lhpdiver

We have been having intermittent check engine light issues - small evap leak. The Jeep had been siting for a couple days. I went out to start it this morning. Everything was off; A/C, fan, radio. The car was in park. I turned the key and immediately heard a ticking sound coming from the center console, near the arm rest. For 15 seconds or so it was a kind of fast tick-tick, tick-tick. Then for 15 seconds it was a slower tick, tick. Then the ticking stopped and immediately the check engine light lit. I almost always have the radio on - maybe that's why I haven't heard the noise before.

Any thoughts appreciated.

extrashaky

Check your gas cap. You may need a new one.

Sound bounces around weirdly sometimes in these vehicles. The ticking noise is probably coming from your evap purge solenoid in the engine bay. Pop the hood and see. I included some photos below to help you find what I'm talking about.

The evap purge solenoid ticks sometimes, which in itself isn't necessarily a problem. However, if you have a vacuum leak in the evap system, it will often tick louder. Such a leak can include the gas cap, a leak in one of the vacuum lines, a leak in the evap purge solenoid itself or a problem with your leak detection pump in the back passenger corner of the engine bay. If you're hearing the ticking for the first time now in conjunction with a new code for an evap leak, the leak is probably what's causing the tick.

You may be able to find the leak by inspecting your vacuum lines and fittings for cracks. If not, you can find it with a smoke test. Either rent a smoke tester or look on Youtube for how to build one yourself out of a paint can.

lhpdiver

Thanks for the reply.

It's not the gas cap. We have already picked up a new one at the dealership.

I've watched the DIY smoke detector videos on Youtube. I might have to go that route. The shop we take the car to has the compressed air source. Even a Jeep dealership in Mexico is not going to have the equipment to do a smoke test.

We go to a very capable mechanic. He and his crew have put a good bit of effort into finding the cause for the CEL. He swears they have gone over all the tubing and it is in good shape. He was wanting to swap out our leak detection pump with another customer's - but the guy stopped coming by.

A new OEM detection pump would run us close to $300 USD. I see that there are cheaper Dorman pumps but for some reason our mechanic swears we can't use them - we need the expensive one. I wish we had a junk yard nearby - but I haven't seen any.

lhpdiver

Upon closer scrutiny the ticking is coming from the evap purge solenoid. When there is a pending code - the next time I start the Jeep I hear the rapid ticking followed by slower ticking. When the ticking stops (about 30 seconds or so) the CEL lights.

Can this valve be cleaned or serviced ?

When working properly should it always tick ? never tick ?

Looks like AutoZone has one for my Jeep - about $35. The brand is their own - DuraLast. Anyone have any experience with DuraLast parts ?

Thanks.