Toyota Pickup & 4Runner Cylinder Head | 22R 22RE | OEM 11101-35080

Technical Q&A: Toyota 22R/22RE Cylinder Head

How do I identify the difference between Round and Pear exhaust ports?

Identification is critical for fitment. Pre-1985 Toyota 22R engines used “Round” exhaust ports and a taller block height (OEM 11101-35050). The 1985–1995 “Laser Block” (OEM 11101-35080) features “Pear-shaped” ports which have a flat bottom and curved top. Our pear-port head is the industry standard for the common 2.4L 4Runner and Pickup series; it will not seal correctly against round-port exhaust manifolds or early tall-block timing components.

What causes the persistent exhaust manifold leak in the 22RE engine?

Exhaust leaks are most frequently caused by the aluminum threads stripping for the manifold studs. Over thousands of heat cycles, the exhaust studs pull out of the head, breaking the seal. Our replacement 22RE heads feature a denser aluminum alloy and reinforced thread bosses. We recommend using a high-quality stud kit and ensuring a final torque of 33 ft-lb (45 Nm) to maintain long-term compression at the manifold face.

Can a failed timing chain guide damage the 22RE cylinder head?

Yes. The Toyota 22RE uses a timing chain with plastic guides that can become brittle and shatter. Once the guides fail, the slack chain scores the timing cover and the bottom edge of the cylinder head casting. This often allows oil to mix with the coolant. When replacing your 11101-35080 head, always inspect the timing chain system and consider upgrading to steel-backed guides to prevent catastrophic damage to the new casting.