Is this a problem?

[duckling]

Just got off the highway after a 45 minute drive at 100km/h. When I came to a a stop I heard something like construction hammering outside. Turned out it was my engine. Just a tick at idle and when revved a little it was a banging. I was ready to call a tow truck and figured the 3b was toast. Came out 15 minutes later. Started up and it ran fine. Drove it all the way home at highway speed without a peep. It does have a noticeable tick (kind of metallic sounding). This ticking started after I put new nozzles in the injectors. I did have the cracking pressures adjusted. But I mileage did improve from 25 to 31 mpg. On another occasion, the truck did lots of bucking when I had driven over a crunky ice covered road. In this case, I had just hammered three speed bumps. I wonder if there is not dirt somewhere near the fuel pump that is getting stirred up when I hit bumps at speed. Then again, maybe it's something more sinister. I adjust the valves every year, but have not yet done it this year. The truck is my only driver. Thanks for any advice.

84 BJ60 265 km

[Tapage]

mmmm I didn't like this kind of sound ..

How it's your oil press .?

My best bet shoul be inspect the engine form under ( oil pan ) and see what you get ..

[duckling]

Tapage, it does drip a little but has done so for a long time. The oil pressure has not changed. It is a little under half when warm.

[lostmarbles]

Originally Posted by duckling

.....When I came to a a stop I heard something like construction hammering outside. Turned out it was my engine. Just a tick at idle and when revved a little it was a banging. ...........

This sounds very serious indeed!

....Came out 15 minutes later. Started up and it ran fine. Drove it all the way home at highway speed without a peep........

Well I doubt it could have made the sound you described earlier without leaving visable/lasting damage somewhere inside your engine. Sounds to me like something dropped into a cylinder and was then "smashed to smitherines by the piston" before getting spat out in little pieces? But I would expect your engine to now be "missing at idle" (due to poor compression in that cylinder) and not just "ticking at idle".

"Ticking" is normally associated with a tappet that has too much clearance (which is a minor problem and easily corrected).

... It does have a noticeable tick (kind of metallic sounding). This ticking started after I put new nozzles in the injectors. .....

Hmmmmm. "Metallic-sounding".
Who did that work? Did you do it yourself? (Because exactly what was done then could be the key to finding out what has gone wrong now.)

.....On another occasion, the truck did lots of bucking when I had driven over a crunky ice covered road. In this case, I had just hammered three speed bumps. I wonder if there is not dirt somewhere near the fuel pump that is getting stirred up when I hit bumps at speed. .....

I'm puzzled that you can connect "driving over a crunky ice covered road and/or speed humps" with engine noise. (Although I did once see a Jeep hit a small bank at full throttle, exploding its front diff when it relanded at full-power, and at the same time the flailing driveshaft ripped off the engine oil filter.) If you have a proper fuel filter - any dirt in the tank shouldn't make it any further than that.

Originally Posted by Tapage

....How it's your oil press .? My best bet shoul be inspect the engine form under ( oil pan ) and see what you get ..

Originally Posted by duckling

Tapage, it does drip a little but has done so for a long time. The oil pressure has not changed. It is a little under half when warm.

I think Tapage was suggesting you REMOVE the oil pan to check inside for engine damage. (When an engine makes a noise like a jackhammer it is NEVER good.)



PS. I'm probably not much of help here --- I know.

Perhaps you should identify which cylinder is "ticking", remove that injector, inspect it, and peer down the hole?

[crushers]

ah, no biggie, you probably drop a chunk of prechamber and are slowly killing your piston.

[PressOn]

I had a 3B with a metallic rap at 1 x's rpm and found the problem after I pulled the oil pan. In my case it was a piston missing part of its skirt. The noise was the other side of the piston skirt slapping the cylinder wall. My only solution was a rebuild as I didn't want to pay for the rebuild with a fragged engine.

Keep us posted on what you find.

Jeff

[crushers]

of course, metal objects do not heal themselves so...
bad knocking is ...well...bad.

[mac]

Did you do your own injectors? Where did the nozzles come from? If it were mine I'd be thinking about investigating injector nailing. An injector can make a hell of a lot of noise that can sound a lot like a rod is going to come through the block.

A really bad metallic knock caused by a rod or main or some other serious mechanical failure does not typically come and go.

[gettocruiser]

why not start by draining your oil, checking for...
can you be sure in was the engine and not the tranny?
good luck,
eric

[roscoFJ73]

Its not the fan hitting the shroud by any chance is it??

[canucksafari]

Well, isn't Cushers the positive thinker in this thread?

I am hoping Rosco is right. It is very strange that you had a very loud thumping and it went away to a slight tick. Look at the fan tip and shroud for wear. If so, then check for a broken motor mount.

Never had a precup drop but from what I have read it generally can start out like a slight rock in a tin can rattle as the loose or cracked precup rattles in its place in the head. When it drops, then you get the bang (and sometimes worse). I have never heard of anyone starting back up and driving away with a slight tick after a pre-cup drops.

[crushers]

anything i can do to lighten the mood...


when a precup drops it usually means a dead piston, busted rings, scored cylinder sleeve or wall, cracked head and busted valves... nothing really serious.

[lowenbrau]

From the description, I thought pre-cup too.

[mac]

Rotflmao!!

[eleblanc]

Originally Posted by crushers

anything i can do to lighten the mood...


when a precup drops it usually means a dead piston, busted rings, scored cylinder sleeve or wall, cracked head and busted valves... nothing really serious.

Yep, just like that

IH8MUD™ Forums - View Single Post - Dont' loose a precup, 3B carnage

[lostmarbles]

Originally Posted by canucksafari

....... then check for a broken motor mount................................

I never thought of that. Well done...... Yes. This would certainly connect the "driving over a speed hump" with "engine noise".

And broken engine mounts are hard to spot without jacking the motor up.

(Hopefully "broken engine mounts" is all it is.)

Any news of what you've found Duckling?

[roscoFJ73]

Originally Posted by lostmarbles

I never thought of that. Well done...... Yes. This would certainly connect the "driving over a speed hump" with "engine noise".

And broken engine mounts are hard to spot without jacking the motor up.

(Hopefully "broken engine mounts" is all it is.)

Any news of what you've found Duckling?

Especially over that "crunky ice" too . By the way ,what the hell is "crunky ice"?

[duckling]

You guys are hilarious. I'm glad I wasn't home to read all these posts. I don't know. I just took another trip of an hour and a half. Ran fine. I agree with Canucksafari that it seems pretty unlikely that major engine damage would come and go. I mean, the truck pulled perfectly between incidents. Then about an hour after which the problem started again. Tried bleeding the injector pump and injectors, while running, in case it was air. Started it again after ten minutes and the noise was gone. This morning, the muffler broke off. I have pipe running outside the passenger frame rail, with a v. small muffler (doesn't muffle much) and goes out behind the rear passenger door. I think it may have been banging against the frame at the end of every odd trip just to freak me out. Yeah, I feel stupid.

Mac, I just pulled them apart put the new nozzles in myself without setting the cracking pressures. Maybe they're off. My mileage went from 25 back up to 31 mpg, though (Canadian gallons) and it definitely pulls better.

[duckling]

Rosco, on the east coast, our constant melting, freezing and freezing rain can sometimes make roads that are literally slabs of uneven ice of varying thicknesses. Wet, bumpy and well…chunky. Doesn't happen very often.

[crushers]

LOL!!
you might feel stupid but who cares, it was a cheap fix... that is the important thing.

[mac]

Glad to hear it's worked out for ya.

I had an exhaust system that would occasionally bang against my frame on a BJ60. It was the result of a decaying left side engine mount.

[Eric Winkworth]

I actually had this happen to me, exhaust on these engines rattling loose or against something can make some very bad noises....

[roscoFJ73]

Originally Posted by crushers

LOL!!
you might feel stupid but who cares, it was a cheap fix... that is the important thing.

x2 Better to feel stupid and rich,than wise and poor

[Turbo45]

any time you have what you think could be and engine noise (especially bottom end) remove the oil filter and cut the top off it with a hacksaw. Then pull out the element and cut it down the middle from top to bottom, then then you can take the element and spread it out and inspect it look for metalic peices use a magnet to see if they are aluminum or steel. Messy job but usually tells you a lot of info with out having to take the engine apart.
Glad to hear it was only an exhaust problem