Loud Pinging After Turning Engine Off

[gllexus]

I've done quite a lot of searching in this forum and on the Internet in general, but could not find any answers. Any help would be appreciated:

Lately (within the last few days), I've noticed that when I turn off my engine, there are loud pinging noises coming from under the hood. It lasts for quite a while (5-10 minutes). I know that cars make noises after turning off the engine due to certain parts cooling, but this noise just seems very loud and excessive. I'm not sure if it's normal or something I should worry about.

Also, I do not hear the pinging noise at all while the engine is on (neither idling, nor accelerating).

Thanks in advance.

-Gene

[Revron1]

My 94 does the same thing exactly. It has done it since I have owned it (six months) Hope you find out so I know.....Thanks

[92blackSC400]

You're correct, something is cooling down. Most likely the C/converters as they are the hottest item on the vehicle. They also have thin quage heat shields attached for obvious reasons. As the thinner heat shield cools from ambient conditions and lack of additional recuring heat from the running engine, contraction takes place - audiable tones will be heard during the process. This can also happen to the mufflers.

This is not unique to Lexus vehicle, all vehicles do this to some degree.

I wouldn't worry.

[Theodore]

I got the same problem. a memeber told me its definetly the heat sheilds i guess they are thin and heat up quickly i noticed when i push the car alot it does it more.

Im guessing you can change them with the Hi flow Cats to stop the noicse.

[99lsguy]

yeah,

its just cooling down....my LS doesn't do this ; but my wifes' Toyota Sequoia "pings" quite a bit on occasion...

Not to worry....

99

[BlackSC4]

i took off the heat shields to my cats, and no more pingings. it doesnt seem like anything may be harm from the heat too.

[southernsc300]

its a toyota thing i think, i have never heard any other car cool down as loud as a toyota

[BlackSC4]

my father's 99 v-6 camry is actualyl very quiet, and corollas too. i think it's an sc/ls thing...

[psolov]

This is normal. Has been going on my 95 SC400 for 200k miles, although I don't remember it on the 92 SC400

Paul

[UCF3]

I've done quite a lot of searching in this forum and on the Internet in general, but could not find any answers. Any help would be appreciated:

Lately (within the last few days), I've noticed that when I turn off my engine, there are loud pinging noises coming from under the hood. It lasts for quite a while (5-10 minutes). I know that cars make noises after turning off the engine due to certain parts cooling, but this noise just seems very loud and excessive. I'm not sure if it's normal or something I should worry about.

Also, I do not hear the pinging noise at all while the engine is on (neither idling, nor accelerating).

Thanks in advance.

-Gene

Is the noise coming from the engine or underneath the car?

Someone else has mentioned another pinging noise coming from the engine in another post, and I'm kind of curious about that one.

The centre cat is very thinly shielded.

[Theodore]

that sound is from the cats. heat sheilds.