The wave forms below are taken from a 206 Gti EW10 engine, which was suffering lumpy idle/misfire from cold. They represent a cold crank, comparitive compression test. The red wave form shows the engine as original and the blue wave form shows the engine after the hydraulic tappets were replaced. Note; there is some difference in the amperage, this is due to ambient air temperature only.
The wave form below is taken from a 307 TU5JP4, which was suffering a cylinder misfire. The diagnostics revealed P1336 / P1338, which relate to cylinder No.2. As you can see there is no compression visible on the cylinder, as recorded by current draw, and backed up by conventional testing. All other cylinders produced approximately 14 bars.
This fault was caused by one of the exhaust valves being burnt out.
Comparative Compression test, made with amps clamp on a 307 DW10td. This fault was caused by fuel contamination, which resulted in injector failure and consequently over fueling.
The wave form below shows the cranking current on a TU5jp4 from cold start. This is typical of the valves sticking.
The wave form below is a section of the a full wave showing the cranking current from a DV4td engine at approximately 13°C. The compressions measured 18.5 bar and as can been seen are uniform throughout all cylinders.
Last Reviewed: 11 April 2008Copyright © 2004...2009 Mark Stammers mark@peugeotmt.co.uk