[stew161]

Have a 00 lx with 250,000 km on it. About 3 weeks ago, the engine started ticking. Noise seems to come from the front right of the top of the motor. When first started, there is no noise at all. After about 30 seconds, you hear a knock or two here and there and then after about 1 minute it's steady and loud.

As you rev the engine, the knock gets faster. Engine still runs fine, lots of power, but the knock is driving me nuts. Still sounds as loud when the engine fully warms up too. The strange thing is, I figured out that if you disconnect the front right injector plug... the noise is gone.

I've replaced the injector, but there is no change. If it was a bad or sticking valve, or water pump, tensioners, etc...removing the power to the injector shouldn't have any effect right? I'm just trying to figure out what this could be before it goes into the shop....or up for sale.

I'm starting to think it's a nasty piston slap or worse like bolts coming loose on the rod. This problem also didn't occur slowly over months. One day it was fine...the next..knock city.

Any suggestions or help would be appreciated.

 

[lockon]

If you disconnect the injector plug on the new injector does the noise still go away?

If so, my uneducated guess would be that the injector is running dry (not getting fuel) as though there is a clog in the fuel rail.

Sunil

 

[stew161]

Yeah...pulled the cap on the new injector and the noise goes away. It's amazing how smooth the motor runs on 5 cylinders though. Put the cap back on and the noise is there right away.

 

[wormguy]

Check that the spark plug is completely tight in its socket. A loose plug could produce a clicking sound on that cylinder caused by gases escaping around the threads. By unplugging the injector combustion won't occur so the click goes away.

 

[stew161]

Plug seemed tight. Took it out and it looks normal. Put it back in and tightened it down good. Started the engine and the knock is there.

 

[lockon]

Drive it with the injector plug off and see if you can feel the difference... if not then my theory is still that the injector isn't getting fuel.

Sunil

 

[stew161]

It idles ok on 5 cylinders, but I've tried driving it with the injector unplugged and you notice the difference in power. So you get a quiet engine but one with only 170 hp...

 

[gregersonke]

Sounds like the EGR may be clogged going to the back cylinders. You can use injector cleaner or put in 8 ounces of acetone with your next fill up.

 

[payor_co]

Seafoam? I've used it to clean my TL.

 

[stew161]

I've run a few bottle of injector cleaner through it but there's no change. One thing I did notice when changing the injector is that there seemed to be a build-up of gunk on the top right side of the intake manifold next to the intakes. Never cleaned it out 'cause I was worried about stuff falling into it. Is this the EGR pipe that clogs? Would this cause the noise? The engine seems to idle and run fine so I thought that the EGR was ok.