Fuel Injectors .. Replace or not?

Nostrodamus

Nostrodamus

Well-Known Member
Joined
7 Mar 2011
Messages
3,659
www.cygnus3.com
I have a Volvo MD22 engine which has done approx. 1400 hours and is 14 years old.
At the moment it starts first time every time, runs smoothly without missing a beat and it is not causing me any problems. It oes not appear to be down on power.
The concern I have is that there seems to be too much white smoke no matter if it is ticking over or revving higher under speed. There is also a slight oily residue left on the water from the exhaust which I suspect is unburnt fuel.
There is no emulsification of the oil and seems to be no water in the system.
I suspect the injectors need renewing and mentioned the symptoms to an engineer. He agreed that it may be the injectors but said that these engines do smoke a bit and if it appears ok I should leave it until I start getting problems.
The boat is fairly new to me.
Are the symptoms liable to be the injectors, should I get them done now or later and will it be using a lot more fuel than is necessary?
 
No.
If the smoke was black, running uneven, it could be injectors.
If anything one doesn't replace injectors in the 1st instance, you have them re-set. Wear in the pump unit is more likely (but not in this instance).
I suspect the unit is running cold and would suggest the thermostat to be the culprit.
If you want to change anything change that.

PS Raw-water cooled engines always run colder than those with indirect cooling and there's nothing that can be done about that.
 
Thank you for the reply.
The engine temp is running as per the volvo parameters in the engine manual.
What concerns me is the discharge from the exhaust which is leaving a sheen on the water. Not too much but enough to see.
 
A common cause of unburnt fuel (= white smoke) in the exhaust is that the injector spray pattern has been disrupted. Perhaps the most likely reason is deposits of carbon, or maybe something else, on the nozzles. This affects the flame front in the combustion chamber, leaving some fuel unburnt.

On the basis that the easiest remedy is the first thing to try, give the boat a flat-out run for 15 - 20 minutes. This treatment is often used by marine engine repairers to clear various deposits that occur because yacht engines are customarily under-used. If this is not effective I would suggest you take the injectors to a diesel specialist to have them serviced, which includes checking the spray pattern.
 
white smoke

I did a Yahoo search and came up with a site which may be useful to you.

There is quite info on www.Kent4x4offroading.co.uk
under tabs at the top of page - mechanical/faults/smoking diesels.

Are u sure its not steam rather than white smoke?

We had Thorneycroft ( Mitsubishi 4 cyl) in our boat and never touched the injectors in 6 years the boat had done about 1000 hrs and 24 years old but indirectly cooled.

Peter Joe Hull
 
As a marine engineer i would get them injectors removed cleaned/replaced with new copper washers and put back in. You can remove and replace yourself so all it costs is the injector test and replacement if needed. Your engine is 14 years old and has 1400 hours. I don't care what anyone says "if it ain't broke" and all that twonk. They are well overdue inspection. You will find that your engine will run alot smoother with this done. I have a moody 38 with the same engine, these volvos do smoke a bit, especially when high reved, however it does settle. Good maintenance and regular oil changes etc etc will see the engine run another 14 years.
 
I love this forum.
Where else do you get so many answers, often conflicting, and each one different... dip, dip, my blue ship

What does adding 2 stroke do?
 
1400 hours is vary early in a typical injectors MTBF. [ Mean Time Between Failures ] 10,000 to 15,000 hours is often quoted as the norm.

The symptoms you are describing are not the ones you get with a failing injector. [ Poor starting and black smoke in the exhaust. ]

The 'Italien Tuneup' is very definitely worth doing. Changing the oil immediately afterwards while the engine is nice and hot is a good idea too. Thats what I would do if were mine.
 
I suggest you read your engine manual which will clearly tell you that marine diesel injectors should be removed and tested way before it even reaches 1000 hrs. By all means, do the Italian method first, but this will only cure your problem temporarily.
 
>>>
What does adding 2 stroke do?
>>>
I gather it frees up a lot of slightly sticky components in the system, from pump elements to rings and valves, plus it burns away cleanly. It has certainly reduced my clouds of white smoke on startup. I still get a blue haze both sides, but this is so much less than it was. A bit of WOT later may even remove some of that, although some is plain anno domini.
 
Nostrodamus said:
What does adding 2 stroke do?
Click to expand...

Googling "2-stroke oil in diesel fuel" produces vast numbers of positive experience and I have yet to find a negative. Here are two, written by a German lubricant specialist in an off-road forum.

Due to the pollution control measures of the EC diesel-oil is nearly sulphur free and contains up to 5% of bio-diesel. Sulphur has the property to lubricate the high pressure injection pump and the injectors. Without sulphur, the reduced lubricating property of the new diesel has already shown negative impacts on the long-term stability of the injectors and the high pressure pump. The pump manufacturers have tried to react by lining the moving parts of the pumps with teflon or other suitable material. However, the long term stability is still not achieved as with the old (sulphur containing) diesel.

The engine-research centre of a well known German car manufacurer has conducted some long term tests of diesel additives to find out whether any one of them will have an impact on the long term reliability of the diesel engine components. This introduction to explain where my information comes from.

The results of this research: any diesel additive of any manufacturer presently on the market is not worth the money! BUT: 2-stroke oil, which we use in our motor saws, lawn mower or in 2-stroke motor engines has shown to have an extremely positive impact on diesel engines, if such 2-stroke oil is added to the diesel in a homoeophatic dose of 1:200. In practical terms: 0,300 litre of 2-stroke oil into the 70l diesel tank. The 2-stroke oil will be absorbed by the diesel (emulsion) and lubricate every moving part of the high pressure pump and the injectors.

Besides this, the 2-stroke oil will keep the diesel engine clean, as it burns cleaner than the diesel itself. In other words, the 2-stroke oil has a much lower ash-content than diesel, when burned. This proven fact delays the DPF (diesel particulate (soot) filter) to clog, and the "burn free" process of the DPF will be much less.

One more information: in Germany we have to present our cars every 2 years to the TUV -Technical Supervision Organisation - who will check, amongst others, the pollution of petrol and diesel engines. The measured cloud-factor of a diesel engine without use of 2-stroke oil has been 0,95. The same factor with the use of 2-stroke oil has been 0,47 - reduction of nearly half of the soot particles.

Besides this, the use of 2-stroke oil in the diesel will increase the mileage by 3-5%.

And another: You may all know that Mercedes Benz have conducted in 2007 a long distance reliability test with a number of Mercedes E-Class 320 cdi from Paris to Beijing. Due to the fact that the diesel quality in East European Countries, Russia and China does not meet the DIN requirements, and Mercedes did not want to take the risk of their engines to flop due to lousy fuel, the total tour has been accompanied by diesel tanks to re-fuel the E-Class cdi's. Selected members of the Mercedes clientele could apply to participate in selected parts of this test-tour, and advocats and notaries had to certify the correctness of this long term reliability test.

Although Mercedes does not like it published or made public, it is a fact that the diesel-fuel used for this test did contain 2-stroke oil to lubricate the high pressure pump components and to keep the engines clean during this marathon.

Why our car manufacturers do not officially allow the homoeophatic addition of 2-stroke oil to the diesel fuel has many reasons, mostly of legal nature. Besides this, which car manufacturer has any interest in excessive reliability of their engines? Their repair shops will have great problems.

Meanwhile the "2-stroke-oil to diesel" issue has attracted the interest of a number of Universities in Germany, as this 2-stroke oil has shown to have amazing properties if added in a small doses to diesel fuel (1:200), especially the positive impact on air pollution, reduced fuel consumption and improved long term reliability of the diesel engine. The pro and con discussions will go on for a while. But as soon as an academic report has been published by one of our Universities, this will change very fast.
 
The MD22 is a Perkins Prima painted in Volvo green. In my experience they do smoke a bit at start up and until mad hot put out some oil film on the water.

These engine have somewhat of a reputation for weak cylinder head gaskets and cracking of the aluminium cylinder head. Both of which could lead to the white smoke, or rather steam being generated from water sloshing about where it shouldn't be. If your antifreeze/cooling water is not bubbling when the engine is running or the level going down and needing to be topped up then this is, hopefully, unlikely.

White smoke from unburnt diesel would be an obvious option and I like the idea of the Italian tune up to cure it! Why not try the tune up and if that fails to solve the problem have the injectors serviced? It should be around £100.00 and is worth doing if you are going to go places and at least you would know if they were at fault.

Unfortunately for me the white smoke from our Perkins was unburnt diesel due to lack of compression on number 1 cylinder caused by a bent conrod. I took the opportunity to overhaul the old girl whilst I had her in pieces, sounds great when running now but still smokes,........ although blue this time though! It'll stop when the rings bed in, I am sure................

You could just leave it alone if its running well though.
 
VADROUILLE said:
I suggest you read your engine manual which will clearly tell you that marine diesel injectors should be removed and tested way before it even reaches 1000 hrs. By all means, do the Italian method first, but this will only cure your problem temporarily.
Click to expand...

1000 hours sounds like a very short lifetime to be testing injectors.

Taking your word for it I have just looked in Bukh, Yanmar and Volvo manuals and none recommend any period at all. An internet search throws up vehicles that have done 600,000 miles without ever having injectors serviced. My VW diesel van did 160,000 miles without ever having the injectors removed.

General advice seems to be to do nothing unless the performance of the engine justifies it.
 
This thred has facinated me. I will try the Italian method and the adding of two stroke oil is compelling reading. Has anyone else added 2 stroke oil and noticed any difference. Also what sort and what ammount did you add per 100 L of fuel?
 
vyv_cox said:
1000 hours sounds like a very short lifetime to be testing injectors.

.... I have just looked in Bukh, Yanmar and Volvo manuals and none recommend any period at all. ...
Click to expand...

Yanmar specify checking injector spray pattern & injection timing every 600 hrs (1 year) in the 'GM' series Operation Manual that I have.

Section 4.3.5 (4) & 4.3.5 (6)

Must be honoured more in the breach than the observance :)

I can understand why a little lubricating oil (2 stroke or otherwise) might be a good thing for older diesel engines forced to drink low sulphur diesel, but the article you quote to back that up doesn't do you any favours (IMHO) - it reeks of snake oil rather than 2 stroke oil! Next you'll be telling us to put magnets around the fuel lines ;)

I have to say (2GM20 / 1400hrs) that I'm in the "if it ain't broke, don't fix it" camp.

Andy
 
You must log in or register to reply here.

Other threads that may be of interest

W
  • Locked
KAD32 Injector and sleeves
Replies
0
Views
101
Wobbo
W
O
“The Dog that Didn’t Bark:” Yanmar. 4L HASTE.
Replies
2
Views
249
oldgit
O

Share this page

Top