If my valves chatter a bit at start-up, and then quiet down after about a minute, what does that mean?

Thanks!

 

It is taking awhile for the pump to fill the lifters backup. Either the pump is lazy or the oil is to heavy or the lifters are leaking down after setting for awhile. Some times an oil filter will drain back and cause this issue. Stay away from the Fram filters and there discount house brands. ie (pennzoil filters etc etc)

 

I second that, use quality filters like Wix, Purolator, or Motorcraft. Use a synthetic oil, and switch to a lighter oil. I recommend 5w20 or if you can find it, 0w20, unless your engine already has a oil leak or oil consumption problem then stick with the 5wXX

 

I agree with these guys about the filters. A good filter is just as important as the oil sometimes and won't drain back. Although I've never noticed a problem with the Fram in the stuff I've run, I HAVE noticed it with the "lesser" brands. I prefer to use Motorcraft whenever possible for my oil filters.

I've never heard of 0W20...until I looked it up quick I honestly thought that was a misprint...lol.

 

I recently had the oil changed, and the sound didn't really change. Is it bad for the engine?

I'd switch to synthetic, but the engine has an unknown number of miles on it and seems to have some leaks. They might just be from the valve cover gasket, but it could be a main seal.

Should I just not worry about it?

 

What year is the vehicle, and which engine?

 

It's a 98, and its the 4 cylinder. After that 1 min noise period, i never hear the valves again.

 

Regarding the oil leaks, maybe you could try re-torquing the valve cover bolts, it can't hurt. Just make sure to torque them to spec (9-13Nm, 80-115 lb/in), don't just tighten them by feel.

You can also use a "high mileage" oil (any name brand will do) which could also help to contain leaks (and are very good oils, to boot).

 

In my experience, a lifter will tap after sitting for a while for the simple reason that it has leaked down while under pressure from the valve spring. The leakdown can be caused by a leaky check valve, dirt, or internal leaks within the lifter. Inside the lifter body is another cylinder that is open to oil pressure at regular intervals when the lifter is on the heel of the cam. Oil pressure will fill the internal cavity, and press the internal piston *up* against either the pushrod or a cam follower. [using oil pressure] The oil gets captured when the cam starts to open the valve as the opening gets closed. Incompressible oil is used to open the valve.
Once the engine shuts down, the oil can leak out if a speck of anything makes the check valve leak, if the piston to bore clearance is large, or if the check valve is gummed or worn, or the check ball is grooved, depending on design.

The filter has nothing to do with it, except if the oil passages drain completely empty and don't supply pressure for a 'long' period of time. Most engines will develop oil pressure almost instantaneously when started. The electronic gauges used in most vehicles are slow to respond, at least slower than the actual oil pressure getting developed.
If you are really concerned, get a mechanical gauge and watch how long it takes to develop pressure after starting the engine. If it took as long as the tapping takes to go away, I'd think you'd have a lot of lower end wear already, and more to come. I'd bet your lifter is leaking down, and the viscosity really doesn't matter there either.
But this is just my 45 years of fiddlin' with cars.
tom

 

Tom, I appreciate the info, but this is WAY over my head.

Do you think I should worry about this problem, or just keep driving the truck?

 

IMHO : Just run the truck, go one grade higher on the oil (20-50 perhaps), change it more often. flush it with some seafoam, marvel mystery oil, bardahl, restore, diesel fuel, or whatever in it if it will make you more happy, but it's gonna tick until you do a tear down and replace the offending lifter. They will eventually go bad, but maybe like in another hundred thousand miles. You'll know because then there ought to be a miss in the affected cyl, or it won't pass smog.

 

In short, my answer is: keep driving it. Let it idle until the tap subsides. It might just stop all by itself.
If it really bothers you, find out which lifter is bleeding down, and replace it. Back when hydraulic lifters were new, there were LOTS of FE engines that tapped. Mostly because the design did not flow a lot of oil through the lifters, so they got varnished and would not expand (the oil pressure was not enough to move the piston to take up the slack) to take up the clearance as the valve train wore. They tapped. They tapped until they were sent to the boneyard. But they ran fine, without miss or stumble, for thousands of miles, if not tens of thousands.
tom

 

Thanks for all the advice guys, I appreciate it!

 

Actually the oil filter has a lot to do with it. The factory oil filter has a check valve in it, so that oil gets held in the valvetrain. Yes the valves have their own, but thats not the same.

I will agree this problem was more common when these engines were newer, but oil filters do make a difference. If I put a cheap filter in my Mazda, it starts ticking. If I use a quality filter, it doesn't. I have never had the ticking from the filter being old either.

Using a heavier oil is the opposite of helpful. Most modern engines like lighter oils. Stay away from the "high mileage stuff", its just regular oil with more detergent and a higher price tag. Besides, on a newer vehicle, I don't consider then to be "high mileage" till they hit 250,000.

 

This sounds like a higher milage engine. I know nothing about its history so I have no idea on how it was maintained. To me lifters rattling at startup and continuing for a minute sounds tired. An engine clogged with crud, leaking seals, and poor compression will make exactually that kind of sound. I would start as I did on my late '87 Ranger. Run something in the way of an engine flush first. Go to a heavier weight oil second, and as a last resort some type of 'glue' such as STP as a final stop. I managed to squeeze 5 years out of it without so much as talking a valve cover off of it. At Highway speeds the mains were so worn that my oil pressure would drop to close to zero and the lifters would start clacking. In the end I was running 20w50 with 3 pints of STP in it to keep it quiet. It still started and ran in warm weather. Sub zero mornings were iffy at best, and impossible in the end.
Higher milage formulated oil has additives that swell seals and reduce oil consumption. In personal tests, it does work for "weeping" engines, not for tired ones. There is a world of difference between the two.