Jeep Cherokee and Jeep Renegade are Jeep’s Economical entry into the market both of which are packaged with multiple engine options. Among them are the Fiat 1.4l Multiair and 2.4l Multiair engines. These work a bit different to your usual motors due to their solenoid based variable valvetrain and have specific oil and filter requirements that owners and mechanics should be aware of, similar to the MDS solenoid system in the Hemi’s.
“The MultiAir system is elegantly simple. An electrohydraulic actuator—a high-response, electronically activated solenoid—controls the pressure applied to hydraulic fluid (engine oil drawn from the sump) that fills a thin passageway that connects the intake valves and the camshaft. The solenoid valve regulates the amount of oil that is pumped by the cam action either to the valve or a bypass reservoir.
When pressurized, the hydraulic line behaves like a solid body and transmits the lift schedule imparted by intake cam directly to the intake valve. When the solenoid is disengaged a spring takes over valve actuation duties.
This electrohydraulic link allows independent operation of the two components, which enables near real-time control over the valve lift profiles, said Bernard. Whereas a closed solenoid transmits the pressure generated by the camshaft’s intake profile to the valve in the normal fashion, an open solenoid breaks the hydraulic link between cam and valve, decoupling their operations.”
Society of Automotive Engineering, 2010
For the 1.4l Multiair engine, Jeep states it is essential to use genuine filters and oil, which are only available from their dealerships. Valvoline has a suitable replacement oil but the use of a genuine filter is necessary. The recommend oil to run is 0w40, and advise using any non suitable oil may affect engine performance. The genuine filter is necessary to ensure proper filtration and protection of the engine.
As for the 2.4l Multiair, 0w-20 oil is recommended, but again, it must be used with a genuine filter. Using a non-genuine filter may lead to engine damage or reduced performance.
If you have a Multiair engine that is running poorly, an engine flush can help clean out any accumulated debris or sludge. However, it is crucial to drain the oil when hot to ensure that all the debris is flushed out, providing optimal results.
If you notice your Jeep driving poorly and want a quote or simply want it fixed give us a ring on 9987 2818 or email Workshop@gdlauto.com.au and we will be able to get your Jeep running right.