Miata HLA Question

I did a track day yesterday and was parked next to another 1.8 NA Miata in the pits. After one of his sessions late in the day, the guy pulled in next to me and I could hear the obvious ticking sound of an HLA and I mentioned it to him. He said that it happens to him all the time after long track sessions, but when he starts the car later, the noise is gone.

I've always considered myself lucky that neither of my Miata's has noisy HLA's. I know that they will leak down after sitting for a while, but then pump up after a few minutes of high revs.

I knew that there was a mention of the HLA issue in Keith's first book so I re-read it. He said that it can occur after sitting or after hard driving. That seems counterintuitive if high revs help solve the problem.

Can anybody offer any insight? Is this guy putting his engine at risk?

I've seen BMWs do something similar. I wonder if it's oil foaming? If so, I'd be concerned. Speak up, Keith!

This should be what you need to read. Is it accurate? It's on the internet right!? Honestly, it's the only thing I've ever seen that gives the theory of operation of the HLAs, and it explains why it gets worse with age. I've got 1 (or I suppose a pair could sound the same) that is just horrendous. http://www.miata.net/garage/hla/index.html

Since I bought a long-block I'm rebuilding, I decided to go for this while my head is apart. http://www.miata.net/garage/hla/cleaning.html

So far I've got the cleaning part done. By thursday night I should have some time to get in there and re-oil / assemble those things.

The classic bmw lifter tick can usually be fixed by overfilling by 1/2 to 1 quart.

I took some apart & sent them through my ultrasonic cleaner. Even after a good hot bath & overnight soak in agitene (and cleanup with carb cleaner) - I still had some that were sticky & some collapsed.

Kendall

Heh, a couple weekends ago I attended a Miata club autox on Saturday, and a BMW club event on Sunday. By the end of the weekend, I started being confused if I didn't presently hear clattering lifters in grid.

My Miata does it after autox runs sometimes, and again for a few moments on startup if you shut it off hot (no cooldown period after the run). I'm not terribly concerned about it. My 328i doesn't seem to do it, but I don't take it on rev-limiter abusing autocross runs like I do with the Miata every weekend.

I thought noisy HLAs were just on the 1.6 cars (like mine) and the 1.8 cars have solid lifters. You learn something new every day.

The race kaa (1.6) did it when it was street driven ONLY if the car sat for more than three days. Now it can sit for months and light right up with no clatter. However, just putting the thing on the trailer will make it rattle like a can of bolts. I think it's afraid of heights.

My 1.6 has had this issue since I got it at 140k miles. It's at 202k and will still do it after sitting for a while or after driving it hard. An oil change usually fixes it for about 2500 miles then it starts again. Miata.net mentions trying different weights and types of oil, but I've had no luck. It's never been a problem, just annoying. And I was turbocharged for 5k miles of that time.

All NA Miata (<-1997, 1.6 or 1.8) can have noisy HLAs. I think 99+ had solid lifters, but won't swear to it.

My 97 makes plenty of HLA noise, on first start, or after a really long hard drive. On first start, it's lack of oil. After a hard drive, I assume it's thinner oil draining out quickly, but maybe it's something else. Either way, it doesn't hurt anything, that I can tell. My Harley does the same thing - damn thing sounds like it's going to explode sometimes.

HLAs are an ongoing issue with several manufacturers. The older KIAs with the Miata type setup were noisy. Mazda and Isuzu both used the little bitty ones that go in the tip of the rocker arm, and they get noisy too. Chrysler now uses a similar design on the V6 motors, after several days of sitting they tick as well. I suppose it could be fixed with a better engineered HLA, but that costs $$.

Does anyone here with a Miata not get at least occasional lifter clatter? Lo, though the gods gave us an almost perfect vehicle, they spake that occasionally, we would be smited with noisy lifters, cracked interior pieces, and occasional other maladies....

(goes outside to change the slave cylinder on his '92)

I use my noisy lifters to my advantage. When it reaches a point that I get lifter tick for 1min+ on startup, I know it's time for an oil change.

Both my BMW and my Miata get lifter tick. The BMW is worse.

Yeah, I use it as a reminder it's time for an oil change as well. Works better than the odometer.

Info dump! 1999-05 Miatas got solid lifters, 1990-97 have HLAs. Interchangeable ones, BTW. And there are oil feeds for HLAs in a 1999-00 head (my Targa car is set up this way so I can change cams around) but not on the 2001-05.

Yes, they get noisy on startup with old oil. And they get noisy after track use - I'm guessing thinned oil from heat. Some cars never make noise, others are downright chatty. Go figure. I once had one refuse to pump up after a head change, and a week of commuting at 6000 rpm solved that problem never to return.

They're mysterious and enigmatic.

I've never heard any lifter noise from my 2000 Miata, but I'm sure it's solid lifters, so I wouldn't expect any.

The hydraulic lifters in the 1.8 Mazda engine in ~My Race Escort~ are sometimes noisy on startup after sitting, but it goes away and is never noisy after a race. The engine is an old, high-mileage street engine, so I keep it under 7000.

One of the Spec miata cheats was to plug the oil squirters. This apparently ran the pistons hotter (and leaner), but also supplied more oil to the HLA to keep them pumped up...

Kendall

aeronca65t, your 2000 does have solid lifters. You'll hear a little bit of noise from under the valve cover, but probably not with the hood closed.

Plugging the squirters will also drop the amount of oil mist in the crankcase atmosphere, cutting down on aero drag acting on the crank. Seriously.

I never made the connection, but I have (legally) plugged oil squirters on my Targa engine. That thing has redonkulous oil pressure, always has. Makes sense. It's had a few run-ins with HLA noise though.

Jensenman wrote: HLAs are an ongoing issue with several manufacturers. The older KIAs with the Miata type setup were noisy.

If I am not mistaken this is because Kia was using the same series engine as the Mazda. I am pretty sure I saw that somewhere.

Yeah, KIA licensed some engine designs from Mazda pre-Hyundai takeover.

IMHO, about half of the problem with the various HLA designs is there's no way to constantly feed fresh oil through them; oil can get in but it can't get out (at least not easily). That's because people hate to hear HLA clatter at startup so the mfgs. build them to be quiet for the first 50K or so. After that, it's likely out of warranty.

Way back when, yer basic SBC or SBF fed oil into the lifter through a hole in the side which then made its way through the hollow pushrod to spray the valve train. This meant a constantly renewed supply of oil went though them. It also meant they'd 'bleed down' if the car sat a couple of days and would rattle at startup until the lifters filled with oil. Not harmful, just noisy. Of course nice Miz Gramma was embarrassed that the neighbors would hear her new car clattering early on Sunday morning after she didn't drive it for a week and enough of them complained that the mfgs. compromised the other way entirely. Oh, well.

Keith wrote: And they get noisy after track use - I'm guessing thinned oil from heat.

So...is the answer to use heavier oil for track use?

Except heavy oil costs you power...

Oil services between runs would help.

Keith wrote: aeronca65t, your 2000 does have solid lifters. You'll hear a little bit of noise from under the valve cover, but probably not with the hood closed.

It's a Miata. I never have to open the hood.

In any event, I'm probably deaf to any slight valve tap....my other street car is an MGB (0.015" lash).

I ran 120k hard miles on my 1990 Miata & used 10-30 Mobil 1 - ticking only occurred when it was near time for oil change at 5k miles...

I'm resurrecting this.

My '94 has developed interminable lifter tick. I'd be worried it was rod knock, but it varies in intensity; sometimes louder, sometimes softer, but doesn't seem to go away completely.

Seemed to happen after car went a bit too long (5-6k miles) between oil changes on conventional oil. (Car seemed to be fond of good synthetic oil, but I haven't fed it the good stuff since I stopped tracking it.) Also, I think I overfilled the oil by about 1/2-3/4 of a quart.

I don't really feel like disassembling everything. I'm thinking maybe throwing in some MMO and revving the bejezus out of it for about a week might do something. Thoughts?