Bank Holiday Tinkerings: Adjusting tappets on 200TDI

First off: Big thanks to the +Land Rover Toolbox Videos and Mr. Higgins (some sterling work you're doing chief!) . Your recent video on adjusting the tappets on a 300TDI was a big help.

So on a somewhat dull bank holiday weekend when the kids are napping, its an opportunity to get the spanners out and tinker under the hood of the landy.

Mines a 200TDI under the hood: a sturdy lump, 2.5litre turbo charged diesel engine with no electronics for timing - simple & robust (provided its looked after)

Whenever I get a bit of time I watch Chris's videos, in particular today, whilst I was doing the washing up. Anyway he mentioned that his vehicle was a bit smokey and had a faint whiff of oil - bit like mine. So thought I'd give mine a look using the video as a guide.

First off was this "rule of nine" which I'd never heard of, being a newbie to this procedure.

Fortunately, this is also covered in one of Chris's earlier videos.

Basically: on a 4-cylinder engine there are typically 8 valves (inlet & exhaust), the order you adjust them should equal 9 - lets uses an example:

• valve 1 down - valve 8 open; 1+8=9
• valve 2 down - valve 7 open; 2+7=9
• valve 3 down - valve 6 open; 3+6=9
• etc, etc

This is how you set the valves you want to adjust before you adjust them. To do this, you turn the crank shaft over manually till you get the valve you want in the right position.

Armed with this knowledge, and the kids having a snooze, 200TDI workshop manual on tablet, I armed myself with some tools and head to the landy.

Tools

• 8mm socket
• for rocker cover bolts and cyclone breather bolt removal
•  30mm socket
• to turn crank over
• 1/2" drive ratchet
• or long bar
• if no long bar, some tubing to extend the reach on the ratchet
• 3/8" drive ratchet
• 13mm spanner
• stubby flat head screw driver
• feeler/thickness gauge (cranked ones are an advantage)

Procedure

 First off you need to remove the cyclone breather and vacuum tubing off the rocker cover using an 8mm socket or spanner and a flat head to loosen any jubilee clips

Once off you can then remove the rocker cover off the top of the engine, take care when removing the cover as the gasket seal comes off with it. When reading the 200TDI service manual though - I did come across this interesting snippet:

Basically its asking to put down a silicone based sealant for the gasket. Yet mine is a rubber one part seal, so older 200TDI owners may possibly need to be aware of this?

Useful note here: Valve #1 is at the front of the engine (bottom of this photo is front), #8 is towards the bulkhead

THICKNESS OF GAUGE YOU SHOULD BE USING IS 0.2mm, THIS IS SPECIFIED IN THE WORKSHOP MANUAL

Its a good idea to have a notepad to hand to record your findings. Bear in mind that you should CHECK first BEFORE you adjust.

With the rocker cover off; you can now begin the procedure of checking the clearance. Here I have taken a screen shot from the 200TDI workshop manual I was using:

Turn the engine over using the 30mm socket and ratchet (with bar if necessary) and follow the order as above. From the video, the valve is full down when the tappet comes down and pauses a short while, whilst the crank is still being turned.

As you can see, using a straight set of gauges is quite tight, but I found that re-positioning them on the holder, you can get the fingers on the same plane as the gap your measuring, thus removing errors from the gauge flexing.

Your looking for just enough clearance to get the gauge between the valve spring cover and the tappet, with the smallest amount of friction. I found there was a little either way on some of them, but not enough to make me consider adjustment.

'scuse the handwriting

 From my readings, I found that valves 2 & 7 were a bit tighter than some, so went ahead and gave them a tweak.

As you can see from the manual illustration and the video's: To adjust the tappet you crack the nut holding the screw in place then using the screw driver and thickness gauges, adjust so the gauge passes under with the tiniest amount of fiction holding it (as per video). Then holding the screw driver in place, nip up the nut again. Afterwards you can torque them up to the exact spec (as stated in the video).

Once done I re-fitted everything and whilst I had the cyclone breather off, I replace the o-ring on it as it had a square edge, like it had been squished. Can't hurt to replace it.

So all in all this took about an hour, tops. Nothing too taxing, just nice and methodical, and could improve your emissions and maybe even recover some lost performance, depending on how far out they were.

I'll see if it has made a difference on my trip to work. But I doubt I'll notice.

If your looking for a 200TDI manual: here's a link to a shared copy on my google drive

This procedure is quite a way down so just keep hammer pgdn till you see it. Also this manual includes a turbo maintenance guide, procedure on how to remove and re-fit a 200TDI in a defender and a guide on fitting a full sized intercooler along with findings on performance from the guy who wrote it (all at the end)

Keep tinkering!