carguy123

I have a 2005 Accord EX that I bought used with 5200 miles. The car now has 11,000 miles. Since the temperature has been dropping below 50F I have noticed a knocking noise upon startup lasting up to 10 minutes depending on how cold it is outside(the colder, the longer the noise will last). The noise is coming from the right side of the engine compartment. The noise sounds like an engine knock noise or like a deisel engine noise or something is loose and is rattling. This noise start after the car is started and you shift to Reverse or Drive and start applying gas. You will not hear this noise if the car is left in Park or Neutral. The noise gets louder if you accelerate to catch up to the flow of traffic. When the engine warms up thecar is nice and smooth. Changing to premium gas and different brands does not help.
I have brought my car to the dealership to have them tell me that this is normal noise Honda 4cyl engine makes, the tech did not hear anything abnormal(I have owned Honda 4 and 6cyl models in the past and none of them makes this noise on startup). After insisting that the service manager and tech drive with me in my car and another 05 4cyl Accord, the manager had to agreed my car does make this noise. They adjust the valve clearance on the car, this did not stop the noise, the car still sounds the same at startup. It was 3 days before Christmas and I did not want to argue with them or leave the car with them further.
I would appreciate any suggestion. I plan to take the car to another dealership in a another month. It would be nice if I know to suggest to them where to look instead of having them tell me again that this is normal.
I am using 5W20 conventional oil and a Honda fiter. Changed the oil myself(been doing this for 18 years myself, the oil level is normal,. Oil changed every 3K).

e3NiNe

sounds like your valves need adjusting ... already? Something's really not right.

Thooks

Change the oil. Make sure it's a 5W20, maybe Havoline. Take a chance and get a Honda filter.

GenXer

Could this be a trans. problem since you only hear it when it's in gear?

At least it's documented so that you may have more leverage later when something lets go. Make sure to keep good maintenance records too.

carguy123

The transmission is shifting smoothly, the trans fluid level is normal and color is perfectly fine, no burnt odor. This tranny is shifting smoother than my 99 Accord V6 4spd auto ever has. I will keep a closer eye out for the tranny just to be sure.
Could this also be an oil pump problem? The pump not delivering enough pressure when cold until the oil is warmed up to operating temperatures?

Accord1278

It's normal for the car to make that noise. My '98 has about 75k miles on it and recently started doing the same thing when it's cold outside. It's no big deal, just that the valves need to be adjusted. I'll get mine done when I go in to get a timing belt change, etc. No big deal, the noise is gone once the car warms up.

motoguy128

You said the sound is comming from the right side of the engine compartment. Is that right side when facing the open hood, or when sitting in the drivers seat (passenger side or driver side)?

If the problem goes away when warm, I can only assuem that it's the valves and it may be normal. The colder it is, the more clearance there will be in the valves. Because of this, the clearance must be checked when warm.

The other possibility is that the cam chain (timing chain) tensioner is not working properly. I beleive this also utilizes oil pressure to tension the chain.

As mentioned before, this could be partially related to oil viscocity. This car recommends 5W20. If 10W30 or 10W40 were used, you might have excessive valve clatter when cold.

I doubt the noise is actual engine knocking. When cold, the mixture is set rich by the computer. Rich mixtures slow fuel combustion and are therefore less likely to cause knocking.

wvrktguy

I've had the same problem on a 97 Civic and am now having it on a 2000 Accord EX. Both were 4cly models and both had a mild ticking sound when it was cold. The sound would go away as soon as the engine made it up to operating temp. However, I didn't start noticing this until the engines started approaching 100K miles. Had the valves adjusted on both and no change. Tried additives, tried cleaners (thought I had a clogged oil jet). No luck. Best bet always seemed to just let it warm up before driving on cold days.