GC and Mazda HLAs (YAGCT*)

[Narcoleptic]

I have a '96 Mazda Miata with the 1.8L DOHC I-4 which is quite famous for HLA noise upon cold start-up. I was using Mobil 1 5W-30 and 10W-30 when I first got the car. I decided to try German Castrol and its been in for about 1,000 miles now.

With the Mobil 1, I'd get HLA noise when the oil had been in for 4,000 miles. I took this as a sign as to when the change the oil. It would also turn black. I know visual cues aren't the best, I'm just a bit paranoid. The GC has already started with the HLA noise.

Would the 0W cause greater HLA leak down and more HLA noise? It usually happens when the car has been sitting for 8-10 hours and during colder weather.

(* Yet Another German Castrol Thread)

 

[cryptokid]

a cure for hla noise, that i have confirmed with another mazda driver is to use a diesel oil, like rotella, delo, or my favourite, pennzoil long life.
it took my car 800 miles on diesel oil to stop the noise, but it has not been back for about a year now, same with another driver.
try one out.

 

[Losiho]

For some reason I get no HLA noise at startup on my 93 MX-6 V6, they only start tapping once the engine is up to operating temp.

 

[Jeffrey Behr]

OK lovers of undefined acronyms, what does 'HLA' mean?

 

[Losiho]

Hydraulic Lash Adjuster - hydraulic lifters.

 

[VaderSS]

Guess this is getting a bit persnickety, but a hydraulic lifter actually rides on the cam.

A hydraulic lash adjuster does exactly what is indicated, and usually sits at the pivot point of a finger type cam follower.
This picture shows the difference, the lifter being on the left, the HLA being at the pivot point of the OHC valvetrain image.

 

[Jeffrey Behr]

quote:

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Originally posted by Losiho:
Hydraulic Lash Adjuster - hydraulic lifters.

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TYVM (that's thank you very much).

And thnx, VaderSS; I knew that difference. I keep telling my son they're not 'rocker' covers on his 4.6 Ford, they're cam covers, but he likes to use the same terms his semiliterate fellow Mustang-forum participants use.