My ticky-tock-tock

[Larryjb]

OK, I have to keep my subject different from Mikes, so the tock tock.

I've been chasing my tick for awhile. At first I thought it was lifter noise. But because it is only obvious on the cold engine, I have begun to suspect piston slap because it goes away after about 30 seconds.

I got a mechanics stethoscope because they were on sale and I figured I could use one. I have yet to go over every inch of the heads and block, but so far I cannot hear it resonating though anything.

I have checked several points on the heads, exhaust manifold, engine belly, transmission bell housing, and so far even when I can hear a slight tick from outside, I do not hear it through the stethoscope.

Because it disappears fairly quickly while warming up, are there some other areas which have been known to make such a tick sound? It does become more rapid with engine speed.

 

[Scottydoggs]

busted off exhaust manifold bolt head, or it just fell out. will be the last bolt in the back, or the front of the engine.

mine went to the dealer for this issue, they could not figure it out. i was doing my brakes and saw the black soot coming from the manifold. and the bolt was gone. put a new stud and nut on there, no more ticking when cold.

 

[Larryjb]

Hmm, I'll check the torque on mine. I did the heads and installed new exhaust bolts 2 years ago. However, they could be loose I guess.

 

[OR VietVet]

One of the best ways for you to spend money is that stethoscope you bought. It saves so much time, most of the time.

 

[Larryjb]

You better believe I'll be using it!

I could use checking the exhaust bolt torque anyway though.

 

[OR VietVet]

Usually, whenever I checked anyway, the lifter tick tended to last longer but piston skirt slap was pretty quick.

 

[OR VietVet]

Another thing to consider is taking the belt(s) off and do a cold start and see if the noise is still there. If is gone then check all pulleys/bearings for play and noise when turning with hand and if you feel roughness in your hand. The p/s pulley will have slight in and out play when you push/pull it. Long shot? Maybe?

 

[Larryjb]

Actually I was just thinking of doing this. In addition, remove the fan and fan clutch. The fan and clutch is one thing I cannot check easily with the stethoscope.

 

[iamdub]

It's really common for a tick to be caused by a lifter draining down when parked for a while or over night. They usually go away pretty quickly after startup cuz the oil pumps it back up and gets it all lubed up again.

Next time you go to cold start it, hold the throttle to the floor and crank it until the PCM stops it, which should be about 10 seconds. Let it rest a minute or so, then repeat. After that second round, release the throttle and start it as normal. If the ticking doesn't happen, you have a lifter draining down.

Since it does it for 30 seconds, I'm more inclined to believe it's an exhaust leak that's sealing off with heat/expanded metal. The drained lifter thing usually quiets down after just a few seconds since the oil system builds pressure quickly after startup.

 

[Larryjb]

I'm inclined to agree it's not a lifter. There is no tapping from the valve covers when I used the stethoscope, and the tapping often begins a few seconds AFTER the engine starts, then it lasts until the engine gets to about 70°F.