Clicking sound - piston slap or cracked manifold?

[Noahfn]

I've noticed the 2006 V8 SR5 I purchased a few weeks ago makes a sort of loud clicking sound when started cold. It is barely audible when in park or neutral, but gets loud when I put it in gear. It goes away after driving a short distance.

I'm trying to figure out if I might have piston slap, or a cracked exhaust manifold. Does anyone have any tips for figuring out which it is?

It is under warranty, but it seems unlikely that the dealer would hear unless I left it there overnight.

 

[gm350reratliff]

Cracked manifold and/or leaking from manifold gaskets.

 

[Ebbsnflows]

A cracked manifold/leaking gasket will get louder as the engine comes under strain. I've had leaky headers on some of my past muscle cars. To diagnose, I would roll my widow down, shift into higher gears (4th or 5th) and drive up a steep hill. The stress of climbing a hill in a weak gear would easily expose the "ticking" of a leaking manifold. Of course this method will be a bit trickier in an automatic transmission, like our 4R's have as they will try to downshift to a stronger gear.

Another trick: With the engine/manifolds cold and the hood lifted, Wet a thick rag. Start the motor and have a friend BRIEFLY hold the wet rag over the tail pipe. It will cause an sharp increase in exhaust back pressure. The exhaust gases will seek another way to escape. The leak should then be able to be heard or felt if it's severe enough. Do not cover the exhaust tip too long or the engine will stall.

The fact that the noise subsides after the engine is warm makes me think piston slap. My 2002 SS had it badly. It was almost embarrassing at start up but would completely disipate after 5 minutes of driving.

 

[V8Limited4wd]

the v8 is known to make a loud clicking noise on a cold startup... mine has been making the noise as far back as i can remember. i'm not sure if anyone has gotten a verified diagnosis of whether it's just piston slap or a cracked manifold but I need to figure out if something needs to be replaced before my plat warranty runs out in a year.

 

[ALLEGRO]

As annoying as it is, new higher-performance engines exhibit some piston slap. GM's LSx series is notorious for the slap. There seems to be no damage or long-term issue, but it is a bothersome sound.

By the way, my 07 Limited V8 does it as well.

Probably just live with it......good luck

 

[Ebbsnflows]

As annoying as it is, new higher-performance engines exhibit some piston slap. GM's LSx series is notorious for the slap. There seems to be no damage or long-term issue, but it is a bothersome sound.

Exactly as I was saying. As incredible as the LS series motors are, in GM's performance line of vehicles, piston slap is very common. Although my current Z06 does not have it, both my 99 Z28 and 02' SS did (along w/ about 75% of the Camaro/Trans-am guys I hung out with). None of us ever experienced any mechanical issues as a result...although I did send the #7 piston through the side of my block...but I think that was probably due to the 250 hp shot of N20 and fuel starvation :biggrin2:

I don't know that much about the V8's in 4runners, but if it is indeed piston slap, its unlikely that Toyota will do anything under warranty (GM wouldn't).

 

[scottm]

Try switching to synthetic oil, I've had good luck in reducing engine ticks that way. Synthetic is especially good at cushioning impact forces, and flows better when cold. My personal preference is Shell Rotella T6 Synthetic, in gallon jugs at WalMart.

 

[progress4m]

the v8 is known to make a loud clicking noise on a cold startup... mine has been making the noise as far back as i can remember. i'm not sure if anyone has gotten a verified diagnosis of whether it's just piston slap or a cracked manifold but I need to figure out if something needs to be replaced before my plat warranty runs out in a year.

I have a V8 and I never heard a clicking noise out that engine…
I know that probability of that is very slim, but you not referring to AC clicking… if you have AC or defrost “on” or “Auto” all the time?

 

[V8Limited4wd]

I have a V8 and I never heard a clicking noise out that engine…
I know that probability of that is very slim, but you not referring to AC clicking… if you have AC or defrost “on” or “Auto” all the time?

unless you have temps lower than 40F than you won't hear it. It only happens in cold weather.

 

[progress4m]

unless you have temps lower than 40F than you won't hear it. It only happens in cold weather.

If are talking about AC, I believe that is incorrect, you going to hear AC clicking regardless of the temp….
As far as my truck, I have not heard any clicking from the engine in any temperature including the time of a gold snaps we got this winter (It got to 9 degrees F for a couple of days).

 

[4-Legged-Runner]

I've noticed the 2006 V8 SR5 I purchased a few weeks ago makes a sort of loud clicking sound when started cold. It is barely audible when in park or neutral, but gets loud when I put it in gear. It goes away after driving a short distance.QUOTE]

I have the same thing here. Additionally, I read somewhere else on here about the fan clutch roaring at cold start-up. I let the truck warm for a moment (10-20 secs) until the fan roar quiets - and it seems the slap subsides within the same time.

Matt

 

[Noahfn]

The sound I'm hearing is definitely not related to the air conditioner. I've made sure it is off and not set to "auto".

 

[scottm]

I bought my '03 with a fresh oil change from the dealer. Whole lotta tappin' was going on. I finally changed the oil, the Shell I mentioned above, and no more tap. Give it a try.

 

[chaz]

i agree, switch to synthetic.

 

[4runnerman09]

i also have this problem and when i talked to my mechanic about it he said to try and replace 1 qt of oil with a bottle of lucas oil. it did wonders. i would say took over 50% of the ticking away. he said over time there is dirt that builds up on the rockers and rods and the lucas oil cleans it out. it took about 5 min of the engine running to make the difference.

 

[SecretAgent]

i also have this problem and when i talked to my mechanic about it he said to try and replace 1 qt of oil with a bottle of lucas oil. it did wonders. i would say took over 50% of the ticking away. he said over time there is dirt that builds up on the rockers and rods and the lucas oil cleans it out. it took about 5 min of the engine running to make the difference.

lmao...that's a load of bs. the only reason the lucas oil lessens the noise is because it's thick as hell and doesn't run off as fast as normal weight oil will.

 

[midnight runner]

unless you have temps lower than 40F than you won't hear it. It only happens in cold weather.

It's about 60 here in the morning, and I get it.

 

[Uneek]

lmao...that's a load of bs. the only reason the lucas oil lessens the noise is because it's thick as hell and doesn't run off as fast as normal weight oil will.

:iagree: and both engines are DOHC.

 

[4runnerman09]

i used the full synthetic lucas oil and its not that think. also i only did it on two oil changes and no longer use it ($14 a bottle), so i will have to disagree with you.

 

[midnight runner]

So has anyone figured out what this is?