In engineering practice, we tend to solve problems, from the least to the complex. That way, one won't be trying to solve an issue, without understanding the basics first!

In today's, attempt to identify, and profer solutions to a significant power loss experienced by a client of this Siena vehicle, after our investigations on the least suspects of systems or parts, that could be the culprit, and all checked good, we discovered as we went further in the diagnosis, that major some major work was donee on the client's engine, which needed reviewing.

So now, here we go!

1. The vehicle's timing belt, which was supposed to be a maintenance item, had never been replaced, since it was imported into Nigeria from the USA.

The belt was shredded, with it's ribbons worn out.
Engines with timing belts and not chains, require that the timing belt(s), be replaced at particular intervals recommended by the manufacturer. Not doing this, would result into an underperforming vehicle, and may lead to engine damage, if the engine was an inteference one.

2. Crankshaft pulley, crankshaft sprocket keyways, were all damaged, including the "key" itself was crushed.
This, and the shredded timing chain belt, was the reasons a P0335 crankshaft sensor "A" circuit was on display on our sccantool, leading to the loss of power problem.

The fix?!
Yeah, what we did was not just going ahead and replacing parts, but we went a further mile, identifying what actually triggered all these chain reactions that resulted in to this customer's vehicle problem.

All damaged parts, identified, were replaced, and vehicle testdriven to ascertain state of repairs.

Note: Don't ignore engine noises, and a P0335 trouble codes on a scantool, when you get such results from scans ran.
Pls try to fix such issues. They don't disappear on their own.
You got to fix the root cause(s) of the problem, before they clear.


Regards,
Joseph

Figure showing damaged and replaced parts displayed side by side.

On display also

Comparison of both crankshaft pulleys.
The old one has its keyway damaged, due to a crushed crankshaft key.

Take a look at the damaged timing belt

Got another crankshaft"key" as a replacement for the crushed one shown here.

Take a closer look at the crankshaft gear(sprocket) key. The old one has it's keyway diameter expanded as a result of the crushed keyway, as compared to the normal diameter of the replacement.

TRYGO:
Take a look at the damaged timing belt

The belt was shredded, with it's ribbons worn out.

But the belt Im seeing is not shredded

aryzgreat:



The belt was shredded, with it's ribbons worn out.

But the belt Im seeing is not shredded

Yeah!!!! You're correct na.

Good job bro