Miata Rattle - HLA's, Rod Knock, Spun Bearing, Something Else?

[xVShowTeKVx]

its your HLA's buddy!

get lighter weighted oil or synthetic and do a full oil change.

[RUDAMENTRY]

I had a feeling it had something to do with the timing belt...i had the same issue with mine. Puttin those suckers on to me was a big challenge.

[TheFlankRIght]

latingq is right it is a comon miata problem. i had it in my 91 i moved to full synthetic 5w20 with lucas oil stabilizer and its virtually gone. it only happens when im parked on a downhill but i think thats beacuse i need a new oil pump

[Stealthsoldier20]

A good way to get rid of the HLA tick is using Lucas Heavy Duty oil stabilizer. It's virtually non-existent in my car. I think it's probably something to do with your transmission because your engine sounds fine, aside from the valve tick. My car has a rattly raspy noise also when I accelerate but I think it's worn bearings or gears which is probably what you're hearing too..

Mine is a '91 with around 153K miles on it and I just rebuilt the rear diff. so I know it's coming from my transmission.

[bboyredcel]

I fixed the whirring. It was that the timing belt tensioner and idler pulleys were shot.

[BLADE69906]

I have the same sound coming from my civic? definitely has something to do with the valves or even timing? did you fix it?

[evenexchange]

It isn't rod knock. Or engine damage.. It happens with increased RPMS.. so its not anything that's damaged internally.

[tristantao]

does rod knock and other things make noise when idling? because i have this noise, kind of tapping/knocking-ish. not that loud... but happens only around 2.5-3.5 rpm. what can be the problem. its a 1999 miata.

[latingq]

OK... I've heard that's a common issue with Miatas. There's a kit to fix this problem - though, good luck finding it. I heard it's because of the gap between the lobes of the cams and the valves/ lifters. Since they aren't adjustable, you need the kit to fix it and a feeler gauge.

[roskan76]

i can only guess,but noise can even be coming from a bad water pump,unadjusted valve clearance or some bearings somewhere.Wish i could tell you more