Toyota Vitz engine Rebuild Again

[saadhaq]

As mentioned, pressure plates were weak and gear shifting was sometimes late and with a jhatka at 50-60 kmp/h so could this be the possible reason? or do you think it will not happen suddenly and it is surely installation issue?

[rajaatta]

Yes transmission doesnt fails unless their is some installation error btw i do rebuild a lot of engines with weak transmissions but we dont pull out the torque converter and if needed when we have to replace the torque converter oil seal then we double and triple check the converter seating a mild mistake can result in transmission failure.
So what is the situation now any shuddring or clanking noises when engine starts or nothing happens

[capsat]

pressure plates were weak

in an auto transmission there is nothing as pressure plates or may be the term used by your mechanic is not understood correctly, by me.

in lay men terms it has the torque converter, solenoid circuit, combination of clutch pack which controls the shifting with respect to ATF pressure and ECU command

[Xulfiqar]

did your mechanic tell you that "pressure plates are weak"

and you have an automatic transmission vehicle?

[saadhaq]

It's Automatic

[Xulfiqar]

your mechanic feeding you a story, there is no "pressure plate" in an automatic transmission.

The clutches are wet style and are in multiple numbers to control different parts of the gearsets - they have steel and friction plates sandwiched together which are applied by hydraulic pressure and released with gentle springs in the apply pistons on the clutch drums.

[saadhaq]

Maybe he is talking about clutch pressure plate?

[saadhaq]

Right before the transmission failure, there was hallow type clanking sound. No such sound as of yet since transmission not working. Car starts normally with normal engine noise.

[Xulfiqar]

there are no pressure plate assemblies in any clutch unit of any automatic transmission. The pressure on the clutch is done by hydraulic oil pressure.

as I said - its a story.

aka "topi" in street language

[saadhaq]

Thank you. Let me talk with the mechanic.

[saadhaq]

If car fuel pump or filter is faulty and not generating required fuel pressure so does it in any way effect:

car starting, acceleration, pick and hard to gain top speed?

[Hassan1991]

Yes all of those.

[saadhaq]

OK, i got a new fuel pump in june'20. That was completely brand new and genuine so could be possible to be faulty in just a short time?

[Hassan1991]

No I don't think so.
Check the fuel rail pressure.

[saadhaq]

ok i'll get it checked. Also can you let me know if faulty fuel pump could cause damage to engine?

[Hassan1991]

Not actually. Just issues mention above. Until you keep driving like that for years.

[saadhaq]

Thank you

[Xulfiqar]

Is your fuel pump actually strong enough?

A regular fuel pump should be able to generate twice its running fuel pressure for atleast 30 seconds straight.

Also test its amp pull and you can also use an oscope to see the commutator pulses, you can also check rpm of it by checking it against a time plot if you know the commutator leg count.

[saadhaq]

Salam

Recently had my car's engine overhauled, but i am having approx 8km/L fuel average without AC. Done approx 1700 kms uptil now.

1- Have tuned after 1000 kms, every thing is clear and working fine
2- Have fuel pump changed, car is now more smooth, light and responsive.
3- Using fully synthetic motor oil.

Need guidance what could be the reason behind? It should be giving around 11-12 km/l within city in my opinion.

recently Catalytic converter got choked so when opened its net/jali was broken, all cleared and fitted back which made the car more smooth and responsive.
Do you think if it has to do any thing with fuel? please note that car is running smooth with timely gear shifting. I think choked CAT will effect fuel.

Thank you.

[aziz.rehan]

Is fan auto
Thermostat valve installed?