Ask Xulfiqar - An Automotive Encyclopedia

[Xulfiqar]

@Xulfiqar my w203 has had a intermittent faint hissing noise from the AC form behind the dashboard ever since i bought it, the cooling had been very good but occasionally on idle or while stopped the Ac would stop working completely but start blowing cold as soon as the car was revved up or while driving. somebody indicated it to me that the hissing is because of low refrigerant and it rushing past the txv valve.

if my car was on low refrigerant would it make such a noise? and would the EC button not light up as i understand the climate control shuts of the AC if the system is low to protect the compressor and the EC lights up, the button works fine otherwise.

can you do a diagnostic on the advanced climate control panel and manually read the codes and values like you can on a w210 i believe? the car was on STAR a while back and had no error codes stored or otherwise in this regard even though the hissing noise was present then as well. i believe the compressor spins all the time and has no clutch on these cars also as it drops water form ac drain in summers as well as winters now.

And if the level refrigerant level is indeed low estimated form high and low pressures can the gas be retopped up assuming no leaks and no compressor oil added or would all the gas have to be removed and vacuumed then filled again? it takes pag 46 oil? and can PAO ISO oil be substituted?

hissing noise is a sign of low refrigerant, your compressor is variable stroke and tuning the AC with such system is a right thorn in the side. If you are going on the pressure tests then wait till the temperature outside is about 26-30C - if you are doing this in the winter then only do a weighted charge - find a place that can recover your refrigerant and weigh it - then add the exact amount as required for your car. Should be close to 1 KG of R134 and I think Honda/Toyota dealers along with some nicer A/C shops can do such service.

The oil used is PAG 46

[arzaam.bhatti]

hissing noise is a sign of low refrigerant, your compressor is variable stroke and tuning the AC with such system is a right thorn in the side. If you are going on the pressure tests then wait till the temperature outside is about 26-30C - if you are doing this in the winter then only do a weighted charge - find a place that can recover your refrigerant and weigh it - then add the exact amount as required for your car. Should be close to 1 KG of R134 and I think Honda/Toyota dealers along with some nicer A/C shops can do such service.

The oil used is PAG 46

Btw when old charge is recovered and if put back does new compressor oil need to be added as well ? Or only when some component is opened ?

Edit: I checked with Shahnawaz and they said they don't have gas recovery machine and will check refer refrigerant level using Star for a accurate reading rather than pressure garages. They say they use Honeywell refrigerent and fill by weight

So can star accurately tell refrigerant level in this weather as well ?

Sent from my iPhone using PW Forums

[umar47]

@xulfiqar kindly guide me on this one of the front shocks (right side) of my cultus has gone hard the mechanic said you can replace it with kabli one but one of my friend is saying that if i am replacing it i should replace both of them otherwise the new one will make the older one hard is this true? should i go for replacement or repair ? Kindly guide

[ziyad.ahmad.391]

you have ground your discs twice to resolve this?

are your brake pads wearing perfectly even? are they free to move in the pad carrier or are they siezed in the carrier? A pad not able to move freely in the pad carrier will cause uneven braking and will cause steering vibration. I would advise to remove the discs, put them on a lathe and use a steel wire rotary brush to deglaze the discs, then remove the steel clips from the pad carrier, buff the carrier ears with a steel wire brush, apply slight silicon grease to the ears of the carrier, install clips, install pads making sure they can easily slide in the carrier (if they are jammed because they are not genuine parts then use a file to grind them down and make them easy to slide), clean pins completely, apply silicone grease to them assemble brake and retest.

THANKU for ur reply @xulfiqar Sir..I got the pads changed from honda; bought oem akebano pads..The old ones were nissin but their genuinity was a question as told by the mechanics because they had gone hard..The rotors were put on a lathe maching and tooled and silicone grease as well as the grease that came wid oem pads were applied...All this was done from a honda 3s under my own supervision..The brakes now feel great as previously more brake pedal pressure was needed to apply the breaks but the now even on the slightest touch of the break pedal the breaks apply..Tie rod ends were also replaced; oem parts from honda..The car handles much better now alhumdullilah

[hash737]

a hard shifting is associated to gear box or clutch plate .. even a non adjusted cable can cause hard shifting .. get cable adjustment checked .. then clutch plate and still if problem persists get gear box checked

Salam,

The problem has been diagnosed, its the bent level underneath which is causing the issue. i took car to mechanic in Sultan ka kho Rawalpindi and he diagnosed it. it just moved it a little and the gear shift became butter smooth but that was not the permanent fix and its bent and needs to be straightened.

Kind sir in local language he said (LEVER TERA HAI, and BUSH CHANGE HONAY WALAY HAIN , ABHI SHAAM HO RAHI HAI KAL AJANA 1 HOUR KA KAAM)

i cant take my car from islamabad to rawalpindi again, can you please guide me how can the lever be straigtened and wHAt bush are their exactly and what are they called so i can buy them and get them replaced and straightened up from a mechanic in islamabad?

Please please address this issue @Xulfiqar @Naweed

[hamz80]

The car under discussion is my 8th gen manual civic. The car was working perfectly fine until our recent trip to the northern areas. i will narrate the issues faced and would request your feedback:

On motorway, the car started puffing black smoke when pushed above 120km. Even on static position, one can see black smoke being emitted from the silencer.
One particular thing that has been there since the purchase is smoke emitted from the oil filler cap which is quite significant. i have had the PCV valve cleaned (not replaced) but it hasnt helped muck. The car is not reducing water but did reduce some oil on our recent trip to the northern side (approximately 1200kms).

We did conduct the compression test and the results were 175, 160, 160, 160.

Where i seek your advice is:

Is the compression alright for all the cylinders?
Why is the smoke being emitted from the oil filler cap?
There is some smell of petrol from the tail pipe if the car is sitting at idle?

Please note that the car was scanned properly and there was no issue with any of the sensors. Mechanic was of the view that the engine is weak which i am not willing to buy as the car packs a lot of power and does not show any such signs? I have received healthy feedback from fellow pakwheelers but would love to hear your views.

[Vaqas1]

@xulfiqar bhai Faced a weird issue. My Cooling system has no leaks and its very clean with Caltex coolant and Using thermostat so its overall in excellent condition. I was using SNA Radiator cap and switched to ND one 0.9 now ND one worked ok for a day or two than I noticed in traffic jam my fan was turning on more than usual. On inspection the Radiator hose was lose, System was not holding up any pressure.

After that I tried a brand new japanese cap I bought that didnt work, Tried one more new SNA and that also didnt work.

Than the old SNA the rubber seals were in bad shape so I tried that and it worked fine system was holding pressure but today because its old and needs replacement I replaced it with another SNA and that is having same issue not holding pressure. So again switched to that bad condition SNA cap and now that is also not holding pressure haha, The radiator side is fine I dun know whats going on. :S.

[NiGhTShAdE]

Map sensor error could pop up with leak in intake manifold check for leaks

Problem looks solved apparently. When i opened the air cleaner box i found the wire of air flow control valve broken and solenoid which meant solenoid was not being operated keeping valve closed geneating excessive vaacum when throttle was released at high rpm. Secondly small poly bag pieces were stucked all over the airfilter clogging it. Replaced it too...

[Xulfiqar]

@Xulfiqar bhai Faced a weird issue. My Cooling system has no leaks and its very clean with Caltex coolant and Using thermostat so its overall in excellent condition. I was using SNA Radiator cap and switched to ND one 0.9 now ND one worked ok for a day or two than I noticed in traffic jam my fan was turning on more than usual. On inspection the Radiator hose was lose, System was not holding up any pressure.

After that I tried a brand new japanese cap I bought that didnt work, Tried one more new SNA and that also didnt work.

Than the old SNA the rubber seals were in bad shape so I tried that and it worked fine system was holding pressure but today because its old and needs replacement I replaced it with another SNA and that is having same issue not holding pressure. So again switched to that bad condition SNA cap and now that is also not holding pressure haha, The radiator side is fine I dun know whats going on. :S.

remove the cap and inspect the lip in the radiator fill neck where the pressure valve seals. if its damaged the system wont hold pressure.

[Xulfiqar]

Btw when old charge is recovered and if put back does new compressor oil need to be added as well ? Or only when some component is opened ?

Edit: I checked with Shahnawaz and they said they don't have gas recovery machine and will check refer refrigerant level using Star for a accurate reading rather than pressure garages. They say they use Honeywell refrigerent and fill by weight

So can star accurately tell refrigerant level in this weather as well ?

Sent from my iPhone using PW Forums

No oil is lost in recovering refrigerant.

the car has low and high pressure sensors in the lines - the STAR unit can read them but it also has some failure points - what if the sensors are bad/slow/blinded.. - thats why the use of analog gauges is preferred in pressure testing.

The STAR is good for cycling the compressor to maximum when refilling as it reduces work time for the technician but even if you use the plain old R134a manifold and a weight scale its easily done - just takes 30 minutes to an hour to fully fill the unit correctly.

once the system is recovered, vacuum it down, connect manifold - with engine off fill some liquid in the high side line till you see about 10 psi in the vapor line - close the liquid service valve in the manifold and make sure everything is off/closed/sealed - start the engine cycle the AC to max and slowly fill the vapor in the system till the correct weight is achieved. The injection of liquid creates the required head pressure at the compressor in order for it to start working correctly - old mitsubishi vane compressors had this issue too. slugging liquid in it would fracture the valve plates and you suddenly would have a large bill for replacement of compressor.

Be extra careful when doing the liquid fill and seal because if you leave it open - high pressure liquid can enter the refrigerant tank and make it explode.

im sure some honda/toyota dealers have the ac recovery machine and can do this service.

Doing a pressure test in cold weather in this car is very misleading as the compressor is variable displacement.

[arzaam.bhatti]

got it ill take care of all these points thanks
btw if climate is set to low(below 17C) on both sides wouldn't the compressor run on full strength regardless of cold weather

[Xulfiqar]

got it ill take care of all these points thanks
btw if climate is set to low(below 17C) on both sides wouldn't the compressor run on full strength regardless of cold weather

no it wont run on full if the weather is below 17C outside the car, the system will literally turn on the heating in that case.

[wasim625]

@xulfiqar
Bhai can/should we use CV grease in between spring leafs while packing them back? And what diesel engines does the tractors we have in Pakistan use, do they have any kind of service repair manuals?

Sent from my 07-18G using Tapatalk

[Xulfiqar]

The car under discussion is my 8th gen manual civic. The car was working perfectly fine until our recent trip to the northern areas. i will narrate the issues faced and would request your feedback:

On motorway, the car started puffing black smoke when pushed above 120km. Even on static position, one can see black smoke being emitted from the silencer.
One particular thing that has been there since the purchase is smoke emitted from the oil filler cap which is quite significant. i have had the PCV valve cleaned (not replaced) but it hasnt helped muck. The car is not reducing water but did reduce some oil on our recent trip to the northern side (approximately 1200kms).

We did conduct the compression test and the results were 175, 160, 160, 160.

Where i seek your advice is:

Is the compression alright for all the cylinders?
Why is the smoke being emitted from the oil filler cap?
There is some smell of petrol from the tail pipe if the car is sitting at idle?

Please note that the car was scanned properly and there was no issue with any of the sensors. Mechanic was of the view that the engine is weak which i am not willing to buy as the car packs a lot of power and does not show any such signs? I have received healthy feedback from fellow pakwheelers but would love to hear your views.

can you test further? - as in get the fuel trim data?

the compression numbers are not fully promising but can also be due to bad valve clearances.
black smoke is over rich fuel mixture, a bad MAF can do that - its not the ultimate solution but maybe a cause. Your fuel smell at idle is also a rich sign, if you keep on driving in this condition the engine will wear out very quickly.

oil smoke from the oil fill cap is normal at idle, you can increase the rpm to 2000 and it will disappear.

[arzaam.bhatti]

Sorry for asking over and over again
One last query would it be better to wait till summer and use the car less then check and fill up AC refrigerent of necessary or relying on the hissing noise and the fact that in the service history the last time AC gas was topped up was in early 2008 check and refill now so as not to cause damage to the compressor or any other component by running low on refrigerant

I can't decide if damage can be caused to compressor in a w203 if possible low gas or more damage can be caused by filling the charge in correctly with cold ambient weather

Sent from my iPhone using PW Forums

[Xulfiqar]

the system will continue to run without issue if it can somewhat cool down.

If the charge gets so low that its dangerous the low pressure safety switch will kill the A/C compressor function to save it. In most cases its recommended to immediately drive to the repair center to repair this issue.

[ali_ak]

@xulfiqar

I got Installed OEM toyota INSERTS in my front struts. Although my car toyota corolla 1990 2.0 D, OEM inserts i got were for Toyota Carina and Celica of same year. Any ways i bought it, working fine so far.

Dealer told me its OEM toyota shock made by KYB, KYB is written on it as well.

KYB warns against using any ATF or other liquid as heat absorber, they say all their shocks are designed not to require any liquid medium, yet i got confused as those shocks are not listed in KYB catalog.

So i added small amount of ATF any ways.

Am i in any danger??

[Vaqas1]

remove the cap and inspect the lip in the radiator fill neck where the pressure valve seals. if its damaged the system wont hold pressure.

After trying many caps and tightening all pipes again its working now. Thx

[a_k]

@Xulfiqar, Car is ke70 1982, engine 4K,
should i go for k50 5speed gearbox or not? currently i have k40 4speed which is working fine, at speeds above 80/90 kmph fifth is always desired otherwise working fine. Please advice.

i was surfing net and saw few people discussing that k50 is weak gearbox. is it true

[junox]

Aoa mri gari ka temperature gauge switch jo k fan ko auto start krta hy wo khrab hy,, fan direct kye huy hn to ye

1) islamabad ki winters me b thek hy??

2) ya 1 fan off krwa dun 1 chalny dun winter me??

3). Or switch ko check krny k lye electrician engine ko itna gram krty hn k engine sy smell any lgti hy,, is it a gud practice?? Ic k ilawa koi triqa ni auto fan switch check krny ka??

Car is city 2002