Motor and Transmission Mounts on a Chevy Prizm or 1998 to 2002 Toyota Corolla

I'm surprised to learn how many motor mount configurations there are for my 1999 Chevy Prizm.

What we have here is pictures of locally available motor mounts. I see that the 3 speed transmission (left picture) has a different motor mount than my 4 speed transmission. Then the center is the motor or transmission mount, which I should refer to to being over my transmission on the driver's side of the engine bay. I should inspect this one more closely for cracks or weakness.

The transmission mount on the right of the picture above is for manual transmissions.

On to the next set of mounts available for my car, and I'll get to my point:

On the left is the front motor mount (common name), but it literally is connected to my transmission. That is the correct one for either the 3 speed or 4 speed transmission like I have. The point is that the motor mount on the right is for the manual transmission. That's what I just pulled out of my 4 speed transmission car! I'm sure they bolt up the same or I wouldn't have been able to have the "wrong" one in, but now I'm relieved as it's broken that I'm getting the correct transmission mount installed.

The 2nd from the left motor mount is the only "true" motor mount on my Chevy Prizm. It's on the passenger side (in left hand drive cars) on the top/side of the engine.

2nd from the right is the motor mount (sorry, strong habit, it's literally a transmission mount), which I first noticed failed on my car. I've gotten a quality one from Toyota. Boy that was hard to get! Every sub part of that part is super high quality! Great steel, at least for how it looks and feels. Great rubber! Super good...then I looked closer at the welds. Those steel welds have something to be desired for strength, see my YouTube video below, "My New Motor Mount, long awaited, crappy welds!"

The locally available motor mounts have good welds at the moment, but the rubber is poor and I expect failure like before so I want to window weld them with 60 shore strength. Once drag racer of a Hyundai Elantra on the Jafromobile YouTube channel uses 80 shore strength, but seeing as how I can't find that and he has literally 4 times the acceleration that I have in my Chevy Prizm, I think 60 shore strength is plenty strong to plus up this lower quality locally obtainable part.

Sure, you may say, just get another one from Toyota (a Chevy Prizm is basically a Toyota Corolla), but that took a month, I'm not going 2 months without my car. The rear transmission mount is what is hours of work to get to the, the front one can be removed with much less subframe disassembly.

I'm working literally on uploading a video to show the Toyota, USA made motor or rather transmission mount as you read. :)

Here's my uninstallation of the front and rear motor mounts:

Source: Motor mounts front and back removal part 1 by DENichols

The next video I'm in the process of editing is a motor mount inspection video and half of the installation. What are different problems they can have? Failed welds, sure, most commonly the rubber gets cracks. Some cracking with age can be okay if the engine still is held firmly in place when you brake torque the engine. That's where you put the car in drive or reverse, hold the brake, and press the gas some. The engine should move some, but mine was flopping like a fish!

Motor Mounts Front & Back Installation Part 2:

Source: Motor Mounts Front & Back Installation Part 2 of 3 by DENichols

Motor Mounts Front and Back Installation part 3 Finishing End links mostly:

I'm embedding the part 2 video in my article when I last brought up replacing at least one of the same motor mounts! Shocks, Struts and the Steadiness of Your Car or Truck

By AutoBravado

O2 Sensor Upstream Diagnostics

Upstream O2 sensors should switch up and down across 450 millivolts. Above 450 millivolts or .45 volts is rich and below is lean. This should be on a .1 to .9 volt scale. I've seen oxygen sensors that were getting stuck lean. Fuel trims kept going up and up until they were maxed. At this point the O2 sensor would finally read rich and get even above 1 volt. As fuel trims decreased the graph would flatline again.

Upstream O2 sensors defined:

This is the O2 sensor which is the first to see your exhaust off the manifold. Because it's before the catalytic converter it's "upstream". Modern cars replace upstream O2 sensors with Air/Fuel sensors which can see a broader scale across versus seeing just barely up and down from the rich/lean that a catalytic converter needs to stay healthy.

I've had trouble for the last year with a running rich condition at idle. The OEM sensor I chose was reporting below 100 millivolts. While further experience with it's warranty replacement shows that oxygen sensors do indeed go below 100 millivolts, or at least it does from the manufacturer Denso, most of the time that it would operate in this range, it's before the engine has heated up and the engine has gone into closed loop operation.

Closed loop operation:

This is a condition where the PCM (Powertrain Control Module) has determined that the conditions are set that the information from the O2 sensor can now be deemed reliable (it's gotten hot enough). My vehicle would usually be in closed loop instantly. Normally, you want to be in closed loop as soon as possible. It uses less gasoline and helps with your car's mpg. This was too fast. Even though my heater circuit was 15 ohms; same as my warrantied replacement, that really isn't a complete test and I suspect that the heater core had a problem that my PCM couldn't detect.

A full test would be to have the heater in heating operation and see what the voltage drop is, but I doubt that's a procedure I could get specs on. Ohm meters use very little current. When you have more current something that looks right can suddenly test poorly. Only 1 fragile wire for example could show that a battery cable is good on an ohm meter, but it couldn't carry enough current it and it would show voltage drop when you place leads on each end of it. The voltage measured is the mount of voltage lost to that wire out of the available voltage from a battery for example.

Something I notice my PCM doing when it doubts if it has a good O2 sensor, is that it'll run rich and instead of switching back to lean like it should, it'll go even richer for a moment. This is s a test to ensure correct operation. If it keeps going richer the O2 sensor is failing the test. If it goes lean after this brief test it passed.

Realize you have to have a good testing method:

I typically rely on live scanners. These devices plug into the OBDII port, can pull trouble codes, and can show live streaming data. Except it's really not live streaming data. It shows a timeline sure, but the information isn't updated frequently to rely be "live". Such methods are fraught with difficulty when it comes to O2 sensors. O2 sensors and PCM's are communicating far faster than the live data from a scanner shows. Until an O2 sensor has gotten very bad, it can be difficult to diagnose. 

Plugging into the wiring directly from a DVOM isn't accurate either. It's sampling rate isn't bad, but it averages the data it receives and switches the screen slowly. Part of this design is intentional. You can't really see a screen and have it processed in your mind if it switched faster than you eye can see. 

An oscilloscope would be my next diagnostic tool, but they are spendy.

The catalytic converter link I put above links to my article about beating the P0420/P0430 diagnostic code. It'll also give you insight into downstream O2 sensors.

Also check out my newer article about the oxygen sensors 4 stages of death.

Check out my YouTube video for a downpipe modification that made my O2 sensor go in much easier to my 1999 Chevy Prizm (usually same as 1998-2002 Toyota Corolla). I also talk about some diagnostics that were specific to this situation.

Written and produced by AutoBravado.

Head Gasket repair on a 1999 Chevrolet Prizm

I had the loveliest surprise last week when I discovered that my 3 years of minor oil leaking was actually coming from my head gasket.

It's common on the 1998 to 2002 line of Chevrolet Prizms for there to be an oil leak on the passenger backside of the engine. It's not leaking there. There's a seal there, that I believe comes with a timing chain set. I've had the timing chain tensioner and seal for a year or so, just not getting around to this minor leak.

If you've seen any of my blogs like www.autobravado.com or carmilespergallon.blogspot.com you'll see articles relating to much more important repair in the last five years. It's leaking squarely on the passenger side of the engine, not front or back, very close to the serpentine belt tensioner. At this height there's just nothing else it can be. It's the head gasket.

Now if you check out my milky oil cap article and a video attached from a fellow mechanic you'll know exactly what I'm not seeing. I see no evidence of any oil or coolant being mixed in the oil, the coolant, or out the exhaust.

I have had a slow decline in my car's mpg from the low 30's in the city to 27. (27 is a new low, hadn't seen worse than 28 in a LONG time.)

Compression is still good and within normal limits. I just bought my own compression tester and leak down tester so that I can redo this specifically being sure that there's nothing deeply wrong other than a small oil leak. This oil leak doesn't even have the decency to get on the ground unless I'm in a Southern Utah summer where the engine is warmed up when I turn it on when it hadn't been on that day yet. So for all but summer, I about forgot about it every year until I had a problem with my transmission that was beyond my abilities.

The owner commented, "It's a mess under there." Wounded, I cleaned up all the grease all over from something I repaired which REALLY leaked badly and I had never cleaned it up. After spending a few hours making things prettier that most people will never see, the next day I look and now I'm aware of this oil leak...

....I've spent days online buying and buying for what I'll do while the cylinder head is off! All I'm saying for now!

If you like, the best hint I'll give is series of pictures of things I'm buying:

June 2015 update for HP when my engine bay is heat soaked:

50 MPH HP run with the fully family. See how the PCM allows higher RPMS only when there is greater load? It'll shift much earlier with less weight in the car:

I 

This upgrade idea seemed tempting, but it's missing the flex the exhaust needs to help protect the engine. The engine is supposed to move some to protect the transmission. The only way to add a flex pipe, would be to add it after the catalytic converter, and that's too little too late.

Okay, the following pictures reveal what all the tool upgrades above are for. A port and polish:

Above points out some land marks on this cylinder head. Of course the intake and exhaust will get get smoothed from their original casting. They'll also get opened up some, how much depends on an ultrasonic metal thickness tester, which I also need to purchase, to know where the intake and exhaust runner are thin and can't be opened up.

The machinist ridge makes some of the most important differences in flow. Without removing it and blending it, the intake and exhaust valves have to open a great deal more for flow to really start. As the fuel mist from the fuel injectors hit the machinist ridge, the mist/fuel droplets tumble and hit each other causing them to get bigger and get a less complete burn.

9/22

A book recommended to me by Hugh O'Brien per our discussion on the Jafromobile channel:

https://www.youtube.com/all_comments?lc=yF3DeDuFSLdxl7Mm4lui8yDYGS0pfQeM2VgE8UJxaj0&v=7cXoxvkDOHE

Hugh explained this book will help me with the unique problems 

with porting and polishing 4 valve heads. 

The information Hugh gave me has been incredible. For example, NA heads don't need the bowl side of the valve opened as much has force inducted engines - 3/16". The burrs I was choosing above were terrible choices. I need single cut burrs, preferably with 6 inch shanks so I can see what I'm doing. The trouble I'm having is I can't find any diagrams of where the coolant jackets are so I know what I can remove and work with. Also, the clyinder style burrs are terrible as they will leave scratches. I'll need to work with single cut carbide burrs only, oval and elongated only.

Recent update included pictures of good single cut carbide bits instead of double cut which are too hard to clean. I took down the cheap eBay carbide bits pictures. Here's some part numbers if you want them all, but if you only want one, I think I mixed up the packaging. Couldn't tell you which is which, lol.

Feb 22, 2016 Update:

This is not where I thought this would end...(for now, I'm taking the engine a part and the series has more to go with a part 6 coming out soone!).

 by AutoBravado

For the latest on this project, check out my next article, and remember that there's another half article after that!

Port and Air Flow Theory, part in practice

Misfires, fuel, ignition, or timing on P0300, P0301, P0302, P0303, P0304, or shall we say P030x?

Something I catch with my ear that ECU's* cannot. I listen with a screw driver or my favorite socket which is larger than most people's breaker bars. It's large and it reduces the volume of outside noises. I close the ear flap of my ear with one end to also deaden outside noises. I listen to each spark plug as best I can - of course with them all running.

Whichever sounds brighter is typically running strong enough or "on time". Whichever is sounding duller is late or weak. If I can't listen on the spark plug coil or wire, I'll listen as close as I can to the combustion chamber. Sometimes on the intake side, sometimes on the exhaust for where I can reach.

Coils that are bad can make a little electric crackle. The test above is comparable to an ECU counting misfires on a cylinder, except that it catches much smaller problems that may not come up as a misfire yet. It may not be bad enough. It, like the computer check for misfire can't distinguish between spark plug wire or coil on spark plug setup, not for sure what cylinder is misfiring.

Like I listen for a misfire the computer can mistake an echo. When I'm evening the spark out across an engine on a V engine what sounds bad on 1 bank may be a problem coming from the other bank opposite of the cylinder on the V. If in the firing order the previous cylinder doesn't have good enough spark, the next cylinder will sound weak when it may have been strong.

Long story short, this is why ECU's can get which cylinder is misfiring wrong. This video has a very effective way of ruling out more than one problem at once. Logically, I recommend it in a coil on spark plug setup over a spark plug wire to spark plug setup, as the chances of mixing up spark plug wires is much higher.

Thank you for inspiring this article Shrodinger's Box:
P0304 misfire Quick Diagnosis with just CodeReader-no scan tool
by AutoBravado

On my own cars and trucks, I usually get rid of a "misfire" before it's significant enough to show up as a check engine light issue. I'm making engines run smoother, and it really is a bit of a misfire, but not enough for the PCM to declare emergency with a blinking Check Engine Light (CEL). I show these techniques here:

PCV Valve and your Car's MPG

I've learned about the PCV finally. :) (often called PCV valve, or positive crankcase ventilation valve).

If you're getting black on your air filters, maybe all in one area? Perhaps near where the PCV connects via a hose to your air filter? This means your PCV is fouled or "broken" and is being a negative flow instead. I've seen that a lot in Toyota Corollas or the Geo/Chevy Prizms**, more than just mine, so I thought to pass that on.*

...I tried cleaning mine, if the labor wasn't free buying a new one is cheaper. 45 minutes of banging on the PCV valve (with my hands only) against rags, using break cleaner on it, etc., I got the entire life of the car's cake of oil and carbon out.

Next time, I'd leave it to soak in gasoline over night, probably would have been easier.

I failed to do one test so I need to get back in there. If it rattles when you shake it, you should be good. (this was probably possible earlier in the cleaning, but I thought it best to have less goop to prevent a faster re-clog.)

Finding your PCV valve...unless you want to YouTube it ;) there's a new channel on YouTube that I'm fairly unimpressed with that helped me find it (so sorry, I don't think I'll have luck finding the video to give credit; kind of rude of me maybe, but sometimes helpful information isn't in a glamorous place). There are two tubes off your valve cover. One that comes at you if your at the front of the car, and one that points to the driverside. The driverside one has is your PCV valve.

If it has it's original clamps it's easy to pinch it and pull the hose off. If it's hard or cracked it should be replaced. The PCV valve can then be unscrewed with a 17mm deep socket or box handle wrench. Be sure to have some teflon tape to put back on the threads before restoring it in the car.

A quality Toyota PCV is all metal, and if you're willing to clean it, I suspect it's possible to be a forever part. If you chose just to replace it, at least see if it rattles first, it's fine, don't replace it. I've seen plastic ones for sale for our car on eBay that cost about what the metal one would, aftermarket ones are fine, just don't go plastic.

The PCV threads in, but has multiple pieces of rubber around it even where you thread it into the valve cover; replace any that are bad. I spotted everything for sure that could be bad on ebay for cheap, except maybe the tube that goes from the PCV to the throttle body. (take it to a local parts store to match the INNER diameter if not).

*Ooops, I think that means our PCV system can't foul the air filter...maybe I need to look at my brothers 7th generation Corolla/Geo Prizm again**. This part of my information is more general to cars maybe than just to ours. I learned most of what I did about PCV valves from Briansmobile1 channel on YouTube.

Saved for last an explanation of what it does? lol, you can watch Brians video on it, or read my regurgitation:
See, engines sometimes have vacuum on your PCV valve and sometimes it has pressure. When it has pressure, unburnt gases from combustion sneak up under your valve cover and modern cars for better emissions send that through the PCV valve back to the intake so your engine can burn it off (arguably more efficient on a car's MPG, especially on bigger engines). Older designs took care of this pressure problem with a filtered cap that doubled as your oil cap.

When the "pressure" or vacuum is present in an the valve cover the PCV prevents air from coming from your intake into this part of the engine, which is then a vacuum leak (definitely reduces your car's MPG and deserves it's own article). Without this valve functioning correctly, the pressure build and builds, and will help even more unburnt fuel and exhaust past the piston rings and down into your crank case. Piston ring blow by reduces the viscosity of your oil over time. And that can be really bad news for the longevity of your engine. If this is in addition to worn piston rings and/or the bore, then your engine can really be worn faster than it needs to be.

(Severe blow by can push out the oil dipstick, if you have the regular habit of checking your oil like you should, and it keeps being pushed out, uh oh. Even if it doesn't push the dipstick off, this is a good way to find a worn engine to not buy a used car because you know now about problems with lots of blow by.) Check out my article about Synthetic Oil Controversy.

**Note:
1998 to 2002 is the 8th generation Toyota Corolla/ Chevy Prizm
93? to 96 is the 7th generation Toyota Corolla/Geo Prizm

by AutoBravado

O2 sensor ground, is it rusty? Make it easier to remove for the next guy....that might just be you.

**Sept 22 update:
Original article:

O2 sensors being grounded by the exhaust, is a concept for 1 wire O2 sensors. 4 wire O2 sensors are wired with their own ground and are not grounded by the exhaust.**

I hadn't thought about checking if the O2 sensor was cleanly grounded. Cleaning up rust always helps O2 Sensor Mod and Diagnosis)with a good connection. Yes, anti-seize. When I was early DIY rather than nearly a technician I installed a new O2 sensor, up river, and got my 1999 Chevrolet Prizm running nicely again (same as 1998-02 Toyota Corolla). The Chevy wasn't that rusty then. Now....until I own an acetylene torch or replace that manifold that O2 sensor better not fail. So rusted in (I can't take the down pipe off my manifold until the oxygen sensor is out of the way. Thankfully just replacing one of the springs cleared the exhaust leak ...still wanting a new doughnut gasket in there, but don't fix what isn't broken, it runs soooo much better). . . So yes, use anti-seize but don't get any on the sensor! (8/23/15 update: The aftermarket Bosch oxygen sensor appeared to have a normal oxygen sensor socket install, but it actually includes a flange with 2 bolts. It's an interference fit with the down pipes. I've made a video with the solutions! I got back to a OEM Denso which you can see doesn't have a nut next to the flange, which confused me into believing it wasn't removeable.)

Anyway, I just meant to say that only 8 years ago I installed the Bosch oxygen sensor and I wish I knew to put in anti-seize. The rust really isn't that bad but it's enough. I destroyed my harbor freight oxygen sensor socket...may have already done that a few job's ago that I worked around not removing the oxygen sensor. I now have a much more expensive Powerbuilt socket (never in water, quickly rusted. :p - got it super cheap on Amazon, maybe it was a Powerbuilt knock off). I haven't bought a lot from them, but whenever I break an inexpensive tool, I replace it with this brand and I never have a problem again. My new Powerbuilt O2 sensor remover worked brilliantly. It's removing all the oxygen sensors that I thought were rusted in badly, almost easily.


The last Bosch oxygen sensors I installed on my mom's 1999 Mercury Sable ran okay...but with them all new it ran sooooo much better (Same as 1999 Ford Taurus). I was surprised that the down river O2 sensors helped it run better....I guess the car's willing to run a little richer for some punch when it's not dirtying the environment? I might have imagined that part of the improvement. Bosch includes the perfect amount of anti-seize on the O2 sensor threads now. I had to love them for that little touch.

And remember, don't blame an oxygen sensor or a catalytic converter for an exhaust leak. I have a live scanner now and my new cat gave me 50% more horse power (possible to find out using a torque app and some open freeway, gps confirmed *HP as long as you report the weight of your vehicle accurately) and almost removed the condition of the rear oxygen sensor voltage switching up and down too quickly. That shows on my live scanner ...sign of a bad cat? Sure. The catalytic converter does a lot better, but you can't have an exhaust leak before the cat and know for sure if that cat is really bad without checking upstream before you finish your diagnosis.

The old catalytic converter nearly showed the same reading before and after the catalytic converter indicating that it was almost doing nothing for the car. Need more analysis for how O2 sensors should be running? Check out my article and video on the subject. Here's a link to O2 Senors, The 4 Stages of Death.

by AutoBravado

Weapon R Dragon Intake Review

I recently purchased a Weapon R Dragon Intake for my 1999 Chevrolet Prizm. To give you some history, my choice for this upgrade was different than you might think. I didn't just go in to get a short ram intake because I wanted an upgrade. About 3 years ago my car got smashed and and I had to replace 1/2 of my headlights and signal lights...not to mention my bumper. ;) A had a large canister inside the bumper that was supposed to help get some cold air into the car that broke and could not be put back in. Seeing as how the whole system still looked sealed from the weather, I counted my lucky stars and left a gaping hole that could gulp cold air into my car rather than sip through 5 tiny holes that the canister breathed through.

A couple months ago, I noticed that my wheel well was getting less sealed to the bumper and I was risking Hydro-lock. Hydro-lock is where water goes into your air intake system, combines with the fuel/air mixture and doesn't compress - water doesn't compress - and "BAM!" Your engine is broken and will often need replacement. So, terrified, knowing I was coming up on a typically rainy drive soon I needed to fix this situation fast.

I didn't even want to figure out how to replace the air canister. I didn't really know what it was called and suspected a very high price at the dealer or no availability for a part since the dealers don't sell much past 10 years. So....I went for the fix and upgrade replacement Weapon R Dragon Intake.

The Weapon R Dragon Intake came in a record fast time, a day before my road trip so I didn't have to spend valuable driving time on installation. Quite excited, I was in my car clothes within minutes and I was installing it.

I immediately noticed the extra loud noise that was new to my car. Everyone said online that the Weapon R Dragon Intake was the loudest intake on the market. (Most seem excited about that.) This worried me because I love performance but I don't like things being too loud. Turns out, once it warms up, it's pretty quiet. Plus, I really only notice the sound of the Weapon R at low speeds.

I immediately noticed that my 2.5 inch opened exhaust was louder, and that was driving gentle, since I'm all about getting the best car mpg possible, I was excited that this was a sign that my car was getting more air moved through it, dragon style :). On my trip, I had to go over mountains and I quickly noticed that when I came out of overdrive for these mountains that instead of my car sounding like it was working hard, the hills sounded natural.

Two days before my trip, I lost valuable preparation for my traveling installing the Weapon R Dragon Intake, I made up for lost time and drove faster. I usually notice a drop in car mpg when I do this, but my car mpg stayed the same even though I was driving faster. I'm not much of a speeder, I just more frequently did 80 in the posted 80 mph zones when I more often go about 75 because I get better mpg that way.

The short of it? I notice some areas where I believe I have more acceleration. It's hard to tell when I just replaced the valve that makes my 1999 Chevrolet Prizm have it's year 2000 motor with VVT-i fully functional. This valve syncs up the oil flow in the valves based on the RPM of the engine based on what the Cam Shaft Position Sensor is telling the engine what to do. This already opened up a lot more power 2 weeks ago, so not being used to that I can't really tell you. I haven't seen enough car mpg numbers to report yet, but when I do, I'll do less of a story and more of an article on my main autobravado website.

Car mpg numbers included now! Weapon R Dragon Intake Review - final review?

*Note: 1999 Chevrolet Prizm is the same as a 2000 or 2001-02, except that my 1999 Chevrolet Prizm has a 2000 LSI engine with improvements not available in 1999. Except the one improvement of a variable valve timing (VVTi), it's the same engine and parts for anything you'd replace except in association with those valves. This was during a time that Chevrolet and Toyota were in a joint partnership and made the car together, so it really is a Chevy and a Toyota, a 1998, 1999, 2000. 2001, or 2002 Toyota Corolla are the same as well.

Add snow to the AutoBravado car for extra beauty. :)

Written and produced by AutoBravado.