If you are talking about induction leaks causing poor running and an uneven tick over a handy way to hone in on the location is to spray lightly around induction areas such as inlet manifold where it joins the head with a WD40 aerosol, as this is flammable if you locate the leak your idle speed will increase.
Also there are quite a lot of breather hoses small and large in the same area which are prone to cracking and if you locate one of these your WD40 will have the same result.
Good luck.
It leaks from the failed part.
How to check for leaks on vacuum hoses for a dodge diesel
To put oil in a gear box of a Chrysler PT Cruiser, first plug minor coolant leaks.
To check the purge flow on a 2004 PT Cruiser, first locate the purge solenoid, which is typically found near the engine or on the intake manifold. With the engine running, disconnect the purge line from the solenoid and use a vacuum gauge to measure the vacuum pressure while the engine is at idle. If there's no or insufficient vacuum, the solenoid may be malfunctioning. Additionally, you can check for any leaks in the vacuum lines or inspect the solenoid for proper operation.
Idle speed on a 1998 Chrysler is computer controlled and is not adjustable. If idle speed is incorrect, you have a sensor, actuator, or mechanical failure. Places to start are, check for engine fault codes. Check for vacuum leaks.
check for vacuum leaks
The NVLD (Natural Vacuum Leak Detection) device on a 2003 Chrysler PT Cruiser is typically a small, cylindrical component located near the fuel tank. It usually has a plastic housing with electrical connectors and vacuum lines attached. The device is designed to monitor the integrity of the fuel system by detecting leaks and is integrated into the vehicle's emissions control system. Its appearance can vary slightly, but it generally resembles other similar sensors found in modern vehicles.
Proper method is: Vacuum system and wait 15 minutes to see if vacuum is held (to check for leaks) add proper type and amount of compressor oil add proper amount of 134a
check your timing and vacuum advance and vacuum leaks. from there check fuel delivery system.
Check for vacuum leaks.
allot of reasons check the carb. check for vacuum leaks. check the timing. check the comp codes.
check the vacuum diaphragm for leaks. Might be a hole in the vacuum line.