Replace spark plugs

[Hlkh]

Hi any one here change your own spark plugs??

how to judge to tighnest of the spark plugs??

[Genie47]

With torque wrench. Anywhere from 30-35Nm.

 

Without torque wrench, Agar agar 1/2 -3/4 more after it is tight. Confirm not accurate. 30Nm is tighter than the 3/4 more after it is tight.

[Hlkh]

ok ... i just change plug myself after hand tight then spanner 1/2 round ok?

[Yeobh]

If this is yr first try then chance you just don't have the feeling. If the plug is brand new,first try to thread in as much as you can freely with the spark plug socket & T bar. Once you feel the resistance keep going until the washer is compressed. Now try to wrench the T bar probably another 1/4 turns , you should have manually torque the spark plug.

 

PS photo shows socket( thin wall type) with correctly designed T bar handle to provide the manual wrenching and the plug is finally tighten with a torque wrench

Edited April 13, 2006 by Yeobh

[Hlkh]

ok ... i will look for the T bar socket to reconfirm.

but if not tighten enough or over tighten what will happen?

[Cordia_gsr]

Over tighten, you will snap the plug's thread into the cylinder top block. And in the worst scenerio, you got to take the top block apart to remove that snapped portion. No joke.

[Yeobh]

Never try to replace spark plugs when the engine is till hot - let it cool down. Cylinder head now a days are mainly make of cast alumiumin and if you try to tigthen the spark plugs when the cyl head is hot chances hairline cracks will develop overtime due to the material stress taking place when it cool down to ambient temp.

 

Compression leakage will happen if the plugs are not properly torque down - this will have an effect on the engine performance and fuel comsumption. Over tightening will creat problem when you want to replace the plugs.

Edited April 15, 2006 by Yeobh

[Hlkh]

I just check the recommended turn after hand cant be tighten.

i found out that it is recommended at about 2/3turn but i only turn about 1/2 turn only.

should i take out and reinstall? or it about 1/2 also can?

 

but now i feel my car got power only fuel consumption drop by around 1km/l like that before i change to irdium

Edited April 15, 2006 by Hlkh

[Genie47]

Grease your plug threads before you screw them in with high temperature grease.

[Hlkh]

where can get the grease?

[Cbx750p]

Yo ! That is a No No to grease your plugs ! High temperature grease or not, nothing can withstand the kind of heat that would be put up from the combustion chambers ! In my many years of automotive working, never heard of putting high temperature grease onto the plugs ! The grease would eventually burn and freeze the plugs if you don't remove them on time.

 

Just use a new set of plugs or make sure the old one is very clean....use a wire brush to get rid of all the carbon build up on the thread.

 

CBX

[Genie47]

I've used grease no problems. I got problems with anti-sieze. Actually plug installers have two camps just like oil filter intallers.

 

Oil filter installers:

 

Camp 1: Use engine oil to lube gasket.

Camp 2: Use grease to lube gasket.

 

Spark plug installers:

 

Camp 1: Use anti-sieze on threads.

Camp 2: Use high temperature grease on threads.

 

Which camp you belong to actually depends on how much bad luck you have with the method at first!

[Trex101]

Grease will work just fine, too much anti-seize will actually seize the plugs.

[Eyebm]

heh...I didn't know that we can use grease on the spark plugs?

[Genie47]

Can use. No problem but depends on your luck. Like I've said, if you got bad luck using HT grease, you most likely have better luck using antisieze and vice versa.

 

Anything to remove it easier next time.

[Wyx03_2002]

any lobang to get a torque wrench? What's the estimated cost?

thanks.

[Yeobh]

Hard to find torque wrench for DIY in our market.Check with Genie47 he may have the info or try ebay.com

[Wyx03_2002]

I searched around in Msia and P'pines hardware shops for a month liao, couldn't find one. Mayb hv to try my luck in ebay then, thanks.