Engine Knockin

[Deano96GS]

Can someone please define/describe, what engine KNOCKING is. Is it thesound? LIke knocking? Or is that just a term,<BR>My 1.8 V6, occasioanlly, makes this 'knocking' noise, when i first start up, but if i turnt he car off, then on again, its all good, CAn you help me out.? Thanks.

[Blavac]

when you first start it up does the noise fade away or stay constant?

[Deano96GS]

Fades away, eventually, but when i hear it, i just shut the car off, then turn it on, and its gone

[ProtegeSTS]

Engine Knock 101 <P>As the piston is coming up for the compression stroke, you ideally want the to get the most power out the combustion process. To do this, you advance the timing until the flame front is just beginning to push the piston down as it makes it over TDC. This will result in the most efficient power stroke, and therefore more power. If you advance it too much, or have gas with a lower octane that what your engine is tuned for, and therefore, ignition starts too early...then the flame front will impact the piston as it is still trying to move up towards TDC. This impact between the flame front and piston is what we call "knocking". This impact also throws all sorts of extra heat energy into the system, and makes it even easier for preignition in the next cycle of the engine, as with more heat, the combustion process will begin even earlier.

[ADB98]

So in lame man terms I think he's saying bad gas.

[mr.hunt]

Ok since class is out. Is this the only possiable cause for "knocking' what about low oil or bad rings. not saying that this is the problem but just wondering I have as well experiance this time to time so is this the only thing or are there other options. Thanks in advance

[Frenchguy0]

Deano, my car has the same poblem. I notice the knocking gets loude3r when my oil gets old (3000 miles). and my engine sounds way better with new oil. So first I'll check with just an oil change. If your car has high mileage (as many of us), you can actually switch to 5W30 grade oil. It helps the engine runs smoothlier when old. Don't use synthetic oil, it can damage your engine specially when it's an old engine.<BR>If that doesn't help, you might have to check your lifters ( difficult to access and kinda expensive).<BR>I know that before Spring mine will get a total work out: new spark plugs and wires, complete tune'up, head gasket, valve cover gasket, check hose from and to intake and lifters....I'll drop some heavy dough but hey if you want to keep your baby running for a long time, you need to take care of that old lady. Mine is a 92 GS with 155000 miles on it.<BR>My 2 cents. Let me know what you found, it might help me too. [img]shrug.gif"%20border="0[/img]

[jansonm]

Mine '93 GS V6 also had a knocking noise in engine but then i changed FRICTION GEAR SPRINGS and no knocking anymore! You can read TSB in mx-3.com under TSB section and number of TSB is B007-95. [img]shrug.gif"%20border="0[/img]<p>[ January 01, 2002: Message edited by: Martins ]