elior77

97 turbo miata.

what do you think ?

Thanks

Leafy

iTrader: (1)

Does it do it again once its cooled down? It sounds like lifter tick but theres a whole bunch of weird scrapy wheezy engine noise that's trying to overpower it.

elior77

When cooled it does not do that, even when hot, only after hard driving.
The tick is from the injectors - checked.

When the camera gets closer to the valve cover you can here the noise best.

hornetball

iTrader: (4)

What oil are you running?

krissetsfire

iTrader: (1)

compressor wheel friction? check your oil level? how many miles does the oil have on it. I could be completely off but I agree with hornet. sounds oil related.

Could be water pump too maybe? My dodge van makes a similar sound after it heats up.

edit: I got a ninja edit in. sorry.

elior77

5w-40 i-sint



The noise was before the turbo too and with other oils.

hornetball

iTrader: (4)

You must be in Europe! Don't have that oil here.

In any case, you might consider switching to a diesel truck oil. Most modern car oils have dropped the additives (mainly zinc and phosphorus) that are helpful for flat tappet engines like ours (most car engines these days have roller tappets). That oil, in particular, has dropped those additives for emissions reasons. Unfortunately, I don't know if you have high-ZDDP diesel oil available in Europe.

elior77

So what does most miata (turbo miata?) owners use ?

Special oil with high zddp ?
Diesel truck oil ?
Normal oil ?

Thanks

hornetball

iTrader: (4)

I use Shell Rotella T-6 in 5W40.

elior77

What the zddp level in it ?

hornetball

iTrader: (4)

Formulations evolve over time and, I think, are also geographically dependent (especially since emissions laws in the US vs. EU are different). Recommend you find a good website that is EU specific. But at least you know what to look for.

Mrvalles91

Change the oil or add oil. I'm sure most miata's burn some oil after driving hard.

dieselmiata

iTrader: (3)

Correct me if I'm wrong, but I thought ZDDP was only required for flat tappet engines, not HLA's like we have.

Most have great luck with the Rotella T6. I've been running it for a few years and it's cleaned my engines up nicely. I'd recommend giving it a try for a few thousand miles, and see if that helps the noise. It doesn't sound like anything piston related to me, and the odds of a collapsed lifter are pretty low.

Edit: I just listened to it again, and it sounds very much like when I cleaned all of my HLA's and they hadn't been pumped full of oil yet. The noise went away after they had filled.

Leafy

iTrader: (1)

We have flat tappet HLAs (for NAs). Flat tappet and roller tappet have nothing to do with hydraulic lash adjusters and solid lash adjusters. You can have any combination of the two, ie a solid with roller tappet.

dieselmiata

iTrader: (3)

Gotcha. I guess I didn't really understand the difference (and I didn't bother to find out before I spoke).

Much I have heard and read about ZDDP has led me to believe that modern oils have diminished the requirement for it to the point of almost nonexistence, and that adding it can seriously diminish the lubricating properties of the oil. Perhaps that is part of the noise issue?

hornetball

iTrader: (4)

That's correct. The latest specification for oils is more based upon emissions and fuel economy than upon lubricating properties. I'd bet that this is even more so in Europe.

Flat tappet just means that the surface of the lifter that is in contact with the camshaft lobe is a flat, solid surface. The contact point is designed to be a bit off-center so that the lifter rotates in its bore and provides some "rolling action." But that is a far cry from having a true roller.

Rotella T-6 would be good if OP can get it. I'm not sure it's available in Europe though -- and even if it is, the European formulation may be quite different.

elior77

It was the CAS bearing.

Fixed!