I know one or two people with this same problem on this forum its when you start the car from a cold start the engine makes a quick rattle noise that lasts only seconds. Has anyone come across this before? If so what is it?
I drive a 2000 Sunfire GT 2.4l
Mike MacNeil
JANS CHAIRMAN
I think i know what you mean, mine does it also, i think it does that because the engine is not lubricated properly at a cold start like from sitting all night because all the oil drained into the pan, so it takes that sec to get it all flowing again so basically its a dry start, i didnt have that problem before, i only got it after switching from Castrol GTX 5w 30 to Mobil 1 synthetic 5w 30 makes sense because synthetic oil is far much more fluid like and will flow to the bottom of the pan better than regular oil, the only way i can think to stop this would be to get a K&N oil filter with the drain back valve that way it will not allow dry starts, i dont use that filter because i would have to order it all the time when i do an oil change and thats a pain i just use the ac delco but i get that noise with it, now im not saying this is exactly what the problem is, i am just saying thats what i think it is, someone correct me if im wrong
Well when I do my oil change I may use sythetic oil to see if it makes a difference. How many KMS do you have on yours?
Mike MacNeil
JANS CHAIRMAN
i use synthetic and i get it, when i didnt use synthetic i didnt get it, i have 85,000 km on it and its a 2000 2.4
i have that noise on my car. i've been using Mobil 1 since 25k miles and didnt get the noise until about 60k miles. my car now has 87k miles. im planning on taking an audio clip of the noise to a GM dealer and see if i can get an opinion on what it could be.
Peace Out!!!
Doesn't sound right to me, my car was much quieter after switching to Mobil 1 synthetic.
The bottom line is that synthetic is just a much more effective lubricant. It clings to the surfaces that it touches, and its so slippery that friction is almost non existent when compared to conventional oil.
However, due on the engines design, I suppose that it is possible for the top end to not be getting enough lubrication on startup. If you seriously think that its an issue, try some Lucas oil Treatment. Comes on a big cone-shaped bottle, just pour it over the valvetrain or into the oil fill, and see if it makes any difference. its much thicker than regular oil, and it's supposed to really cling to the surfaces that it touches.
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so that noise could be coming from the CAM? The lucas oil is what I was thinking of putting in it. I was told it could be a rod bearing from a local mechanic but I thought once a bearing goes you constantly hear it.
Mike MacNeil
JANS CHAIRMAN
if its just on start up , its the lifters , both my 97 2.4 and my 00 2.4 did it
what happens is the oil in the lifters bleeds out , and it takes a few seconds for the oil to pump them back up
only real fix is replacing the lifters , which on the 2.4 is like 400+ in just lifters
its really nothing to worry about, i dont think that its the lifters that are bad, i just think that its a dry start because the oil seeps down into the pan and not enough stays up there to lube the lifters thus thats why you hear that sound it takes not even a sec for the oil to recerculate in the engine, its the same noise as if you just did an oil change and started it up for the first time after the oil change its because there is not enough loob on the parts so it has some friction till the oil circulates, a filter with a drain back valve will solve the dry start problem such as a k&n even k&n says it will solve dry starts, outher than that it will not really do any harm the friction is so little and so quick that you would have to start your car tons and tons of times before you are actually wearing anything else, by that time you will not even have your car
I switched over to Mobil 1 on my 00 Cavi with 2.4. Engine has 97k on it and it seems to idle better and be quieter than before the syn switch.
when i switched it sounds exactly the same and idles the same the only difference is i get that sound now and before i didn't
