knocking engine

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knocking engine

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knocking engine - 8/9/2008 12:36:46 PM

chevy

Posts: 11
Joined: 2/27/2007
Status: offline

guys.........i replaced the cylinder head on my 1.6 dohc engine.

now there is a knocking sound coming from the head similar to tappets.

please help me get rid of this tapping.

Post #: 1

RE: knocking engine - 8/11/2008 3:48:48 PM

chevy

Posts: 11
Joined: 2/27/2007
Status: offline

i did some research on the internet and learnt that this may be possible due to gunk buildup, and they reccommended that i try a thicker body oil and replace one quart with transmission fluid.....run the car for a week or two. the ATF has cleaning properties that would not harm the engine.

(in reply to chevy)

Post #: 2

RE: knocking engine - 8/16/2008 4:00:06 PM

Posts: 12
Joined: 11/9/2007
Status: offline

Hi
I''ve got same sh** Knock under load and pinging on my wife''s Mazda
1.Dirty Cranckshaft Pos. Sensor
2. Her car doesn''t have a Knock sensor - so I had to move backward Distributor Cap Body / there are two screws and space for adj.
Regards , JS > Maryland

(in reply to chevy)

Post #: 3

RE: knocking engine - 8/17/2008 6:57:23 PM

wsoape281

Posts: 977
Joined: 3/1/2007
Status: offline

these motors are famous for pre-ignition. if the tapping just sounds kind of clicky, odds are that you brought the compression back up in the motor by putting a new head on it. if it sounds more metal-on-metal, there is a chance that you got a head that been milled (machined) to be true again. stay with me on this one, kind of hard to follow and i always start shit when i bring this up.

when the cylinder head gets milled, it brings the cam gear and the crank closer together. a few miata guys experienced this a few years ago on the same motor. this relocation, even though it is so slight, can cause the timing to either advance or retard depending on which way the tension is held on it. the valves then come closer to the pistons and click, or just cause a pre-ignition due to the valve position and raised compression at the time of ignition. run a premium gas through your car along with an octane booster for a week and see if the sound goes away. if not, you may need to put on an adjustable cam gear.

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