Top Dead Center Tool 8016MRG TDC Whistle – Universal Top Dead Center Indicator with 14mm/18mm Spark Plug Ports – Top Dead Center Whistle for Distributor Installation, Timing & Valve Adjustment

Precise TDC Detection: The TDC whistle produces a clear, audible sound as the piston approaches top dead center (TDC) during the compression stroke—stopping right when TDC is reached. This makes it easy to pinpoint TDC for ignition timing, valve adjustments, and cylinder diagnostics

Compatible with 14mm & 18mm Spark Plug Ports: Top dead center tool features a dual-size threaded fitting that easily installs into both 14mm and 18mm spark plug holes—compatible with most gasoline engines. Not for use on diesel engines

Versatile Applications for Engine Work: Top dead center whistle perfect for distributor installation, individual cylinder valve setting, timing belt or chain inspection, and cylinder leak down testing—essential for mechanics and DIYers alike

Quick, Tool-Free Installation: No tools required—just hand-thread the TDC whistle into the spark plug port and you're ready to go. The 27-inch overall length makes it easy to position and hear, even in tight engine bays

Audible Compression Stroke Indicator: The TDC whistle tool makes it easy to detect the compression stroke by ear—no need to visually inspect pistons or rely solely on timing marks. MainUseool TDC compression indicator perfect for both beginners and professional mechanics