CBZA engine oil change question / chain tensioner draining out?

[briscaF1]

Hi,

 

How long can the (2014) CBZA engine be left without any oil in it? 

Is there an issue with the cam chain tensioner draining and the chain skipping on start up if the engine is left without oil in it for too long?

 

On one hand, this seems unlikely as the oil will drain out into the sump, over time, anyway but I'm just double-checking.

 

If so, this seems to be a poor design if you were doing a job  on the engine that meant it was without oil for a few days or more. 

What is the procedure for dealing with this? Do I crank the engine with the plug leads removed from the coil pack to allow oil to circulate before I start it proper? 

 

Thanks in advance.

[Warrior193]

Hello, I would say that this will not be an issue, as you say, the oil will drain back from the tensioner while the engine is stopped. Just refill and restart as normal with one proviso - don't ever permit the engine to turn over in reverse direction while the cam chain tensioner is unpressurised. 

[sepulchrave]

This is not an issue, simply start the engine and let it idle for a few seconds.

[briscaF1]

5 hours ago, sepulchrave said:

This is not an issue, simply start the engine and let it idle for a few seconds.

You were correct. All good 

[briscaF1]

7 hours ago, Warrior193 said:

Hello, I would say that this will not be an issue, as you say, the oil will drain back from the tensioner while the engine is stopped. Just refill and restart as normal with one proviso - don't ever permit the engine to turn over in reverse direction while the cam chain tensioner is unpressurised. 

In reverse? Would this be with a spanner on the crank? 

[Warrior193]

Just now, briscaF1 said:

In reverse? Would this be with a spanner on the crank? 

No, from what I've read in other sections of this forum, an issue can arise if the tensioner is past its best, and the vehicle is allowed to roll backwards with engine stopped and in gear. Apparently this can result in the chain jumping teeth on the chain sprocket. 

[briscaF1]

1 hour ago, Warrior193 said:

No, from what I've read in other sections of this forum, an issue can arise if the tensioner is past its best, and the vehicle is allowed to roll backwards with engine stopped and in gear. Apparently this can result in the chain jumping teeth on the chain sprocket. 

That's interesting. I guess that could happen if someone rolls off ramps after an oil change and gets into this situation.

[sepulchrave]

58 minutes ago, briscaF1 said:

That's interesting. I guess that could happen if someone rolls off ramps after an oil change and gets into this situation.

 

I doubt it, I think you're worrying too much and definitely overthinking things.

 

The absence of oil pressure doesn't empty the system, the tappets stay full apart from the two or four that are under valve spring tension and the tensioner piston simply relaxes until oil pressure is restored, whereupon, like any hydraulic system, that pressure is transferred almost immediately throughout the entire system.

[briscaF1]

13 hours ago, sepulchrave said:

 

I doubt it, I think you're worrying too much and definitely overthinking things.

 

The absence of oil pressure doesn't empty the system, the tappets stay full apart from the two or four that are under valve spring tension and the tensioner piston simply relaxes until oil pressure is restored, whereupon, like any hydraulic system, that pressure is transferred almost immediately throughout the entire system.

I usually do overthink things, to be fair. Thanks for the explanation