Ask Xulfiqar - An Automotive Encyclopedia

[Xulfiqar]

if the tempearture needle goes beyond the half or 60% position then make sure that your cooling system is actually good, is your engine cooled with tap water?

[Rustle]

if the tempearture needle goes beyond the half or 60% position then make sure that your cooling system is actually good, is your engine cooled with tap water?

Coolant! When its level reduces then I add water... I might add coolant in it tomorrow. Can u please tell how can i check whether it has a thermostat or not??? I recently changed its radiator..

[Rustle]

If the fan runs when engine is switched on does it mean it doesnt have a thermostat? Does thermostat have any relstion with direct fan??

[dani_kk]

I have a Nissan b11 with QG18de wire driven engine.

Once timing chain adjuster broke so i replaced the whole timing kit.
After that the engine's cam got rubbed because of timing chain issue so it had little bit of noise.
Petrol consumption was however around 11-12kml on local. I had pump issues so replaced it with a walbro.
Enjoyed the car's immense acceleration on walbro.
But after sometime it's filter got choked so i installed a new pump. That was now of altis. It was kabli and when i shook that pump it was like sounding something broken in it. Anyways i installed it. But my car felt like immense loss of power. And plugs were like orange.
So i again replaced the pump, got a walbro Gs 190lph.
It is a very good pump, gave good pressure. But what i I am facing is whenever i throttle the car suddenly. The car takes on rpm very slowly. And from idle to sudden throttling sounds as if the car is an v8. And I've replaced fuel rail, coolant sensor, air flow maf sensor, coils.
But still the issue is there.
My. Mechanic said the intake valve seat of second cylinder is loosened and parallel exhaust valve seat is tight. So he told me to go for new valve seats. Please suggest me what to do?

[Xulfiqar]

If the fan runs when engine is switched on does it mean it doesnt have a thermostat? Does thermostat have any relstion with direct fan??

both have no relation, the fan is controlled by a thermoswitch in the bottom of the radiator, the thermostat valve is a mechanical device that regulates coolant flow out of the engine.

[Xulfiqar]

I have a Nissan b11 with QG18de wire driven engine.

Once timing chain adjuster broke so i replaced the whole timing kit.
After that the engine's cam got rubbed because of timing chain issue so it had little bit of noise.
Petrol consumption was however around 11-12kml on local. I had pump issues so replaced it with a walbro.
Enjoyed the car's immense acceleration on walbro.
But after sometime it's filter got choked so i installed a new pump. That was now of altis. It was kabli and when i shook that pump it was like sounding something broken in it. Anyways i installed it. But my car felt like immense loss of power. And plugs were like orange.
So i again replaced the pump, got a walbro Gs 190lph.
It is a very good pump, gave good pressure. But what i I am facing is whenever i throttle the car suddenly. The car takes on rpm very slowly. And from idle to sudden throttling sounds as if the car is an v8. And I've replaced fuel rail, coolant sensor, air flow maf sensor, coils.
But still the issue is there.
My. Mechanic said the intake valve seat of second cylinder is loosened and parallel exhaust valve seat is tight. So he told me to go for new valve seats. Please suggest me what to do?

firstly - I doubt your valve "seats" are loose. If they were and you were driving the car the engine will completely destroy itself in a matter of seconds.

Your issue is more related to engine control, for that you need more tests to verify, e.g. fuel pressure, fuel trims, MAF response etc.

[Rustle]

both have no relation, the fan is controlled by a thermoswitch in the bottom of the radiator, the thermostat valve is a mechanical device that regulates coolant flow out of the engine.

Thanku sooo much for clearing my ambiguity! One last question! Should i install the thermoswitch or not?

[dani_kk]

I've replaced three Maf's, response was same.
Changed injectors first and then whole fuel rail but no success.
The walbro on which car was accelerating like champ was even having more pressure than my current walbro. But now i think valve seats are the culprits, mechanic has shown me with the gauge. They are loose. And some are tight.

What do you suggest? I don't want to do any more experiments. If it's head I'm thinking to replace it completely. It will cost me 7k.
And valve seats+valve seals +cams will cost me around 10-11k total. So what's the good suggestion?

[nasirjavaid]

Thanku sooo much for clearing my ambiguity! One last question! Should i install the thermoswitch or not?

Its highly recommended though your cooling system needs to be in perfect condition so it doesn't get blocked .... Although I am running without it

[saboor73]

Its highly recommended though your cooling system needs to be in perfect condition so it doesn't get blocked .... Although I am running without it

Dosoro ko nasiyat khud miya fasiyat

[Rustle]

Its highly recommended though your cooling system needs to be in perfect condition so it doesn't get blocked .... Although I am running without it

Any specific reason for runninh without it?

[nasirjavaid]

Dosoro ko nasiyat khud miya fasiyat

hahaha... bhai issi lye me ne likha ha k cooling system should be in perfect condition. Mine is not so not using it. Hope its clear

[overspeed111]

AOA, Sir hope you are good in health,
so today i went again to the scrap yard to find that suzuki MX17 automatic transmission, so found 3 similar transmissions, the guy said that it came from japan and not used here but very dirty my first question is that how to initially check the good one and the other is that all of them do not have TCU neither i have with mine so have to find out which will work with it any picture of it would be of great help.
the other thing i want to ask that how does that TCU works means what benefit i would get by installing it as earlier i was using transmission without it as its a semi automatic transmission the driver can change gears any time, or by installing TCU it will work like fully automatic? can you please shed some light on it as i am confused. b.t.w i am getting the transmission for Rs 5000 with old gear is price right?
my initial plan to pour TYPE A fluid to check if the tranny works alright then draining that fluid and pouring ZIC Dexron iv is it appropriate or i pour dexron fluid in it ?

[2x2wheels]

AOA, I hope you are well. First of all, i would like to appreciate your contribution to this forum and for providing and sharing your valuable suggestions and knowledge.
I am a bit confused in selecting a AC compressor for Alto nd Khyber. My ac mechanic is suggesting me to opt for Teris Kid (kabli) compressor for khyber and another kabuli for alto aswell. However, i myself inclined towards Senden new compressor which would cost around 12k as i visited senden karachi office last week.
I believe a new thing is always hustle free and on the other hand could not trust kabuli items nd its reliability

I would appreciaite if you can help in this regard.

[Xulfiqar]

I've replaced three Maf's, response was same.
Changed injectors first and then whole fuel rail but no success.
The walbro on which car was accelerating like champ was even having more pressure than my current walbro. But now i think valve seats are the culprits, mechanic has shown me with the gauge. They are loose. And some are tight.

What do you suggest? I don't want to do any more experiments. If it's head I'm thinking to replace it completely. It will cost me 7k.
And valve seats+valve seals +cams will cost me around 10-11k total. So what's the good suggestion?

why not do some homework first, test the fuel pressure, test the fuel trims, spark advance, timing etc. Your issue can be from an o2 sensor too. I would suggest testing before shooting parts at it.

[Xulfiqar]

AOA, Sir hope you are good in health,
so today i went again to the scrap yard to find that suzuki MX17 automatic transmission, so found 3 similar transmissions, the guy said that it came from japan and not used here but very dirty my first question is that how to initially check the good one and the other is that all of them do not have TCU neither i have with mine so have to find out which will work with it any picture of it would be of great help.
the other thing i want to ask that how does that TCU works means what benefit i would get by installing it as earlier i was using transmission without it as its a semi automatic transmission the driver can change gears any time, or by installing TCU it will work like fully automatic? can you please shed some light on it as i am confused. b.t.w i am getting the transmission for Rs 5000 with old gear is price right?
my initial plan to pour TYPE A fluid to check if the tranny works alright then draining that fluid and pouring ZIC Dexron iv is it appropriate or i pour dexron fluid in it ?

the only way you can check an automatic is by driving it, The TCU actually shifts the ratios - meaning it will be a real automatic where you just shift to D and drive off.

For the TCU ask the body dealer scrappies for the "card" behind the glovebox, it should have a small green connector near it too - (its the checking and testing port)

[Xulfiqar]

AOA, I hope you are well. First of all, i would like to appreciate your contribution to this forum and for providing and sharing your valuable suggestions and knowledge.
I am a bit confused in selecting a AC compressor for Alto nd Khyber. My ac mechanic is suggesting me to opt for Teris Kid (kabli) compressor for khyber and another kabuli for alto aswell. However, i myself inclined towards Senden new compressor which would cost around 12k as i visited senden karachi office last week.
I believe a new thing is always hustle free and on the other hand could not trust kabuli items nd its reliability

I would appreciaite if you can help in this regard.

The original denso units from the factory were great, what refrigerant are you going to use? R12 or R134?

[dani_kk]

Can you please refer me stepwise diagnosis? And instruments too for testing?

[2x2wheels]

R134. Are new Denso units available in karachi or would you suggest for kabuli? And how is it with regard to load on engine?

[deltree]

@xulfiqar Sir, when doing a valve seal replacement job the short way the one where the whole head does not need meddling with, what other seals should one consider replacing? I believe the valve cover will come off, there's a gasket there at 180k mileage what is the best way to go about this, replace it even if it has not shown a single sign of failure yet or re-use it. I don't even know whether it is the paste based or rubber based gasket though. Also how important is torque when re-tightening the valve cover?