sometimes When AC on Bumbaba rpm/idle (400-500) ang normal idle 800 when ac on

[alyx1705]

Help mga sir. may time kase na kapag on ko ung AC biglang baba ung RPm idle nya 400-500 tapos pag umaandar na ganun padin pag mgbrake ako biglang baba rpm malapit na mamatayan ng makina. Ano po ba ang problem nito? Nadala ko na sa casa na overhaul na AAC valve, Maf sensor narewired na din, after a week biglang nagloloko nanaman, napansin ko din pag mainit na yung makina tapos pagpinatay ko and start ko na uli with AC on dun magloloko ung idle. tagal ko ng problem to, bago ko ibalik sa casa ulit ask lang po ako ng advise. Basta pag AC on lang Siya nagkakaproblema Parang walang power yung engine, pag off ok naman ung idle 700-800) na adjust nadin pala ung normal idle ganun padin biglang bumababa pag AC ON. Pahelp po..T_T

(my time din na nangyari sakin biglang ayaw magstart tapos wait ko pa ng mga 30 minutes para magstart ulit, and yung speedometer ko din hindi accurate minsan, mga 40kph palang ako yung speedometer ko nasa 80kph na)

my ride is nissan exalta 2000 sta matic.
pasensya na po newbie lang dito hindi ko alam san magpopost

[alyx1705]

up... Help po sa may mga alam.... T_T

[v6dreamer]

The idle solenoid seems to have failed. This keeps the RPM up while there is load on the engine at idle. Have the car scanned for codes to be sure or it could be an electical power drain, the A/C is drawing more power than the car can provide. It could be that your Generator is not working as it should, or the A/C is faulty. Check them all out.

[alyx1705]

Thanks for the reply, i already brought it to nissan quezon avenue about a month ago and they did an aac overhaul but still after a week my idle drops again, Is it possible that it is my alternator? nung pinacheck ko din sa AC expert sabi servo daw yung problem wala sa aircon. ngayon I'm thinking saan ko pwede ipacheck lahat ng sinsabi mo, nagdadalawang isip nako sa casa eh, I don't even know if na overhaul ba talaga nila ung aac valve. Napansin ko din na kapag mainit na ung engine saka magloloko, i mean, kapag nakapag drive nako for about one hour or pagmainit na engine tapos pagpinatay na makina then inistart uli parang walang power pero normal ung idle 700-800 tapos paginopen ung aircon biglang mag drop na ung idle 400-500. but if walang aircon ok naman idle nya. my alam ba kayong magandang shop at magaling? matagal ko ng problem to eh. TIA..

[v6dreamer]

Oh boy, your car is much more serious than I thought.
Head gaskets are there too make an air tight seal and keep the compression you build inside the piston chamber. If there is a leak in the gasket you will loose compression and overall power. So if you feel you are lossing power then you probably have a bad head gasket. Not always the case though. A compression test should be the easiest way to find out if your head gasket is bad or not. You have to get the piston to the bottom dead center and the proceed to have it go to TDC (top dead center) to get an accurate reading.

Try answer Y or N:
Was A/C working properly? Is it blowing cold air, no clunkly noise on the compresor other than engine died out when turn on the A/C?

Is this happened when you were at idle only?

Is this happened when you were at rate speed(driving)?

[alyx1705]

nissan already replace the head gasket, and i think it's not the head gasket but if you prefer to test it,how will i test it?...

Yes A/C is working properly, its blowing cold air, There was no clunky noise, engine wouldnt die it only reaches up to 500-300 but when its about to die i press the gas pedal together with the brake, so i use my two feet to have thenormal rpm.

no, When i Shift to drive it actualy goes down 500-400rpm.

When im driving and pressing on the gas pedal my rpm is good but while im about to stop specially in traffic and stoplights and pressing the brake, the rpm will eventually drop again to 500-400 like the engine stalls. It's like when ac on the normal idle is 400-500 but the real normal idle of my car would be 750-900 right??
what seems to be the problem? i think this happens only when my engine is already warm and i started it again, the rpm would drop to 400-500 , but when in cold start my idle is normal when ac on.

[simarun]

This is exactly what my problem before, then pinalitan lang ang mga ito. Cost including labor nasa 500 lang sa mga Aircon shop. Hope it helps.

[alyx1705]

ano po tawag jan?

[alyx1705]

ano po tawag jan? and saan banda nakalocate yan??

[rusem]

sakit ng exalta yan. posted the same thread topic years before for my gf's exalta... di alam ng casa gagawin dyan. my gf' brought it to speedyfix for diagnostics... they found an errant sensor. guys from speedyfix recommended a shop at banawe. that solved the problem. can't rememeber what shop it was years ago na. maybe you want to try bringing it to a shop who can read diganostics for you first.

[alyx1705]

i see, Parang ayaw ko na nga ibalik sa casa hindi ko alam kung ginagawa ba talaga nila doon ung mga dapat gawin, what sensor are you talking about? air flow sensor? if air flow sensor narewired nadin ng casa un, what shop would you recommend? wala kase ako alam na magandang shop. tagal ko ng problem to eh.

[4JGtootsie]

Its probably a sensor from AC compressor. When compressor is engaged it sends signal to the ECU to increase RPM. Older models use the step up vacuum switch and vacuum actuator like that in the picture. I dont know what is in use in your exalta.

[alyx1705]

i Already ask an aircon specialist but they told me that this problem doesn't affeect ac compressor but i don't have any idea if My car had an ac compressor sensor. Can you tell me what's that best way to do?

[miked]

sir alyx, you may want to check also ung air hose connecting your hydrovac and engine for leaks. hope this helps

[rotber]

I think 4JGtootsie is correct. Pag malamig pa makina naka automatic chock yan kaya hindi pa bumababa rpm maski on a/c. kung may a/c sensor yan na naka connect sa ecu dapat naka on ang check engine, pag wala maybe vacuum hose type yan. dali lang yan.

[edgar75]

Help mga sir. may time kase na kapag on ko ung AC biglang baba ung RPm idle nya 400-500 tapos pag umaandar na ganun padin pag mgbrake ako biglang baba rpm malapit na mamatayan ng makina. Ano po ba ang problem nito? Nadala ko na sa casa na overhaul na AAC valve, Maf sensor narewired na din, after a week biglang nagloloko nanaman, napansin ko din pag mainit na yung makina tapos pagpinatay ko and start ko na uli with AC on dun magloloko ung idle. tagal ko ng problem to, bago ko ibalik sa casa ulit ask lang po ako ng advise. Basta pag AC on lang Siya nagkakaproblema Parang walang power yung engine, pag off ok naman ung idle 700-800) na adjust nadin pala ung normal idle ganun padin biglang bumababa pag AC ON. Pahelp po..T_T

(my time din na nangyari sakin biglang ayaw magstart tapos wait ko pa ng mga 30 minutes para magstart ulit, and yung speedometer ko din hindi accurate minsan, mga 40kph palang ako yung speedometer ko nasa 80kph na)

my ride is nissan exalta 2000 sta matic.
pasensya na po newbie lang dito hindi ko alam san magpopost

Parang pareho tayo problema. Im using 93corolla. Namamtayan na ako ng makina kapag naka on na A/C ko kahit mainit na makina. HIndi naman dati namamatay engine ko kapag on a/C. At Pag nakaoff naman wala naman problema at maganda pa nga takbo ng sasakyan. need ideas also bago ko dalhin sa mechanic.. thanks.

[mazdae2000]

have ur IAC checked and cleaned and and also ur ICT yan kasi ang mga load sensors

[sum1]

bro pareha pala tayo...pero once lang...ok ang idle pero pag nag brake babagsak ng 600 rpm ko...pero tataas din agad...ngaun wala na...i think dahil nag palit ako ng langis...kasi mineral 15w-40 lang langis ko...pero nagpalit ako ng semi-syn 10w-40..un naisip ko dahilan...after three days of driving ok naman na... ....siguro nag dajust lang makina ko sa langis....hehehhehe

[mighty-rain]

This is exactly happening with my Kia Picanto 2017. Pag ON ang AC then aapakan mo yung break para huminto babagsak ang RPM below normal level then aakyat ulit.
Napatingin ko na rin sa CASA and wala silang magawa palagi nalng sinasabi na wala silang makitang problem. But the fact na bumababa sa below normal ang RPM means something is wrong! kung di lang mavovoid warranty gusto ko 'to ipatingin sa ibang shops. Parang walang alam nasa casa eh trabaho pa naman nila iyon.

what they did so far is:
- checked for vacuum leak - wala silang makita
- changed spark plugs - sabi nila ito daw yung cause, but until now nadun parin.
- clean throttle valve - ito paligi nila ginagaw everytime nagcocomplain ako sa kanila

I'm planing na ibalik ulit unit ko sa casa, and asking if may suggestions na pwd ko ipacheck sa casa. TIA!

[Walter]

Check the idle control valve ...