01 Corolla - Sounding A Little Aged - Corolland: the Toyota Corolla Forums

hi everyone,

I have a 2001 Corolla LE Auto, with 140k on it. I bought it when it had just under 130k.

The motor, especially when cold, almost sounds like it's knocking. It's not quite a knock, but you can hear a distinct repeating sound, especially when accelerating. If I accelerate (without it downshifting), it makes a similar sound. As soon as it downshifts, and the RPM get up, the sound goes away. Like I said, it's especially noticeable when it is cold.

It's hard to describe - it just doesn't sound pure like a newer corolla, or even my old '92 Camry (which has over 200k on it). I had a mechanic look at it, and he said something about needing to adjust my injectors. He wasn't worried about, he just said you could hear them when it was cold. And I had another guy ask me if I had adjusted my injectors yet. I wasn't aware (nor am I finding any resources) that you could adjust injectors.

Any ideas? The only thing I've done to it since I have owned it is replace the tires, front brakes, and change the tranny fluid / filter.

Only reason I ask now is it's begun sounding a little worse recently.

Something else I should mention is that when I first accelerate (less than 5MPH), it makes a loud sound. I was told this is the AC compressor, and the sounds goes away as soon as I give it any gas (it won't do it in neutral, only in drive). I am also throwing an EVAP leak code on the engine.

Where should I begin? I know about changing basic things like the spark plug and wires, but if someone has some input, I wanted to start there first. Can the timing chain stretch at all, and make it get a little out of time?

Jared

hi everyone,

I have a 2001 Corolla LE Auto, with 140k on it. I bought it when it had just under 130k.
The motor, especially when cold, almost sounds like it's knocking. It's not quite a knock, but you can hear a distinct repeating sound, especially when accelerating. If I accelerate (without it downshifting), it makes a similar sound. As soon as it downshifts, and the RPM get up, the sound goes away. Like I said, it's especially noticeable when it is cold.
It's hard to describe - it just doesn't sound pure like a newer corolla, or even my old '92 Camry (which has over 200k on it). I had a mechanic look at it, and he said something about needing to adjust my injectors. He wasn't worried about, he just said you could hear them when it was cold. And I had another guy ask me if I had adjusted my injectors yet. I wasn't aware (nor am I finding any resources) that you could adjust injectors.
Any ideas? The only thing I've done to it since I have owned it is replace the tires, front brakes, and change the tranny fluid / filter.
Only reason I ask now is it's begun sounding a little worse recently.
Something else I should mention is that when I first accelerate (less than 5MPH), it makes a loud sound. I was told this is the AC compressor, and the sounds goes away as soon as I give it any gas (it won't do it in neutral, only in drive). I am also throwing an EVAP leak code on the engine.
Where should I begin? I know about changing basic things like the spark plug and wires, but if someone has some input, I wanted to start there first. Can the timing chain stretch at all, and make it get a little out of time?
Jared

Having the injectors checked out is a good idea. While not the same make of car, I had a similar experience with my '91 Dodge Shadow. I bought it new in December of '90, and since I was in Wabash, Indiana at the time, it was definitely cold every morning! I took it in to the dealer, and they replaced something having to do with the injectors. Problem solved!

Injectors do not need to be "adjusted" - nothing to adjust, but they may need to be cleaned or have the spacers/o-rings replaced. A misfire under load is pretty common on any engine that has a lot of miles on it, with the cylinder head/piston crown design of the 1ZZ-FE, with an excessive amount of carbon build up - seems to very prone to this misfire. With no EGR to "cool" or slowdown the combustion process, it has to be handled by the head/piston crown and can manifest as a knocking noise.

As long as the noise subsides once the engine is warm - there is no issue with the engine. The 1ZZ-FE is a noise engine to begin with, even when running properly. Given the mileage - possible that the valves will need to be adjusted. To verify, need to pop off the valve cover and check valve clearances. If the clearance between the lobe and the lifter cup is out of spec, then that could be the cause of the noise.

A clogged VVT-i system, especially the OCV (Oil Control Valve) and the OCV filter, may have been clogged with varnish and deposits. The OCV filter could be clogged with debris, and starving the OCV of proper oil pressure. Once this happens, the VVT-i system doesn't apply the correct valve timing. This can also cause quite a bit of noise, especially so on partial acceleration or light to moderate loads.

I'd start with a comprehensive "tune-up" just to rule out the simple stuff. Stick with iridium plugs (OEM ones are good for up to 120K miles) - should come pregapped, but verify they are set to 0.044", no plug wires on this car - distributorless coil on plug ignition system, double check the condition of the serpentine belt and especially the serpentine belt tensioner. On some models, a worn tensioner was responsible for noises that sounded exactly like rod knock. On closer inspection, the tensioner was actually vibrating and the noise transmitted caused that knocking noise.

Check all fluids, if coolant hasn't been replace, I'd looking into having that flushed out. Same with powersteering, transaxle fluid (automatics and manuals I personally like to do a drain and refill every 30K miles - cheap insurance), brake fluid/master clutch cylinder fluid.

Yep the valves are what may need adjusting like Fish said, not the injectors. If I remember right Toyota recommends doing that every 100k. These cars have what sounds like a slight knock during warmup that goes away after a few minutes. Mine was more loud when I used pennzoil but it's more quiet with havoline so that is what I use now.

Guest iabditn

Thanks to all of you for this input. My 2001 LE also has exactly this same symptom. I do notice a slight difference between Shell gas and Chevron gas.