dipstick at the MAX level. No obvious leaks from underneath. Where has the oil gone? I know it had been filled during the service as I checked before we drove it to the New Forest the day after the service.

At that point, gave up, didn't have time / ability to start pulling things off in the street (won't fit in garage). Had it towed to the garage where the cam belt change had been done.

Anyway, they've had a look, and although they've not finished it yet. They've found a broken heater plug (end snapped off), and what they think is a flat on the valves / piston but they say they can't adjust this, and suspect a cam follower has died. They've checked the injectors and appearantly they're OK. Appearantly they've now got her to run but she's knocking quite badly.

My concern is what else they are likely to find.

Would anybody on here have any idea what may have gone? I'm thinking head / gasket / turbo at the very least? And furthermore whether anything that may or may not have been done during the cam belt change may have affected / caused it?

We bought the landy as a way of learing how to maintain and sort out or own vehicles (being fairly simple to work on and fun). We weren't quite prepared for this though!

Any helpful advice would be really appreciated.



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If the oil was getting into any of the combustion chambers it would smoke a lot, so it must have leaked out onto the road. When they did the cam belt did they replace the crank seal (or possibly damaging it if they only replaced the crank sprocket). White/grey smoke is unburnt fuel, but not engine oil - usually down to poor timing/injector fault. If the engine was clattering and down on power it tends to point to something going wrong with the cam belt timing. Did they replace just the belt or the tensioner and idler wheel as well?


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Suspect its head gasket or possibly timing belt has snapped/jumped a tooth. Quick check for latter is does the valve gear still move - this will confirm belt is ok. To check timing check forum for cambelt change, in there will be how to check pump timing against crank timing.

Its probably head gasket though, mine had the same symptoms. Cooling system was fully intact, pressurised and full. Mine went between no 4 cyl and no 8 pushrod hole. Its smoked like mad (black smoke) and no power. It would run but very rough. Oil was off bottom of dipstick where it had been burning it as oil from the oilways was getting into cyl. About 1 litre to bring it back on dipstick. Fortunately it didn't runaway on the oil.

Compression test will confirm head gasket. It may be yours is too low on compression to run. Unlikely to be a follower as there is no where for the roller to go. Valve caps do break but that would increase tappet clearance.

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