ford 2725 6cylinder naturally aspirated

[atlowers]

Looked at a potential purchase yesterday with twin installation 2725`s. At cold start much smoke with blue tint and small fuel evidence at exhaust. After running for 10 mins at idle engine tone suddenly changed for maybe 15 seconds and heard something akin to a loud clapping noise. Took boat for a trip and no further incident. smoking reduced under load and boat performance as expected. We ran on both emgines individually and seemed fine. Sellor stated that he had never heard noise before and guaranteed engines lost no oil. Spoke to lancing marine today who said naturally aspirated diesels should not smoke excessively unlike the turbo versions. Mechanic friend suggested injectors causing diesel knock was noise but I am nervous about potential problem. Like the boat but not sure wether to walk as have had bad experience before. Any thoughts or experiences would be appreciated. The engines look superb are 120hp and 3500hrs.

[Sandyman]

Do you know anything about the history of the donks ? such as how well maintained ? have they had regular oil changes as per maintenance spec ?? etc etc.

The loud clapping noise you refer to could be something very simple and of no concern.
Have you tried to start them again to see if the same symptoms appear ?
Do the engine gauges show anything abnormal ?

If still unhappy then I would hold back and get both donks surveyed.

I have the 95hp version. 35 years old. 1800 Hrs and still going well. Fingers crossed and hopefully not tempting fait.

[atlowers]

Do not know much history but looked very well maintained from external condition. Started them several times after the incident and no problems except the smoke. Guages all appeared fine re pressure and coming up to temp. Any idea what could have caused the sudden clanky noises which lasted 10 to 15 sec and occured at idle some 5 mins after engine start?

[Sandyman]

Originally Posted by atlowers

Do not know much history but looked very well maintained from external condition. Started them several times after the incident and no problems except the smoke. Guages all appeared fine re pressure and coming up to temp. Any idea what could have caused the sudden clanky noises which lasted 10 to 15 sec and occured at idle some 5 mins after engine start?

Have put thinking head on but no idea as to what it could be.
Thinking along the lines of what happens after 5 mins or so after start up.
The stat would likely be be opening but I cant see that making such a noise.

Just a thought, do your engines have the Minimec Injector pump ??

Do not go on the condition of the engine by there external condition.

[njthake]

Your intermittent clatter is probably an injector sticking and giving a slug of fuel instead of an atomised mist.
Any metalic noise from a running engine is always reason for concern.
There is simple a way to check the heart of an engine for damage. Any internal damage and wear is generating metal and an ongoing thing that does not heal up! Therefore there is always evidence in the oil filter.
I know it is messy but the health of any engine is obvious when you scrutinise the contents of the oil filter for metal particles. It used to be easy with old cartridge filters to open them up, flush the contents with petrol through a filter(coffee filter is ideal), and check for metal. Now you have to open up the metal cartridge with a pair of tinsnips (not a hacksaw). Once it is open wash out the contents with plenty of petrol and have a good look.
A few small dust specs can can usually be put down to normal wear and tear but if there are any large bits that can be identified as flakes then watch out !
If you want to monitor your engine for wear then pick up the clean metal flecks with a piece of sellotape and tape them to a card with engine hours .
good luck Nick

[atlowers]

Nick
Thanks for the reply useful info. member since 2006 and first post, more of the same please. cheers