Engine idle "knock" ...

Sonix · **Posted:** Mon Nov 16, 2009 7:19 am

Yesterday the worst thing that could happen to a diesel, happened to me (well maybe there are worse things, but this was BAD) ... The engine oil level got waaayyyyy too low, and caused the engine to make a "knocking sound" when idling ...
After getting the oil level back to normal, the knock got a little bit quieter, but you can still distinctly hear it, when the engine is idling ... what could be the cause of the knock? The lifters?
I'm prepared to take the valve/top cover off, but if I'm going to have to take the top off, it's not gonna be funny .... I'll have to mentally prepare myself for at least a week before I take the top off (did it a year ago, when all 16 rocker arms broke)

ATXKJ · **Posted:** Mon Nov 16, 2009 8:21 am

it may be worst than that.

These engines do not like low oil

there have been at least 2 that have blown rods through the bottom of the engine

However the fails tend to be catastrophic

http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?p=430902#430902

http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?p=404827#404827

BlackLibertyCRD · **Posted:** Mon Nov 16, 2009 11:55 am

Sonix wrote:

Yesterday the worst thing that could happen to a diesel, happened to me (well maybe there are worse things, but this was BAD) ... The engine oil level got waaayyyyy too low, and caused the engine to make a "knocking sound" when idling ...
After getting the oil level back to normal, the knock got a little bit quieter, but you can still distinctly hear it, when the engine is idling ... what could be the cause of the knock? The lifters?
I'm prepared to take the valve/top cover off, but if I'm going to have to take the top off, it's not gonna be funny .... I'll have to mentally prepare myself for at least a week before I take the top off (did it a year ago, when all 16 rocker arms broke)

It would be best to pull the pan first. Stop running it until you fix the problem.

warp2diesel · **Posted:** Mon Nov 16, 2009 4:49 pm

Lifter click is half the Engine RPM and comes from the top of the engine.
Rod knock is the same frequency as the Engine RPM and located lower in the block.

onthehunt · **Posted:** Mon Nov 16, 2009 11:38 pm

Quote:

It would be best to pull the pan first. Stop running it until you fix the problem

X2

Learn from other peoples mistakes.

Quote:

However the fails tend to be catastrophic

http://www.lostjeeps.com/forum/phpBB3/vie ... 902#430902

http://www.lostjeeps.com/forum/phpBB3/vie ... 827#404827

geordi · **Posted:** Tue Nov 17, 2009 12:20 am

I'm not surprised that I was one of those links. The sound you are hearing is your engine politely saying STOP RUNNING ME. You have already done damage if it is ticking. That is what mine was doing before it completely grenaded.

If the engine hasn't detonated yet, I would pull the cylinder head and manually rotate the assembly to see what the pistons look like. It might be a bit extreme, but if it shows WHY the thing is ticking BEFORE you go through what I did... You are ahead of the game.

My engine detonated the #1 piston, the rod inverted after DEMOLISHING the cylinder sleeve... And it ejected the mess through the oil pan as was shown. I have the old block now, and will be taking pictures as I disassemble it... For parting out. I have come to the conclusion that the block that I bought IN my CRD is not worth the effort, and there is a strong possibility that the plan of putting it into my ZJ is also not worth the effort. I would need to completely fool or duplicate the computer-controlled nature of that engine to make it run on a rack, which is a requirement for me before I put that rack-running assembly into the ZJ's body. I may get crazy ideas if I blunder into a boneyard donor in the future...

But you don't want to follow me down this road. IT SUCKED.

Sonix · **Posted:** Tue Nov 17, 2009 4:48 am

ok ... I've used a automotive stethoscope to try and pinpoint the "click"
At the bottom of the engine there are no funny sounds .....
On the top-cover, I can hear the sound clearly, aspecially to the front ....so I'm almost dead sure it's one of the lifters that packed up ... Will start to dis-assemble the engine this evening ....will take photos of everything.... last year November when I did the same thing, I forgot about the photos ..
Once the lifter is replaced or fixed ....will I have to inspect the bearings on the crank at the bottom as well? ...even if the engine is running smoothe after replacing the lifter?

ATXKJ · **Posted:** Tue Nov 17, 2009 7:38 am

If you've isolated it to the lifter and it's smooth
then extra troubleshooting is likely to cause problems not fix them.

but if it's coming from the bottom end - there's not much of a time window before there's a lot of damage

warp2diesel · **Posted:** Tue Nov 17, 2009 8:13 am

In the US we never had a CDR before 05 and both the 05 & 06 call for synthetic oil.
If the 03 uses mineral oil it may be why the lifter failed, assuming the noise is a lifter.
In the old days, hydraulic lifters would ofter go bad before the engine needed any other major work.
I used to put a Chevrolet small block lifter into a role of nickles and leave it on the restaurant table when I had poor service, those days are gone:lol: :lol:

If you are using mineral oil and have had another lifter failure, this may be why VM switched over to synthetic oil.
A common cause of lifter failure was being gummed up from tired old additives, asphalt, or paraffin in mineral oil. Many snake oil products addressed this problem.
Synthetic oil costs more but does not have these problems.
Let us know so we can connect the dots.

Sonix · **Posted:** Tue Nov 17, 2009 9:58 am

I used synthetic oil for the past 12 months ... about 20 000km ...so I guess that rules that out (I replaced all 16 lifters and rockers 12 months ago, and after that only used synthetic oil)
I've been given the following "advice" .... what do you people think of it? :
I've been told to let the engine idle and let the oil warm up .... (CONSTANTLY listening if there's any change in the click sound) .... then turn the engine off and drain the hot oil (drain EVERYTHING out, so let it drain overnight and with the oil filter disconnected) ... then fill it up with new oil again and let it idle again till oil is hot ... apparently 80% of the time this will clear out any blockage on the lifter, and the click will go away .... if the click does NOT go away, I will have to open up and manually clean the lifter, or replace it ..
I'm just scared of running the engine, and all of a sudden BAM ... but I guess while there is sufficient oil , a seized bearing will be highly unlikely?

warp2diesel · **Posted:** Tue Nov 17, 2009 10:26 pm

Sonix wrote:

I used synthetic oil for the past 12 months ... about 20 000km ...so I guess that rules that out (I replaced all 16 lifters and rockers 12 months ago, and after that only used synthetic oil)
I've been given the following "advice" .... what do you people think of it? :
I've been told to let the engine idle and let the oil warm up .... (CONSTANTLY listening if there's any change in the click sound) .... then turn the engine off and drain the hot oil (drain EVERYTHING out, so let it drain overnight and with the oil filter disconnected) ... then fill it up with new oil again and let it idle again till oil is hot ... apparently 80% of the time this will clear out any blockage on the lifter, and the click will go away .... if the click does NOT go away, I will have to open up and manually clean the lifter, or replace it ..
I'm just scared of running the engine, and all of a sudden BAM ... but I guess while there is sufficient oil , a seized bearing will be highly unlikely?

Use a mechanical gauge, don't trust sensor readouts that go through the ECM and are passed onto a scanner. Sensors lie like politicians. If your oil pressure is below spec it may be what is causing the lifter problem. Also check your cam lobes, make sure they are not worn down.

Good Luck

geordi · **Posted:** Tue Nov 17, 2009 11:13 pm

Warp is right on. That was what I first suspected when I heard the ticking on my engine... The sender for the ECU's pressure reading is mounted opposite the filter. VERY easy to find, and if you wanted to install your own gauge sender on a T connection... This would be a nice place to do it.

That said... Chances are, you are up to your eyeballs in oil pressure from that point in the system. The problem I see with this design - The sender is mounted at the BOTTOM of the system, almost directly in front of the filter's outlet. So it is getting POUNDED with pressurized oil all the time... Even if you only had 1 quart in the system, where is most of that gonna be after it gets picked up by the gear-driven pump? Right into that sender!

What it isn't going to tell you is how much pressure (and lubrication) is making its way to the TOP of the oil galleries to get the bearing surfaces.

What I think did my engine in, was a lack of oil flow (even while the idiot light never came on!) and loss of pressure into the rod bearing's passages b/c of the bleeding out the turbo... Which is directly connected to the #1 cylinder. Cause a pressure drop (leak) on one end of a split tube, is the other gonna maintain pressure and flow? Nope! Simple fluid dynamics, leading to catastrophic damage.

I REALLY hope yours doesn't end up like mine did. With any luck, you just had a cylinder pressure change that damaged a rocker, and that is what is ticking. But there isn't any way to know. What I have learned the hard way is: These do NOT fix themselves. If you have a noise, it won't go away without some work. If it does... Beware: It may have just gone to collect reinforcements for the real frontal assault on your wallet.

warp2diesel · **Posted:** Wed Nov 18, 2009 12:24 am

Prayer, deep thought, and meditation are known to generate stem cells to heal and repair the human body. Unlike our human bodies, engines don't have stem cells and none of the snake oils will generate stem cells. The only snake oils that work are lubrication additives and those who produce lubricants are always on the hunt to find a snake oil additive that works even better.
Find the part that has failed and replace it.
geordi is right.

Sonix · **Posted:** Wed Nov 18, 2009 2:34 am

I guess you'll see some photos of a stripped engine then soon ... :roll:

Thanx for the advice ...

Joe Romas · **Posted:** Wed Nov 18, 2009 7:37 am

One "snake oil" I found that works is/was RESTORE :lol:

It's main ingredient use to be ZINK but that's been removed to avoid catalic converter damadge.
I owned a knocking 96 high mileage XJ. So I replaced the rod bearings using assemblie lube that contains zink. The engine was a quiet as a church mouse... till I changed the oil and it was back :oops:

Then I found restore but I have no idea how their new formula additive is. Lucas markets a Break in and assemblie oil. I've used it to quiet down a couple of single cylinder Chineese diesel engines and it seems to work. Other then the XJ that it worked in instantly I have no long term experience. I saw a report showing zink levels in motor oils and Shell Rotella contained the most but it did not specifify white or blue bottle.
Zink protects cam and lifter contact damadge :wink:

nursecosmo · **Posted:** Wed Nov 18, 2009 10:48 am

Why did it get low?

Sonix · **Posted:** Wed Nov 18, 2009 2:21 pm

Looks like there's a oil leak somewhere .... the car stands on grass during the evening, so I didn't notice the oil leaking ...maybe if I did my normal service like I was suppose to 3 weeks ago, this wouldn't have happened ....so I can only blame myself ... :cry:

warp2diesel · **Posted:** Wed Nov 18, 2009 5:21 pm

Joe Romas wrote:

One "snake oil" I found that works is/was RESTORE :lol:

It's main ingredient use to be ZINK but that's been removed to avoid catalic converter damadge.
I owned a knocking 96 high mileage XJ. So I replaced the rod bearings using assemblie lube that contains zink. The engine was a quiet as a church mouse... till I changed the oil and it was back :oops:

Then I found restore but I have no idea how their new formula additive is. Lucas markets a Break in and assemblie oil. I've used it to quiet down a couple of single cylinder Chineese diesel engines and it seems to work. Other then the XJ that it worked in instantly I have no long term experience. I saw a report showing zink levels in motor oils and Shell Rotella contained the most but it did not specifify white or blue bottle.
Zink protects cam and lifter contact damadge :wink:

As we all know aldehydes stink and make any Diesel smell more pungent. If they can damage the converter, I suspect they get into the combustion chamber.
As far as human or animal health issues go, many of us need in Zinc in our diets. Also zinc helps remove other heavy metals like lead from our bodies.
So the greenie winnies can go eat some zinc free dirt.

nursecosmo · **Posted:** Wed Nov 18, 2009 7:33 pm

I don't think that aldehydes are commonly found in diesel fuel or additives (in any appreciable quantities), nor should they damage the CAT. They are however a byproduct of catalyzed biodiesel exhaust gas. They are one of the components of those pungent eye-burning fumes you get when bio is burnt in the CRD. That is the primary reason for which I gutted my cat.

warp2diesel · **Posted:** Wed Nov 18, 2009 7:57 pm

nursecosmo wrote:

I don't think that aldehydes are commonly found in diesel fuel or additives (in any appreciable quantities), nor should they damage the CAT. They are however a byproduct of catalyzed biodiesel exhaust gas. They are one of the components of those pungent eye-burning fumes you get when bio is burnt in the CRD. That is the primary reason for which I gutted my cat.

Or is someone making a new perfume called biodieselaldahydenstink?
My point is zinc acts like a cataylist to produce aldehydes that stink, at least that is my opinion.
Does yours differ?

Engine idle "knock" ...

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