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Isuzusweet · 09-15-2019, 08:41 PM

Okay all; need your opinions

The other day I was visiting a friend and using her driveway as a base of operations to conduct a KLR tour of her area. I parked on her driveway and tried my best to level out the rig , but the fridge crapped out on me, which resulted in me moving the coach to a more level spot at the bottom of her drive. I backed into the spot and decided what thickness platforms I needed to get her fairly level; upon backing onto the platforms and just as I shut down, my Isuzu turbo diesel made a fairly nasty noise as it shut down. Every once in a while I do find it does a hard shutdown, but not often. It's like a hard knock.

What scared the bejeezers out of me this morning upon start up, was an engine noise akin to it just about to throw a rod through the side of the block. The engine ran, but sounded uneven with a severe metal on metal knocking noise; and I do mean loud. I immediately shut down, and went hunting for things that were amiss; oil was good, coolant fine etc, etc. I then tried the glow plugs, thinking maybe a cylinder wasn't lighting off; no effect, same noise. I gently applied the accelerator to raise the rpms to 1000, which smoothed out the knocking a fair bit, but the knocking returned once returned to idle. Out of desperation I put the coach in gear and came off the blocks on the ground; the severe knocking engine noise completely disappeared, and she ran just like normal.
Question:
Would placing a bright yellow 3/4" block on the passenger front wheel be enough to torque the frame into contact with the motor?
The noise reminded me of the time I got too much snow into the engine compartment of my 1988 Toyota Tercel. The snow melted into the engine mounts, re-froze, essentially reducing the mounts to blocks of solid matter and severe engine knock was the result.
The only mount that I could conceive giving me problems, or at least close to the frame is the A/C mount; which coincidentally did crack and was rewarded sometime in the past.

Anyone else had this happen, and possibly know the culprit?

Cheers
Sidekick Tony

uncle_bob · 09-15-2019, 09:52 PM

Hi

Best bet is to find a mechanic who knows that engine and see what he can find. Most of the time, stuff that sounds bad is bad.

Bob

ROBERTSUNRUS · 09-15-2019, 10:31 PM

Hi, I would check for bad motor mounts allowing for something on the engine to be very close to the frame. I would also check clearances of the exhaust system.

Smartstream · 09-15-2019, 11:43 PM

Tony, you had to come up with a way to tax our brains on a Sunday night.

A 3/4" block isn't much, how much blocking on the other wheels? Try backing on the blocks again and see if you can duplicate the noise. Check around the frame below the injection pump, it's pretty tight around there. Open the doghouse and start the engine watching to see any indication of it jumping around, loose or broken motor mounts. With your foot planted firmly on the brake, put it in gear again watching for movement. Try giving it a little throttle again watching for movement or changing sounds. Also look around the bellhousing and starter to make sure everything is good and tight. Good luck

bkahler · 09-16-2019, 11:35 AM

Quote:

Originally Posted by Smartstream

Tony, you had to come up with a way to tax our brains on a Sunday night.

A 3/4" block isn't much, how much blocking on the other wheels? Try backing on the blocks again and see if you can duplicate the noise. Check around the frame below the injection pump, it's pretty tight around there. Open the doghouse and start the engine watching to see any indication of it jumping around, loose or broken motor mounts. With your foot planted firmly on the brake, put it in gear again watching for movement. Try giving it a little throttle again watching for movement or changing sounds. Also look around the bellhousing and starter to make sure everything is good and tight. Good luck

Did Tony mean a 3" or 4" block? That sounds more like what could cause a tweaking of the frame.

Isuzusweet · 09-16-2019, 03:35 PM

Quote:

Originally Posted by bkahler

Did Tony mean a 3" or 4" block? That sounds more like what could cause a tweaking of the frame.

I had one 3/4" thick lego block style leveller under the front passenger side; two thicknesses under passenger rear and one thickness drivers rear.

Seriously, it was weird; as soon as the coach moved that 6" off the block the noise disappeared.

I will check tomorrow; blood work, ECG and Onocology today; this round of chemo put off one week as my blood levels weren't good.

Cheers
Sidekick Tony

PS If it is an engine mount, (which I suspect); what kind of engine mount would it be? Anyone got part numbers????

bkahler · 09-16-2019, 05:42 PM

That's definitely weird. You would think being on the blocks meant the frame was not twisted and moving off the blocks would twist the frame.

Needless to say it'll be interesting to see what you find out.

Please do get your blood levels squared away so you can put that all behind you.

Brad

mehes · 09-17-2019, 05:54 AM

You'd never have this problem with a gas engine.

bkahler · 09-17-2019, 09:34 AM

Quote:

Originally Posted by mehes

You'd never have this problem with a gas engine.

Ok, I've got some popcorn and I'm ready to watch the fireworks from up north.....

dadstoy · 09-17-2019, 09:04 PM

Those diesel knocks can be nasty!

https://youtu.be/wzp0DAtYPGE

mehes · 09-18-2019, 04:24 AM

I can’t help throwing gasoline on a fire.

uncle_bob · 09-18-2019, 08:35 AM

Quote:

Originally Posted by mehes

You'd never have this problem with a gas engine.

Hi

You also would only be on your fifth or sixth oxen team if you had just stuck with the "tried and true"

Bob

mayco · 09-18-2019, 08:51 AM

That's really strange Tony. I've had the 310 on various configurations of blocking to try n level it, never had any affect on how the motor sounds. Of course knocks, clunks, whistles, and pings are pretty standard sounds on these old buckets of bolts. Yours sounded scary.

perryg114 · 09-18-2019, 09:37 AM

Baring a mechanical problem, I expect you have a bad injector. If you have a leaking injector that cylinder can fire early and it makes a lot of noise because the engine is working against that pressure in the cylinder. It needs to be fixed before major problems. It you loosen the line on that particular injector, the noise should stop if it is the injector. You have to do this one by one till you find which cylinder has the bad injector. It could also be caused be oil being drawn into the cylinder but you will probably see a lot of blue smoke. Also is it smoking a lot when it does this?

Perry

Isuzusweet · 09-18-2019, 04:32 PM

Not a bad injector as I do know what to look for; no extra black smoke; motor ran smoothly once off the blocks.
The knocking was very severe, and then nothing once moved 6".
Had a chance to investigate further and found no abnormal motor flex, even under load which would point to a bad motor mount; but the drive belts were quite loose and were causing the rear of the alternator to bounce around a fair bit. It is fairly close to a stuctural element to cause a severve knock if it made contact.

I'll keep an eye on it.

Cheers
Sidekick Tony

uncle_bob · 09-19-2019, 09:11 AM

Hi

If indeed something like an alternator is / was hitting something else, you should be able to see where the impact happened. Yes, that depends a bit on how many dusty roads you have been down since the event ....

Bob

Kota · 09-20-2019, 11:05 AM

Exhaust banging on something?

davejay · 09-21-2019, 01:13 PM

Hey tony,
I don't think you got an engine problem. If it didn't t do it before the leveling took place? Then what changed. I'm thinking something weird like maybe a binding of some kind. Pulley rubbing on the cross member, flex plate maybe rubbing on the block. It's a rotational noise, so it's got something to do with the engine running. A missing injector will make the diesal buck, but it won't sound like grating metal. How was your oil pressure at the time. I can't see how lifting it an inch could affect that. Maybe you got water in the fuel. That could make it run really bad, until it works thru the pump. Try to imitate the problem again. You got a weird one there. Could it be a power steering pump? They make some weird noises .
You want my excursion with a 7.3. And a brand new rebuilt trans. That's an option if you got a bad motor. 320 K on the motor less than 3000 on the trans.
DJ

guskmg · 09-29-2019, 11:38 AM

I had that happen with my GMC Duramax after I pulled over to change a tire on the way to Alaska. It never hapenened again. I theorized it was the frame in a slight twist causing the drive train to touch somewhere. See if it will repeat on level ground.
guskmg