03 Nissan Sentra ser 2.5L.. The noise seemed to start this winter. When the engine is cold (to me it sounds like valvetrain noise) I hear a ticking noise that speeds up with the revs. Really bad when first started and driven a little. When the engine gets nice and hot the noise seems to disappear or quiets enough where it isn't audible over regular engine, exhaust, road noise. Any ideas as to what the noise could be, fixes, and problably causes? Last winter I didn't hear anything anytime.

Thanks Gee

 

Sounds like a convincing lifter peck to me. Do you know if your engine has hydroulic lifters? Another thing it COULD be, though not as likely, is a timing noise. Some timing chain/belt tensioners are hydraulic as well and could conceivably cause some noise like that if malfunctioning. I would definitely lean towards the lifter peck though...especially since it goes away when the engine warms up.

Take a mechanics stethescope (or a long screwdriver with your ear to it) and strategically place it on various parts of the engine while it's running and making the noise(ex. valve covers, timing cover, etc) to see if you can isolate more exactly where the noise is coming from.

 

You can also try to switch to a slicker engine oil, maybe a 5w-20 for cold weather only or even a full synthetic or synthetic blend and see what happens.

 

Had same noise with my nissan maxima and sure enough it was the lifters.

 

Thanks everyone. Is there anyway to free up the lifters without opening the engine? I'd rather try outside fixes before going inside. If not, what would the next best step be to free them up?

Gee

 

It really depends on what type of lifters the engine has. If they are hydraulic then there is not much you can do to adjust them other than find out which one/s it is and replace it or all of them. This could prove to be more that you would want to tackle though...I don't know.

You can certainly try, as was previously suggested, going to a lighter weight oil and see if that helps. You could also try running some of that "engine flush" through there in hopes of dissolving some of the varnish or "gum" that could be causing the lifters to malfunction, but there are risks to using that stuff that might outweigh the possible benefits.

If they are mechanical lifters then you may just need to adjust your rocker arms. Find a repair manual and do some research on your specific valve train system and let us know what you come up with and we can better advise you from there.

 

Thanks. I am going to try to buy a manual (Hayes, I think is the kind I can get).

Gee

 

transmission fluid has more detergents than the oil. you can either pour in about 8 ounces of it and run about a month before your next oil change, or add an additive for lifter sticking. sounds like the oil needs changed more often or you need a cleaner oil. you didn't say what kind of oil you use. all oil is not created equal.