Sorry for the mundane question, but I scanned the FAQ's and didn't see definitive answer.


My son and I have started to tinker with our 1990 F250 7.3L project truck. This being my first diesel there are a few things foreign to me. We have replaced the glow plugs, changed the oil, replaced all the fuel lines on the top of the engine. Running pretty good but we have now a definite smoking problem at idle. No smoke whatsoever once you get your foot into the pedal. I have heard/told its Injectors? If so what's the best choice of replacements on the market?

Thanks ... John

 

check ebay theres a company that sells complete rebuilt sets with no core for around 100$ thats who i use all the time.

 

Before you replace anything, what color is the smoke?
Is it heavy or light?
How cold it is where you are?
And does it smoke when idling when its warm, or only when its cold.

The ebay injectors sound like Pensacola... this company has mixed results on this forum, many people say to avoid them like the plague... There are a few other threads on injectors on here with many people supporting R&D injectors, idiperformance.com. They may cost more, but you'll be guaranteed they work.

 

more than likely it is time to replace the injection system, also if your son played with the injection timing to try and get more power that can make them smoke.

 

Buy /new/ injectors. DO NOT BUY REBUILT. Rebuilt injectors are just cleaned up, re-pressure-tested and sent on their way. The wear parts are all old, and they will wear at different rates.
I've gone through this mess enough to say just buy /new/ injectors. You should be able to find them for in the $385 range on Ebay, or for a top quality set, idiperformance.com is the best place.

 

odds are it is worn injectors, my van has about 10,000 miles on new injectors. no smoke when idling, proly not timing but it helps ones state of mind to know it is correct. if it is bluish and smells like a old tractor, then worn injectors, remember to run her hard now and then to (burn the carbon out) they love it. Napa gold fuel filter, and best oil filter if it will fit is the mobile 1 601 its a power stroke filter that filters some of the oil to 5 microns, it's bigger longer and fits most 7.3 applications.

 

This is useful information to have in diagnosing the issue. It's normal for some light smoke to be present when extended idling and cold are combined. The exhaust temp can drop enough to cause an incomplete burn resulting in some smoke. Even at operating temps, if I let my truck idle for too long the EGT can drop to under 300* and I will get a little haze.

 

Thanks for the replies to date. To answer TECGOD13. I would offer its white to very light bluish. More on the white side the bluish or gray.
It's not cold where I live (CA) and it seems to smoke more when its warm for sure and its definitely noticeable to embarrassing :-(


I also have noticed that I am losing water in the Radiator and I now have a pretty ugly oil leak that I am having difficulty tracing. Could it be a Head Gasket? In fact the oil is a pretty wet and black oil and I just change the oil a week ago. Not what I would expect to see after an oil/filter change. I just too had the Radiator flushed with no leaks I can see around it or hoses.


Appreciate any guidance you guys can offer.

 

On that note, a pressure test of the cooling system may be in order. You can usually rent a test tool from an auto parts store for next to nothing.

 

i always get my injectors from that pensicola florida place you listed, never had a problem.

 

The oil in these engines turns pitch black in like 5-10 minutes, it's just the nature of the beast. Nothing to worry about there.

 

Well I had a written out a good bit of a reply riding back from my aunt's house, but apparently my phone hates me and it didn't get posted....

Here's the gist of what I had down...
White smoke that smells kinda acrid and burns your eyes would be unburnt diesel, like what you see coming out of the pipe when you can't get your truck started in the winter because the glow plugs aren't working or its not spinning fast enough, but the injectors are firing (the fuel isn't igniting though and just goes out the tailpipe). You shouldn't see this on a running engine unless something is drastically wrong with one cylinder not getting any compression, like a valve stuck open.

Sweet smelling white smoke is coolant, like sycostang mentioned, a coolant pressure test is in order. It could be a blown headgasket. Less likely would be cavitation forming pinholes in a cylinder. Most likely the smoke you're seeing is from coolant, sniff it to see if it is sweet like coolant.

Blue smoke is oil burning. This can be caused by bad piston rings, leaking valve seals, or oil sucking through the CDR valve.

Black smoke is partially burnt diesel, 'rolling coal'. There are a few causes, too much fuel, clogged air filter, timing way off, idiot driver cranking up the pump and flooring the pedal (stupid..).

The oil leak is probably unrelated. If it is leaking down the back of the engine, like above the starter, there is a good chance is coming from the valley pan. The valley pan drain comes out the back of the engine above where the starter is. When the return lines on the injectors leak, the fuel collects in the valley pan, dissolves any oil and dirt that has collected there and dribbles out the drain looking like oil. It is very common for the o-rings on the injector caps to leak if they have been disturbed. My bet is that either you or your son moved one of the caps, or otherwise disturbed the system and caused a leak in the return lines. Another common oil leak on these engines is the valve covers, which could drool out all over.

Thanks for answering the questions, the idea is for us to help you diagnose the actual problem, instead of just randomly throwing parts at your first guess.