Topic: Knocking sound as soon as the nights become cool

[epicurien]

Another question about my 10 year old civic:

I find that as soon as we get a cool night, when I start it up in the morning the motor is a bit loud like a knocking sound, a piston sticking? It goes away as soon as the engine warms up. I am running Amsoil 5/30. Any ideas from anyone about what might be causing this sound which I find so aggravating? Is it something minor that I shouldn't worry about or could it be something I need to get fixed? I asked the mechanic who does my oil changes and he didn't seem to think anything of it.

[barrie1]

I would be more inclined to think a noisy or stickey lifter to begin with then a loose piston. Either one will give you noise like you describe. It could be a moisture thing as well in your ignition that dosen't quite warm up right to start with when cold. A bad piston skirt as well will make a ticking noise on some engines. I would try a Container of EOS,  Engine Oil Supplement from GM for around $5.00. This lubricates the top end stuff really well and shuts up a lot of weird noises in most engines. It will loosen up any stickey parts and coat them really well.

[tpl]

I think that one would have to hear the noise before diagnosis.

How long does it take to go away? seconds, minutes?
is it rpm dependent?
is it worse when you are driving with the engine under load?
Or is it worst when decellerating?

it is a clicking like a clock tick
clonking a hollow sound
knocking    
tapping
rattling?

high frequency or low?

is the engine idle smooth when this is happening?
does it coincide with the engine light problem

I wonder if it is related to your earlier problem and the diagnosis of a bad timing belt or belt tensioner is the culprit

[safristi]

Haven't had many cool nights this Summer in Ontario.....maybe 15C a coupla times...so what part would "contract" that much with such a small temp drop....Sherlock begins his sleuthing...bring me my pipe and Cocaine Watson....!!!!!banging,"knock..knick" my head on computer desk....!!!??

[Sterling]

Aren't Civics known for their sticky lifters.

[Minou]

Could a restrictive oil filter be the culprit?

What's on the car at this time?

[barrie1]

I am starting to wonder if with this happening more so with the cooler nights maybe the exhaust system is expanding and contracting a little more then usual as it heats up. Possibly one of the donuts on the engine is starting to leak. Just a Thought.

[epicurien]

I think that one would have to hear the noise before diagnosis. How long does it take to go away? seconds, minutes?

ANSWER: maybe a couple of minutes.
 
is it rpm dependent?

Answer: yes  

is it worse when you are driving with the engine under load?  

Answer: I don't think so

Or is it worst when decellerating?  

Answer: no

it is a clicking like a clock tick  
clonking a hollow sound  
knocking  
tapping  
rattling?  
high frequency or low?

ANSWER:  not hollow, not a rattle, knocking I think, like tick,tick tick but no tock, more high than low
 

is the engine idle smooth when this is happening?  - YES

does it coincide with the engine light problem

Answer: no more engine light problems for awhile now  

I wonder if it is related to your earlier problem and the diagnosis of a bad timing belt or belt tensioner is the culprit

ANSWER: the timing belt was changed by the first owner at 62,000km. There is now 130,000km on it

So, I'm tempted to go with Barrie1 idea and buy some fluid at GM. }

[chrischasescars]

I'm with Barrie and his sticky lifter suggestion. My car does that too in cold weather when it takes a few minutes for the oil to work its way into the tiny nooks and crannies in the valve train.