The Toyota 2AZ-FE inline 16-valve four-cylinder engine was installed in a number of popular Toyota models – Camry, RAV4, Alphard, Harrier and some others up until 2019. Today, let’s figure out how to adjust the valve clearances in 2AZ-FE engines, when to do it, and what’s best to replace along the way.
When to adjust the valves on Toyota Camry, RAW4 2AZ-FE
The Toyota 2AZ-FE 2.4L engine is considered very reliable. Not for nothing it was kept on the assembly line from 2000 to 2019. However, it has been repeatedly upgraded due to a number of issues. For example, in 2006, they increased the length of the bolt threads of the block head from 24 to 30 mm due to frequent stalling when tightening.
The timing chain lasts a little over 180,000 km, which is not too much. The chain is quite thin and at 130,000 km it gets stretched out and needs to be replaced. The phasor on the intake camshaft will not work more than 200 thousand km, and oil consumption (o-rings, valve seals) is most often shown by 120-130 thousand km.
Therefore, many drivers try to optimize the operation and save time, money and resource of the 2AZ-FE motor. To do this, the timing chain and valve caps are changed during valve adjustment.
Valve clearance adjustment on Toyota 2AZ-FE engines is necessary at mileage from 130 to 150 thousand km. You should not delay with the adjustment, as it can severely compromise the overall resource of the engine.
Service stations are reluctant to take on such work, because it takes a lot of time, and the price of valve gap adjustment Toyota 2AZ-FE is not worth it. And if they take it, they charge a lot of money. And there is no guarantee that the master will comply with all standards on the strength of the tightening of fixtures and replacement of worn parts.
What you need to adjust the valve clearance of a Toyota 2AZ-FE
The main symptom of increased valve clearance is noisy engine operation. The higher the RPM, the noisier the engine. In especially neglected cases, the engine will overheat, start badly, and fuel consumption will increase.
In any case, the symptoms of increased valve clearance should be listened to after 100,000 km of mileage.
You will need the following tools and parts for adjustment:
- standard set of sockets and wrenches;
- a torque wrench, mandatory;
- micrometer to measure the thickness of the bottom of the tappet (if they are unnumbered);
- a set of flat feeler gauges to measure the clearance between the hydraulic tappet and the cam of the camshaft;
- a set of tappets according to the wear level of the set;
- cylinder head cover gasket 08826-00080;
- chain tensioner gasket, original 13552-28010
Further on as needed:
- timing chain, original Toyota #13506-28010 or ASParts AS4674;
- oil caps (valve seals) – No. 90913-02111 exhaust valve cap, No. 90913-02101 intake valve cap;
- original chain tensioner 135400H030;
- original chain damper 135610H030;
- chain guide 135590H030.
You can also buy a complete chain replacement kit if you need to change the chain. Its price is about $200, but it has everything you need. The optimal kit is NIPPARTS N1152008.
How to check and adjust valve clearances on a Toyota 2AZ-FE engine
The whole process of adjusting the valves on Toyota 2AZ-FE engines is quite time consuming and can take almost a whole day. However, it is worth it, because the service station will ask at least $250-350 for such work. And with the money saved, you can buy a complete repair kit and have a full tank of gas left over.
It is important to remember that any work with the timing mechanism, including measuring the clearances between the tappets and cams of the camshaft, is carried out on a cold engine, maximum +20-25 °C.
To measure the valve gaps, unscrew the spark plugs and set the piston of the first cylinder at TDC. To do this:
- Remove the right front wheel, the right fender cover, which is mounted on two bolts under the head 10 mm. This gives access to the crankshaft pulley.
- Remove the decorative cover of the engine, unscrewing the two nuts with a 10 mm head, remove the ignition coils (four bolts at 10 mm) and wiring harness on the right side of the cover, take it aside.
- Unscrew the cover of the head block (bolts under the head 10 mm) and remove it by pulling the wiring harness to the side.
- Using a 19 mm socket with an extension cord and a screwdriver to turn the crankshaft clockwise to match the marks on the pulley and on the cover of the timing chain, mark “0”.
Now we look at the situation in the blockhead. To properly check the valve clearances, you need to have the cams of the camshaft over the tappets looking up or sideways.
Note that when you turn the crankshaft 360°, the camshaft rotates 180°!
Make sure that the marks on the timing gears and coincided with the marks on the chain, as shown in the figure.
In this position, the first cylinder piston is at TDC of the compression stroke.
The permissible valve clearances for the intake and exhaust camshafts are shown in the table.
Check the clearance with the feeler gauge only in those valves that are marked in the diagram below.
Rotate the crankshaft 360°, then check the clearances on the fourth cylinder and those shown in the diagram below.
Write down the obtained clearances, indicating the number of the cylinder and valve, as well as the clearance.
The gauge with the nominal thickness should pass with little force, all data are marked in our table.
How to remove the tappets on a Toyota 2AZ-FE engine
After measuring, both camshafts must be removed to get the tappets. It may be necessary to replace the oil caps as well. Work carefully so as not to damage the tappets.
First you must loosen the chain tension. To do this, remove the tensioner by unscrewing the two bolts as shown in the figure.
To remove the exhaust camshaft, use a 24 mm wrench to hold the camshaft and a ring spanner to loosen the gear mounting bolt.
It is important not to forget to put the marks on the camshaft gears and on the chain, after dismantling camshafts, the crankshaft must not be rotated.
Unscrew the 10 bearing cup bolts of the exhaust camshaft (the one closest to us), remove the five base bolts and carefully pull the shaft out toward you.
Make sure that the chain does not fall inside the engine. For this purpose it is better to tie it up with wire or plastic coupler.
Take out those tappets that need adjustment. If there is a need to replace the oil caps, you will have to take out all the tappets, numbering them and putting them in a certain order so as not to mix them up.
Now you need to remove the intake camshaft in a similar pattern – unscrew the 10 bolts and remove the five camshaft bearings cups.
Calculate the thickness of the new tappet using the formula, using the tables.
Here is an example:
- (Inlet) Measured valve clearance = 0.44 mm (0.0173 in.);
- 0.44 mm (0.0173 in) – 0.24 mm (0.0094 in) = 0.20 mm (0.0079 in) (Measured – Norm = Excessive clearance);
- Old pushrod thickness = 5.30 mm (0.2087 in.);
- 0.20 mm (0.0079 inch) + 5.30 mm (0.2087 inch) = 5.50 mm (0.2165 inch) (Excess clearance + used tappet = perfect new tappet);
- Proper new tappet = 5.50 mm (0.2165 in.) = tappet No. “50”.
Here is a table of the heights of repair tappets that are commercially available and should be purchased to correct excessive valve clearance:
In addition, pushers are often marked – either on the bottom of the cup its thickness is indicated, or the size will be marked on top.
If there are no marks on the pusher, use an accurate micrometer.
Next, everything is simple – replace those tappets that are visually worn or measurements that showed an increased clearance.
Practice shows that it is better to re-insure and replace the suspicious tappet than to do the same job a second time. After installing the tappets in place, proceed to reassemble the cylinder head.
How to assemble the cylinder head on a Toyota 2AZ-FE engine
Be sure to use fresh engine oil to reassemble the cylinder head and a torque wrench to tighten the fasteners. This is critical, because a stripped thread or loose bolt can be a big problem in the future.
First of all, thoroughly lubricate camshaft journals and bearings with fresh engine oil. Next step by step:
- Install the timing chain on the inlet camshaft pinion, aligning the paint mark with the setting marks on the gear.
- Inspect the front markings and numbers of the 5 bearing caps and install them. Then install the 10 bearing cap bolts. Tighten the bolts evenly in the sequence shown in the illustration.
- Tighten the 10 mm socket bolts to 9 N∙m, the bolts of the first bearing cover to 30 N∙m.
- Install the exhaust camshaft on the bearing pedestals, having previously lubricated them with fresh oil. Observe the alignment of the timing mark on the exhaust camshaft pinion and the timing chain mark.
- Lift the front of the exhaust camshaft and bolt the sprocket, making sure the marks match.
- Similar to the inlet camshaft, install and fasten the outlet camshaft according to the diagram. The tightening torque is the same – 9 and 30 N∙m.
- Hold the exhaust camshaft with a wrench and tighten the sprocket bolt to 54 N∙m.
- Check the marks again – the marks on the timing chain must match the marks on the camshaft sprockets, the mark on the crankshaft pulley must match the “0” mark on the front cover.
- If the marks are correct, install the chain tensioner. It is important to replace the tensioner housing gasket. If the old gasket is installed, oil will leak.
- Before installing the tensioner, you must check the plunger mobility, clean it, then install the retainer (hook), hooking it on the pin, as in the photo below.
- Tighten the two chain tensioner nuts to a torque of 9 N∙m.
- Turn the crankshaft clockwise, and then release the plunger by unhooking the locking hook.
- Turn the crankshaft clockwise and make sure the tensioner is doing its job – tensioning the timing chain.
- Almost done. Clean off the old sealant from the cylinder head, degrease with acetone or any solvent if possible, and wipe dry.
- Apply a thin layer of sealant to the entire plane of the head block, before you do it is desirable to read the instructions for the sealant.
- Install the head cover gasket (original number 08826-00080). It is important to install the gasket exactly in place. To do this, use the installation points indicated in the figure.
- After applying sealant, install the head cover and tighten the 8 bolts and two nuts. Tighten in a crisscross pattern, starting from the center to the edges, to a torque of 11 N∙m.
Reassemble the remaining components in reverse order. After the first start of the engine (not earlier than 2-3 hours after applying the sealant) it is important to check the gaskets (timing chain tensioner and head cover) for oil leakage.