What is the torque specification for EA888 cylinder head bolts in Nm?
3 Answers
EA888 engine cylinder head bolt torque is 90Nm. Below is an extended introduction: Cylinder head with valve lift switching function: The EA888 engine has developed a new cylinder head that integrates the exhaust manifold into the cylinder head. This allows exhaust gas recirculation cooling to take place within the cylinder head, with exhaust gas flowing inside the cylinder head. Both intake and exhaust camshafts feature variable valve timing. Variable Valve Lift Technology (AVS): The variable valve lift technology primarily optimizes gas exchange control for each cylinder through valve lift switching on the electronic valves of the exhaust camshaft and variable timing on the intake and exhaust valve camshafts. The engine control unit determines which cam to use based on current engine load conditions. The smaller cam is only used at low speeds.
The cylinder head bolts of the EA888 engine must be tightened in steps. First, pre-tighten all bolts to 40Nm, then tighten them sequentially by 90 degrees, and finally add another 90 degrees to complete the process. This is because the plastic cylinder head is prone to deformation, and step-by-step tightening ensures even force distribution. Remember to always use new bolts—the original VW bolts are stretch-designed, and reusing them after removal compromises sealing. I once encountered someone trying to save money by reusing old bolts during my own repairs, and the cylinder head gasket blew within two months. There are slight torque variations for different EA888 model years—for example, older versions require tightening to 20Nm first, followed by two 90-degree turns. Always check the manual or use a diagnostic tool to retrieve repair parameters before starting work. Never tighten by feel; a warped cylinder head leads to expensive repairs.
Having worked on over a dozen EA888 engines, I can tell you there's no fixed torque value for the cylinder head bolts - you must follow the manufacturer's specified procedure. Typically, you first torque them to 40Nm using a torque wrench, then use an angle gauge to turn them 90 degrees in two stages. The tightening sequence is crucial: always follow the crisscross pattern working from center outward, otherwise uneven cylinder pressure can cause deformation. Another critical point - bolt holes must be thoroughly cleaned. Last time I encountered a car with carbon buildup in the threads; even after torquing to spec, it still leaked. Also, invest in proper tools - avoid those cheap torque wrenches from discount platforms as their significant margin of error can easily strip threads. For such precision work, it's best to find a shop experienced with EA888 engines. I've seen at least five cases where roadside mechanics ruined cylinder blocks.
