Loud engine tick

[madtrinjax]

Daughter's 2018 CX-5 with the 2.5 for the past few weeks has been making a very loud (substantially louder than normal at startup) ticking sound. The odd part is it is only happening at startup when she is in the mountains of western north carolina. when home in Raleigh no ticking sound. She works at a park there during the summer and this has happened 4 weeks in a row, but only once or twice a week. Saw a video online where she can run the idle higher and bring it down after a few seconds (essentially revving the engine) and this has worked for her to eliminate the tick after a few rounds of this. I was thinking it was the HLA issue but shouldn't that be at every startup? I religiously change the oil every 5k miles with 0W-20. Thinking of switching it to 5W-30, car has 84k miles on it. I was thinking of taking it to a Mazda dealer here at home when she gets back this week but not sure they will do much to replicate it. Wondering if it is an oil issue of starvation at startup due to the elevation or if it is the HLA issue and is at early onset and that is why it is not every day? I'm lost with this one. Any help/advice would be greatly appreciated. thank you all

 

[a69mach1377]

Pretty loud...are you sure it's not the fuel pump?
Free bump...

 

[madar]

Has it had the software update for the rocker arm issue?

 

[madtrinjax]

Has it had the software update for the rocker arm issue?

Not sure, she bought it used. I will have to check on that.

 

[madtrinjax]

I was able to validate that it has had the software update according to Mazda's website

 

[yrwei52]

Daughter's 2018 CX-5 with the 2.5 for the past few weeks has been making a very loud (substantially louder than normal at startup) ticking sound. The odd part is it is only happening at startup when she is in the mountains of western north carolina. when home in Raleigh no ticking sound. She works at a park there during the summer and this has happened 4 weeks in a row, but only once or twice a week. Saw a video online where she can run the idle higher and bring it down after a few seconds (essentially revving the engine) and this has worked for her to eliminate the tick after a few rounds of this. I was thinking it was the HLA issue but shouldn't that be at every startup? I religiously change the oil every 5k miles with 0W-20. Thinking of switching it to 5W-30, car has 84k miles on it. I was thinking of taking it to a Mazda dealer here at home when she gets back this week but not sure they will do much to replicate it. Wondering if it is an oil issue of starvation at startup due to the elevation or if it is the HLA issue and is at early onset and that is why it is not every day? I'm lost with this one. Any help/advice would be greatly appreciated. thank you all
View attachment 336934

The valve ticking noise is due to the original switchable hydraulic lash adjusters used on cylinder #1 and #4 are failing IMO. It’s a common problem on the 2.5L NA with cylinder deactivation and Mazda has revised those switchable HLA’s used for CD to fix the issue. See the TSB:

2018 CX-5 GT Ticking sound?

And:

CX-5 engine rattle

 

[madtrinjax]

I am leaning that way as well based upon all the research so did, but it just seems odd that it only happens once or twice a week and only when she is up in the mountains. I would have figured it would not be location dependent and happen more frequently- but I guess it could just be coincidental when/where it keeps happening. Appreciate the feedback and help.

 

[Lazy2.5]

does that click increase when you rev the engine?

 

[madar]

Might go away with 5w-30, Chrysler has a similar problem with their hemi engines with CDA, people report the problem going away when bumping up to 5w-30. Can't hurt.

 

[yrwei52]

I am leaning that way as well based upon all the research so did, but it just seems odd that it only happens once or twice a week and only when she is up in the mountains. I would have figured it would not be location dependent and happen more frequently- but I guess it could just be coincidental when/where it keeps happening. Appreciate the feedback and help.

No, it isn’t location dependent but the faulty design of the switchable HLAs which IMO is related to the PCM update to fix the early rocker arm falling problem on cylinder deactivation. If you read the entire thread posted above, and the early Service Alerts and TSBs, you’ll see the early fix of this valve tapping noise is to raise the engine to 2,000 rpm for 5 minutes to get rid of air bubbles accumulated in the oil passage in the switchable HLAs. This means once you actually drive the vehicle, the air bubbles could be gone and the tapping noise would be reduced. Of course this “2,000 rpm for 5 minutes” is a joke and it can never truly fix the problem. Mazda eventually did something as outlined in the latest TSB: “the switchable HLA has been modified for increased oil supply to reduce air bubbles in the oil passage”.

Early Service Alerts and TSBs for Engine Tapping Noise

Here's the most recent TSB on 'Tapping noise from engine', which supersedes all prior communication on this subject. It has additional information, but IMO in no way will make anyone feel happier about owning a 2018-20 Skyactiv-CD engine.

The most important new statement from Mazda in this revised TSB is that 'the switchable HLA has been modified for increased oil supply to reduce air bubbles in the oil passage'. So this certainly sounds like confirmation from the automaker that the factory switchable HLAs are not subject to 'failing', but instead were designed incorrectly by not providing for enough oil flow.

And so the new question question becomes, how many engines will eventually produce whatever set of conditions are required to create the low oil flow, air bubbles, and the noise? Just another episode in the Skyactiv CD horror show.

So if you really want to get rid of the valve tapping noise, the only way is to replace your original switchable HLAs with revised switchable HLAs.

 

[madtrinjax]

Yes it does increase and then goes away within a few revs of the motor.

 

[Lazy2.5]

Yes it does increase and then goes away within a few revs of the motor.

I agree on trying 5w30.

Been using it in my 2.5 for several years now.

 

[Lazy2.5]

So if you really want to get rid of the valve tapping noise, the only way is to replace your original switchable HLAs with revised switchable HLAs.

Agreed. But the oil can help for now.

 

[yrwei52]

So if you really want to get rid of the valve tapping noise, the only way is to replace your original switchable HLAs with revised switchable HLAs.

Agreed. But the oil can help for now.

For OP, switching to 5W-30 oil is a cheap way to try. But based on Mazda’s TSB they increased oil supply in modified switchable HLA’s oil passage to reduce air bubbles. Thicker 5W-30 oil may actually achieve opposite result.

 

[Lazy2.5]

For OP, switching to 5W-30 oil is a cheap way to try. But based on Mazda’s TSB they increased oil supply in modified switchable HLA’s oil passage to reduce air bubbles. Thicker 5W-30 oil may actually achieve opposite result.

5W30 isn't exactly thick enough to impact oil circulation.

 

[yrwei52]

5W30 isn't exactly thick enough to impact oil circulation.

Then it won’t be able to increase the oil supply to original switchable HLA oil passage to reduce air bubbles.