Perkins 4108 overheat and black smoke...

[lowey49er]

Hi, all my first comment, whats the state of your air filter?
clogged or blocked air intake makes lots of smoke.

[Jwnorris]

I had a similar problem with my Volvo-Penta and it turned out that my alternator had a bad voltage controller that caused excessive load on the engine and it eventually melted down my batteries before I discovered the source.

[Kokanee]

Not reaching full rpm and black smoke out the exhaust is a sure sign of being over-propped. If you have run your engine hard under these conditions for an extended period you may have done some damage due to unburnt fuel in the cylinders (scored cylinders, failed rings)
It is like driving a car up a long steep hill without shifting down a gear; Not good for the engine.

[stocru]

I had a 100hp perkins that did that. Turned out to be an internally collapsed and partly blocked silencer.

Good luck, stocru

[sigmasailor]

Agree with all of the above. Try to eliminate the easy stuff first. Before you attack the HP fuel pump have a look at the injectors. You can have a specialized shop 'pop' them for a few dollars. Work on the HP pump is specialized and costly. I don't think the pump is the problem; a bad injector might just be it.

Yep, injectors can suddenly fail (broken spring or seize)....... Running on 3 cylinders might cause black smoke.

[Cheechako]

Good advice above. This is a NEW problem on an engine that was fine before.(right?)

-I never ran my 4-108 to 2900 rpm, so don't know it's effects on temp.
- blocked exhaust is a good possibility.
-as mentioned, black exhaust is a fuel problem. Maybe a fouled injector? two?
-Does your engine have a heat exchanger for the transmission? Have you had an impellor fail? If so you could have chunks of impellor blocking the exchanger.
-Are you sure it has the right impellor in it? If a bit too small that could be your problem. There are many that are similar but not quite right.
-Someone mentioned a fresh water impellor loose on the shaft. I have heard of that before on other engines.

[avazquez]

Wow excellent ideas. Things I,ve done: 1. Replaced impeller and cleaned strainer. 2. Removed and cleaned heat exchanger, 3. Checked oil level. 4. Adjusted valves. 5. Removed fresh water pump and verified condition and reinstalled with new gaskets. 5. Checked Maxprop and nothing seemed abnormal, 6. Removed and reinstalled mixing elbow whichwas clean.

[stevebein]

Have you tried running at the rpm's suggested? Does it overheat and smoke at 2100? I have never run mine at the high rpm's you use and have never had that problem. This being only my experience, I defer to those who use them more. I did a run from Los Angeles to Puerto Vallarta, some motoring, some sailing , some combined. Never ran over 2100, never had smoke.
But, this is just my experience.

[Oceanride007]

Had a problem once, with duel engines, one overheated.

Answer was a previous anode replacement in the the cooler, a corroded anode, neatly the size of the outlet pipe had lodged itself inside the pipe before the connection to the wet exhaust.

Smoky exhaust is also a symptom of low SW flow, as the exhaust is scrubbed by the SW spray.

Sometimes flexible pipes collapse inside. Check SW flow at the mixing elbow and if blocked work backwards. I bet your Fuel system is fine.

[Oceanride007]

Come to think of it, that Anode blockage (Mentioned above) was extremely difficult to find because water flow would push it up to the next fitting, causing the blockage only when the engine was run, then drop down out of sight when I went looking for it. Everything looked so clean.

[RodgerC]

I had a 4-108 start smoking like you describe. It had a clogged up exhaust system, especially the T-can silencer/muffler which had rusted up over many years, looked OK from the outside. This can fall apart quickly once it gets going, create a lot of back-pressure on the exhaust side. Look for un-burned diesel in the exhaust, can leave a little slick in the water.

[Peter200]

I look forward to the daily digest and the wise informative answers. I have a Perkins 3426 and in neautral l can rev the engine to full revs but when in gear after a quarter throttle the revs do not rise at all, back to neautral and she revs up fine again?
Appreciate your assistance.

[leftbrainstuff]

Originally Posted by avazquez

Here is the situation:

Problem:

Under normal operation engine used to overheat and begin to smoke black after around steady 2900 rpm or more.

Suddenly engine began to overheat and upon investigation found loose belt and after tightening the belt - still overheating at around 2400 rpm.

At 2500 rpm engine will smoke a bit black smoke and slowly overheat above 200F.

Things I've done:

a. Removed heat exchanger and was clean so I cleaned it again.
b. Verified thermostat operation by removing it by checking its opening temperature etc.
c. Adjusted valves.
d. Verified impeller and was ok.
e. Cleaned raw water strainer.
f. Removed and verified the fresh water pump. Reinstalled with proper gaskets and plate etc.
g. Removed and cleaned mixing elbow.
h. Verified cleanliness of air intake screen.

The thing is that this happened suddenly and I have run out of ideas on what to check next.

High rpm. Do you normally run this hard?

Sounds like your fuel metering might be a problem. Remember a diesel is fuel regulated. So any wear based fuel system issues will be exacerbated near max rpm.

I assume you've checked all the usual cooling system candidates.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[Golden Echo]

OK you removed cleaned and reinstalled the heat exchanger. Then you refilled the closed system with anti freeze. Does this system remain full?