5Th Injector And Regen Burn?

[Paul99]

Hi,

I have seen talk on here about a fifth injector and a re-gen burn. Why are there 5 injectors on a 4 cylinder engine and what is the re-gen burn, when does it happen and what does it do?

Curious Paul

[dervdave]

Hi,

I have seen talk on here about a fifth injector and a re-gen burn. Why are there 5 injectors on a 4 cylinder engine and what is the re-gen burn, when does it happen and what does it do?

Curious Paul

http://www.theaa.com/motoring_advice/fuels-and-environment/diesel-particulate-filters.html

[Steve84]

The 5th injector is all to do with the diesel partial filter (DPF) it injects diesel in to the dpf to burn all the soot that bulid up in the dpf. When the soot is being burnt this is known has a regen burn.

[OldSkoO1]

The EGR valve plays the most significant part in the requirement for a 5th injector.

The EGR operation is so aggressive on the T180, half of the exhaust gasses can be re-introduced to the combustion process. Exhaust gas has a higher heat capacity than air and therefore lowers the max combustion temperature. Not only does it mean less power can be extracted by the piston it also leaves more un-burn't fuel which ends up solidifying into tiny parts of carbon which of course exit and get collected in the DPF.

They then fight against each other, requiring more fuel to produce power and a 5th injector to inject fuel into the exhaust to raise the exhaust temperature to assist the burn off in the DPF.

Other manufacturers have clever DPF applications where it uses residual heat from the turbo's to raise the exhaust temp's and these setups also have lower levels of NOX filtering requiring less aggressive circulation of exhaust gases through the EGR.

Toyota have only done this to put heavy NOX filtering in a production car tried and tested for long periods. You could essentially class us as guinea pigs. It's all in anticipation of possible euro legislation stating the upper limit for NOX emissions.

[Sean n]

How do you clean the fifth injector 

[yossarian247]

2 hours ago, Sean n said:

How do you clean the fifth injector 

Your profile says that your car is a 2017 model? If so, yours will have the BMW diesel engine which is totally different to the earlier Toyota engine being discussed above, and AFAIK doesn't have a fifth injector?

[Scotty64]

How easy is it to change the 5th injector do they come out easily my 180 has started blue smoking when not at operating temp the soking completely goes away when hot its driving me mad theres loads of smoke but no warning lights or under performance the car is a rocketship 

how do i force a regen

or because its just started out of the blue could the 5th be not working