2007-’11 CX-7 2.3L Turbo vehicles with VINs lower than JM3ER******352482 (prod. before Sept. 29, 2010)
2007-’11 Mazdaspeed3 vehicles with VINs lower than JM1BL******398222 (prod. before Sept. 29, 2010)
With the engine warmed up, some vehicles may exhibit a knocking/rattle type noise from the front timing cover and/or valve (cylinder head) cover below 2,000 rpm.
The noise is caused by excessive stretching of the timing chain.
1. Verify that proper oil change intervals have been performed.
2. Verify that the noise is coming from the front timing chain cover and/or cylinder head area.
The noise is heard inside the vehicle with all of the windows rolled up, all accessories turned off and engine running at normal operating temperature.
The knock pulse is at camshaft speed (1/2 the engine rpms).
The knock can usually be felt on the No. 3 engine mount.
3. Remove the engine front cover according to the on-line MS3 instructions or the workshop manual.
4. Check the protrusion length of the chain adjuster plunger.
– If it’s 17 mm (nine exposed notches) (see Fig. 1) or more, replace the timing chain with a modified one according to the on-line MS3 instructions or the workshop manual.
Note: Do not replace the chain adjuster.
If it’s less than 17 mm, the noise is not the result of the timing chain stretching concern. Refer to the “Engine Noise” diagnostic procedure in TSB 01-036/10 “Diagnostic Procedure For Engine Noise Repair.”
5. Verify the repair.
Courtesy of ALLDATA.