Grand Scenic 1.4 TCe cuka

Kamele0N

YUGOslovanski mehanik Dmitri Mendeleev
23. jul 2008
42.361
5.651
113
Sem se ob tem članku spomnil na tole temo!

Očitno gre za LSPI (Low speed pre-Ignition fenomen)....pač klenkanje motorja v režimu relativno velike obremenitve pod malim gasom....

https://www.oronite.com/products/lspi.asp

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Causes of LSPI

Low Speed Pre-Ignition (LSPI) is a premature combustion event, occurring prior to spark ignition in turbocharged, downsized gasoline vehicles. As the name implies, it occurs when engines operate at low speeds and high loads. It can result in extremely high cylinder-pressures and can lead to heavy knock. At a minimum, LSPI can generate an audible knocking noise noticeable to the driver. Repeated exposure to these conditions can cause engine hardware failure, including broken spark plugs and cracked pistons. A characteristic of LSPI is that one event often leads to subsequent events. The events will frequently occur in an alternating pattern between pre-ignition and regular combustion.

Several theories exist to explain the mechanism of LSPI. One theory is centered on an oil droplet entering the combustion chamber from a crevice between the piston and cylinder wall. In this mechanism, the oil droplet mixes with fuel and auto-ignites. A second theory focuses on deposits as the ignition source for LSPI. Evidence has been shown for both mechanisms, and they are not necessarily mutually exclusive.

Chevron Oronite is conducting extensive research in this area to help advance the understanding of LSPI, particularly on the impact of lubricant additives. From these studies, solutions are beginning to emerge to help mitigate the effects of LSPI.

2 teorije zarote......krivita neprimerno olje v motorju...oziroma aditive v olju ( kalcij v funkciji detergenta)

1) da je olje pač tako da pride mimo obročkov ( neustrezna bazna grupa....al pa preredko pač) in pride do predvžiga le tega v zgorevalni komori....

2) aditivi v olju (kalcij) povzroča saje v zgorevalni komori ki se sčasoma akumulirajo v zgorevalni komori in rahlo povišajo kompresijsko razmerje...kar privede do klenkanja

Samo pač kot zanimivost
pozdrav.gif
 

luka51

Guru
16. avg 2007
14.494
5.790
113
Citat:
Uporabnik koliko pravi:
To s cukanjem pa ni normalno. Ker je avto predelan na plin je verjetno tu potrebno iskati vzrok. Iz prakse vem vsaj tako na hitro enih 5 primerov ko so predelani avtomobili na plin z mrzlim motorjem cukali. Pri Audi-ju 1.6 je celo gorela lučka za motor, ki pa je ugasnila ko se je motor segrel.

plin nima veze. če cuka mrzel motor prvih par 100m še ni prekloplo na plin.
 

Kamele0N

YUGOslovanski mehanik Dmitri Mendeleev
23. jul 2008
42.361
5.651
113
Pripravljajo se tudi že nova olja za TGDI motorje...

Tako ILSAC GF-6 standard...kot ACEA (ne vem oznake)

www.gf-6.com
 

roblek007

Pripravnik
19. apr 2009
228
3
18
Verjetno je problem v injektorjih. no saj pri meni je bil. Imel sem podobne simptome, samo da je v zadnjem stadiju cukalo tudi pri ugretem motorju. Ko so mi zamenjali injektorje dela vse OK.
 

roblek007

Pripravnik
19. apr 2009
228
3
18
Ja, ni pa to pocen - moji so bili na srečo še v garanciji.
Če pa kdo ve, kje se jih po preteku garancije, da dobiti po razumni ceni, naj sporoči še meni.