Piston Slap or Rod Knock?

[majdoob]

I have a 91 with 61k miles and when I start the car cold, I hear a repetitive "ticking" sound which lasts for a bit until the car gets warm. It is not very loud, and you can only notice it if you are standing outside the car near the engine. Once the car warms up, it stops. A search uncovered two threads from a couple years back, but no clear answers....so I am posting this and looking for some guidance.

A bit more background...in looking through the records that I have from the previous owner, he took it to Acura for a routine tune up and mentioed this issue. That was 2 years ago when the car had 51k miles. The dealer wrote on the work order "heard lower end noise...may be piston slap or rod knock...have customer monitor noise".

Anyone experience this issue? How can I tell if my car is having an issue with piston slap or rod knock? I am willing to take it to the Acura dealer, but want to be a bit educated before I go in...I don't want someone tinkering around and guessing at what the issue may be...especially if it might be serious. Any thoughts?

 

[Acura NsX Pilot]

My 91 has had it for years and I assure you its normal.

 

[Ponyboy]

Common valve adjustment or LMA (Lost Motion Assemblies) should do the trick.

 

[Batmobl]

My 91 has had it for years and I assure you its normal.

Your car may be in need of a really expensive repair soon then. NSX's don't have hydraulic lifters YOU HAVE TO HAVE ROUTINE VALVE ADJUSTMENTS!

 

[nigel]

It' not rod knock or piston slap. It goes away because the oil gets pumped up to the valve train after the engine runs for a few seconds. Probably just valves need adjust or just on the loose side of the tollerances.

Cheers
nigel