diesel problem

[K5dreamer]

hey all, my truck decided it wanted to be cute this morning. i went out to fire it up, cranked, fired, didnt sound happy about it, and ran. but the idle speed was going up and down like someone was reving it, nothing crazy, just like one or two hundred rpm, did that for a few seconds then the truck stalled out and died. i cranked it again it fired, and ran, but did not sound happy, i had a metallic, not really tapping sound, but thats the best word to describe it, as if like a cam lifter wasnt getting enough lubrication, or like a tapping rocker arm or something down inside the engine. but thats not what it was. could my pump be going bad?

 

[sope]

That's my first guess from what you've described. Have little expiereince with 6.2's and 6.5's but have lots on IHC 7.3's and that sounds similar when their pumps go.

 

[K5dreamer]

so to update, i checked the oil, it was a quart low, so i put another quart in, and i also added a diesel fuel treatment, and fired it up. its running like a top but it still has that rather disconcerting tapping sound. which i think might be my aircleaner lid, the wingnuts keep working loose, theyre stripped. so imma go get some wingnuts at the hardware store to replace em.

however at this point, i have a more pressing concern. i was hanging over the engine trying to figure out where the sound was coming from when i noticed that the v-belt on the passenger side alternator was flopping around pretty bad, maybe 2in back and forth. but when the engine wasnt running the belt seems to have perfectly good tension. i also saw the crank pully was wobbling, nothing crazy, but enough to have me worried seeing as these engines are known to have harmonic balancers fail and snap the crankshaft.

is this crank pully wobble something i should be really worried about? ive seen some wobble on small block chevys that wasnt anything to be worried about, but im a bit sketched out on the diesel.

 

[k204dr]

some of those actually have a rubber dampened belt pulley that you need to check. but it sounds like you might have a leaking fuel line somewhere allowing air into the system. air in the system can cause the rpm to go up and down and die.

 

[K5dreamer]

so how would i check the damper and the rubber lined pully for wear or warning of imminent failure??? are there markings, or measurements, or just the good ol, grab it and try to wiggle it test? ive sunk a bit of money in this truck and its my daily driver, so id rather drop some money on a fluid damper before the crank snaps and seperates the two sides of the engine permanently. but i dont want to drop the dime if i dont have to.

 

[tRustyK5]

The check for the balancer is a visual. The critical area is the rubber between the inner and outer rings. If it's squeezing out and cracked, chunks hanging etc, it's definitely time for a new one. i'm unaware of any aftermarket balancers for 6.2's though. If you find one post up the brand and pn please.

The tapping could be injector knock...

The variation in idle speed could also be a fuel delivery problem like the lift pump getting weak.

Rene

 

[MaxPF]

The check for the balancer is a visual. The critical area is the rubber between the inner and outer rings. If it's squeezing out and cracked, chunks hanging etc, it's definitely time for a new one. i'm unaware of any aftermarket balancers for 6.2's though. If you find one post up the brand and pn please.

The tapping could be injector knock...

The variation in idle speed could also be a fuel delivery problem like the lift pump getting weak.

Rene

Fluidampr Part # 800141 Fits 6.5, but also (from what I have been told) comes with a spacer ring to allow use on the 6.2 and mechanically injected 6.5's, so it is basically a "universal" damper for all 6.2/6.5 motors.

 

[K5dreamer]

injector knock????? youll have to excuse my diesel noobiness, im familiar with knock in gasoline engines, what would injector knock be? and how would i fix it? i ran the fuel additive through which was supposed to lubricate the pump and clean the injectors, and the truck is running alot more quietly, is that a quick fix for that problem?

the only thing that confuses me i i havent put cheap fuel in it, its always sunoco or shell.

 

[tRustyK5]

If the injector is fouled or in need of a rebuild it won't spray the fuel correctly. This can cause a bit of a knock...

"Good" fuel or regular diesel both need fuel additives to keep the injector pump and injectors happy. When these engines were designed diesel had a good amount of sulphur in it which lubed the fuel system. Fast forward to now and they have all but eliminated the sulphur from diesel and it's hard on parts unless you runn additives regularly.

Max, thanks for the PN...

Rene

 

[K5dreamer]

ok, that makes alot of sense, im kinda annoyed i didnt think of that lol. cuz the kid i bought it from obvisouly didnt take care of it, and ive put probly 5000 miles on it since i bought it, and it never got a fuel system treatment. ill cross my fingers, fire it up tomorrow and see how it goes ith the additives

 

[BKinzey]

Sunoco= good fuel? Ah, nevermind

As for fuel it's more important you get fresh diesel than brand. Try to pick a place that pumps a lot of diesel. Diesel goes bad much faster than gas, water separation & such. If where you are buying only gets a delivery once a month or so you take a greater risk of fuel problems.

I'm going with a bad Harmonic Balancer as well. Spray some engine cleaner on the balancer, they get pretty dirty, and look for cracks. The larger the cracks the worse it is. If there are chunks missing it's definitely bad. If you have holes in it it's really bad. I've uploaded pics of a good one.

 

[BKinzey]

Oh, it's been about 2 months since I've checked but at that time FluidDampnr had yet to deliver product for the 6.2/6.5 and they were 2 months behind then I too await for my build and I don't have one at all

If it's not the balancer take a dowel rod or broomstick, anything solid but breakable should you drop it into anything spinning and place one end on the engine. Hold it with your thumb over the other end. Now stick your thumb's knuckle in your ear. Yes you look silly but if you move the stick to other parts of the engine you'll be surprised on how you can isolate internal sounds. Put it on the injection pump and you'll know right away if it is making the sound you are concerned about.

 

[MaxPF]

Oh, it's been about 2 months since I've checked but at that time FluidDampnr had yet to deliver product for the 6.2/6.5 and they were 2 months behind then I too await for my build and I don't have one at all

Someone on another forum got one and installed it, so they are apparently available now. He claimed the engine ran much smoother than before, and that he had nearly no whip in his v-belts (early style setup with no belt damper/isolator). I like the idea that it doesn't wear out. Diesels in general are hard on dampeners, so having one less thing to worry about wearing out is a good thing IMO.

 

[K5dreamer]

i actually have the mechanics stethascope so i wont have to use a silly broomstick (although i have used a length of garden hose from time to time to find squeeky pullys and such. but i must admit i hadnt thought to use it to listen to the pump (smacks forhead) would it also make sense to listen to each injector and make sure they are making the same noise? listen for maybe one or two injectors that sound different than the other ones? ill swing by the parts store and get some engine/brake cleaner and check out the balancer tomorrow.