[mercedised]

There's a long story behind this incident, I will cut it short to say, my Tata Safari engine caught fire and after that I was in the process of restoring her.

Today, we finally started the car, everything was fine she started in 1st crank after almost 2 months of restoration.

But as soon as the engine got hot, there was heavy KNOCKING from the engine and the car emitted black smoke crazily.

What could be the cause of such behavior? Earlier before the fire incident took place the car was running fine. The mechanic told me that the Injectors either will be repaired or replaced.

I want suggestions from bhpians on what to do now and what might be the causes of engine knocking after attaining its normal temperature.

Tomorrow I am going to try out System D and hope it helps!

Thanks.

[mercedised]

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[ssh1979]

Mercedised, sorry to hear about the accident. But I think you need to give a few more details for the experts here to be able to suggest anything to help you. Some questions from my side:

- How many kms on odo before the accident
- Brief description of what caused the accident and how you put the fires out
- When you say restore, what are the parts replaced & repaired
- It would help to describe how you restored this, where (A.S.S.?)
- Is the cooling system fine, well sealed?

To me, it looks like oil reaching the combustion chamber (faulty rings?). But really can't comment much more without knowing more details from you.

[blackfire_9]

I do not have any experience with diesel engines but then we once undertook a trip to Shimla in a Tata Sumo. The Sumo developed some problem & had to be taken to a workshop. The workshop messed up the vehicle like anything, & finally the issue was isolated to the fuel pump timing (if there is such a thing in a diesel).

Once that was set, everything was fine.

[v&v]

I feel you should check following too before repair of injectors.

a) Bad fuel quality
b) Chocked fuel filter (When was last changed ? )
c) Sedimenter drain
d) Check the fuel pump

once these are eliminated, then injectors or others can be considered.

[dadu]

Yes, like everyone said, Fuel Pump is key.

[DerAlte]

Quite likely it is one of the crank sensors. Not the crank sensors themselves per se, but the contacts and wires. Effectively, injection is not happening at the right time, and the time is specified by the ECU, which depends on the crankshaft angle reference provided by the sensors.

Would be good if you take the vehicle for ECU diagnostics - there would be a bunch of errors stored. Didn't the engine malfunction light come on when this happened? I assume this was happening in idle (as in Neutral, not being driven).

Fuel Pump in Common Rail injection only feeds the rail, and has no impact on the timing - unless it is having problems keeping up the rail pressure. In a Sumo with a Distributor pump, there can be timing issues. The other culprits could be
- the rail pressure regulator
- valve timing
- fouled injectors

[Sutripta]

Originally Posted by mercedised

But as soon as the engine got hot, there was heavy KNOCKING from the engine and the car emitted black smoke crazily.

Not enough air:- Turbo, turbo hoses, intercooler, air filter etc.
or
injection quantity/ timing very badly out.

Being a DICOR, first suspect would be the ECU/ sensors. Easiest is to scan.

Regards
Sutripta

[mercedised]

Originally Posted by ssh1979

- How many kms on odo before the accident
- Brief description of what caused the accident and how you put the fires out
- When you say restore, what are the parts replaced & repaired
- It would help to describe how you restored this, where (A.S.S.?)
- Is the cooling system fine, well sealed?

To me, it looks like oil reaching the combustion chamber (faulty rings?). But really can't comment much more without knowing more details from you.

64000 kms clocked till date, I will put up a thread once the car is restored fully explaining every thing involved. Cooling system is fine. All the sensors were replaced. The engine is in top-notch condition.

Originally Posted by blackfire_9

I do not have any experience with diesel engines but then we once undertook a trip to Shimla in a Tata Sumo. The Sumo developed some problem & had to be taken to a workshop. The workshop messed up the vehicle like anything, & finally the issue was isolated to the fuel pump timing (if there is such a thing in a diesel).

Once that was set, everything was fine.

Its a DICOR so fuel pump timing should not be the cause IMO.

Originally Posted by v&v

I feel you should check following too before repair of injectors.

a) Bad fuel quality
b) Chocked fuel filter (When was last changed ? )
c) Sedimenter drain
d) Check the fuel pump

once these are eliminated, then injectors or others can be considered.

Fuel is good, the car was running absolutely fine before this accident took place. The fuel filter is new, sedimenter is drained. Will check the fuel pump.

Originally Posted by dadu

Yes, like everyone said, Fuel Pump is key.

Originally Posted by DerAlte

Quite likely it is one of the crank sensors. Not the crank sensors themselves per se, but the contacts and wires. Effectively, injection is not happening at the right time, and the time is specified by the ECU, which depends on the crankshaft angle reference provided by the sensors.

Would be good if you take the vehicle for ECU diagnostics - there would be a bunch of errors stored. Didn't the engine malfunction light come on when this happened? I assume this was happening in idle (as in Neutral, not being driven).

Fuel Pump in Common Rail injection only feeds the rail, and has no impact on the timing - unless it is having problems keeping up the rail pressure. In a Sumo with a Distributor pump, there can be timing issues. The other culprits could be
- the rail pressure regulator
- valve timing
- fouled injectors

Yes, I too think either it is crank sensor or fuel injector gone kaput. But, if it were crank sensors would'nt the car knock right from the cold-start. Knocking appears after engine warms-up. My mechanic is looking at the vehicle, I will ask him to check the above mentioned point.

No check-engine light.

Originally Posted by Sutripta

Not enough air:- Turbo, turbo hoses, intercooler, air filter etc.
or
injection quantity/ timing very badly out.

Being a DICOR, first suspect would be the ECU/ sensors. Easiest is to scan.

Regards
Sutripta

Timing cannot be out IMO as the vehicle was in OFF condition when the car caught fire and it was after that the first time we started the vehicle.

[DerAlte]

Originally Posted by mercedised

... if it were crank sensors would'nt the car knock right from the cold-start. Knocking appears after engine warms-up. ...

No, the crank sensors would be fine (that is why it worked fine after cold start), but quite likely either there is an intermittent short in the wiring, or some connector is intermittently loose by vibration.

Do consider what @Sutripta pointed out as one of the basic reasons for black smoke: insufficient air. Though if the black smoke is appearing at idling after warm up, the turbo circuit will not be the culprit.

Does the excessive black smoke / knocking happen at idling or some other RPM? Does the RPM change when this is happening?

[mercedised]

Originally Posted by DerAlte

No, the crank sensors would be fine (that is why it worked fine after cold start), but quite likely either there is an intermittent short in the wiring, or some connector is intermittently loose by vibration.

Do consider what @Sutripta pointed out as one of the basic reasons for black smoke: insufficient air. Though if the black smoke is appearing at idling after warm up, the turbo circuit will not be the culprit.

Does the excessive black smoke / knocking happen at idling or some other RPM? Does the RPM change when this is happening?

There is a short in injector 1, you are right.

I met with the mechanic, he connected the laptop and found out following errors:

1) Manifold pressure fault
2) Rail pressure control error (he said we will swap rail pressure sensor and see if it makes difference)
3) Cylinder balancing fault (injector 1 is struck closed; this is what you suggested in this post)
4) ECU watchdog fault (injector unlock during start-up)
5) Fuel temperature sensor fault.

Finally we diagonised the problem tobe with Injectors, those are given for service, lets see the outcome.

[DerAlte]

Oops, that injector is toast! The Watchdog Fault says "At Start-up, I tried for x time to get a result from Injector1 but didn't get any" and the Cylinder Balancing Fault says "Since not enough power is coming from Cylinder 1, I tried pushing more fuel into the other Cylinders". (More here is slightly more - not alarming) No wonder! Injector 1 is kaput and Cylinder Balancing (that is an Engine NVH software function in the ECU) is landing up causing copious black smoke. Despite Injector1 not working, it didn't happen at Startup because the Cylinder Balancing kicks in some time later (Watchdogs take time).

All the other errors are cascading from the first one - Injector fault. Rail pressure fault may be due to insufficient power (75% due to 3 cylinders firing) going to Fuel Pump. Fuel temperature sensor or it's wiring may also have gone bad.

[mercedised]

@deralte:

I agree with you, when we removed the injector it was fully black in color and the tip from where the diesel is released into the cylinder was pitch dark in color.

So does that means that the particular injector will need tobe replaced? If yes should I go for a repaired one or a new one?

Also would like to ask what is a watchdog error, the error code was P1608? Will check the fuel temperature sensor as the whole wiring loom of the engine bay is NEW! (bought straight from the Pune spareparts warehouse of TATA)

NOTE: When today we started the vehicle it knocked from the very first second.

[v&v]

How come there was no check engine light?

P1608 obd error stands for ECM malfunction or communication error.

[Sutripta]

@Mercedised, keep us posted please.

Regards
Sutripta