In Summary
  • Many people can share your experience: there will be one major breakdown or mechanical issue that will teach you infinitely more about an engine.

  • Or how cars work than you have learnt over the rest of your life. Many of us can identify with that.

Dear Baraza,

I truly and humbly appreciate your response to my cry for help. I would like to share some good news about one of the articles you responded to on October 9, 2019.

As you were contemplating your response, I was also doing a lot of research and brainstorming sessions with other car enthusiasts. I eventually got an honourable mechanic who worked closely with me to resolve the issues my car had.

I replaced the cylinder heads, which were measured and confirmed to be standard. I had the engine block tested again and we found that due to excess misfires, the block was overheating and thus had bent slightly. This was schemed and restored.

We assembled the engine but the misfires didn’t go away and so dissembled the engine several times until we sat down with the mechanic and realised our compression ratios were completely off.

We decided to recheck the block and, after a sixth disassembly, we found the two bank piston rings were stuck. The beauty of this engine is that it has sleeves or/liners since it’s an aluminium cast block and so we took the block to the machine shop to be re-bored and re-sleeved afresh for all cylinders. The block came back and we assembled the car but the misfires persisted. After some further brainstorming and calling a wiring guy, we removed the pre cat O2 sensor and drove the car without it and all firing came back to normal.

We checked the cat converters and found the previous mechanic had drilled holes but left them half way and upon further checking, all the four cat converters had been completely blocked and thus were choking the engine due to excess back pressure. This is what had been creating the misfires all along.

We gutted all the cats and changed the Bank 2 Sensor 1 precat but we had some micro misfires. The car’s power and push jumped two-fold and the engine was restored with all timing counterchecked and combustion at optimum. I picked the car last Saturday, after spending two weeks at the garage.

I have driven the car now since last week and so far the only problem is the post cat O2 sensor projecting an engine light on my dashboard due to the gutting of the cat converters.

After further research, I stumbled on information about how Europeans cheat on emission tests, (we don’t have emissions tests in Kenya so I can use this option) by using a spark plug non-fouler which are used to extend the O2 sensor element such that the amount of flow in the exhaust is limited, thereby removing the engine light and also controlling feedback to the ECU on oxygen levels in the fuel which in turn sends a signal to the precat and ECU and injectors on fuel management.

I have ordered the parts from Amazon and I will share an update once it’s installed but, all in all, your response in the paper has helped me get a new front as I work towards another one.

The lesson picked is that my cat converters were the main problem from day one and if I had gutted them beforehand I wouldn’t have reached these lengths. I have also learnt that I can sleeve a cast iron engine block which is my next project for my Pajero IO Farina Pinin 1999 Model (I love this car).

I learnt more about my engine in two weeks than I have in 10 years.

Thanks in advance,

Morris K.

Hi Morris,

What a read! It all points out to the response I gave on October 9: that cars are fiendishly complex machines and sometimes the root of a problem is something that is not immediately apparent despite the obviousness of the symptoms. Who would have thought that the catalytic converters were the culprit since they had blocked holes in them?

I am glad the car is running again, even after two weeks of trial and tribulation, and I am glad this column was instrumental towards that end. That emissions cheat of yours is a new one to me (live and learn); the path I would have taken is simply access the ECU and delete that entry in the programming.

It is the same way a DPF-delete operation works: remove the DPF then hack the ECU to tell the car that it doesn’t have a DPF, so could it please stop throwing a check engine light? Let us know how the parts from Jeff Bezos’ pantry treat you.

It is possible to re-sleeve an engine, which is usually a critical component in the engine overhauling process; but before you embark on this, first find out if it is possible on a particular engine that you want to work on. For some, all it takes is to replace the sleeves; in others you may need to do reboring, which is carving away at the engine block itself along the cylinder walls. This one is usually a lot more delicate and involving, so not many people opt for it.

Welcome to the dark side of motor vehicle ownership. Many people can share your experience: there will be one major breakdown or mechanical issue that will teach you infinitely more about an engine or how cars work than you have learnt over the rest of your life. Many of us can identify with that.

My alternator drive belts don’t last

Dear Baraza,

I have owned a 2005 ex-UK Pajero Shogun for the past three years. All was well until I replaced the alternator drive belts. They hardly go for more than three months. The car has stalled on three occasions because of the same. I buy them at Simba Colt Motors.

Kindly tell me what the problem could be and a possible remedy. Thanks.

Regards, Irungu

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