Norfolk Garage
Richard Hall gets nostalgic about a 1994 Range Rover and gives 300Tdi owners a quick money-saving tip
Out here in the wilds of Norfolk I don’t see too many firstgeneration Range Rovers any more. That is a pity, because the original David Bache-designed Range Rover is one of my favourite cars of all time. It is one of those designs which is just right in every way. A few years ago I bought a 1983 Range Rover very cheaply, unseen on ebay, with the intention of quickly moving it on and making a couple of hundred quid on it. I drove it home, fell in love with it within the first couple of miles, and put it up for sale at a deliberately outrageous price to deter anyone from actually buying the old beast. It hung around for a couple of years, always theoretically for sale, until I finally got bored with a very slow vehicle that did 12 mpg (it was an early three-speed automatic on Stromberg carburettors, and fitted with an ex-military low-compression engine for extra sluggishness) and let it go to a chap who promised to restore it. He did, and last thing I heard it was looking for a new home at about ten times the price I had sold it for.
Since then I have been tempted a few times by cheap, Mot-failed Range Rovers but never quite succumbed. My ideal vehicle would be a two-door with the truck-like four-speed gearbox and optional Fairey overdrive, with that fabulous velour ‘teddy bear’ interior trim, Rostyle wheels and pressed steel grille. Original was best in my opinion, and attempts to update the vehicle in later years somehow lost some of the coherence of the original design. But now I’m just being fussy: in truth I would quite happily live with any example of this remarkable vehicle, and I was reminded of just how lovely they are when a very late, 300Tdi-engined example limped into the workshop sounding rather unhappy.
This was a Vogue SE with the soft dash interior, air suspension and every electrical toy that could possibly be specified on a motor car in 1994. Nowadays one expects a similar level of equipment on a base-model Korean hatchback, but never mind. I have always had mixed feelings about diesel-engined Range Rovers. I have a huge amount of respect for the Tdi engine, but I have never been quite convinced that a rather rough, agricultural-sounding four-banger really makes an adequate substitute for the smooth, woofly petrol V8. I have to confess that I hadn’t actually driven a Range Rover with either 200Tdi or 300Tdi power, but this particular example seemed unlikely to convert me, given that it sounded in imminent danger of blowing up. There was a very loud clattery tapping noise coming from the top half of the engine, which increased with speed but not load. The engine seemed to be running on slightly fewer than the full four cylinders as well. Not a happy Range Rover and I was, it appeared, its last hope. If the engine problem could not be rectified at reasonable cost in time for its imminent MOT test, off to the scrapyard it would go.
The owner filled me in on some of the history. At around 160,000 miles the vehicle had suffered a split radiator hose, dumped all its coolant at high speed, and got very hot indeed in a short space of time, resulting in the journey home being completed on the back of a big yellow lorry. A backstreet garage in London suburbia (its usual home) had taken on the task of repairing it, charged £1500 for a cylinder head skim and new head gasket, and returned it to its owner sounding like an accident in a castanet factory. “They all do that, sir. Nothing to worry about, just needs to bed in a bit,” you get the picture. So, I agreed to lift the cylinder head, see what I found and take it from there.
It’s a nice, straightforward job on a 300Tdi, complicated slightly in this case by the back of the engine being tucked under the scuttle panel, so that number four injector and the two rear head bolts could not be withdrawn while the head was in place. I made a mental note to make sure I had these components in place before refitting the head. I noted in passing that the valve clearances seemed very tight, to the point where I doubted that all the valves would be closing fully when the engine was hot. I wondered whether this might be the cause of the engine sounding slightly ‘off’ a cylinder. With the head lifted clear and placed to one side for later inspection I shone a
torch down into the cylinders to see what I could find.
The first thing I noticed was some light scoring on the bores of cylinders two and four. Given the engine’s recent history I was pretty much expecting that a couple of pistons would have ‘picked up’ and partially seized. The bore damage was nothing that a very light hone wouldn’t sort, but meant that the pistons and conrods would have to come out for inspection. The second thing I noticed was that all four pistons had shallow valve-shaped indentations in the crowns. I have seen this kind of damage on engines where the timing belt has broken, but these marks looked very recent in origin, with clean shiny metal exposed simply by running a finger across the marks. That explained the tapping noise, but what had caused it?
On the 300Tdi engine, the exhaust valves close a few degrees after top dead centre (TDC) and the inlet valves open a few degrees before it. So at TDC on the induction stroke, both valves are slightly open. The clearance between valves and pistons on a 300Tdi is not huge, but is ample in normal circumstances. On this particular engine I identified three separate problems that, taken together, could result in valves and pistons meeting. First, the incorrect valve clearances mentioned above. This would make the valves open slightly earlier and close slightly later. Secondly, the head gasket. These are available in four thicknesses, from 1.3 mm to 1.6 mm, identified by the number of holes punched in the edge. In theory the head gasket should be selected by measuring the piston protrusion at top dead centre: in practice most people just fit a threehole 1.5 mm gasket. This engine had a 1.4 mm gasket – whether this had been selected after careful measurement or just chosen at random I could not say.
But the most significant contribution to the clearance issue came from the cylinder head itself. It had clearly been skimmed, and not just a little bit either. The 300Tdi has an aluminium head, and this can warp quite badly if allowed to get very hot. A warped head will not seal properly against the block, so that the new head gasket will fail within a very short time. Normal workshop practice in such cases will be to have the cylinder head refaced or skimmed, a process in which a small amount of metal is machined off the face of the head to leave it perfectly flat.
The factory workshop manual advises that 300Tdi cylinder heads should not be refaced although it does not trouble to explain why not. When replacing a failed head gasket on a 300Tdi engine I will always have the head very lightly refaced and pressure tested, rather than just trying to ascertain its flatness with a straight edge. I have never had any problems as a result, but my experience is that if a 300Tdi head has got hot enough to need serious skimming, it will probably have cracked internally anyway. All in all there was more than enough reason to bin this cylinder head, especially as brand-new Spanish-made ones are remarkably inexpensive (typically around £400 fully built up with new valves and springs).
Removing the pistons and conrods was easy enough, apart from the vehicle having a slight leak on the air suspension which meant it was sitting almost on the bumpstops, leaving insufficient clearance above the front axle for the sump to come off. Tractor jack to the rescue! I bought this old lump of ironmongery at a farm clearance auction near Boston about 25 years ago. From memory I paid 50p for it. It is a simple mechanical screw jack with a lift height of around three feet and has got me out of trouble more times than I care to remember. In this instance I placed it under the front crossmember and pumped the handle until I had enough room to fidget the sump out past the engine backplate.
Two pistons looked okay; two had started to melt and weld themselves to the bores. I decided to replace all four. The bearing shells still had some life in them but were replaced as a matter of course and crank journals were all clean and unmarked. At the front end the engine was treated to a new timing belt kit and crank oil seal. The toothed crank pulley was of the type with spot-welded ‘shoulders’ which have a nasty habit of detaching themselves, so it went in the bin to be replaced by a superior one-piece cast pulley (part number LHH100660). The new head went on with an Elring three-hole gasket, ensuring that the two hollow locating dowels between head and block were in place and undamaged. If these are omitted the head can move around fractionally and fret away at the head gasket until it fails.
Moment of truth. I turned the key and after a good deal of cranking the engine started and sounded just like a healthy 300Tdi should. I wasn’t too impressed by its reluctance to fire up: granted the injector pipes had been disconnected and needed to be purged of air, but normally on a 300Tdi that will take only a few seconds. This one ran the battery almost flat before it finally clattered into life. The cause? A failed lift pump. While the vehicle had been standing with the fuel lines disconnected and its nose in the air, some of the fuel in the filter and injection pump had drained back into the tank. With the lift pump doing nothing at all (broken internal linkage as usual) the system was relying on injection pump suction alone to purge the system. A new lift pump along with one of my 5 mm spacer kits cured that problem.
Time for a test drive. I settled into something which resembled more of a comfortable leather armchair than a car seat, selected ‘D’ and bumbled around the lanes of rural Norfolk to get the engine up to normal working temperature and check for leaks. This 300Tdi-engined Range Rover surprised me. It was slow (like my old V8) but surprisingly quiet and refined, retaining all the traditional Range Rover virtues such as the commanding driving position, excellent all-round visibility and pothole-swallowing long travel suspension.
I was actually glad to return it to the workshop and find a minor leak from one of the heater hoses: it gave me the excuse for another road test…