tap or knock

[Topdis]

I just bought a 2002 Protoge 5 with 80,000 miles on it. This is the first time I ever rode one of these. I hear a knock or tap that is not too loud. It reminds me of a diesel motor. It is only obvious at low speeds or just accelerating. At speeds over 25 mph I do not hear it. Is the motor normally a little noisy?

 

[redpr5]

i got an 02 and i just crossed 70K with no tap or knock...did you check your oil when you bought the car? might be time for a change.

 

[kk52736]

i got the knocking sound on my car when rolling slowly (actually from the back of car), but if drive over 20 km i cannot hear because engine noise is cover them, and i got my car in for warranty checkup, they said it is stabilizer link at rear need to replace.

 

[Moonman8]

Easiest thing to check are the plugs, they might be a bit fried at 80,000 depending on the previous owner's maintenance.

Also, as previously mentioned, a good oil change would be a good thing to do. There is a lot of debate over which oil is best for our cars but I swear by Castrol Syntec 5w-30, but the weight depends on your climate.

I learned a good tip from a technician friend of mine for oil changes: every couple of oil changes I let all the oil drain out (duh) and then I pour about 3/4 quart of really cheap but brand new oil into the crankcase before reinstalling the drain plug. This washes out the old oil that doesn't quite drain due to gravity. Wait for the cheap oil to drain completely then reinstall the drain plug and fill it with the good stuff.

I know that our valvetrain is a bit on the noisy side as are most Mazdas (high mileage Miatas are the worst from what I can tell), so it might just be the valve tappets doing their thing.