what causes my car to vibrate?

most common is failed ineer cv joints. have them checked to verify.

axles are about 80 new and 1.5 hours per side to replace

Roy

the sound of the car is generally heavy and is mixed with a leaking exaust sound. But I have taken it for checks and its confirmed the exaust is not leaking. I observed the engine mount on top at the passenger side is cracked, could it be the cause?

cracked no, broken, yes. did you have the inner cv joints checked as i suggested??

Roy

Symptom indicates possible EGR fault. Is the vibration vehicle speed or engine rpm related?

Both engine speed and rpm, but is worse when the car is in motion. I have replaced the broken engine mount, but vibration is still there.

Check the EGR system.

I have checked all sugestions and vibration remains. I have been told it could be a balance shaft issue, could this be true? That would require a big job if right.

This engine does not use any balance shaft.

The upper engine mount is just a torque rod for preventing the engine from twisting too much when torsional force is applied.

The engine mounts below and the transmission mounts are the ones to cause vibrations.

Any vibrations due to bad engine mounts ( unless they are completely destroyed) would not be felt during driving.

If the vibrations are more pronounced during slight acceleration, Roy had it correct. The CV inner joints are bad.

Check the inner CV joints for excessive side play and broken boots. Tell tale signs would be grease splashed all over surrounding areas.

If the vibrations also occurs while coasting in neutral at the speed that vibrations occurs, you need to have the wheels checked. They requires balancing.

The vibration is engine rpm dependent. Even when the transmission is not engaged, you can feel the vibration as soon as rpm gets to between 1500 - 2500. When it gets up to 3000 vibration stops.

That is more likely to be engine performance related and most common cause is the EGR system.

Is the MIL indicating and have you checked for trouble codes?

No, how do I check for the codes? Nothing is showing on the dashboard. Engine check indicator shows when engine starts and disappears soon after.

https://www.2carpros.com/articles/toyota-trouble-code-definitions-and-code-gathering-method-1990-1995

Above link explains how to check for trouble codes. When the MIL goes off after engine starts, it usually means no trouble codes for for earlier models, some codes do not trigger the MIL so there is no harm trying.

Btw is your engine 4 or 6 cylinder? I would still suspect the EGR to be the cause. TRy removong the EGR to check if the passages are clogged. The MIL would only indicate if the circuit is faulty but if it is clogged, it might not show.

My engine is 4 cylinder 5s FE

Give the EGR a check. After so many years and the mileage, the passages are due for cleaning anyway.

Ok thanks. I will get it checked

You're welcome.

vibrations more pronounced during acceleration 90% of the time are inner cv joints bad mounts will cause the inner joints to wear . Thic can be hard to see . With the car on a lift jack the left side of the engine so it sits like its excel orating . Spin the front wheels and feel for binding .

Could EGR problem cause high fuel consumption?

Yes, it would because you are running with misfires and you need to accelerate more to get the power desired.

I have just checked the EGR system and it is in good shape.

The body of the car vibrates when rpm gets up to 1500-2500 whether the car is in motion or is parked.

Did you checke the spark plug and related components conditions? I believe you have a misfiring causing the condition and at higher rpms, the engine is running with less load so any misfiring would not be easily noticed.

I checked the spark plugs and they are ok. Just FYI the thermostat controlling the fan was removed to avoid overheating. Could it have any other impact on the car?

It is so annoying, the vibration is there all through driving as long as rpm is between 1500-2500. And I mostly drive within that range in the city. Will there ever be a solution? I have tried everything.

Removing the thermostat would not cause this but it would cuse higher fuel consumption and erratic idling at times.

For fuel injected engines, the thermostat is an important part of the system and should never be removed. If there are overheating issues, removing the thermostat is not going to solve the problem, you are only delaying it.

Disconnect the EGR and test if problem goes away.

Is it the EGR valve or the modulator? How do I disconect it? I disconected the modulator and problem was still there.

Disconnect the vacuum to the EGR valve.

Its a black hose that you will remove and plug off