Toyota car and truck forums

Greetings,
I have 1995 Base Corolla with 210,000 miles that has developed a serious vibration in the motor or tranny somewhere. It vibrates at idle as well as in gear and the vibration changes with the engine rpm. I have, thus far, spent $900 in repairs and finally received the "we give up" notice from the mechanic shop today.

Performed thus far: Transmission fluid change, including filter/screen. Full inspection by Transmission shop. Major tuneup including plugs, plug wires, rotor, distributor cap, timing belt. The water pump was also replaced because it sprung a leak during the other maintenance.

All motor mounts have been thoroughly inspected and deemed in good condition. Again, both the Transmission Shop and the Mechanic Shop claim they "cant find the problem."

The vibration is present cold or warm but seems to be more severe when cold.

Any informative suggestions highly appreciated!!! :-)

I assume you've had it checked for computer error codes already and there is no misfire or other such malady.
I wonder, is the engine internally or externally balanced? If externally, could it have thrown a weight? (I'm just GUESSING here)

The "misfire" is precisely what the mechanic shop deemed as the source - which resulted in the $900 major tuneup effort. Alas, no change after that work was done. They then took the car themselves over to a transmission place - who subsequently decided nothing was wrong with the transmission but they figured the transmission mount could be the source. So, that was done and it too did not correct the problem. :-(

Can you list what was done to the car so far? What have the mechanics ruled out so far?

I'm assuming at the very least - you got a comprehensive tuneup, which should have included, at the very minimum:
- fluid changes (engine oil and transmission fluid)
- new cap and rotor
- new plug wires
- new sparkplugs
- new air filter
- injector flush or cleaned the injectors
- throttle body cleaning
- new PCV valve
- new fuel filter

Should have inspected/adjusted:
- timing belt (checked engine timing)
- EGR valve (check for vacuum leaks and cleaned the valve as neccessary)
- checked the throttle body TPS sensor, AIC valve
- checked for general vacuum leaks
- did a compression test
- confirmed proper fuel pressure (fuel pump, hard and soft lines, fuel rail)
- comfirm ignition (checked the coil pack, verify spark, verify spark plug gap)
- all four mounts (motor and transaxle)
- scanned the ECM for trouble codes, place ECM into a diagnostic mode to check key parameters
- checked all ground points, all power sources
- checked the harmonic balancer on the engine
- checked all the pulleys and accessories (vibration could be coming from a faulty accessory, like a bad alternator or A/C compressor etc).
- general audible engine noises, may need to use an engine stethoscope to isolate the sounds (injector cycling, piston slap, detonation, etc.)

Plus a bunch more that I cant think of off the top of my head. Should have gotten all of this for $900 + more, if the guys are worth their salt, so to speak.

Mis-fire has a specific cause behind it - if that is the best they can come up with, they probably didnt cover all their basics. DId they check compression? Check for fuel and fire? Timing? I'm hoping that this shop specializes in imports - as the 7th gen Corolla (1993-1997) have pretty tough engines, but have very specific potential failure points.

Hey! Thanks for the comprehensive response. From the paperwork, they provided:
- "31-Point Inspection" (all items checked off as okay except "Engine" which was marked as rough idle)

They spent about 45 minutes to an hour with the car and determined that the car was misfiring - that the intake valves were not fully seating when firing and that was causing the vibration. They performed a compression test on all cylinders to confirm no valve damage had already occurred. All four were 60lbs.

So, I approved their "Major Tuneup" work since they assured me it was the root cause. Work performed:

- "Remove and replace timing belt"
- "Remove and replace timing belt tensioner pulley"
- "Tune Electronic Ignition" (Timing Kit, Plug Wires, Rotor, Dist. Cap)
- "4-Part Fuel System Service" (Air filter, Vacuum Hoses, PCV, Fuel Additive) (Engine, Crankcase, and Throttle Body)

All this for the tidy little sum of $420 in labor and $394 in parts. Additional work performed at no charge was replacement of the waterpump which developed a leak the next day after servicing and the transmission mount after they took the car to a transmission shop who confirmed the transmission was okay. (I dont have confirmation on what they did to determine that)

UPDATE: In driving the car the last 2 days, I realized something new. The vibration is most severe when the car is cold. When you first start the car, after being outside in the cold, your eardrums buzz due to the low frequency of the vibration. Its not just the sound of the car's body parts and the dash items making noise, the entire car vibrates. It resonates during this time but once the car warms to operating temperature, it will idle a bit smoother/quieter - however, once on the gas to drive at speed, the vibration returns. Sitting at a stoplight, with car in park or neutral, you can rev the engine and feel the vibration return at all rpm levels, the resonance changes in severity at different rpms. Again, the vibration resonates through the entire car - to the point of making you feel as though the car has massage chairs for seats! :-) I literally feel the vibration in my spine through the driver's seat as I drive down the highway.

I'm concerned about continuing to drive the car in this condition but equally concerned about the expense on this car. According to NADA, I've already spent half of the car's trade-in value on repairs. Considering that I've already had tires put on the car in the last year and just put in a new 5-year battery, I've spent well over half the car's value in upkeep. I'm stuck between throwing that money away and getting rid of the car and putting another several-hundred-dollars worth of effort to finally get it running right. (If that is even possible without replacing the engine)

I've read several cases online of folks in this same situation, I just havent seen conclusions that give me confidence I've uncovered what is wrong with the car or that I ever will.

I appreciate everyone's thoughtful suggestions as I continue to ponder what to do here.

JC

Well, this thread can be closed out with the following solution: I achieved approximately 90% reduction in vibration by replacing the passenger-side motor mount. This is plenty for me to be happy with the car again.

The dealership wanted $325-ish to replace this mount but I did the job for just shy of $60. A good price for this mount is $55. You'll see them range from $59.99 to $74.99. I talked my way into a $5 discount on the $59.99 price at my local Advanced Auto Parts store.

It took me about an hour and fifteen minutes to thoroughly review how, and then remove the motor mount from the car. I removed it with the engine mount (male part) still bolted to the mount. Once free from the car, it was easier to get to the nut needing to be removed. Advice: You will need serious leverage to break this nut loose. If you have a large, securely fastened vice, you should be fine. I didnt, so I had to manufacture a method to secure the bracked while going at it with a rod and long-handled socket wrench. I also suggest penetrant.

With 210,000 miles and counting, I now have confidence this car has more life in her. :-)

Cheers!