I’m curious when diesel injectors should be tested or maintained- when there are symptoms of a problem with the injector? Proactively based on use/hours? Whenever you have extra money you don’t know what to do with? Although the question broadly applies to all diesels I’m specifically curious about the injectors in a Cat excavator (s/n 8GR00401) with the Cat 3064 engine. Machine reads 6
Most mfrs have a defined service life for nearly all components in the operation and maintenance manual. It may say ie. After your 2k service interval, 4500 hrs, DPF & SCR service. 10k , fuel injectors. Nearly all mfrs want that valve cover off between 1 & 2k for a valve adjustment. In reality, aside from Nige and his crew, I don't think anybody even breaks the paint until something goes wrong.
Most everything I've checked the overhead on hasn't needed adjustment unless something isn't right. My forklift i bought at auction, I think the previous owner figured it needed an engine. It ran ok until it got cold, then was a nightmare to get started, if it would at all. Only 1 cylinder had full compression from the valves being so out of adjustment they were no longer fully closing. 1 cylinder was completely dead and 2 were 50-60 psi. As far as injectors, I've seen them last the lifetime of the machine or only last a couple thousand hours. So many variables.
In most manuals there will be a guide for what maintenance and when.. If it’s a 1 owner machine, they don’t get checked until there’s a problem.. miss, smoking, low power.. If it’s for a fleet, they’ll get checked at regular service intervals..
Valid points, and I should have checked the manual for the maintenance schedule. I’ll do that and add a post with their recommended interval for discussion’s sake. What are the common signs that an injector is failing or needs attention?
Hard start, frequent regen, excess fuel consumption
Ours (Brazilian 6.6l) was smoking excessively & low on power. Number 6 had a broken off tip. Found 6 nos Bosch injectors in Ohio for $300. Installed and smoking gone and a noticeable increase in “power” (lol…170hp rating) This was an ex-street sweeper and undoubtedly had many hours of very low speed operation.
Most Brazilian 6.6s smoked at idle even when nothing wrong with them.
6.6 & 7.8 built in a mirror. Stupid pump on the wrong side of the engine.
That is true! Our 7.8l with intercooler was a fair bit more powerful and it did not smoke at all! I have a spare parts truck (much to wife’s chagrin) so if new pump is needed it is available. I tightened the governor springs 3 clicks to give us 95km/h road speed. Usually just drive at 85km/h but means less wear and tear on foot as not having to hold throttle tight to floor mats (lol!) I must be getting old as I am the slowest driver on the road! Saves a bunch of fuel! Sure made me appreciate a 1999 Cat C-12 which is in our single axle ihi 9200!
This is really a loaded question in so many ways. Most of it all depends on service intervals and the quality of the fuel--plus whether the injectors were built on a Wednesday instead of Friday or Monday. The company I worked for--we kept the service intervals tight/on schedule, Cat filters were used on cat, Detroit filters on Detroit's-some would argue that should make no difference, so be it. The other is fuel--the company bought fuel from good sources with know good tanks and filtering. Below is one of nine that belonged to a grain commodity broker, we took care of there services & maintenance issues. Most of their trucks had high hours with very little fuel related issues. This one only had the overheads run on a regular program, never had the head or oil pan removed, only one water pump and one turbo. Only fuel items done were leaking fuel lines from age. It finally went down with just a hair under a million miles, but it was used allot for cleaning up ground piles------- Total hours hit 37,000, lugging 105,500 constantly with nothing more than a 10 speed. It lived in a constant cloud of grain dust and field dirt. Really it depends on some luck & good servicing. Original injectors. *
Normally valve adjustment out of spec is from dusting or the last person in there. And injector failure us from pre filling filters or a **** load of water in fuel. I normally wait to it starts to run rough, knock or blow smoke (frequent regeneration) before i start looking. Typically about 5000 to 10000 hours.