92civichatchsir

my car knocks on cold start ups for like 4 seconds then goes aways,only does it when the car has been sitting for more then 2 hours or so,someone said it might be the rod bearings?

I need to figure it out before I turbo


oh and its a 96 gsr motor

!hybrid

hard to diagnose without hearing the "knock"

!hybrid

try something simple, like a heavier grade of motor oil. Wal-mart sells an oil called supertech, and that crap will make rod and lifter noise like you poured water into the engine where oil should go...ha ha.

92civichatchsir

I am using 5w30 mobil 1

civic_driver

If the car has more than 100K, try 10W30.

Combustion Contraption

The above suggestions are good. Also try this.

Disable the ignition by pulling the ECU fuse from the underhood fuse box. Crank the engine over for 20-30 seconds. (if the battery sounds like its gonna die, stop.) Put the ecu fuse back, turn the key to the ON position, let the fuel pump prime and fire it up. Does it still make the knocking noise?

92civichatchsir

what will that do?

HondaTechPro

Knocking on cold-start up is a normal condition on most engines, not just Honda. It is cause when the pistons.... not yet warmed up and expanded, tap against the cylinder walls. Once the engine warms up, even a little, the knock will go away. Honda will not even warranty this sound. "Normal" can last for up to 2 minutes afetr start up. It's not hurting anything in the engine, and thicker oil won't help. Use 5w30 like the engine was designed to run with.

92civichatchsir

so its normal?that really doesnt sound right

Combustion Contraption

Did you perform the procecure i mentioned above? This will prime your oiling system by pumping oil at a relative low rpm, probably around 150-250 without starting the car.

Then you can start it and listen for that knocking again. If its its still there, it not oil related.

92civichatchsir

yeah I did that and it didnt make the knocking noise,so what does that mean

dpkelly

Maybe a sticky valve. Try using 10W30 synthetic blend after a few oil changes to clean things up a bit. Does it idle rough or sputter?

92civichatchsir

no its idles great

Combustion Contraption

Its means the knock is due to lubrication problem somewhere during cold start-up. Try a thicker grade oil.

92civichatchsir

what should I go to 10w30 or what

92civichatchsir

should I just use rural purple

dpkelly

Hondatechpro is right. It's probably "piston slap". I have this bigtime in the winter with my '95 Odyssey. I have it a little with my '92 civic. I'm installing an engine block heater for the Odyssey. GM used to be notorious for it in their trucks but have gotten around it by using "floating wrist pins" for the pistons connected to the rods. If you read up about it, you'll see it doesn't mean much. Just let your car warm up a bit first so you endup burning less oil.

NINE TRE

is ur motor stock? or does it have sleeves? (since ur goin turbo)...
if u have the motor sleeved, it's normal to hear that...
my itr is sleeved, and it has that knockin noise when i start it cold

Kyles ej1

ok well my car was knocking and i thought it was rod knock so i havent drove it in a while but this morning i started it and it knocked when i started it and turned it off.....i just did what LsVtec92Hatch said it didnt knock, what does that usually mean?

HondaTechPro

Here is the reason that I doubt it is a bad bearing or even a lubrication problem. First off, you don't have an oil pressure warning light on do you? Secondly.... when oil is cold, it's thicker.... when it warms up it's thinner. Usually is there is a bad bearing, it will be MORE noticable when it's hot, and actually be quieter when it's cold. This is exactly what Honda says in the May 2000 issue of Servicenews:

Cold Start Knock
To some degree, cold start knock (piston slap) is a
normal characteristic on 4-stroke gasoline engines. It
happens when the engine is cold (piston-to-cylinder
clearance at its greatest, and most of the oil has
drained back into the pan). As the engine warms up,
the knock should quickly diminish, usually within 2
to 3 minutes.

92civichatchsir

yeah mine goes away within 10 seconds

Combustion Contraption

I havent ever heard piston slap on a healthy stock b series engine. How many miles on the GSR engine?

92civichatchsir

around 70,000 or so

ek_kid

it might also just need a valve adjustment.

92civichatchsir

thats kinda what I am thinking


I am starting to get mad at this car haha look what happened now