Servicing a Diesel

[Bogger]

G'day

I have serviced my own cars for years, but always petrol engines. Girlfriend and I have just got a new (old but new to us) diesel powered Cruiser. I have gone over it and changed all the filters (air, oil, fuel), new oil in engine, gearbox and diffs. All just as a precaution and so that I know where I am starting at. Then it occurred to me that as I have never had a diesel before, I did not know anything about glowplugs. I have been told that they don't need changing as often as sparkplugs, but how long should they last? Am I right in thinking that as the previous owner had the car for 40 000 km and never had them changed that I should put new ones in, just in case. Is there anything else that I should be checking so that I can get the engine into the best of health and keep it that way?

[ISUZUROVER]

Basic rules to follow for diesel engines are to get the injectors serviced/checked regularly (every 50000kms or so), and replace the injector nozzles when they need it usually every 150000km depending on the engine.

A dribbling injector can melt a piston crown. Specialist diesel places (Diesel Australia if you are near rocklea QLD) will test the injectors for practically nothing if you take them out yourself.

I only replace my glow plugs if they stop working - you will notice if a glow plug isn't working as the engine will become harder to start. Indirect injection diesels (like your cruiser) need the glow plugs a lot more than DI diesels, but they should still last a long time.

Other than that just make sure the fuel is as clean as possible. I always install at least one extra filter.

[Bogger]

Thanks IsuzuRover, so leave the plugs alone (it starts fine even when it is only -2 degrees outside). No mention of any injector service from the last owner, so probably not a bad idea to look into one now, even if it is a little early I will know that it should be OK for 50K. Is this a costly sort of excercise?

[ISUZUROVER]

even if it is a little early I will know that it should be OK for 50K. Is this a costly sort of excercise?

If you remove the injectors yourself it should be somewhere between $0-20 to test all the injectors (if they are OK - more if they need new nozzles - if you need the nozzles replaced the test should be free). Make sure they let you watch the test, so they don't just tell you they need new nozzles when the spray pattern is fine.

You will need a seal kit to reinstall - shouldn't cost much, but nest to ask about this on the toyota forum.

[spazbot]

change the engine oil every 5k

some ppl do fuel and oil filters every 5 aswell of do them and gear oils etc every 10k

[joel HJ60]

[hijack] This is for the newi crew. Where's a good diesel place in newi. thanks joel [/hijack]

[Shadow]

What car/engine is it? Advice will differ depending on what engine and vehicle you have. If its only done 40k im assuming its a 100series? which would be 1HZ powered if its not a turbo...

Toyota recomends injector servicing every 100k on most of thier diesel cars (cruisers hilux etc). I believe the latest turbo diesels may be down to 50k service intervals.

With indirect injected engines the injectors arent (AS) important as in direct injected engines as ISUZUROVER said.

However, i would disagree with the servicing ISUZUROVER suggests for the injectors. An injector does not need to have a perfect spray pattern to do thier job. Eventually an incorrect spray pattern will cause a loss of power and efficiency, but in an indirect injected engine, the pre-combustion chamber helps fuel atomisation and means the injectors dont need to be working 100%.

I would probably not worry about your injectors unless you are down on power, have excess black smoke, or some other problem is noticed. I guess since the car is new to you it is impossible for you to know if its blowing more smoke than usual, or if its down on power, but if its a 2H, it shouldnt blow any black smoke up to 2500rpm, above that it may blow a little, but if it blows alot you probably have a problem.

My 89 cruiser (2H engine) has done nearly 400 thousand and has never had an injector replaced (has never had them pulled out). It blows no black smoke except above 2500revs. Of course ideally it should'nt blow smoke at all through the rev range, (0-3500?) however a little at the top of its rev range doesnt do any harm, and also generally means your getting the most power out of the engine you can.

So yeh, if its not blowing alot/any black smoke, then "I" wouldnt worry about injectors until it does.

If its a direct injected engine (12HT 1HDT 1HDFT 1HDFET), its probably more wise to get the injectors serviced, just to be safe.


Glow plugs last a long time, and as ISUZUROVER suggests, you will know when they need replacing when the car gets harder to start, or you hear a cylinder mis-firing when the engine is cold. Replace them all at once. My first injector died at about 350thousand(being in qld most of its life helped this im sure).


Diesels also dont like short trips. Impurities such as carbon gets into the diesel oil no matter what you do, however, when the engine is cold alot more get passed the rings etc. A petrol engine burns alot of these impurities off when its at operating temperature, however, the impurities generated by a disel engine (carbon etc) cannot be burnt off and remain in the oil until you change it.

Avoid short trips!

If you do alot of short trips consider changing your oil more regularly. If you do only long trips, you may not need to change your oil at 5000km intervals (however i would highly recomend you still do).

More advice specific to your engine could be offered aswell.

[ISUZUROVER]

However, i would disagree with the servicing ISUZUROVER suggests for the injectors. An injector does not need to have a perfect spray pattern to do thier job. Eventually an incorrect spray pattern will cause a loss of power and efficiency, but in an indirect injected engine, the pre-combustion chamber helps fuel atomisation and means the injectors dont need to be working 100%.

If its a direct injected engine (12HT 1HDT 1HDFT 1HDFET), its probably more wise to get the injectors serviced, just to be safe..

While I agree with most of what you say, for the cost of a few dollars and a bit of time, it is worth knowing your injectors are ok, and at least to get the pop-off pressures reset.

While I agree that an indirectly injected motor is not as likely to be damaged by an injector that is not working correctly, the pre-combustion chamber cannot improve atomisation, only mixing of the fuel and air after it is atomised by the injector.

And some indirect injectors - e.g. CAV - are prone to the nozzles cracking over time (especially if the engine is overheated). The injector still works acceptably until the point the nozzle breaks up completely. I wouldn't want to leave the injectors too long and have bits of nozzle in the engine (indurect or otherwise). Maybe toyota injectors (Denso? Kiki?) aren't prone to this problem - but for the sake of a few $$$ knowing your injectors are good for another 100000k's or so is worth it.