Recently, I’ve been diving back into car repairs and joined a Jaguar and Land Rover dealership just a month ago. Last week, we had a vehicle come in with fault codes indicating issues with the exhaust VVT solenoids, triggering the engine light. The service manager advised replacing the solenoids, mentioning it’s a common problem on the 2.0-liter petrol engines.
The very next day, another car arrived for routine service with a customer complaint about an unstable engine idle. Scanning for codes revealed, again, fault codes related to the VVT solenoids. Following protocol, I replaced the solenoids. However, the engine still didn’t feel quite right.
Over the past eight months, I’ve been focusing on improving my diagnostic skills. Even though solenoids are relatively inexpensive, around $20 each, I’m driven to understand how to properly diagnose these kinds of fault codes. Simply replacing parts isn’t always the solution. I recall a case from three months ago where a friend replaced solenoids on a car still showing a P0014 code. It turned out the issue was with faulty adjusters, not the solenoids themselves. Cam and crank correlation testing ultimately pinpointed the real problem.
This experience leads me to a crucial question: how can we efficiently and effectively test solenoids to confirm they are genuinely faulty? Is using a scope to check cam and crank signals the quickest method? Accessing the camshaft sensors on these engines is quite straightforward, but I’m still looking for the quickest way to test the crankshaft sensor in relation to solenoid operation. I understand the temptation to just replace these cheap solenoids, but I’ve been pondering for a week now about a more robust and rapid testing procedure. When I replaced the solenoids in the described cases, their resistance readings were within spec. The only anomaly I observed was that the tiny rod inside the solenoid seemed a bit too easily pushed back when energized, which might indicate an internal mechanical failure, but this observation is not quantifiable without a proper test.
