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View Full Version : *HOW TO* isuzu td guide to resetting valve clearances



davidfox280585
02-08-09, 03:08 PM
as above suitable for all the isuzu range
1.5, 1.5td 1.7d 1.7td
vectra,cavalier,nova,corsa and astra
with thanks to buskmann from vxon for this helpful guide
thought you png guys could make use of this for your poor starting isuzu diesels:thumb:

You probably will need four shims, if you're not able to swap internally.

Shims are easy to exchange, but it's job for two people. One man depresses the valve, the other uses a magnetic tool to extract the shim.

To measure valve clearances however, is very easy. You can do it yourself. You must measure valve clearances prior to exchanging shims. A feeler gauge (http://en.wikipedia.org/wiki/Feeler_gauge) is all you need and it costs about £2. Make sure the engine is cold, you should let it rest overnight before conducting the measurements.

Measurement procedure:
Remove black plastic camshaft cover. It has a red TURBO label on it. Ten bolts are used to attach it to the head. Be gentle with the gasket if you plan to reuse it. Disconnect the hose leading from the air pipe as well.
Select 5th gear and push the car so the no 1 inlet valve lope points upwards (away from the valve).
Use a feeler gauge between the valve (shim) and camshaft lobe to measure the clearance. Use sensible force when inserting the blades.
Inlet valve clearances should be 0.15 mm and outlet valve clearances 0.25 mm.
Repeat step 2-4 for the seven other valves.How do you know which valves are inlet and outlet? You can use your eyesight and compare with the manifolds. The inlet manifold is on windshield side of the engine and the exhaust manifold is on the radiator side of the engine. There is a oddball valve layout of alternate inlet and exhaust valves.

No 1 cylinder is closest to the timing belt. Order of measurements doesn't matter, off course. You should be able to measure multiple valves without moving the car.

http://lagrebilder.no/out.php/i7393_shim.PNG

What to do when you have confirmed erroneous valve clearances? You have to remove the corresponding shims, measure them and replace with new shims.

Removal procedure:
As in measurement.
As in measurement.
Man (or woman) no 1 uses a screwdriver to depress the bucket of the shim in question. It is essential to push only on the edge. You have to use some muscle force here.
While the valve is depressed, man no 2 uses an awl and a magnetic tool to extract the shim. It may be advantageous to make use of the groove in the bucket. If the groove isn't visible, rotate the bucket.
http://lagrebilder.no/out.php/i7392_screw.PNGYou now hold the poor shim in your hands, well done. The shim's thickness should be stamped on the shim. Otherwise use a micrometer to measure it.

Let's say the shim thickness is 2.67 mm and the corresponding measured inlet valve clearance is 0.04 mm. That is 0.11 mm less than specified. The new shim should be 2.56 mm, which will yield a valve clearance of 0.15 mm.

Do the other valves if needed and swap shims internally if possible. Order new shims from your dealer. Save the old shims for future reuse.

Fitting of shims is opposite of removal