First, I apologize. Either the search function isn't working properly, or I'm not using it correctly.

I have a 98 accord. On cold start up the engine sounds vaguely like a diesel. The sound disappears as the engine warms up. The warm engine is super quiet.

From searching the internet it seems that this may be piston slap, and that it is normal and harmless. Is this a correct diagnosis?

I just purchased this car, and would like a little piece of mind. I used to have a 97 EX (same motor) that I don't remember doing this, so I'm not so sure it's normal.

 

Piston slap is never an ok thing and I think people are confuzing it with low oil pressure. When you first start up your car all the oil is in the bottom of the oil pan and is working its way up to the top of the engine were your hearing all the noise and when it gets there it quiets down. This is normal on a lot of cars. Keeping your oil fresh will help this, also a thinner oil and synthetic will help this also. I use Mobil 1 full synthetic on everything. Royal Purple is great also but a bit pricey. If it gets worse you may need a new oil pump and pick-up. Hope this helps.

 

RP is good stuff, but more for a race engne than a DD since it can leave graphite deposits over time. IMHO, Amsoil is the best for a DD.

 

yea. piston slap is never a good thing at all. But I agree with the 1st post. Sounds like low oil pressure

 

Could also be clutch chatter, saw that you have a manual. Just check the oil and you should be fine

 

?? If it goes away in 15 or 20 seconds then it is a pick up problem. If the sound takes a few minutes to go away it is piston slap which is normal. Piston slap is common to all vehicles, some more than others. My Honda's seem to exhibit more than other vehicles but this is not a problem. The sound goes away when the pistons heat up and expand in size. Normal, normal, normal. My Accord did it when I first got it and it still does it with 253,000 miles on it. My Odyssey did it when new and still does it 155,000 miles and so did my Civic. Also this sound will be a little more prominent in the winter time then in the summer time. I really don't think I had an oil pick up problem on all three cars and not one of them ever had an engine problem, blew smoke or lost oil.

My advice is just to be easy on the car until it reaches operating temperature which is probably what you do anyway.

 

Well just had my 2005 V6 rebuilt because of piston slap. started at 95,000 miles and noticed at the beginning of the winter. Engine noise sounded like a diesel at startup and went away after 5 min. After a year and half and 30,000 miles later it made the noise all the time. Too bad Honda can't take care of this issue after all they know that their is a problem with this engine from the people Iv'e talked to at Honda. O well After tear down found 2 pistons number 5 and 6 were the cause. After rebuilt and $2,200 later runs like new again. I Saw some people had their valves adjusted and that fixed their noise, didn't work for me. Hope I don't have to do this again.