Autopapyrus · Chevrolet Tracker 2.0 (J20A, 2002)
https://autopapyrus.com/guides/chevrolet/tracker/checking-and-adjusting-valve-clearances/
https://autopapyrus.com/guides/chevrolet/tracker/checking-and-adjusting-valve-clearances/
Compiled automatically from service literature and owner experience. Specs are for the typical configuration — check them against your exact car before you start.
Chevrolet Tracker 2.0 (J20A, 2002): Checking and Adjusting Valve Clearances
The 2.0 16V engine (J20A) has no hydraulic lifters. Valve clearance is set by calibrated shims in the tappets, so you check it with a feeler gauge and replace shims if the clearance is out of spec. Do the work on a cold engine (coolant temperature about 15-25 °C (59-77 °F)).
Parts
3| № | Part |
|---|---|
| 01 | Valve tappet adjusting shims (calibrated, various thicknesses)if needed, based on clearance measurements |
| 02 | Valve cover gasket 2.0 16V (with spark plug well seals) |
| 03 | Spark plugsif needed |
Tools
8- Socket and wrench set
- torque wrench (low range)
- feeler gauge set
- micrometer for measuring shims
- crankshaft turning wrench
- tappet hold-down tool (retainer) and tweezers or a magnet for removing shims
- new valve cover gasket
- sealant
Step by step
11 steps- Let the engine cool down completely. Disconnect the negative battery terminal. Remove the decorative covers, then disconnect from the valve cover the crankcase ventilation hoses, wires, and the ignition coils or spark plug wires (mark their order), plus any connectors and hoses that get in the way.
- Remove the spark plugs: this makes the engine easier to turn over and makes it easier to find each cylinder's position.
- Loosen the valve cover bolts evenly and remove the cover. Remove the old gasket and the spark plug well seals, and clean the mating surface of oil and sealant residue.
- Turn the crankshaft in its normal direction of rotation with a wrench on the pulley bolt. Do not turn it by the camshaft bolts. Set the No. 1 cylinder piston to TDC on the compression stroke using the marks on the pulley and the timing drive cover. The No. 1 cylinder cam lobes should point up, away from the tappets, meaning the valves are closed.
- Using a feeler gauge, measure the clearance between the back of the cam lobe and the tappet shim on the valves of the cylinders whose lobes point up. Cold engine, reference values: intake 0.18-0.22 mm, exhaust 0.28-0.32 mm. The feeler gauge should slide through with light drag. Record all values for each valve (in a diagram: cylinder, intake/exhaust).
- Turn the crankshaft 180° (the camshafts turn 90°) and measure the next group of valves. Repeat until you have checked all 16 valves. Follow the firing order 1-3-4-2.
- For each valve that is out of spec, calculate the new shim thickness: new = old + measured clearance − nominal clearance (the middle of the range). Measure the old shim's thickness with a micrometer rather than trusting its marking, which may be worn off.
- To replace a shim, turn the crankshaft so that the cam lobe of the valve in question points up, away from the tappet. Press down the tappet with the special retainer tool. Remove the shim with tweezers or a magnet, install the new one (marking down, toward the tappet), and remove the retainer. Do not remove the camshafts unless necessary: if you do remove them, you will need to recheck the valve timing marks.
- After replacing all the shims, recheck the clearances on all valves until every value is within spec.
- Install a new valve cover gasket and spark plug well seals. If needed, apply sealant to the half-round joints as recommended by the gasket manufacturer. Tighten the cover bolts in a crisscross pattern in 2-3 passes. The torque is low, reference 8-12 N·m (6-9 lb-ft) (do not overtighten, since the cover and the threads in the head are aluminum). Tighten the spark plugs to 20-30 N·m (15-22 lb-ft).
- Reconnect everything you removed, including the battery, warm up the engine, and check the cover for leaks and the engine for smooth running.
Common mistakes and warnings
- Intake and exhaust clearances differ, so do not mix up the specifications
- Too little clearance prevents the valve from seating tightly and burns the valve seat, while too much clearance causes ticking noise and a loss of power
- Working with shims requires care: do not drop them into the oil passages, and do not let foreign objects get into the cylinder head
- If you have no experience and no tappet hold-down tool, leave the job to a repair shop