DIY Toyota Camry 5SFE Engine Oil Leak Repair
Three Common Causes of Oil Leaks From the 4-Cylinder Camry
Here are the three most common sources of oil leaks from the Camry I4 5SFE engine.
- Worn oil seals from the camshaft, the crankshaft, and the oil pump sprocket seal and gasket. These seals and gaskets are typically checked and replaced when performing a timing belt replacement. If leakage becomes excessive, you might want to go ahead and replace your timing belt ahead of schedule, since oil contact with the belt will reduce its longevity. A timing belt saturated with oil will eventually break prematurely and without warning.
- The valve cover gasket has shrunk, dry rotted, or simply lost its ability to seal. Since the top of the engine is tilted towards the firewall, the majority of the oil leak will accumulate on top of the intake manifold by the fuel injectors. The oil may continue to migrate down to the oil pan which may give the illusion that the oil pan gasket requires replacement. Applying silicone-gasket-maker material onto the valve cover gasket, a trick I've seen tried often, does not work, and oil will continue to leak.
- The rubber coating on the valve cover/cylinder head plug (located to the right of the engine when facing the engine), has shrunk or cannot maintain a good seal. Toyota added this plug when they replaced their camshaft-driven ignition distributor system with solid-state coil packs.
If Item 1 is your problem, you will want to replace your timing belt, as discussed in my other article. This DIY article will address items 2 and 3.
A Fourth Source of Leaks
If a leak is detected between the inner CV axle shaft and the transmission—if you see seepage stains below where the CV axle meets the differential, or drip marks on the ground in that area—the problem may be a transmission fluid leak from a worn axle shaft seal. A leak here will cause the level of transmission fluid (ATF) to drop gradually. Another article of mine shows how to replace the axle and seal.
Identifying the Source of the Leak
Leak Behind the Passenger-Side Front Wheel
If the number one and two fuel injectors show a film of fresh oil, or accumulated dirty oil, the valve cover may be the culprit. The source can be further validated by removing the front passenger-side wheel and inspecting the power-steering pump. If the pump is wet with oil, the leak has migrated from the intake runner down to the back of the engine block and then to the power-steering pump. This is assuming that the power-steering pump itself is not leaking; if it is, the power steering fluid level will be dropping.
Leak Beside the Passenger-Side Front Wheel
Again, the source of the leak can be verified by removing the front passenger-side wheel. If an oil film appears at the base of the lower timing belt cover where it meets the engine block, then the camshaft or crankshaft seal, or the oil pump seal or gasket, may be leaking. The timing belt cover must be removed to determine the exact cause.
Leak Between the Front Wheels, Below the Transmission
Unless the leak is transmission fluid coming from the inner CV axle shaft seal, the cylinder head plug (the half-circle hump on the right side of the engine by the ignition coil packs) is leaking oil.
Valve Cover Gasket Replacement and Valve Cover Plug Seal Procedure
- Remove the ignition wires. Using either bent-end or needle-nose hose pliers will ease removal.
- Disconnect the vacuum line from the right side of the valve cover.
- Unbolt the two engine hoist hooks from the front left and right side of the valve cover. This will ease the removal and installation of the valve cover.
PCV Valve Removal
- Move the hose clamp closest to the intake runner.
- Using needle-nose pliers, pry the PCV valve up out of the valve cover.
- Twist off the PCV hose, with the PCV valve attached, from the intake runner.
Remove the Valve Cover Hold-Down Nuts/Rings
- Using a 30 mm socket, unbolt the four 30 mm hold-down nuts/rings.
- The valve cover can now be removed. The rubber gasket may be slightly fused to the cylinder head; using a pry tool will ease removal.
Unbolt Plug Cap, Remove Plug, and Clean
- Two 10 mm bolts retain the plug cap. Remove the two bolts.
- Pry the cap off using a thin-tipped screwdriver.
- Clean the area where the cap sat, removing oil and debris. Finish by using any brake-cleaning product to remove oil residue.
Coat Cap Contact Surfaces With RTV and Reconnect Cap Cover
- Use any RTV product with gasket-sealing properties.
- Coat the base where the plug sits with RTV, along with the cap.
- Position the plug on the cylinder header.
- Secure the cap on the plug and re-bolt.
New Valve Cover Gasket Installation
My personal preference is to use silicone valve cover gaskets instead of rubber. Rubber will eventually shrink, crack, dry rot, and leak again. Silicone gaskets, if you can find them, last longer and retain their elasticity better than their rubber counterparts. When the new rubber gasket shrinks, re-tightening the valve cover rings will offset shrinkage, but this solution will only work for a while.
- Dab RTV sealant at the edges where the semi-circle hump ends.
- Clean the valve cover grooves where the new gasket is to be placed. Removing all oil residue from the grooves will allow the new gasket to adhere to the grooves, which will be helpful during installation of the cover. If the new gasket will not stay put, apply a small amount of RTV in the grooves.
- Re-install the valve cover. The remaining steps are the reversal of the removal process. When torquing down the valve cover rings, spread the tension equally among the four rings. This will help distribute hold-down tension on the new gasket and should provide a good seal.