Injectors - when should these be checked/changed?

[aviator]

I have Volvo engines but I guess the question is the same for all.

During a service last year the mechanic mentioned that I should really go for re-conditioned injectors - hours at that point >500.

I pondered if this could ever be true since these are really lorry engines which would do 500 hours in a couple of months and these things just run and run.

I have a service coming up and checked the owners manual which says to pressure test the injectors 'at least every 24 months or 2k hours'.

What does the team think? Is testing necessary?

There are no signs of white smoke but the word that faulty injectors causes major damage just makes me cautious, OK VERY cautious!

 

[Pendana]

Most Volvo Penta engines are marine engines and were never used as truck engines particularly the AD & KAD series. Injectors should be serviced at 600 hours usually.
Have them removed and take them to your local Bosch service agent who will clean, re-shim and replace the springs and nozzles if neccessary.
I had 8 done 3 years ago at about £25 each.
Worth investing in £30 for the special tool to remove the injectors.

Eddie

 

[brianhumber]

Injectors can
a) wear internally due to poor quality fuel ( very unusual if you are in NW Europe)

b) get deposits on the tips ( trumpeting) due to poor combustion ( worn rings, low turbocharge pressure, overload etc)

White smelly smoke is unburnt fuel vapour, dark is indication of poor combustion.

Unless you have trouble starting on freezing mornings, or are getting smoke you do not have to change or inspect injectors. Mechanic are there to earn money for themselves not provide you with a service, they follow guides written for engines that might be running on poor fuel located in wet/dusty engine compartments anywhere worldwide.

When I bought Ronhilda 13 years ago I had the injectors serviced and I checked them two years after 5,000 miles sailing - imalculate. They have not been seen since and my Ford engine started in freezing conditons last winter with 7 year old now weak battery and does not smoke although it is 21 years old.


I appreciate that if you do not have a exprienced practical engineering background then comments like 'you should and the manual says' can be worrying, its the same with the prattle you read everywhere about engines will acid corrode away before your very eyes if you do not change the lube oil every winter - those in the know and commercially you only change oil when the analysis says so , in my case about every 5 years.

B

 

[Peanuts]

Hi
Although I appreciate that the injectors should be serviced during their lifetime I cannot find the timescale recorded in any of my manuals. However in the VP workshop manual chapter for fuel system it clearly states in bold wording 'Do not inspect an injector unless there is a definite indication that it is not functioning normally (excessive exhaust emissions for example)'

 

[Sultans_Kapitein]

[ QUOTE ]
it clearly states in bold wording 'Do not inspect an injector unless there is a definite indication that it is not functioning normally (excessive exhaust emissions for example)'

[/ QUOTE ]
Someone after my own heart 'Don't fix what ain't broke!'

Mal

 

[[2068]]

Trouble is, if an injector starts hosing, the first thing you will notice is rough running and extra smoke. The second thing you will notice will be an expensive "bang" type sound.

 

[Latestarter1]

Regardless of how old injectors are they will start hose when they have had water or dirty fuel though them.

The Bosch view is that provided fuel is CLEAN injectors are fix as fail, easily 20,000 hrs plus. However like all rules there are exeptions, for example MAN have a 1000 Hr injector service change out on certain engine models and Yanmar have an injector service proceedure at 400 hrs on the 6LYA3.

 

[aviator]

Thanks to all for most interesting information. If the VP manual as quoted by Peanuts says that then I will wait to see what Mr Serviceman says on Thursday and if necessary ask to see the manual.

The only caveat is quote by S28, it the injectors do start to hose an expensive fault situation rapidly ensues.

I had a duff turbo on one side last year and wonder if that would reduce the life of injectors since there was loads of black smoke on that side. Fortunately I only had to run back from the Needles to the Hamble on low revs.......

 

[volvopaul]

Not all mechanics are in it to earn money from there work by creating unnecessary work!!!, most volvo engines need them removed at 1000 hours if only to test and reset the opening pressures.

Imagine 5 good injectors and one hosing, in time you will have a hole in your piston and a big bill in the post.

If the engine starts from cold with little effort, doesnt plume grey/white smoke for too long then dont worry.

If its 20 years old and has done say 800 hours and you have no history then I would advise having them checked.

 

[Sneds]

Very well said and good advice IMO

 

[Pendana]

Just looked in WM and whilst injectors can be serviced for AD 31,41,KAD 32,42,43, the injectors in KAD 44 & 300 with 2 spring injectors need to be exchanged. Don't know about D series.

Eddie

 

[AndieMac]

I would think a truely 'good' mechanic would be far too busy with a full job list, to even think about needing to create extra work.

 

[vasant]

found this thread interesting.
I own a almost 40y old volvo md7a. No issues whatsover. Starts good has some white smoke at the beginning....
On one hand i believe there wasnt any serious service from previous owners. On the other hand i am afraid to end up creating more work when trying to remove the injectors, without obvious reason....

 

[KevB]

I know we should compare but..... when was the last time you took your car diesel injectors out for inspection or heard of a car engine go bang because of hosing?
I appreciate different environments but given the 'mechanical' bit is nicely sealed in the engine, apart from dodgy fuel what harm can the fact that they are in a boat do to them that being in a car can't.

 

[timv]

My engines are 19 yrs old and very low hours but they have certainly had dirty fuel through them as you know , they start first time with no real smoke ,and they aren't common rail high pressure .[ cat 3116 ] . Do you think I need to have them serviced Paul ? Like everyone else the stories of a hosing injectors fill me with dread !!

thanks

Not all mechanics are in it to earn money from there work by creating unnecessary work!!!, most volvo engines need them removed at 1000 hours if only to test and reset the opening pressures.

Imagine 5 good injectors and one hosing, in time you will have a hole in your piston and a big bill in the post.

If the engine starts from cold with little effort, doesnt plume grey/white smoke for too long then dont worry.

If its 20 years old and has done say 800 hours and you have no history then I would advise having them checked.

 

[vasant]

I know we should compare but..... when was the last time you took your car diesel injectors out for inspection or heard of a car engine go bang because of hosing?
I appreciate different environments but given the 'mechanical' bit is nicely sealed in the engine, apart from dodgy fuel what harm can the fact that they are in a boat do to them that being in a car can't.

Αctualy i have spoken with a workshop guy and he claims trucks go in after 5-7 years for injector service. But i agree with your point

 

[TQA]

Admittedly this was back in the late 80s and the engines involved were Gardners but we had a large sample to work with and well kept records to analyze.

For many years the local bus company had removed and refurbished the injectors on a regular basis but a smart kid noticed that they often had injector problems after this. They then took to sending the injectors back to the manufacturers for the work to be done. They still found they had injector problems at a higher than normal rate.

Finally they carried out an experiment with half the fleet getting injector work as before and half not.

They found fewer injector failures in the half that were left untouched. The injectors would outlast then engines.

 

[KevB]

Αctualy i have spoken with a workshop guy and he claims trucks go in after 5-7 years for injector service. But i agree with your point

I can appreciate why a truck may have them checked every few years, their hourly usage must be astronomical even compared to the most highly used boat.
A truck probably does more hours in a week than the average boater does in a year.

 

[QBhoy]

500 hours is a good start...or sooner if they start throwing fuel out the exhaust

 

[sailorman]

500 hours is a good start...or sooner if they start throwing fuel out the exhaust

So a lorry shifting containers up the M Way would have injectors serviced every 8 > 10 weeks