Engine Knock Sound

[osanda19]

hi guys.i have a toyota vitz(scp10) 1000cc YOM 2001..which has done 135000km on the clock (100% genuine)

since last month when i accelerate the car (while driving only)something like engine knock sound("kata kata") something like rattle sound (but not a engine knock) coming from engine after few seconds its vanished.but no any difference with engine performance ..pickup or gear changing.last week i did a engine tuneup & sensors checked .but no luck with that too.my mechanic says he cant predict it tooo because car performance is very well...what should i have to check now?does any one had a similar problem like this??pls guys help me

Edited April 7, 2015 by osanda19

[hrm]

Even I have this problem in my Vitz 2007. It only appears when engine come to it's operating temperature. No sound if I accelerate smoothly. No check engine light yet.

[gayanath]

hi guys!! im very sorry for the late reply ..but i think i have to share about my experience..

at last i decided to forget about that engine knocking sound & live with it(because i had no choice)!!

but after few months check engine light came on when im travelling to jaffna..but no different with performance..but i noticed that fuel consumption is little bit higher than earlier..after returning the trip i went to meet my mechanic & got a scan report..and it says "FUEL LEAN"..then we decided to change the petrol filter ..after that check engine light gone off and that knocking sound also gone..i was very happy..but after few days suddenly came back that check engine light with that knocking rattling sound..after that we got a freeze frame data report & my mechanic analyzed it and decided to change the MAF(mass air flow sensor)...then we changed it and every thing became normal( actually better than early)engine sound became smooth..that knocking ratteling sound gone forever..fuel consumption became very low and car performance became noticeable change..

Highly appreciate your experience sharing. That's what required as professionals.

So, final conclusion = Problem in MAF (Mass air fow sensor), isn't it?

[osanda19]

@gayanath..-ha..ha,, yes...thanks bro!!

[osanda19]

@hrm- in my case..my engine is 1000cc 4 cylinder vvti engine (2001 model)..i think may be your one is 3 cylinder 1000 cc engine..r u getting ang performance differences?

[hrm]

@hrm- in my case..my engine is 1000cc 4 cylinder vvti engine (2001 model)..i think may be your one is 3 cylinder 1000 cc engine..r u getting ang performance differences?

Nope performance was not affected neither fuel consumption. Mine is also 4 cylinder 1300cc 2SZ-Fe. I got my MAF sensor cleaned through a mechanic yesterday (after reading this post) and seems issue has disappeared for now and throttle response improved as well.

Edited November 1, 2015 by hrm

[osanda19]

ha..ha..really!! happy to hear that

[MAS]

@ osanda19, so after replacing the MAF, so far no issue ? for how long ? I am facing a similar issue and want to try to clean the MAF first.

[osanda19]

@MAS now about 4 months.no errors...there is a special chemical for clean MAF sensors..because MAF sensor a very sensitive one it can damage very easily! whats your car model?

[MAS]

@MAS now about 4 months.no errors...there is a special chemical for clean MAF sensors..because MAF sensor a very sensitive one it can damage very easily! whats your car model?

I plan to use electrical contact cleaner. But appreciate if you could get the name of the cleaner your mechanic used. My vehicle is a Hyundai Tucson.

[hrm]

I plan to use electrical contact cleaner. But appreciate if you could get the name of the cleaner your mechanic used. My vehicle is a Hyundai Tucson.

check this http://forum.autolanka.com/topic/15895-mass-air-flow-sensor-cleaner/

[hrm]

@MAS now about 4 months.no errors...there is a special chemical for clean MAF sensors..because MAF sensor a very sensitive one it can damage very easily! whats your car model?

btw how much is the MAF sensor? Did you bought it brand new or recon?

[osanda19]

I bought a good condition recon one for 2500/= from negombo..I went there with my mechanic and before pay money I got a scan report to check the MAF sensor data..& did a test run..

[osanda19]

@mas-I didn't cleaned my old one..but I think that u can get a one from good motor spare parts shop

[osanda19]

@mas-I didn't cleaned my old one..but I think that u can get a one from good motor spare parts shop

[MAS]

@osanda19.... man I owe you many beers !

After cleaning the MAF with CRC CO Contact Cleaner, my rattle can sound in the engine disappeared. A big improvement in acceleration under load.

I have been having this headache for couple of years and never thought it was the MAF. I almost changed the fuel pump and injectors because it was clear the engine was starving for fuel under load. This thread saved me money. I hope mods can stick this thread right up where it belongs :-) and help others with similar engine rattles.

So so happy now :-)

[osanda19]

Ha..ha.cheers!!!.really..im very happy to hear that..seems like many of us having this MAF sensor issue!!