Camshaft Breakage on Nissan QR25DE Engine
Author: ETP Engine Parts Date Posted:10 December 2019
Applies to model variants:
- 2007 – 2014 Nissan X- Trail
In the industry broken camshafts on Nissan QR25DE engines is a common occurence. Typically the reason for the breakage is because mechanics need to get to the cylinder head bolts, thus the camshaft needs to be removed first. Removal of the camshaft has to be done in a specific order, otherwise damage will occur.
It is vital that the correct procedure must be followed for removal and fitment. If not, it will without question, every time, cause the camshaft to break. This is a very sensitive area of the QR25DE engine. If the fitment instructions are not followed, the camshaft will lift up during rotation and bind in the thrust area. The resultant leverage and pull from the valve spring will cause the camshaft to snap entirely.
The cost and inconvenience of this breakage comes from having to source another camshaft but also having to bore and clean the cam journals again, with comes with additional rework cost.
Process for Camshaft Loosening:
To remove the camshaft, all you need to do is loosen all the bolts in the reverse order from the fitment order outlined below.
Process for refitting Camshafts:
Properly apply the defined amount of sealant to the outer edge of the front bearing cap.
When fitting the bearing caps, they must be fitted in order. On the intake shaft, this means numbers 2 to 5 are fitting in order. On the exhaust shaft, this means A through D are fitted in order. This must be read from the exhaust side of the engine.
Tighten up the camshaft bearing cap bolts in the sequence below.
- 1st: Bolts 9 to 11 on the front bearing cap to 2 Nm.
- 2nd: Bolts 1 to 8 to 2 Nm.
- 3rd: Tighten all bolts in order to 5.9 Nm.
- 4th: Tighten all bolts in order to 10.4 Nm.
Once all bolts are properly tightened, wipe of any excess sealant as any sealant overflow can block oil or coolant galleries thus causing damage elsewhere.
Of course, if you need Nissan QR25DE camshafts or replacement cylinder heads, come and talk to us at ETP Online!