Cam Rattle

Need a bit more information.

How much oil is the car consuming over mileage - i.e., car burns X number of quarts every X miles? Two quarts in roughly 10 days does sound fairly excessive - but how excessive depends on the miles driven and if you have any other issue, like oil leaks and whatnot. If you drove 2000 miles over that week and a half, that would put you at 1 quart every 1000 miles or so - not really good, but not terrible either, especially with a car with a lot of miles on the clock.

Also depends on the mileage you have on the engine, what transmission it has, and how it is driven. Also be nice to know the type of motor oil used, oil viscosity, interval between oil changes, etc. Oil changes done by yourself or quick lube places/dealership? This will be more important if you really do have a cam rattling issue.

The 1ZZ-FE engine is known to be very noisy at idle and at speed. See if you can pinpoint the noise more precisely - you mentioned higher RPMs, what kind of RPMs are we talking about - 3000RPMS, 4000RPMS, redline? Since this is a 2000 model year, they also introduced VVT-i to this engine - that has an associated oil control valve and oil control valve filter. If the car is running through a lot of oil, there is a good chance that the filter or control valve itself is clogged up. This will prevent the variable valve timing system from functioning properly - would cause some vibrations and rattles, due to the timing not being optimum for that particular load/RPM range.

1ZZ-FE is not really known for cam issue - but things that could be causing the rattling noise at speed - VVTi system being clogged, running too heavy of motor oil (starve the bearings in some cases), running with too little motor oil (again, starves bearings), bad oil pump, bad accessories, worn serpentine belt tensioner, or tired engine.

Some 8th gen Corollas had very high oil consumption - some on the order of a quart over hundreds of miles. Some are as bad as a quart every 100 miles or worse. Most are due to stuck piston rings, many are associated with 3-speed autos option on earlier 8th gen Corollas without VVTi (1998-1999 model years). Later models had some redesignes that seemed to help,m but some still had some excessive oil consumption. Sort of hit or miss - some have had no problems at all running hundreds of miles on their cars, some had problems from basically day one.

The oil control valve and the oil control valve filter are almost immediately to the right of the alternator, just to the left of the far intake manifold runner. I started a thread on the OCV filter some time ago - here's the link to it: https://www.corolland.com/forums/index.php?/topic/22499-diy-info-some-uncommon-maintenance-items/page__view__findpost__p__159456

113K is not a lot of miles on this car, definitely find out what the oil consumption is like, as that will play a big part of what is happening. I mentioned quick lube places earlier, as there is a history of bent valvecover baffles on this engine family. The baffle is located directly under the oil cap, since most shops use a oil gun where the nozzle attaches to the valvecover with a clip or is just simply wedged in there - this can actually bend the baffle downward enough to touch the camshaft. Many dealerships also can cause this damage - depends on the dealership. Unfortunately, the only way to find out is to pull the valve cover off.

The behavior of the rattling most noticeable at a light loading/unloading of the engine sounds more likely to be a OCV / VVTi issue. Really no power loss or driveability problesm, more of an annoying rattle. Doesn't just affect Corollas - many Celicas and MR2s also have this noise issue, Lotuses with the Toyota 2ZZ-GE have be reputed to have this noise too. Newer Corollas/Matrix and other Toyota engines with VVTi can make this noise, but generally less noticeable.

Heavier oil will generally help overall noise - but I would not recommend that as a solution. Definitely would not recommend anything heaver than a 10W30 - if the car has been running conventional oil, stick with that for now. If it is an issue with the OCV filter being clogged (fairly common in cases with this rattling at a light loading/unloading of engine at engine revs off-idle to 4K RPMs) - an oil with greater solvency might make the issue worse (loosen up bigger chunks of engien gunk and totally clog the OCV filter, gum up the VVTi actuator).

The difference between the full mark and the low mark is about a quart. So over that 4K mile interval - you lost atleast a quart of oil. Little more than I'd like to see, but well within reason for a 10 year old car with enough miles on it. I would try to keep up with the oil levels as often as you can. Even dropping 1/2 to a quart, puts a heavy load on the remaining oil left in the crankcase. I would check the level every time you fill up gas or atleast set intervals to monitor oil consumption.

As for the possibility of a clogged or gummed up OCV - quite probable, given your description. Part throttle or light engine loading at speed causing the noise is the key. Careful when doing this project - if the filter drops off the bolt, you must fish it out. The way the filter and bolt sit inside the opening - if you do not perfectly line them up, you could distort or crush the filter. Sometimes you'll find that the filter is already distorted from excessive heat or from too much sludge/deposits stuck on it. You can clean the filter with just about any solvent - just make sure the solvent is not too strong to dissolve the plastic body of the filter.

Seafoam can be used as an engine flush - but I wouldn't go that route just yet. As a solvent, it works pretty well - because of this, if the engine has a decent amount of deposits inside of it - they could loosen all at once, that could lead to clogged oil passage ways and clog filters. Seafoam used in it most popular application, pulled through the intake to clean the upper end, will not help the OCV filter.

Holy smokes! Sounds like the engine starved itself for oil/lubrication - did the oil pump die on you?

I just found this topic today. I'm having this problem and had a mechanic friend pull off my valve cover to inspect my CAMs. I have a 2001 toyota corolla 1.8L 1ZZ-FE. I have dual overhead CAMs. The front CAM, I assume the intake, has chipped lobes on the far left end. (close to the timing chain) Only the 2 left lobes are chipped on the left sides of the lobe. I have no idea what to do besides replace the lifters and the intake CAM. I didn't hear about the OCV thing until now but I'll research it more now that I have. Any idea what would cause the CAM lobes to get chipped? They seemed oiled up and there wasn't any debris inside there at all.

Quite unusal to see chips in that manner. Can be caused by a number of things - if no debris is noted (have you cut open the oil filter yet?, dropped the oil pan and checked the screen on the oil pickup?) - then it is likely worn lifter "cups", which can cock slightly sideways in the bore and then load the edge of the lobe, causing it to chip. Or it could be the cam itself is "walking" (worn bearings, camshaft play), sideloading the lobes and causing them to chip. Check the teeth on the sprockets - do any of them appear chipped/worn? Notice any slack or lack of slack on the timing chain?

I'd suggest pulling some oil and sending it to a used oil analysis shop to look at wear levels. Could give you something to go on, depending on which metals are in the highest concentration. Can try the old school trick of running a magnetic drain plug to catch any ferrous metal that gets past the oil filter.

PCV filter you mean? It actually filters air rather than oil. Did you check oil grade? Noise sounds more like something's loose, to me, (a non-expert)