2000 Toyota Corolla | Misfire codes, Tune Up Needs

[Globalksp]

I've recently started taking an interest in caring for a 2000 Toyota Corolla (100,000+ miles) driven by someone I've taken an interest in

The car is possibly a 2001, but an eighth generation for sure. Haven't gotten around to checking the manual/VIN/Etc... I'd assume it's burning a little bit of oil, but when checked wasn't low enough to cause any alarm on my part.

She's well due for an oil change, could do for a proper shade-tree tune up before winter sets in (Virginia), and returned 3, OBD II cylinder misfire codes.

1) The OBD II threw out 3 misfire codes, each one on a different cylinder (1,3,4, I believe). I tried using the reader to reset the codes to see if it was still misfiring, but alas, you get what you pay for and the car was stubborn and the check engine light remains on. She said the CEL has been on for quite a while, which probably means months. I'm educating myself on misfires, but any thoughts or guidance here?

2) I'm an XJ driver and while I'm new the world of OOK (obsessive oil knowledge) and still studying to pass my AUU (acronym understanding and usage) exam

, I'm not new to maintaining vehicles. That said, anything in particular to watch out for on these fairly-hard-to-kill Toyota engines? I've got a new PCV on the to do list so far.

3) And finally... oil. As stated, new to this depth of understanding, but I was planning on going with enter brand here synthetic 5W-30 and filter. For my '01 XJ, I've stuck with Mobil 1 oils and filters (currently 5W-30 and M1-301) simply because, well, branding. Everyone has their preferred brand for x,y,z reasons, so feel free to let me know them, but is there any worth in High Mileage 5W-30 vs Regular vs Dino?

Thanks all!

 

[JMJNet]

IIRC, misfire code cannot be cleared since it is monitored continously.
In other words, it will code as soon as a misfired condition exist which is when the car is started.

In a Toyota, it is usually caused by bad Spark Plugs, bad spark plug cables/coils (depends on what is in there) and last vacuum leak.
Start by replacing the spark plug first and inspect if oil is coating the spark plug.
If there is oil, then the valve cover gasket and spark plug gasket need to be changed.

If replacing the spark plugs still not solving the problem, then the spark plug cables or coils need to be changed.

If it uses spark plug cables, you can measure the resistance between the 2 ends to test them.
I am sure coil is probably test the same way.

 

[Globalksp]

Originally Posted By: JMJNet
IIRC, misfire code cannot be cleared since it is monitored continously.
In other words, it will code as soon as a misfired condition exist which is when the car is started.

In a Toyota, it is usually caused by bad Spark Plugs, bad spark plug cables/coils (depends on what is in there) and last vacuum leak.
Start by replacing the spark plug first and inspect if oil is coating the spark plug.
If there is oil, then the valve cover gasket and spark plug gasket need to be changed.

If replacing the spark plugs still not solving the problem, then the spark plug cables or coils need to be changed.

If it uses spark plug cables, you can measure the resistance between the 2 ends to test them.
I am sure coil is probably test the same way.


Great, thanks for a good start.

So if I understand correctly... The engine is currently misfiring at startup. If I replace the plugs and they were the cause, the the computer won't throw a code and the check engine light won't illuminate. Correct?

 

[WillsYoda]

My 1999 corolla had the same issue. The valve cover gasket seals come attached to the spark plug gasket seals. The spark plug seals were letting oil get to the spark plugs, and so the misfiring was there. I got a felpro valve cover gasket and installed 4 new spark plugs. Now all is well. I spent about $30 for the whole thing.

 

[Powerglide]

I have a 1995 Corolla 1.8 liter automatic. 190k actual miles. Repainted a year and a half ago. Looks, runs, drives, steers, accelerates, brakes and shifts as new. 5-6k oil changes with 5w or 10w-30 with whatever top tier Dino brand is on sale at Walmart. Same routine since I bought it 8 years ago with 86k miles. It uses a little more than half a quart of oil between changes. The a/c system is original and has never been opened up. I live in Florida. It's on ALL the time. Blows cold and needs topped up with R134a quarterly. VERY slow leak somewhere. The spark plug WIRES need replaced every 3 or 4 years. Probably the most durable, relaible cheapest to own car I've EVER owned.

Oh and 24-34 MPGs city/hwy.

 

[Globalksp]

Originally Posted By: WillsYoda
My 1999 corolla had the same issue. The valve cover gasket seals come attached to the spark plug gasket seals. The spark plug seals were letting oil get to the spark plugs, and so the misfiring was there. I got a felpro valve cover gasket and installed 4 new spark plugs. Now all is well. I spent about $30 for the whole thing.


Just did some more research on this and sounds like a great place to start. Passing along a great article for those who find this in the future: http://troubleshootmyvehicle.com/toyota/1.8/corolla-misfire-case-study-1

 

[WillsYoda]

Originally Posted By: Globalksp
Originally Posted By: WillsYoda
My 1999 corolla had the same issue. The valve cover gasket seals come attached to the spark plug gasket seals. The spark plug seals were letting oil get to the spark plugs, and so the misfiring was there. I got a felpro valve cover gasket and installed 4 new spark plugs. Now all is well. I spent about $30 for the whole thing.


Just did some more research on this and sounds like a great place to start. Passing along a great article for those who find this in the future: http://troubleshootmyvehicle.com/toyota/1.8/corolla-misfire-case-study-1


I diagnosed it by just pulling out the spark plugs tubes and finding oil on some of the plugs. I could see some oil even before removing the spark plugs (after shining a light down onto the screwed in spark plugs). But pull the plugs too. Oil on and around the plugs can be a telltale sign of faulty spark plugs seals. Those seals fail pretty often if you have an older gasket, so it is good to replace them (and the spark plugs) regardless.

 

[barkingspider]

Originally Posted By: WillsYoda
My 1999 corolla had the same issue. The valve cover gasket seals come attached to the spark plug gasket seals. The spark plug seals were letting oil get to the spark plugs, and so the misfiring was there. I got a felpro valve cover gasket and installed 4 new spark plugs. Now all is well. I spent about $30 for the whole thing.


This

 

[LeakySeals]

The 98-02 1.8L Corolla engine has known oil consumption problems. The piston oil return holes clog and nothing can free them short of a teardown to clean and drill more holes. Engineering change in 03 fixed the issue. So if its real low on oil and has a sooty tailpipe you know its getting bad. Usually 1qt per 1-2k

= Clean throttle body.
= Replace intake manifold gasket and while its opened try to clean piston tops with a soak of carb cleaner. random multiple misfires can be plugs but also vacuum. The IMG is likely cause and allows for a good cylinder soak
= Replace the plugs.
= Valve cover gasket replacement if it looks like there is a leak at plug boot as recommended by others.

Use thicker oil. The appetite is too voracious for a nice thin syn. Its tough, thick oil won't hurt it.

 

[Globalksp]

Originally Posted By: LeakySeals
The 98-02 1.8L Corolla engine has known oil consumption problems. The piston oil return holes clog and nothing can free them short of a teardown to clean and drill more holes. Engineering change in 03 fixed the issue. So if its real low on oil and has a sooty tailpipe you know its getting bad. Usually 1qt per 1-2k

= Clean throttle body.
= Replace intake manifold gasket and while its opened try to clean piston tops with a soak of carb cleaner. random multiple misfires can be plugs but also vacuum. The IMG is likely cause and allows for a good cylinder soak
= Replace the plugs.
= Valve cover gasket replacement if it looks like there is a leak at plug boot as recommended by others.

Use thicker oil. The appetite is too voracious for a nice thin syn. Its tough, thick oil won't hurt it.


Great info. I'm not sure it'll get that deep into the work, but if need be, I may.

As for thicker oil... let's see if my burgeoning knowledge is panning out... thicker oil would be a conventional 5W-30 like PYB (which is now, PYSomething)?

 

[LeakySeals]

The IMG on those cars is pretty easy to swap out. Plenty of room to work. Thicker in this case would be 10w40. Or top off with it. Make a blend. That will slow it down some. Is it a 3sp or 4?

 

[Globalksp]

Originally Posted By: LeakySeals
The IMG on those cars is pretty easy to swap out. Plenty of room to work. Thicker in this case would be 10w40. Or top off with it. Make a blend. That will slow it down some. Is it a 3sp or 4?


Noted. Not sure. I'm out of town so will look when I get back.

 

[JMJNet]

Originally Posted By: Globalksp
Originally Posted By: JMJNet
IIRC, misfire code cannot be cleared since it is monitored continously.
In other words, it will code as soon as a misfired condition exist which is when the car is started.

In a Toyota, it is usually caused by bad Spark Plugs, bad spark plug cables/coils (depends on what is in there) and last vacuum leak.
Start by replacing the spark plug first and inspect if oil is coating the spark plug.
If there is oil, then the valve cover gasket and spark plug gasket need to be changed.

If replacing the spark plugs still not solving the problem, then the spark plug cables or coils need to be changed.

If it uses spark plug cables, you can measure the resistance between the 2 ends to test them.
I am sure coil is probably test the same way.


Great, thanks for a good start.

So if I understand correctly... The engine is currently misfiring at startup. If I replace the plugs and they were the cause, the the computer won't throw a code and the check engine light won't illuminate. Correct?


Yes, assuming you don't see any oil on the spark plug.
If you see oil, as said above, you need to take off the valve cover, change the gasket and the spark plug seal gasket.
Make sure to clean the gasket surfaces from old gasket and put a dab of RTV on the bends.
Easy to do in this car.

Then replace the spark plugs after the job.
See if that solve the problem.

 

[Globalksp]

Originally Posted By: JMJNet
Originally Posted By: Globalksp
Originally Posted By: JMJNet
IIRC, misfire code cannot be cleared since it is monitored continously.
In other words, it will code as soon as a misfired condition exist which is when the car is started.

In a Toyota, it is usually caused by bad Spark Plugs, bad spark plug cables/coils (depends on what is in there) and last vacuum leak.
Start by replacing the spark plug first and inspect if oil is coating the spark plug.
If there is oil, then the valve cover gasket and spark plug gasket need to be changed.

If replacing the spark plugs still not solving the problem, then the spark plug cables or coils need to be changed.

If it uses spark plug cables, you can measure the resistance between the 2 ends to test them.
I am sure coil is probably test the same way.


Great, thanks for a good start.

So if I understand correctly... The engine is currently misfiring at startup. If I replace the plugs and they were the cause, the the computer won't throw a code and the check engine light won't illuminate. Correct?


Yes, assuming you don't see any oil on the spark plug.
If you see oil, as said above, you need to take off the valve cover, change the gasket and the spark plug seal gasket.
Make sure to clean the gasket surfaces from old gasket and put a dab of RTV on the bends.
Easy to do in this car.



Seems so. Just watched a couple videos and seems like a piece of cake.

 

[krismoriah72]

Ive seen similar in toyotas with bad injectors. The fuel filter hardly ever gets changed in these vehicles due to the banjo bolt or people just dont change them. Most likely its the spark plug tube seals...but possibly injector or vac leak. lets see if the plugs are oily and the color of the plugs to see whats going on.

 

[Bottom_Feeder]

I just did the plugs and cover gasket (among other things) on my wife's '02 Corolla this past year. It was pretty straightforward and easy.

Running normal OCIs of budget synthetic oil is what helped her consumption issues most... eventually.

 

[GenaFishbeck]

Hi Globalksp - noticed you're in the market for a motor oil recommendation.

Considering the high mileage on the vehicle, we recommend Pennzoil Platinum High Mileage Full Synthetic motor oil in 5W-30. PPHM (for short) is one of our newer options within the Pennzoil Platinum line of motor oils which means it's full synthetic and made from natural gas.

PPHM conditions seals on older engines to deliver less oil burn off than high mileage motor oils made from crude oil. It was specifically formulated to reduce leaks and oil consumption in older vehicles while keeping pistons up to 20% cleaner than the toughest industry standards.

Let us know if you have any questions!
-The Pennzoil Team

 

[Globalksp]

I finally had a chance to take a quick look at the Toyota (read: no time to pull a plug or two).

It looks to me that the valve cover is the culprit:


Since the work does look straightforward enough and the parts cheap enough (while still using quality parts, of course) I'm going to go ahead and see to the gasket, plugs, PCV and an oil change. Settled on Pennzoil HM 5W-30 and a Fram Ultra.

Thanks again for all the responses. We'll see how this goes.

 

[Globalksp]

About to order the PCV Valve for the car and there are many options that "fit" the car according to Amazon.

From the photo it's clear that it's a screw-in valve which means no need for a grommet, right?

Amazon has two Fram valves that look similar, but that have different threads.

My guess is this one. or the similar AC Delco Version .

OR

This Fram Version

 

[Globalksp]

Today, I finally got around to doing the work on the 2000 Corolla. To no avail.

I successfully replaced the valve cover gasket (Fel-Pro), plugs (Denso), PCV Valve (Fram), air filter (Bosch), and changed the oil (Pennzoil HM 5W-30 & Fram Ultra).

Here's what some of the old components looked like:




Was pleased with how smoothly the work went, then started the car only to find the check engine light on and it spit back four codes, 3 active and 1 pending:
P0300
P0301
P0302
P0301-P.

All of these are misfire codes:
*P0300 Random/Multiple Cylinder Misfire Detected
*P0301 Cylinder 1 Misfire Detected
*P0302 Cylinder 2 Misfire Detected

Back to the drawing board...