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.

40,000 km maintenance routines on my Swift VDi

With the odometer at 39,950 km, I got 40,000 km routines carried out today. Following important routines were done in addition to checking fasteners, greasing / oiling, washing and cleaning :

  1. Engine oil, filter and oil drain plug change
  2. Fuel filter change
  3. Transmission oil change
  4. Coolant change
  5. 5-tyre rotation

New transmission oil being put with a syringe with car hoisted

Additionally, both (left and right) front suspension strut bushes were changed. The struts were found loose due to compression of top rubber-metallic bushes.

Coil spring of strut assembly being compressed using special tools

New rubber-metallic top bush being fitted

I also had both wiper blades replaced as they had become hard.

Total expenses : Rs 6188 [parts and consumables : Rs 5006; Labour : Rs 1182 (with Rs 175 discount)].

The replacement of the strut top bushes cost Rs 850 (Rs 400 for 2 nos. bushes + Rs 450 labour). The set of two wipers cost Rs 490. These costs are included in the abovementioned total expenses (Rs 6188).

Maintenance issues over the last 4 years / 40,000 km

Requirement of maintenance has been minimal. In addition to scheduled maintenance routines (at 1,000km, 5,000 km, 10,000 km, 20,000 km, 30,000 km and 40,000 km) only the following needed to be done over the last 4 years and 4 months :

  1. EGR valve had to be cleaned at 19,800 km.
  2. Battery had to be changed at 34,600 km (after 3 ½ years)
  3. Front suspension strut top bushes had to be replaced at 40,000 km.
  4. Wipers were replaced at 40,000 km.

It is relevant to mention that not a single light bulb needed to be replaced so far!