Humvee Engine Knocking (yes it's actual knocking, probably)

[jake20]

Yea.. good point, guess hindsight is always clear. First time doing this so I’m still exploring. Welp, off to do an oil change I go.

 

[MarkM]

Make one of those quarts of oil a quart of Marvel mystery oil as it can help get things unstuck.

Mark

 

[TOBASH]

My buddy on a gasoline engine in his 1999 Durango developed a bad tap. He was going to get a new engine. I changed his oil with engine cleaner and ran it for 5 minutes. I then replaced with cheap oil and ran for 10 minutes. I then replaced with good quality oil. Tap was gone. Engine lasted another 120,000 miles.

Moral of the story, don’t stress out.

 

[osteo16]

Yea I've heard that bad ones can cause it to sound like a bunch of monkeys banging sticks around. A new set of 8 off fleabay looks to run about $270-$350. I just don't want to replace them all and then still end up hearing the noise

I guess that's what I signed up for

My buddy on a gasoline engine in his 1999 Durango developed a bad tap. He was going to get a new engine. I changed his oil with engine cleaner and ran it for 5 minutes. I then replaced with cheap oil and ran for 10 minutes. I then replaced with good quality oil. Tap was gone. Engine lasted another 120,000 miles.

Moral of the story, don’t stress out.

Engine cleaner? Maybe ATF ??

 

[TOBASH]

Engine cleaner? Maybe ATF ??

They make an engine oil cleaner. I forget the name. ATF and Marvel Mystery Oil are all things people use also. This engine oil cleaner has helped me unstick valves before. I just forget the name.

 

[jake20]

Alright so… update on the situation:

I changed the oil and filter yesterday, per the immediate recommendation of some of you. drove it around several times, getting it up to full temp each time. Didn’t hear the knocking the whole day. Now I’m gonna sit here and hope I don’t hear it again.

I shall tuck this knowledge away for future reference, thank you all for your inputs. I’ll monitor this over the next week and hopefully the stick banging gremlins stay at bay.

 

[Mogman]

Alright so… update on the situation:

I changed the oil and filter yesterday, per the immediate recommendation of some of you. drove it around several times, getting it up to full temp each time. Didn’t hear the knocking the whole day. Now I’m gonna sit here and hope I don’t hear it again.

I shall tuck this knowledge away for future reference, thank you all for your inputs. I’ll monitor this over the next week and hopefully the stick banging gremlins stay at bay.

Sound great!
Now change the fluid and filter in the trans and the fluid in the gear hubs, differentials, power steering and brakes to reduce the risk of having issues with those items.

 

[frauhansen]

Engine cleaner? Maybe ATF ??

Most of the TIme i use one of this products here:

Motor Clean – Liqui Moly Shop

www.liqui-moly-shop.ch

A spring clean for the engine

Cleaning the engine in spring: Thanks to LIQUI MOLY products, the engine looks like new from the inside and outside

www.liqui-moly.com

This is what we use here in europe, but there must be a simular product over there.
Mostly there are two types of "engine cleaner". On is to use directly bevore the oel change. Put it in, run the car in idle vor 30min an flush the oil.
The other needs to sit in the engine for 120mi and you have to drive the car in daily mode, but not stressing the engine out.
After that... flush the oil.

In both cases the aditive will change the viscoity of the oil a little bit and it has some surfactans in it that helps to clean up the "tiny places behind the stove".

and aditional to all others.... yes... change every liquit thats in the engine and lubricate all the million places. "I beleve there have done it" is miles away from "i know cause i done it"!

 

[patracy]

It sounds like a lifter to me. But the audio is hard to tell from the video.

 

[MarkM]

An very old engine cleaner was to add a qt of kerosene to the oil with the engine cold then bring it up to temp and let it sit and repeat. Change the oil and filter. The kerosene will cut though and dislodge the sludge buildup and hopefully clear up any issues. It does help.

Mark

 

[jake20]

Yep, looking to source the remainder of the filters (fuel, transmission, power steering). If anyone's got a 100% great source for those, would appreciate a reference. Trying to order off kascar but some things seem out of stock. I may try running some biodiesel through and I've got another oil change I'll do shortly after I get to swapping this injector pump.

 

[Mogman]

I add a little Stanadyne "lubricity" formula to each tank of fuel, they built the IP, I figure they know what's best for it.

 

[RJTM998]

Congrats on the new truck. I am also new to the HMMWV world but have learned a lot in a short amount of time. Like others have said I would change out all the fluids, fill it with fresh fuel add a bottle of Diesel Kleen with the new fuel.

Spindle nut and tab service is a must-do. You do NOT want one of your wheels falling off while driving. Also, make sure you check and torque all half shaft bolts because they can also cause a wheel to fall off. Check tire pressure, lug nuts, etc.

Grounding harness so you can make sure you do not chase your tail with electrical issues that could be cleared up with a harness.

Fix any bad bulbs and electrical issues.

Check and replace any bad belts, hoses, etc

A thorough check of all brake components, steering components, pitman and idler arms, etc. Check for any leaks (transmission, oil, CV boots, coolant, etc)

Go over every inch of the truck looking for anything. The best example I can give you is the positive and negative bolts on my starter were missing with just the wires just pushed onto the studs. I am lucky I didn't burn the truck up with that one.24 Volts is some serious stuff.

I probably missed a few things but you get the idea.


Then once you think everything mechanical is up to par then you can start on the upgrades, cosmetic fixes, etc.

I can say that some of this stuff is fun to me and enjoy wrenching and seeing the truck come together. However, it can get pricey depending on what goes wrong. I am fortunate and have a guy local to me that works on military vehicles for a living. We call him the "Humvee Whisperer" so if I get stuck with an issue I can't resolve or just don't feel like messing with he can handle it and even makes house calls.

I hope you have resolved your issue and dodged an expensive bullet. Again, congrats on the truck and hope you enjoy it.

 

[jake20]

Congrats on the new truck. I am also new to the HMMWV world but have learned a lot in a short amount of time. Like others have said I would change out all the fluids, fill it with fresh fuel add a bottle of Diesel Kleen with the new fuel.

Spindle nut and tab service is a must-do. You do NOT want one of your wheels falling off while driving. Also, make sure you check and torque all half shaft bolts because they can also cause a wheel to fall off. Check tire pressure, lug nuts, etc.

Grounding harness so you can make sure you do not chase your tail with electrical issues that could be cleared up with a harness.

Fix any bad bulbs and electrical issues.

Check and replace any bad belts, hoses, etc

A thorough check of all brake components, steering components, pitman and idler arms, etc. Check for any leaks (transmission, oil, CV boots, coolant, etc)

Go over every inch of the truck looking for anything. The best example I can give you is the positive and negative bolts on my starter were missing with just the wires just pushed onto the studs. I am lucky I didn't burn the truck up with that one.24 Volts is some serious stuff.

I probably missed a few things but you get the idea.


Then once you think everything mechanical is up to par then you can start on the upgrades, cosmetic fixes, etc.

I can say that some of this stuff is fun to me and enjoy wrenching and seeing the truck come together. However, it can get pricey depending on what goes wrong. I am fortunate and have a guy local to me that works on military vehicles for a living. We call him the "Humvee Whisperer" so if I get stuck with an issue I can't resolve or just don't feel like messing with he can handle it and even makes house calls.

I hope you have resolved your issue and dodged an expensive bullet. Again, congrats on the truck and hope you enjoy it.

Just put in a real big kascar order, going to be fun

 

[jake20]

So I guess since I've already got this thread open, I figured I'd ask about engine noise in general. I've got a total of 2 humvees I've been around at this moment, one is mine, one is a friend's that we won on the same auction day. His sounds quieter in general compared to mine, and less diesel-clackity if that makes any sense. Mine sounds more like a traditional diesel with that slight clacking you hear (the loud supposed lifter noise has gone away after the oil change and hasn't re-appeared over the last few days).

I understand that each truck will have its own personality, but I'm wondering if anyone knows some more specifics on this topic.

 

[jake20]

So it looks like I'm re-visiting this thread with a new sound I'm hearing. I've recently swapped my injection pump - more details in this thread: https://www.steelsoldiers.com/threads/govplanet-humvee-arrival-and-inspection.209997/page-4

Once I swapped the pump, the truck started up and acted great, drove it around a little that night to test it. The next morning on a cold start, the engine sounded like there were a bunch of monkeys banging around on the inside of it. After the temp gets past about 180, it sounds/idles normally without any bizarre sounds.

It's been doing this for the past few days, so I cracked each of the injector lines to see if I could isolate it to that. Unfortunately, the results were still the same.

I did however find that one of the injector lines was so tight that it actually started unscrewing the injector when I turned it. I ended up having to monkey around with some crows feet and such to get the line/injector separated from each other. I pulled that injector to inspect/clean it as well since it was already loose.

Basically, I don't know if I should be concerned with the noise or not. It sounds a little less clacky with higher RPMs when cold, but once it warms up, the truck sounds just fine. If anyone else has this and it's normal, I can live with it lol.

Here's a video, note that one of the injector lines is opened up:

Also attached are some pics of the injector, and the exhaust spitting out what looks like water/condensation/soot onto the ground.

 

[Retiredwarhorses]

First off, that spraying injector is allowing air into the system, hence the rough idle, as well as incomplete fuel being introduced into the combustion chamber.
The loud clacking is normal for a cold NA 6.5, this goes away after the cold advance expires, it’s also louder if you have an over advanced injector pump timing.
Till your fuel system is air tight, it won’t run smooth.

 

[jake20]

Yea I had that line cracked specifically since I suspected an issue with that injector, so the rough idle was expected. It still clacks with that line connected, and the cold advance was part of my theory, but I'm missing a few pieces of information to make sense of it.

I thought the cold advance needed the throttle to be nudged forward after setting the switch to "run". Is the normal temp for the advance solenoid to come off around 160-180? That's when the sound goes away. In terms of pump timing, mine is advanced towards the driver side, but a very small amount and less than the previous pump at least. If it's not worth playing with and nothing is getting harmed, I'm completely fine with it hehe

Thanks for the input!

 

[Retiredwarhorses]

Yea I had that line cracked specifically since I suspected an issue with that injector, so the rough idle was expected. It still clacks with that line connected, and the cold advance was part of my theory, but I'm missing a few pieces of information to make sense of it.

I thought the cold advance needed the throttle to be nudged forward after setting the switch to "run". Is the normal temp for the advance solenoid to come off around 160-180? That's when the sound goes away. In terms of pump timing, mine is advanced towards the driver side, but a very small amount and less than the previous pump at least. If it's not worth playing with and nothing is getting harmed, I'm completely fine with it hehe

Thanks for the input!

cold advance is automatic, no need to touch the pedal to se anything. The CA expires at 120, it’s controlled by the CA thermostatic switch on the right rear head. also turn up your idle to about 675-700, they idle better.

 

[jake20]

cold advance is automatic, no need to touch the pedal to se anything. The CA expires at 120, it’s controlled by the CA thermostatic switch on the right rear head. also turn up your idle to about 675-700, they idle better.

So theoretically speaking, if I disconnect the cold advance from the pump itself, should it sound different?