You should use your words better, the word "Knock" is usually used to reffer to The noise you hear when there is detenation.
What your stating sounds like a leaky exaust manifold to me...if it were HLA's the ticking/tapping noise would be there all of the time and would speed up as RPM's increass, but if you hear a ticking noise only when the car is cold it is usualy a leak in the exaust manifold...the reason why the noise goes away after the car warms up is because the crack will expand shut from the heat.
Take you exaust manifold off and send it to a Machine shop to be tested for cracks.. but before you do this, check for broken/backed out studs, or a leaky gasket
Valve (HLA) noise on a cold startup is normal as long as the tapping goes away after the engine warms up. The mazda workshop manual confirms this. My old DX used to make the HLA noise upon startup on cold winter days. It would go away when I started driving.
my car would also tick at start up and then stop ticking when warm......but a couple of days ago my tick multiplied in sound big time and is constantly there.....Magik8, do i have a bigger problem on my hands and should i stop driving untill its checked out?
If it's ticking really loud (loud enough to hear inside the car, doors shut and windows up) you probably have a dirty/collapsed HLA. The engine should normally make a ticking sound from the distributor and fuel injectors, but this is only usually audible with the windows down or the hood raised. HLA noise is LOUD and can be heard from 100+ feet away from the car.
Yeah I never thought of that..I guess the tapping could be HLA's because on a cold start up it takes a bit for the oil to pressurize and become more moveable (oil seems to thinken up when its cold). What you could do to help it is switch to a different oil for colder wether...like 5w-30 or at least 10w-30
I know excatly what you mean by loud ticking luis, my HLA's are tick really bad too.
Ran the engine cleaner in the crankcase for five minutes, added a Napa Gold oil filter, and 4 1/3 qts of Valvoline 5w30: my 89 purrs like a kitten. An older kitten at that, since I have 320,000 on the engine! 9 lives?
A forum community dedicated to Mazda MX-6 owners and enthusiasts. Come join the discussion about restorations, performance, upgrades, modifications, classifieds, troubleshooting, maintenance, and more!