worrying knocking noises from KLZE

[Jforce]

Hello,

I've got some knocking going on in my engine bay.

here are some vids of it:
http://www.youtube.com/watch?v=I0S44JmmrxI

in this on i'm holding the rmp steady:
http://www.youtube.com/watch?v=0qKPvIpJ5LI

Already changed oil, didn't help.

Any thoughts?

Thx

[Ryan]

Where is it loudest? Back? belt side? If you're lucky it is the timing belt tensioner, but it sounds pretty heavy...

[Jforce]

Yeah, its the loudest at the back. Guess middle cylinder on the backside.

thought about TBT too, but its hard to pinpoint. Its quite loud.


what if i'm not lucky? Rod Knock?

that would suck only got this engine for 5 months, never run on low oil, dont burn any oil.

and also no coolant i think never had to refill. dont have white smoke when its heated. Do have white smoke on startup:
http://www.youtube.com/watch?v=UZgZobTJYh8

No power loss, block is a little shacky on idle though

[DeadMaker]

White smoke is natural on startup on winter days or in days with humidity.Specially in the morning..
So if there is no smoke with hot engine don't worry about that.

[Jforce]

ok, something i forgot to mention about the knock, it seems to stop at 3000rpm +, or at least unhearable over the other engine sounds.

[wytbishop]

Assuming it's not the belt tensioner...and if its coming from the rear middle cylinder it probably isn't...there are a couple most likely scenarios.

1. Pre-ignition: this is usually caused by an excess of carbon build up in the combustion chamber, which gets very hot and ignites the mixture before the plug fires. The knock comes from the force of the early ignition pushing the piston and rod back down against normal rotation (because the piston isn't in the intended ignition position yet) and it bangs against the bearing essentially destrying it in very short order. Pretty bad.

2. Detonation: this is the "re-ignition" of the burnt exhaust gases in the combustion chamber before they exit the exhaust valve. Excess heat and pressure in the chamber cause the gases to spontaneously combust and it's the little explosion that you hear as a knock. The trouble here is that it makes things very very hot in there and will eventually melt a hole in your piston. Also very bad.

Here is a good article about it. This might help you understand what's happening. http://www.contactmagazine.com/Issue54/ ... asics.html

[Jforce]

thats some hardcore stuff, i would never think of things like that lol

so what would i do about that stuff?

And here's a scenario of the whole thing:

Jan 2011: bought a ZE, heard it running, super quiet.
Jan 2011: ZE build in my car, swapper filled it with 10W40
Feb 2011: No Problems
March 2011: Ticking noise started to occur at startup 5 sec long.
March 2011: Ticking noises stayed for like 15 min, although after a long drive it would stay away for a week or so.
April 2011: drived on with sometimes the tick.
May 2011: Thought 10W40 might be the cause, so bought some 5W30 and put in. Knocking didn't stop.

Also when im driving its like:

knock,knock,knock...........(3-5sec nothing).........knock,knock,knock..............(3-5sec nothing).............

[wytbishop]

If you have pre-ignition it would usually mean that the engine is very dirty inside and you might have to take it apart. Seafoam might help, but some people have reported scary results from cleaning the engine this way. There are a number of fuel additives you can buy that will attempt to decarbon the combustion chamber. I don't know how well any of them actually work.

Detonation is tougher because there are so many factors that can cause it. Detonation can be very mild and may not even be a problem. If ou eliminate other causes and haven't solved it I would have a mechanic look at it.

Your noise could also be a single siezed or just a really sticky lifter at that cylinder. You could try an engine cleaning type oil additive and see if that helps. I would change the oil to 10W40HD oil. This is High Detergent oil. After about 2 hours of running time it will come out black as night. So go for a decent drive with the HD oil and then change back to your standard 10W40 and a new filter and see if there's any difference. That's the first thing I would do because it's cheap and it can only help.

[Jforce]

Can't get seafoam here, know about that stuff. Tried to get it for my k8.

But youre talking about carbon knock i guess, would be strange this thing was clean as hell. One of the best running ZE's, according to the importer of the blocks.
Also the guy who build the engine in said it runs great, which i agree too. Great low end power, pulls all the way (which i didn't do lately ofcourse ).

But the knock, strange noise. Doesn't sound like any rod knock i've heard, because those knocks are on idle too and there pretty loud, i was pretty close with the camera and its records High Definition. The noise isn't that loud that you can hear it clearly like in this video:
http://www.youtube.com/watch?v=SIrsDEDC9Tg

10W40 couldn't really mess it up like this i guess.

here's a video i made earlier with the 10W40: http://www.youtube.com/watch?v=qqJuGOpUtF4 on cold start, barely audible.
But 2 days later it knocked like the other video for 5 minutes. But the weeks after that i didn't knock for a while.

I swapped the k8 for the same reasons lol, different knock but also not the lifters.

Already have added an cleaning additive for the HLA.

i'm alway's running 98 octane gasoline.

Unlikely to be an lifter i guess
Its pretty loud for an TBT i agree

So how does that friction gear noise sound?

But first i will check the timing belt tensior, and maybe take off the valve cover, and check the rodbearings.

[wytbishop]

it's pretty easy (in theory) for a lifter to collapse. I wouldn't count it out.

The engine itself might be very clean but if it's a bit rich you could have a lot of carbon in the combustion chambers. Pre-ignition is pretty common. Have you looked at your plugs? If they are black with any build up that would indicate at least some carbon build up.

If you haven't I would pull the plugs. You can learn a lot about what's happening in the combustion chambers from the condition of the plugs.

[Jforce]

yeah i will check that good idea.

i'm running on "standard" kl31 ecu, they always run rich this way i heard.

It does NOT stop by 3000rpm like i thought earlier.

here's a plug, looks ok i think.

[Jforce]

Well i've just driving a while on the highway today, the knock dissapears after 10-15 minuters highway.

parked the car for 6 hours started again no knock.

But after a few days of driving short distances it comes back, at least that was the case with the 10W40 Oil.

So i'm guessing it will be no differt with the 5W30.

So this would point more to a very bad HLA i guess?

[wytbishop]

That plug looks ok. no carbon, no oil build up and no damage. So that cylinder at least is probably pretty clean.

I would say bad HLA is the most likely. Other than that you start getting into the wierder more serious stuff.

[Ryan]

Rod knock can be sneaky. I've seen engines that make a little knocking noise, and then it goes away... and comes back later, and eventually it chucks the bearing.

Your options are pretty limited though.

Listen like crazy on the belt side. FGS's are on the top end, you can pretty much rule them in or out by deciding if the noise is coming from there or not.

TBT can be best heard from jacking it up and taking off the passenger side wheel, and that little bit of splash guard. If the TB covers weren't on, you could see it.

Your plugs look pretty minty, so I doubt its detonation

If there are any shavings in your oil (maybe saw your filter in half too to check) then I'd suspect bearings

That 10W40 is too thick for our motors unless you live in Hades or plan on racing the shiz out of it. That could have starved her a little at startup causing bearing issues. Not terribly likely, but a possibility.

HLA's are a pain, but if you just remove the valvecover and poke it with your finger, you can diagnose it. It should squish just enough that you know its squishing, less than a mm or so. If it collapses entirely, the check valve is gunked and not working, and if its rock solid, its seized. Both conditions are bad and can be noisy.

Could be piston slap, but we don't really have that problem, ever. Mazda did a good job with stock clearances. Most 200k engines come out with just a little skirt scuffing and nearly perfectly round sleeves.

Rod bearings you can diagnose by dropping the oil pan, windage tray, and taking off the rod cap to inspect the bearing. This is by far the most pain to check, leave it to last... The work is messy and upside down, and the bolts are next to impossible to reach even with the motor on a stand. I took the block halves apart first.

[Jforce]

yeah 10w40 is too thick, thats one reason why i changed it. Possibly to late

To replace the HLA's u need to remove the cams right, and the timing belt for that. Something i can't do myself.
Also crap that's its on the back side, then i've have to remove the intake too.

couldn't see any shaving in the oil.

But its more like something gets stuck, I use the car to go to work wich is only like 5 miles.

so like 3 times a week its only drives 5 miles, if i take it for a good drive its like i said gone.

Because i'm still in school, i'm able to go to school for free with the train here.

So maybe i'm not driving it enough?

Well i'm least going to check those things u guys mentioned, but for that the knock first has to come back, hehe