Re: How do you check an engine's health?

Topic Approved

Re: How do you check an engine's health?

1. Drastically low mileage
2. Oil consumption
3. Loss of pickup
4. Black/blue smoke
5. Clutch bell making noise
5. Timing chain

The above are some of the things or symptoms of a damaged engine, could be partial or complete.

Cheers,
Sanjay

Re: How do you check an engine's health?

What can you tell by the colour of smoke? If the smoke is white instead of black, what does it indicate? And what about blue smoke?

Re: How do you check an engine's health?

Many old school mechanics will swear by the "idling" sound and rhythm of the engine, a healthy and perfectly tuned engine will have a very even idle ,by reducing idle speed you can hear every stroke evenly. Uneven idling can be due to many reasons , therefore if any bike has a very rhythmic idling like a gatling gun , it means bike engine is in top shape . [MENTION=28527]sibun[/MENTION] what views you have on this topic ? . I personally can vouch this , my splendor had uneven idling but mileage was 60-70. so it was due to weak compression rings and weak charging coil. It was not burning fuel properly at idle, At idle current is low hence it was not enough to complete the combustion. But on xtreme , it has idle like gatling gun , no idle waves . Tacho needle looks like glued to 1.2k rpm in idle. Because it runs perfect AFR and compression is intact.

Re: How do you check an engine's health?


My Yamaha SZ-R 2011 model, idle RPM is 1000 but the RPM meter needle is dancing like 1000 to 1100. Engine sound is like gut-gut----gut----gut-gut.
Is this you are saying uneven RPM. How to rectify this?
Thanks in advance

Re: How do you check an engine's health?

Well, a biker will always know the condition of his/her bike's engine, consciously or subconsciously. I agree with Sanjaysagar and Rohiit's points, but there are also other reasons for the symptoms that are stated. With regard to RE's, the common problems are con rods/Rocker arms going kaput. And the AVL series is notorious for clutch issues.

Low Mileage/acceleration can also be the result of bad valve clearances, hence leading to loss in compression. You really cant generalise the topic unless you've identified an engine that seems funny to you.

has this thread been opened to address the means of identifying a faulty engine during the time of purchase, or is it relating to general maintenance of one's own steed?

Re: How do you check an engine's health?


Color of smoke directly relates mainly to the Mixture your engine is running on.

It can tell us if you have a heavier than or leaner than needed mixture. It can tell if there is incomplete combustion (and hence) fuel particles being expelled from engine, etc.

Re: How do you check an engine's health?

White smoke convey that the piston rings have worn out and the engine oil is burning along with petrol by the entering combustion chamber (in a four stroke engine). In a few cases it may even be the valves which may be culprit, which leads to oil being burnt while combustion.

Re: How do you check an engine's health?

Hi

White smoke is usually indicative of coolant getting into the combustion chambers while blue smoke is that of the engine burning oil

Re: How do you check an engine's health?

Sorry about not being too specific (my bad). I was referring to the whitish blue smoke. My intention was to inform about the air cooled 4 stroke engine. As you said, coolant being burned is the reason for white smoke, in a liquid cooling setup.

Yes, there are things you can look at to determine the current "health" of the engine:

Oil - how quickly does it get dirty? When you change the oil, is there "sludge" building up in the sump? Is there water mixed into the oil? Are there flakes of metal in the oil?

If the oil is getting dirty quickly, it can indicate "blow-by" from the combustion chamber, indicating worn piston rings. If you find sludge, it means the oil hasn't been changed frequently enough in the past, and/or the engine is operating in very dirty conditions and/or gas is getting into the oil, causing it to thin out so that contaminants settle out rather than being captured in the filter. If there's water in the oil, it can indicate a coolant leak on a water-cooled bike, or ingestion of outside water, an indication of severe duty usage and poor maintenance. If there are metal flakes in the oil or sump, it indicates severe wear somewhere in the engine or gearbox and imminent failure of some critical part.

Spark plug color - A pale, chalky plug can indicate the motor is running too lean/hot, which can lead to overheating and engine seizure. A black, powdery plug indicates the motor is running rich, which can foul the plug and cause misfires and poor economy, as well as (eventually) more contamination inside the engine. A blackened, oily plug means oil is getting into the combustion chamber. There are plenty of charts online showing these, and many other, spark plug conditions, so it's best to consult those directly.

Exhaust smoke: Blue smoke indicates oil burning. If you get it at startup, it means worn valve guides. If you see it under acceleration, it means worn rings. Black smoke indicates running rich. White smoke usually indicates moisture, which can mean a coolant leak on a water-cooled bike, or ingestion of water on an aircooled bike, either through a cracked head or spark plug, or possibly water in the fuel.

In addition, you may be able to detect severe problems such as cracked heads, leaking head gaskets, leaking exhaust manifolds, by the appearance of soot at the site of the crack. There will typically be noise associated with compression leaks or exhaust leaks, a sort of loud, repetitive "tick" or "pop". And then there are sounds, such as the click of a loose valve, the rattle of a loose cam chain, or the heavier "thok" of a loose crankshaft bearing.