I’m measuring a 30 degree F temp raise at the 90 degree part on the back of the exhaust elbow. This is where it 90’s up before the water injection port. Would this indicate it is getting plugged or is this normal to see a temperature increase at the first 90?
3YM30 exhaust elbow
- Thread starter aturneye36
- Start date
It is a high rise mixing elbow like this. My temperature increase is at the first 90 that points upward
I wonder if it could just be because that spot is in between the fresh water reservoir on the manifold and the raw water injection. The distance from both cooling sources might make that a hot spot. My 3ym30 has a simple 45 degree pipe instead of the elbow so I can't really shoot it to compare.
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A couple of questions.
When you say "30 degree F temp raise at the 90 degree part on the back of the exhaust elbow." The temperature rise is in relation to where? The engine block? The elbow after the water injection?
Is this a one time measurement? Or the result of several measurements over time?
The water injection serves 2 purposes, to cool the exhaust gases so they can go down a rubber hose and help dampen the exhaust sound.
The easy way to check for carbon fouling is to remove the elbow and take a look. On the Yanmar 3JH2E there are only 4 bolts that hold it on.
When you say "30 degree F temp raise at the 90 degree part on the back of the exhaust elbow." The temperature rise is in relation to where? The engine block? The elbow after the water injection?
Is this a one time measurement? Or the result of several measurements over time?
The water injection serves 2 purposes, to cool the exhaust gases so they can go down a rubber hose and help dampen the exhaust sound.
The easy way to check for carbon fouling is to remove the elbow and take a look. On the Yanmar 3JH2E there are only 4 bolts that hold it on.
You have to take them apart every 50 hrs to check and clean. Start with taking the water inlet fitting apart and look in that hole to see if clogged. The unit threads apart so no gasket material is nessary for removal
Really? Many (most?) go 500, 1000 hours, maybe more, without a problem here. Where did you get 50 hours from? You realize you're saying that HALF the oil change interval you should be taking your exhaust system apart. Ha, ha!
By the book, the 3YM30 exhaust mixing elbow is to be cleaned every year or 250 hours whichever comes first.
How many hours on this elbow? Has the amount or force of the discharge changed? I have the 3YM20, basically the same engine. Replaced the elbow at about 400 hours. Could have gotten more time out of it but had the opportunity to get it done then. I take a temp reading with an infra-red thermometer at several locations on the engine. Temps range from 140 to 200 degrees depending on where I shoot. The elbow will be a bit on the high side but remember that is where the raw water and exhaust gases meet. As long as she is running OK and not overheating, I would continue to monitor. If your experiencing anxiety over this, then just replace it. The $$ spent might just be worth it for your piece of mind.
I did this. I had no idea how old mine was. Bought a stainless steel elbow from HDI. Worries are over.