Saturday, February 11, 2012

Fuel injectors getting jammed in cylinder head of CRDI engines

There have been numerous instances of fuel injectors getting stuck / jammed in the cylinder head of Maruti Swift diesel cars. High-tech CRDI injectors do not require any periodic maintenance and therefore are not removed for years together. But when there is a defect and an injector needs to be removed, in many cases they are found to be jammed / stuck and very difficult to remove. The special tool (puller) used for pulling out the injectors sometimes gets bent but the injector refuses to come out. In such cases the cylinder head assembly has to be removed from the engine and sent to a machine shop to extract the injector (sometimes in pieces).

Some months ago I did a consultancy assignment for Tata Motors and found that many of their DICOR engines (including the Quadrajet engine used in Indica Vista – this engine is identical to the Maruti Multijet engine) are facing the same problem.

According to Maruti Suzuki, the problem is caused by water getting into the minute gap between the injector body and the cavity in the cylinder head which houses the injector. This usually happens during pressure washing of the engine compartment during servicing. Once water / moisture gets into the small gap, it causes rusting and that jams up the injector over a period of time.

Maruti Suzuki have come up with a simple solution – cover the top part of the engine during pressure washing. A picture of the cover placed over the engine in my car can be seen below.


I would advise all diesel Swift owners to:

1) Ensure that the engine cover is used during pressure washing. During the servicing of my car today, the MASS started washing the engine compartment without the cover. The cover was put when I reminded them.

2) Take care while washing the engine compartment at home. Don't direct water spray towards the top of the engine or below the black plastic engine cover.

4 comments:

hari said...

Hi Sir ,

My name is Hari and from bangalore , I have bought a RITZ LDI around 6 months back , and from the first day onwards it is producing black smoke and have visited showroom more than 7 times , Showroom people tell there is no issue and it is usual , but I stick on that and tested the mileage with the help of maruthi service . I have got only 7 KMPL , As per there investigation it is the issue with the injectors , they said 3 injectors having problem and it needs to calibrate . could you please tell me what is this callibration and whether i need to go with caliberation or need to replace it through warranty.

Debashis Mukherjee said...

Dear Hari,

A new Ritz producing black smoke and giving a mileage of only 7 kmpl is simply not acceptable. It seems clear that your MASS is dodging the problem as you have visited them many times without any result.

I would suggest that you should either visit a better reputed MASS or escalate the matter at least to the Regional or Zonal Service Manager of Maruti Suzuki. Their phone numbers and email ID are supposed to be displayed at every MASS.

Maruti has to rectify your problem under warranty whether by calibration or changing injectors. Each injector needs to be individually calibrated and the calibration data stored in the ECU. In a new car there should not be any calibration problem as the 4 injectors are calibrated in the factory. But if your MASS wants to recalibrate the injectors, let them do it.

It seems to me that some of your injectors may need replacement. After replacement, the calibration data of the new injectors have to be fed in your ECU.

It is also possible that nothing is wrong with any of your injectors but the ECU is malfunctioning.

Whatever be the root cause, you must insist that Maruti Suzuki rectify the defect under warranty without delay to your full satisfaction.

Venkateshwaran Subramaniyam said...

Today our swift VDI 79000 km broke down suddenly after the car was drenched in heavy rain and we towed to MASS and on investigation they found four fuel injectors need to be calibrated and they could not open the same and said will try or they need to take it to lathe. The mileage was around 10kmpl I hope the mileage will improve after the calibration of fuel injector

Debashis Mukherjee said...

Dear Venkateshwaran,

The break down due to heavy rain was probably not directly linked to injectors and had some other cause. It seems that while investigating, MASS has found this problem with injectors. 10 KMPL is very poor mileage for a Swift and should certainly improve after servicing / replacement of injectors.