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Knocking in Engine?

What are the Causes of this?

I have an 02 Nissan 4cyl Altima, and when I start it up in the morning it starts rough, and I hear like a gentle knocking sound it increases with speed, but after 30 or so I don’t hear it anymore.

Help?

A few reasons may be low engine oil or chronic low engine oil. Also lax oil change habits are another possible cause. Another possibility is a failed or failing oil pump.

I would get this checked out and not ignore it.

Could be noisy lifters. You don’t happen to use Allied Signal produced oil filters (Fram, Pennzoil,etc.) do you?

What do oil filters have to do with noisy lifters?

poor flow rates and bad anti-drainback valve design can contribute to noisey valvetrains in cold weather. Once the oil is heated up it’s thinnner and flows more easily, so the noise goes away. Allied Signal filters are known for this.

If it’s a “clicking” or “snapping” sound, it could be a partially stuck lifter or just a weak lifter that bleeds down. Normal oil pressure quickly pumps the lifter back up and it goes away. You might try a product that claims to “frees sticky valve lifters” Rislone is a good one…

If the sound is more pronounced, a deeper thump, then piston slap might be the cause. But that usually takes 5 or 10 minutes to subside as the engine warms up. I’m assuming you meant 30 SECONDS as the time interval…If it goes away in 30 seconds, it’s almost always a sticky lifter. The rough running might be another problem. Dirty injectors?

I’m going to respectfully disagree that oil filters have anything to do with valve lifter rattle.
A good valve lifter should be fine even after sitting for a few months. If a lifter requires a different type of filter to shut it up then repair the faulty lifter rather than blame the filter.

The comment about Allied Signal filters (Fram) points back to that internet generated garbage about Fram being bad filters and causing valve lifter knocks. Pure bunk.

When I had my old 92 T-Bird SC. I can tell you without hyperbole that Fram filters can indeed cause noisy lifters. At the time the car had a fairly high amount of mileage on it (about 130,000). Against my better judgment I took it to a quick lube place for an oil change since it was quite cold and raining. I got the oil changed and came home. The next morning I started the car and hear a ticking noise. I disregard it and continue on to school. The noise stopped once the car warmed up. The next morning the same thing happened. I checked the oil level, it was full. The following weekend I decide to change the oil again. I use an OEM Motorcraft filter and the same brand/weight of oil that the oil change place used. And miraculously the next morning, about the same temp/conditions as the previous week, the noise is gone. The oil filter that the oil change place used was a Pennzoil filter which is made (and has been for some time) by Allied Signal. Ever since then, I’ve used Purolator and Motorcraft filters exclusively. Keep in mind this takes place well before the internet reports came up.

The only thing I’m telling you is that an oil filter has zero, zilch, and nada effect on a hydraulic lifter operation.
If an engine has a lifter rattle upon startup that is the fault of the lifter, not the filter.

The lifters are bleeding down for some reason; worn, gummed up, or whatever. The ticking can even be erratic in nature but they’re not rattling because of the filter.

I’ve got a Ford 2.3 engine sitting around waiting for something to put it in. The engine runs great but at times in the past it has exhibited a lifter rattle when started. It may do it once in a month, go for 6 months with no noise, or it may rattle every day for a week. The lifter is at fault, not the filters (which is a Motorcraft).

Feel free to constact any reputable engine builder, trade organization such as ASE or SAE, etc. and pose this question to them if you doubt me.

If you mean 30 seconds or so and it had not been doing it before your last oil and filter change, I would suggest a bad filter. It happens. It is not likely to cause any damage and will go away with the next filter change. On the other hand if it has had the same problem with more than one oil filter, that should not be the problem unless you are getting the wrong filter. Using a quick change place to get your oil changed is a very bad idea and they often use the wrong filters.

Note: the right filter does not mean filter make, but rather the specific filter number specified for your specific engine/car.

I agree that it’s the lifters rather than the filter. A properly operating lifter should have no problem filling its body with oil immediately even if the lifter body had drained of oil, and a properly sealing check valve in the lifter body should have no problem keeping the fluid in under lifter compression.

Of course, my reputability is questionable!

OT, but since anti drainback valves are being discussed, on some engines the problems can be profound when oil pressure is used for newfangled devices like powering variable valve timing. A bad valve can cause hard starting. Here is a quote from a Ford TSB for 2.0 l Zetec engines:

NOTE VEHICLES WITH A VARIABLE CAMSHAFT USE FORD OIL FILTER FL-2005, THIS OIL FILTER HAS AN INTERNAL CHECK VALVE THAT KEEPS THE EXHAUST VALVE CLOSED, WHEN THE ENGINE IS OFF, THIS WILL PREVENT ANY HARD START, OVER-FUELING OR FLOODING CONDITIONS ON INITIAL START UP (FIGURE 1).

Hmmm…you have my attention.

Sounds like the so-called “check valve” actually allows collapse of the exhaust valve lifters. Gotta look into this…enquiring minds want to know.