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DrZ's bulletproof build thread, 97 Corolla DX

48K views 271 replies 22 participants last post by  DrZ 
#1 · (Edited)
While it would be cool to make the car resistant to bullets, I'm referring to making the car as reliable as possible. My plan is to inspect every system and replace old and worn parts that could break soon, and try to approach "like new" reliability.

First some history. I bought this car for $1000 a couple weeks ago. The two main problems are the power steering pressure hose is leaking and there is a misfire/hesitation at load.

I was able to piece some of the history together from service receipts in the glove box.

The original business cards from the dealer in Madison, Wisconsin.

The spec/features sheet from the used car dealer in Oaklawn, Illinois (Oaklawn Toyota). Notable features: Factory security system/keyless entry (I don't have a key fob yet), tinted windows, power windows, power locks, power mirrors, tilt wheel, center arm rest, rear spoiler.

The car. 1997 Corolla DX, 7A-FE, 4-speed automatic.

It looks like the second owner kept a lot of service receipts. She owned it from around 2002/2003 with 48k miles. The last receipt from this owner was from late 2013 at 162k miles with the same last name, so I assume it was still the same owner. The service receipts are all from the Phoenix area, but there was a registration receipt showing it was registered to the same owner in Illinois in 2010 and the receipts showed Illinois plates. Maybe she lived in both places.

It currently has 180k miles. The previous owner says he owned it for one year. I'm not sure if he bought it from the 2002-2013 owner, but there are no other receipts between 2013-2015.

The service records show the brakes were changed a couple times, and had new tires twice. The current tires are 6 years old. The timing belt, cam/crank seals, V-belts were changed by a Toyota dealer in 2/2008 with 111k miles. The front and right motor mounts were replaced in 11/2008 with 127k miles at a Pep Boys. Based on the cost of the parts, they must be an aftermarket brand. There is currently a vibration at highway speeds.

The last owner had the brakes changed in 7/2016. New ceramic pads and rotors. New drum shoes and resurfaced drums. Brake system bled.
 
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#3 · (Edited)
I haven't bulletproofed a car all at once before. I've owned 2 Tercels, my other 90 Corolla, and I've replaced the cylinder head on my friend's 96 Tacoma, so I'm familiar with how Toyota builds cars and what some of the common wear points are.

It looks like the injector seals are leaking a bit.


...and since I need to change the power steering hose, I decided to take off the intake. This will give be access to the power steering hose. I'll be able to take the starter off and check its contacts and internals, and there will be good access to the small coolant hose by the water pump. I might as well replace the fuel filter while I'm working it that area.
 
#4 ·
WOW! Keep us posted. You got youself a hell of a deal since it soundl like you can do all the work yourself. I also live in northern Illinois, be sure to keep the undercarriage washed in the winter. That salt wreaked havoc on my 2009 Avalon. Especially since Toyota LOOOOOOVES to use allen bolts.
 
#5 ·

Yep, that baby looks like it's reached its end of useful days. Here's mine:


But yeah, just unbolt that transfer tube thing from the head, and the hose is easy. Worst part is the wire harness which is tethered with/to the tube...
I actually considered pulling the intake to R&R my starter.
 
#14 ·
Wow, it was a lot of reading ago when I clicked multiquote, but that tube is REALLY gone, isn't it? lol.

I'm a few days behind on these updates...I did a vacuum test and compression test on the engine before taking it apart. I hooked up a vacuum gauge. The needle was steady at idle. There was just a very slight fluctuation at 3000 RPM. I have a video, but I'll have to figure out how to post to YouTube to upload it.

Then I did a compression check. Here are the readings. I did each cylinder twice for about 5-6 seconds of cranking with the gas pedal to the floor (throttle wide open). Six seconds of cranking is about 12 chug, chugs of the engine. I had a battery charger on the battery between tests.

#1 205, 210
#2 200, 202
#3 195, 197
#4 213, 212

The repair manual says normal is 191 psi or more with a difference of 14 or less between cylinders. I'm not sure what to make of it. Maybe some carbon build up in #1 and #4? It's better to be too high than too low, no?

The sparks plugs had a slight reddish color on one side. Do these look normal? Left to right, 1-4.


When I took the #2 spark plug out I noticed a piece of metal debris had been caught under the spark plug gasket. :wtf:
I was able to vacuum the debris out. Please check the spark plug holes before installing your spark plugs!

It had damaged the metal gasket. I'll be replacing the spark plugs anyway.
The high side of good on compression....considering this....
...at 180 compression, I found I needed middle grade fuel after many years of use. Maybe 165k+ miles? Switching to middle grade immediately improved mileage and power.

Since you're a good 10% or more up, I'd recommend at least middle grade. The issue with this high of compression is less the compression, and more all the carbon build up that got you there. It creates hot spots and cause little spots of pre-ignition.

So, while high side of good is good, there's your one negative for it from my personal experience.

Who's manual? I think even 194 is high on the high side of compression from figures I've looked up before on the internet...but then, I never had the manual myself - maybe I'm a victim of internet "accuracy", lol.

Your old plugs are showing perfectly normal wear for a 1ZZ-FE engine. Mine always wear gray too.

Did you put iridium plugs in like the factory recommends? When I finally did it (without realizing it was recommended at the factory) I was blown away about the power and efficiency as compared to platinum plugs!

Those old plugs? Only fault: not iridium. Copper or platinum? No worries.
 
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#6 · (Edited)
I'm a few days behind on these updates...I did a vacuum test and compression test on the engine before taking it apart. I hooked up a vacuum gauge. The needle was steady at idle. There was just a very slight fluctuation at 3000 RPM. I have a video, but I'll have to figure out how to post to YouTube to upload it.

Then I did a compression check. Here are the readings. I did each cylinder twice for about 5-6 seconds of cranking with the gas pedal to the floor (throttle wide open). Six seconds of cranking is about 12 chug, chugs of the engine. I had a battery charger on the battery between tests.

#1 205, 210
#2 200, 202
#3 195, 197
#4 213, 212

The repair manual says normal is 191 psi or more with a difference of 14 or less between cylinders. I'm not sure what to make of it. Maybe some carbon build up in #1 and #4? It's better to be too high than too low, no?

The sparks plugs had a slight reddish color on one side. Do these look normal? Left to right, 1-4.


When I took the #2 spark plug out I noticed a piece of metal debris had been caught under the spark plug gasket. :wtf:
I was able to vacuum the debris out. Please check the spark plug holes before installing your spark plugs!

It had damaged the metal gasket. I'll be replacing the spark plugs anyway.
 
#22 ·
You might be disappointed. I don't think there's much different about my interior, except maybe that it doesn't looked as aged or worn as some other 7th gens. The heavy tinting must have kept the interior temperature down inside, and based on the address of the long time owner's receipts I think it was parked under covered parking at a condo complex.

There are just a few things that don't work inside. The passenger power windows switch doesn't work, but it works from the driver's door. The cup holder doesn't stay pushed in, and the bulb illuminating the AC/heater controls is out. The trip meter doesn't work, but I'm planning on finding a tachometer cluster, so I'll investigate that later. The left knob on the radio needs to be pulled out to adjust balance, but the knob comes off the shaft when pulled.

It has that recently detailed smell. The carpet and dashboard are in good shape, but I'm going to apply some of my Meguiar's Natural Shine Protectant. I think it can make it look better. Before and after pictures at a later date...




 
#8 · (Edited)
Starter inspection

I removed the intake. More on that later. My next few posts regard inspecting the starter, radiator fan motor and alternator.

The starter is a Denso Tennessee.

I suspected it wasn't the original because the battery cable was bolted onto the starter much tighter than the 52 in-lbs of torque specified. Once I had it out, I could see the paint marker marks that junkyards like to put on used parts.

Next I removed the three 7mm bolts holding the end cover on.

The contacts look fairly worn. The repair manual specifies a maximum wear of 0.9mm. These appeared to be over that limit, although I didn't remove them to measure precisely. I'll be ordering the 2 contact rebuild kits from Toyota.

Notice how the contact is angled slightly, probably from the amount of torque I had to use to loosen the overtightened nut holding the cable.

The plunger doesn't wear as much, or at least wears evenly because it spins. Notice how it has a spring in it to allow slight differences in the height of the contacts.

I didn't bother checking the motor brushes because I don't think they wear out like the contacts do. Also, there are a few gaskets/o-rings that should be replaced if the motor is disassembled, but you can get by reusing them if they don't break apart during disassembly. I still may check the brushes later.

The plastic piece that covers the cable at the starter terminal broke into two pieces, so I'll have to find a replacement or find a way to hold them together. It unhooks on one side, but is supposed to be attached on the other side. Maybe a couple of cable ties?
 
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#11 ·
The plastic piece that covers the cable at the starter terminal broke into two pieces, so I'll have to find a replacement or find a way to hold them together. It unhooks on one side, but is supposed to be attached on the other side. Maybe a couple of cable ties?
Speedy25 did just that in his rebuild thread - see towards the end of this post: http://www.toyotanation.com/forum/1...work-has-begun-300k-teardown.html#post6224521.





BTW I love your work here! Very thorough, and I like that you take the time to repair things instead of swapping whole parts (and obviously I'm a fan of OE replacement parts). Color me impressed! I will save your posts here for when I get around to some of the same maintenance. In fact, you could easily re-write your posts above into DIYs for starter maintenance/repair and alternator maintenance/repair when you're done.

I also happen to share your definition and philosophy behind your usage of "bulletproof". It's all about making it a reliable ride that "just works" even when everything else fails.
 
#9 · (Edited)
Radiator Fan Motor Brushes Replacement

In this Phoenix heat, the radiator fan gets a lot of use. The fan motor on my 90 Corolla stopped working a few years ago. The The bushing at the front of the Autozone motor I replaced it with went bad after a year. The free replacement went bad a couple months later, so I decided to open up my original Toyota motor and replace the brushes. That motor has been working for a couple years, so I will check and replace the brushes in the motor on this car.

Here is the fan shroud with the fan blade removed.

The three screws holding the motor on were pretty tight. I used a JIS screwdriver to get a good grip and they came out without stripping them. Next, I had to bend the little tabs holding the back plate onto the motor. Then I tapped a screwdriver into the slot on one side to start prying the back off.

Here it is once it came apart. There is no need to pull the armature out.

The brushes still had some life in them. The exposed length would have to be about half as long to stop making contact with the shaft, but I decided to replace them anyway.

The spring is held in by a metal clip. the clip has 2 small tabs that need to be bend with a small pick, then the clip can be pulled up and the spring removed.

These were the closest brushes I could find when I did the job on the other car's fan motor. The wire comes out of the end, but this actually will allow more of the brush to be used before it wears out. the new one is not much longer, but it probably will have twice the usable length of the old ones. I will discard the spring from the new brush.

I had to file each side of the new brush until it fit snugly into the plastic where the old brush was. It doesn't take much effort to file off a millimeter.

It's kind of tricky soldering the old and new wires together. The old wire needs to be cut as close to the brush as possible. The wire won't really be moving once it's assembled. It will only move slowly as the brush wears out. I don't expect the solder to break down. And there is plenty of room inside the motor, so the solder and wire won't hit the spinning armature. Here is the comparison between old and new brush.

Both new brushes installed.

The last tricky part was pushing the brushes in while reassembling. While pushing down, I was able to use a pick to push the brushes in until they slid down over the shaft. It took a few tries, but I eventually got it. Then I made sure the end plate was aligned correctly and pressed together completely, then I tapped the tabs back down to hold the end plate on.
 
#10 · (Edited)
Inspect Alternator Brushes and Rectifier

Next, I inspected the alternator. It looked like it was recently replaced. There wasn't much dirt on it and the back cover was still shiny. I felt kind of silly taking it apart to inspect, but I'm glad I did after I made a shocking discovery...follow along.

The label says "Remanufactured for Toyota 27060-15110-84, 9661219-508 Denso".

Here is the view after removing the back cover.

Two screws to remove the brush holder. Three screws to remove the voltage regulator.

According to the Toyota Repair Manual the standard exposed length of the brushes is 9.5-11.5mm. Minimum exposed length is 1.5mm. These look to be about 8.5-9mm, so still plenty of life left, at least 100k miles.

Four screws to remove the rectifier holder. Here are the removed parts and screws.

To check the rectifier means checking each of the 8 diodes. To do this you need a multimeter set to the diode check function. First you attach the negative lead to the battery terminal on the rectifier, then touch the positive lead to each for the 4 rectifier terminals (the 4 places where the screws were holding the rectifier on). Each of these should show a voltage drop of about 400-600 millivolts. The picture shows just one of the 4 checks.

Then you reverse the leads. Hook the positive lead to the battery terminal and touch the negative lead to each of the 4 rectifier terminals. Each of these should show no continuity (a "1" on my multimeter).

To check the next 4 diodes, you hook the positive lead to each of the 3 negative rectifier terminals (the 3 holes), then touch the negative lead to each of the rectifier terminals. (12 combinations). Each of these should show a voltage drop of 400-600 mV.

Again, reverse the leads, and each check should show no continuity.

Now for the shocking part. The third rectifier terminal didn't show a voltage drop. It showed no continuity. I thought that was unusual because the rectifier looked nice and new. Upon further inspection I found that the third pair of diodes was missing!!! :pat: :wtf:


This is a Genuine Toyota part (branded as Denso remanufactured) and it's missing one pair of diodes in the rectifier, so the alternator is only working at 75%. How is this possible? I almost have to believe that some supplier is trying to pull a fast one. Almost no one would notice that the alternator isn't producing full power, so they figure they'll just supply rectifiers with only 3 of the 4 pairs of diodes?

What can I do about this? Since I didn't purchase the alternator, do I have any recourse with Toyota (or Denso). I consider this a manufacturing defect. Is there any way I can take this to a Toyota dealer and get a replacement? :dunno:
:help:

Edit: It was pointed out later that some alternators are designed with only 3 pairs of diodes, so this is normal. The repair manual shows 4 pairs of diodes, so I guess they just didn't update the repair manual for the different design of the alternator.
 
#12 ·
Only three pairs of diodes for 3-phase rotor.

edit add...

Also there are two types of winding configurations, delta and wye with optimization for voltage or current output at low RPMs.

The 4th pair of diodes are used to generate a reference/difference voltage for the regulator to switch between delta and wye modes if the stator-windings are connected for both modes.

In short, your alternator is configured correctly. :smile:
 
#15 ·
Well now I feel like a complete and total idiot! :facepalm:

I did a little research, but I don't understand a few things. The stator looks like it has the neutral terminal. What does it do if there are only 3 pairs of diodes? I mean the other two Denso alternators I've looked at recently both had 4 pairs of diodes. What if I put in a rectifier with 4 pairs? Would it still work, or is it matched to the regulator? Are the alternators with 4 pairs of diodes better, worse or just different perfomance-wise?

The high side of good on compression....considering this....
...at 180 compression, I found I needed middle grade fuel after many years of use. Maybe 165k+ miles? Switching to middle grade immediately improved mileage and power.

Since you're a good 10% or more up, I'd recommend at least middle grade. The issue with this high of compression is less the compression, and more all the carbon build up that got you there. It creates hot spots and cause little spots of pre-ignition.

So, while high side of good is good, there's your one negative for it from my personal experience.

Who's manual? I think even 194 is high on the high side of compression from figures I've looked up before on the internet...but then, I never had the manual myself - maybe I'm a victim of internet "accuracy", lol.

Your old plugs are showing perfectly normal wear for a 1ZZ-FE engine. Mine always wear gray too.

Did you put iridium plugs in like the factory recommends? When I finally did it (without realizing it was recommended at the factory) I was blown away about the power and efficiency as compared to platinum plugs!

Those old plugs? Only fault: not iridium. Copper or platinum? No worries.
The Toyota manual just says "Compression pressure: 191psi or more". This is the 7A-FE engine, not 1ZZ-FE. I'm going to put in iridium plugs, though.

Is there anything I can pour into the cylinders to break up some of that carbon? I've only driven the car about 50 miles so I can't say what the effect of different fuel grades is.
 
#16 ·
Cleaners with PEA may be effective. Try spraying some of the newer CRC GDI intake valve cleaner in the cylinders on a warm engine and let it soak down for 12 hours. Bump it over with plugs out to splash it around every few hours and after its all blown out and driven get a second can and use it per directions to clean the intake tract, then clean the throttle butterfly and throttle body bore thoroughly and check/adjust throttle cable slack.
 
#23 ·
I'll have to come up with a plan about what chemicals to use and how much time to spend on it. This can progress on a different timeline from my other repairs/maintenance. I have the intake off, so I can clean the manifold and throttle body thoroughly.
A 50/50 solution of acetone and ATF does really good job of piston cleaning. Do about 3-4cc at a time so you don't dilute oil too much. The a bottle of Redline SI-1 in a tank. After 2-3 soaks and a bottle or two, you should see shiny silver piston tops! :)
I remember certain chemicals do a good job of dissolving carbon, but it's easier with the cylinder head removed and a little scrubbing is possible. Certain gasket removers contain a chemical that will do it. Maybe that chemical is acetone. I was able to loosen the light carbon deposits on the pistons of the Tacoma engine I was working on two years ago with some chemical I had at hand, and I had some acetone, so maybe it was that.
Apologies about the 8th to 7th gen mix up.

ChrisFix on YouTube has a bunch of experiments that show that carbon doesn't get cleaned up that well by anything.
No problem. I'll have to take a look at that video.

Now, a few more notes about the engine...

I took the valve cover off a few days ago. This looks like the Toyota timing belt that was installed 70k miles ago (from the service receipt).

It has an undulating appearance where it has been pressed against the timing gears over time. I guess I'll just go for it and replace it while I'm doing the other things. I just need to figure out what kits (idler pulley, water pump, seals) are available to save some money over dealer prices, but I'll only go with quality parts.


The cylinder head doesn't have any sludge build up, so I guess it's had regular oil changes.


...although it looks like the previous owner doesn't believe in gaskets. "gasket-shmasket, I don't need no stinkin' oil plug gasket!" :facepalm: It's been dripping oil where it sits. It has a 13mm head which doesn't seem like an original drain plug, no?


When I had the valve cover off, I checked the valve clearances. Here are the readings. I measured twice with 2 sets of feeler gauges. One in inches, .009"=.229mm, .010"=.254mm, .011"=.279mm, .012"=.305mm, .013"=.330mm, .014"=.356mm, and the other in millimeters, .20, .25, .30, .35. I list the last size that fit.

Allowable range 0.15-0.25mm
IN 1a .229 .20
IN 1b .229 .25
IN 2a .254 .25
IN 2b .254 .25
IN 3a .254 .25
IN 3b .203 .20
IN 4a .254 .20
IN 4b .203 .20

Allowable range 0.25-0.35mm
EX 1a .330 .30
EX 1b .305 .30
EX 2a .330 .30
EX 2b .330 .30
EX 3a .305 .30
EX 3b .305 .30
EX 4a .356 .35
EX 4b .330 .30

So it looks like 3 intake and 1 exhaust valve clearance is at or just above the upper limit. I probably won't be able to resist not adjusting these. I do have some leftover shims from the Tacoma I worked on. It used the same type of shims, so maybe I won't need to get many new shims. I'll have to try to get more accurate measurements using combinations of 2 feeler gauges together (e.g. .27mm = .20mm + 0.07mm).

 
#21 ·
That CRC cleaner I mentioned removed visible thick carbon from the top of my #3 piston on my 2.0 FSDE Mazda 626. #2 and #3 get the most carbon from the EGR system it seems like, it had been seafoamed a long time ago for light ping on hills and that cleared it up, I decided to do the cleaner because I had some weird idle roughness that I wanted to rule out as a compression issue (low or high) or as dirty valves. I think I have a poor injector at idle on a cylinder but I don't know if I want to mess with it, but anyway....

Yea, the stuff works. I could see a bit of carbon just off center of the piston center with my flashlight, then after I could see a clean piston top and an outline where carbon used to be. I sucked some out of a cylinder and I had little bits of suspended black carbon in the mixture and it was a much darker color than when it went in there.
 
#26 ·
My Geo had a blue interior similar if not the same color and I LOVED it! My seats had different upholstery with more side bolster though, I got asked a few times what brand they were and I was like....uhh....what?



Not my car, just some random one for sale. I'll have to see if I have any of the front seats still. They were comfy.
 
#28 ·
Arrived here by accident from the 2nd Gen Toyota Highlander forums.
This is a great read. Really informative and actually fun to have read. Thanks much and the best of luck with your ride. :smile:
 
#29 ·
Recehcking Valve Clearances

I went ahead and rechecked my valve clearances, but this time I was more precise. I combined two feeler gauges in different combinations to get down to 0.01mm accuracy. It seems obvious to do this and after some research it looks like this is perfectly acceptable. Just to be sure I checked the width of the feeler gauges with a micrometer (both single and the combinations that I would be using). I wrote these measurements down on the bottom of the paper in the picture below. The micrometer was in inches, so I converted everything to millimeters. The feeler gauges all checked out within 0.01mm of expected. One surprise was that my 0.10mm was 0.094mm and my 0.09mm was 0.091, so the 0.10mm had pretty high relative error, but I didn't use this one anyway.

Here are the revised valve clearance measurements:

Intake (spec 0.15-0.25mm)
1a 0.22
1b 0.24
2a 0.25
2b 0.25
3a 0.25
3b 0.20
4a 0.23
4b 0.21

Exhaust (spec 0.25-0.35mm)
1a 0.33
1b 0.32
2a 0.34
2b 0.33
3a 0.32
3b 0.31
4a 0.37
4b 0.34

So just my luck, there is only one (EX 4a) that is out of spec at 0.37mm. Three of the intake are right at the limit of 0.25mm. But most of them are in the upper range of specs.

What do any of you think? Will it make a noticeable difference if I reshimmed these to get them all down to the middle or lower part of the range?

My notes:


The feeler gauges and micrometer:


Checking the width of the feeler gauges:
 
#32 ·
We use Continental timing belt kits at the shop and have been for some time now without any failures. I used a premium AC Delco water pump on my Mazda, it's going well a year or so later. The Continental belt is pretty beefy and uses Asian or German bearings for the tensioner/idler stuff depending on the application and the hydraulic tensioner itself if it's included is always the same brand stamping as the dealer part, just isn't always part of the kit.

However, for $88 I'd go for this http://www.rockauto.com/en/moreinfo.php?pk=4007496&cc=1275689&jsn=439. Get a dealer t-stat and gasket though, they're better stuff for sure. That kit has the WHOLE water pump, not just the pump but also the back housing half which is good to get as it simplifies the work and you don't need to worry about the gasket leaking.
 
#33 ·
Before we trust the micrometer over the feeler gauges, is it checked by a certain unit of measure?

I don't know if I used the right language, but I think you understood.

Better hear them then smell them.

Looser side of right is better, but looser than loose? Bitter's right that it'll prevent a burnt valve.
 
#34 ·
It was the 3 piece micrometer set from harbor freight, but it gets good reviews. It comes with a 1 inch piece of metal to calibrate. I checked it against 2 digital calipers and it was accurate. They can't all be wrong!

My micrometer measurements just verified that the feeler gauges were very close to what they were supposed to be. There is some inherent error in measuring the valve clearances, but I'm confident they are within 0.01mm.

The exhaust valves will burn if the clearances are too tight, but mine are on the loose side. I'm just wondering if the intake valves at 0.17mm would increase power more than say 2% over 0.22mm clearances, or would it not really matter at all?
 
#35 ·
Wow. What I don't know could bite me in the ass! I should probably take heed and check my valve lash or whatever. I don't want any burnt valves, and that I can tell you for sure.
 
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