Engine Knock (rattle)

[78ScottsdaleK20]

Hello and new to forum.

Just picked up a mechanics special 99 Leganza with a 2.2L for dirt cheap. There is a slight intermittent knocking (rattle) sound coming from the Cylinder head, (I confirmed this with a stethoscope). The noise is present when engine is cold and at higher RPM's, but not through the entire RPM range. It seems more apparent at low to mid RPM's and mostly goes away when engine is up to temp, but still there when RPM's are raised.

Engine has 95k miles with a Timing belt change about 30k miles ago. Any thoughts on what it could be? I am leaning towards a bent valve, bad lifter, or a flat lobe on the cam, resulting in some play, causing the knocking (rattle) sound. I plan on pulling the valve cover to see if anything is obvious, and if nothing found, off with the head.

I am used to working on pushrod V8's, so any advice or anything to watch for would be appreciated. Yes I did do a search on the forum for help with my particular problem, but cant sit in front of the puter and look at 600+ pages of posts.

I plan on replacing the Timing Belt, pulleys, and W/P as I have learned its criticallity (is that a word?).
Thanks in advance for any advice comments or suggestions.
Mike

[daewoomofo]

do you hear any backfireing? if not i (personally) dont think its a bent valve. if a valve is bent you will get back fireing (if its an intake valve you would hear the backfires through the throttle body, if its an exhaust valve yo would hear it through the muffler) im not saying that it isnt a valve but thats my thought process. it kind sounds like a worn cam to me or a bad valve spring. how does the car run other wise?

[mr_g]

It's hydraulic valve lifters. no biggy.

[MMamdouh]

It's hydraulic valve lifters. no biggy.

+1

MMamdouh

[78ScottsdaleK20]

Thanks for the replies. The car runs just fine. Just makes that knocking (rattle) sound, and I am afraid to keep driving it for fear that I will do more damage than what is going on in there currently. So when I go to rip the valve cover off is there anything I should be looking for? If nothing found, when I rip the head off, what obvious things should I look for?

Thanks again, and I will post any findings when I got to tear into this thing.

Mike.

[Spider]

If it's a "ticking-tapping-clicking" sound that you hear when it first starts (cold engine) than goes away when it warms up?
It's is probably a lifter that is weak and/or dirty and not pumping up right away. Possibly collapsing.

Try changing your oil and filter.
Twice!
The first time add "Marvel Mystery" additive to it (or about 6 ounces of ATF, no more that that) drive it for a few hundred miles and change the oil and filter again.
A "rattle' could be "piston slap". Thats a piston going side to side in it's bore.
Or another possibility would be "pre-ignition" (pinging) caused by excessive carbon deposits on the valves and piston tops.
Try some injector cleaner for that (like "Sea-Foam" or "Barrymens"B-12")
Also, the sound could possibly be "rod knock" (loose/worn rod/s) but if you hear it on the top-end only? Rod knock is doubtful. Rod knock is more of a rapid "knock" sound. Usually heard on decel. Run up your rpms (in natural) and than let off on the gas quickly to test.
If the rods are loose they will rattle on the decel.
Change your spark-plugs too. Check out the old ones, they should be a lite-cardboard tan in color. (see link)

spark-plug info:
http://www.verrill.com/moto/sellingguid ... rchart.htm

[78ScottsdaleK20]

Thanks for everyones replies. I know this is an older post, but I havent had time to tinker with it lately.

I just changed the oil and filter, from 5w30 to 10w30 and it seems to have gotten worse. It has a ticking or rattle sound near the head (like its valvetrain), then when you raise the rpm's quickly and rev it to 2,500 - 3,000 revs you will hear the loud rapid knocking.

My question is what weight oil do you guys use and have good experience with. I konw these motors are zero clearance so the proper weight and viscosity goes along way here.

On another note...where and what (brand) of parts (valvetrain) are of better choice. How come Schucks, Napa, and other parts tores are so much more expensive than E-bay. I could get a valves (16) and lifters (16) both for around $250 us on E-bay. This seems cheap but are they poorly built and of poorer quality?

I would hate to buy more expensive parts only to have a freak timing belt break and destroy the new parts. And once I have the head off to replace valvetrain components I will do a timing belt as the current one has about 20,000 - 30,000 miles on it.

Any and all suggestions would be appreciated.

Thanks
Mike

[daewoomofo]

this might sound kinda funny but remove the serpantine belt and the ac belt. i remember once in high shcool auto shop a person donated a really nice car to us saying it had a rod knock. it turned out to be the ac compressor going bad. it sounded like a rod knock but it was the ac. ive also heard of altenators and p/s pumps doing that. so i say run it for a minute with no belts on. dont go to long cause you will drain the battery if you do.

[78ScottsdaleK20]

Thanks for the reply and the outside of the box thinking. However I am absolutely positive that this noise is coming from inside the head. #1 You can feel the knock on the head #2 Sound is more prevelant from the Intake Manifold-maybe cuz its aluminum its acting like a speaker for the noise.

I think I'll change the oil again later today back to 5w30 see if the noise goes away a little. If so, and I can get it to change noises by simply changing oil weight, I can be sure its internal.

Is there any brand of gasket sets out on the market (E-bay) that I should stay away from dur to low quality. I saw there was two identical complete gasket sets for the X22SE motor-one was as low as $39 and the other as high as $149. What's up with that?

Anyway once I get my head wrapped around pulling the head off and have an idea of what parts I absuolutely will need to replace, I will proceed with tear down. Anyone have any pointer or tips on a head job?

I know that there is a guy on E-bay that sells rebuilt heads, maybe that's the way to go rather than putting all new parts into my old head.

Any and all suggestions would be appreciated.

Thanks in advance

Mike

[daewoomofo]

call around to machine shops in your area adn get a quote for getting the head redone, if the ebay is cheaper get that

[AntDX316]

its piston slap my car has it cause it cause it was used

i used a lifter fluid fix but the noise was still there

i also used lucas oil stabilizer and 10W-30 but the noise was still there

when the engine was cold and running i poured motor oil in the engine the noise goes away then comes back after a few seconds

people who have seen cars with symptoms of piston slap thought it was rods or lifters and the car would give way at any time but there was this guy who said the car lasted well over 100 or 150 thousand before being sold when it had the problem at 50 or 80k miles

[78ScottsdaleK20]

So I did a search on "Engine Knock Diagnosis" on my toolbar and found this interesting read. I think this could be valuable information for those owning woos since this can be commonplace.

[/url]http://remanufactured-engines.com/page4.htm

So I did a couple of checks and this is what I found.

1. I removed the spark plug cover and removed one spark plug at a time starting at right most plug moving left (#4, #3, #2, #1) , and put a couple of drops of oil in the comb. chamber. Started the engine and listened. The noise did smooth out a little but still remained.

1a. When removing the spark plugs, I found oil at the base of the plug. Is this normal? There was more oil on #1 and #4 then the others. When the plug was removed, liquid that looked like oil but was more runny, dripped off the end of the plug. #2 spark plug was white=leaner A/F condition...not sure why that cylinder is leaner than the others. The others were spot on looking light brown (tan).

2. I hooked a timing light to each plug one at a time starting at #4 then #3, #2, and finally #1. I marked the Crankshaft balancer with a yellow crayon and checked to see if the knock noise was matching up with the flashing of the timing light. It was matching spot on=MORE THAN LIKELY TOP END COMPONENTS (valvetrain). Since the top end components move at half the pace of the bottem end components.

If the noise was not matching up with the timing light, like faster, then it would=Bottem end components.

Well, I think I will feel a little easier when driving the car, since I dont feel like using 5 gallons of fuel a day just to get to work and back home. At $3.75 a gallon with the 300 horsepower V8 in the ol 78 Scottsdale. I'll take my chances.

If it is indeed a valvetrain comp. like a lifter or spring or even spring keepers, then it will more than likely hold up for a while if babied, until I can order some parts and repair it. If it is a rod knock or piston slap, and she blows, it would have needed to be replaced anyway, and Im not sure if it would have been worth sinking the money into it.

I'll take my chances. When I break into it, and do the repairs, I will report back with findings. Who knows, maybe this will help another woo-er down the road.

Thanks for the replies, and any other suggestions or comments are appreciated.

Mike

[78ScottsdaleK20]

Another test I performed was I shorted each comb chambers to verify if the noise either continued or subsided.

Supposedly, if there is no combustion, and the noise goes away, then its the bottom end (piston slap or rod knock).
If the noise continued, then its more than likely not the bottom end and its the top end (valvetrain).

This is not an end all complete test, just some preliminary tests. It settles my mind enough to drive, hopefully not until it blows up on me. We'll see...

Mike

[MazdaX]

Don't mean to hijack the thread but I have the same thing. I was looking for some answers - I have a 2000 Nubira 16V , the timing belt plastic bearing tensioner thing broke and I had a shop here repair it in Utah and now after the timing belt , new valves and tensioners , there is a loud banging coming from my engine. Car only has 61,000 miles and ran like a dream before with no symptoms. I will possibly post a vid.

As ig goes -> Start car -> Idle -> knock knock knock , bang bang bang , rattle rattle rattle , knock , rattle , bang. In random orders :/

[78ScottsdaleK20]

So did a repair shop do the repairs to the timing belt issue. If so, was the car making the noise when they gave it back to you? I cant imagine a repair shop would give a customer their car back if the engine was making the noise you described.

On an important note: ANYTIME the Cylinder head is removed, one MUST TAKE CARE NOT TO GET COLLANT IN THE COMB CHAMBERS. If this happens and is not removed completely, the coolant and engine oil will mix into essentially an acid and eat away at the lubrication properties of the oil and etch your bearings essentially leading to either rod knock due to the now excessive bearing clearance, or the acid will eat away at the cyclinders and walls possibly leading to pistion slap.

The artice I posted earlier, addresses this issue, and anyone else I have talked to about it cant stress the importance enough not to get coolant in the comb chambers, because it will ultimately lead to catastrophic failure.

Good to know info...

MazdaX...if you do some of the above mentioned preliminary tests, and add in there taking a stethoscope and putting on different engine parts you should be able to narrow down exactly where and what parts are the culprit, if nothing else, be able to narrow it down to top end or bottom end. But should be able to pinpoint EXACTLY what is going on even if your mildly mechanically inclined.