Does Replacing Engine Valves Require Grinding?
3 Answers
Replacing engine valves requires a running-in period, but they will automatically break in, and about 2 hours of running-in is sufficient. Here is some information about valves: Function: The valve (Valve) is responsible for introducing fuel into the engine and expelling exhaust gases. Traditional engines have only one intake valve and one exhaust valve per cylinder. This design is relatively simple, cost-effective, easy to maintain, and performs well at low speeds. However, its drawback is that it is difficult to increase power, especially at high speeds where the charging efficiency is low and performance is weaker. Multi-valve: To improve intake and exhaust efficiency, multi-valve technology is now commonly used, typically with 4 valves per cylinder.
I love tinkering with engines in my spare time, and when replacing valves, grinding is an absolute must. Valves are like door switches—if you install a new valve on an old seat without grinding, it may look flush on the surface, but tiny gaps can remain, leading to air leaks and insufficient compression. I’ve seen too many car owners skip this small step, only to end up with a sluggish engine, skyrocketing fuel consumption, or even oil burning in severe cases. Every time I help friends with car repairs, I check the seat wear: if there are deep pits, I use grinding paste to smooth it out manually, ensuring a tight and smooth seal. I also recommend double-checking the interface for new valves. This step takes less than half an hour but prevents major overhauls. Engine maintenance is a meticulous job—do it thoroughly to save hassle and avoid causing trouble for your engine.
When tinkering with the engine myself, I made a mistake—I installed new valves without grinding them, thinking it would save time. As a result, the engine made chaotic noises after starting, and upon inspection, I found the valve seats were uneven, causing severe leakage. I had to disassemble and reassemble everything, using a simple grinding tool to polish the seats a few times before the issue was resolved. Installing new valves doesn't always require grinding, but you must check the sealing. If the seats are in good condition, you can skip it, but most older cars have worn seats, so grinding is a safer bet. The tools aren't expensive—you can buy them on Taobao. Skipping this step could cost you big bucks in engine repairs later. DIY enthusiasts, start here—grind diligently, and your engine will run smoothly.
