Rod knock Question (with pics)

[jukematt]

I was driving to the grocery store and heard a slight knocking sound. I popped the hood and it sounded like it was coming from right under the valve cover. It would also not do it at idle but only if the RPMs were at about 2000 or higher. They would also get louder and faster the higher the RPM.

Well, it sounded like it was coming from cylinder one side and I drove home and hadn't driven since for fear of some kind of damage (I drove MAYBE ten miles since I first heard it). My buddy said to pull the spark plug wire to see if the sound goes away. Well, after shocking myself trying to remove it with the car running, I shut it off, removed it, then started. I saw what looked like a mini lightening bolt going from my coil pack as it tried to contact a metal surface. And I could still hear the noise when revving the engine.

My buddy came over and I revved the engine again at idle (though this time it was quieter and could only hear it a little at certain RPMs past 2000 instead of the increasing speed and tone at higher RPMs which was weird). He said it sounds like rod knock and when he listened, he said it sounded like it was coming from cylinder four area. I only tested cylinder one though. Well, we got my car to his house, jacked it up, and I proceeded to follow Haynes/Chilton to remove the oil pan and all that to get at my crank. I took pictures along the way:

Rod Knock

The damage seems pretty bad for only driving a short distance once I first heard it.

On to my question.. From the looks of it, I think I had multiple bad bearings and possibly spun both a main and at least one rod. Is there anything else I should look for? Or should I just follow people's recommendations when I searched and drop the tranny, pull my crank, and have a machine shop inspect it, polish, etc? Like would the damage be caused by only the bearings or something else?

Sorry for the essay.

 

[richard33]

On to my question.. From the looks of it, I think I had multiple bad bearings and possibly spun both a main and at least one rod. Is there anything else I should look for? Or should I just follow people's recommendations when I searched and drop the tranny, pull my crank, and have a machine shop inspect it, polish, etc? Like would the damage be caused by only the bearings or something else?

Sorry for the essay.

First you need to find out why this happened. You dont want to assemble a new motor for this to happen again right away. That crank is probably trash unless you want to cut it. You need to take the motor out of the car and clean everything really good too. Those metal flakes got circulated throughout the entire motor.

Pretty much you need a new engine and I wouldn't reuse anything from that one of importance.

 

[doubleclutch99]

It looks like good old fashion oil starvation to me. possibly oil contamination. either way it's a bottom end rebuild. also if you do rebuild on this engine or any other going into this car, you should make sure the oil cooler is clean as well or purchase a new one. i've seen where people forget that part and then can't figure out why their new engine developed a knock after only a hundred miles. just a thought , good luck.

 

[CrawlinZX14]

Well im a little concerned after reading your comments on the pictures. That green thingy you were talking about was an axle shaft. That tray under your oil pan is called a windage tray. it keeps oil away from your crank causing parasitic loss. Further more, it looks like oil starvation or a spun bearing based on that first main with the gouge all the way from retainer to retainer. The distortion in the bearings is when they didnt get oil and you over heated them. They became pliable and the forces put on them caused them to flatten and thin out. as they would thin, they will hit a spot where they would start to curl up. Im surprised you didnt seize your motor with that kind of damage. That is not from just going to the grocery store either. That is weeks of damage. Unless you were racing off every light and making good power doing so.

Its time for a rebuild no matter how u cut it. You need to pull that motor and have it tanked, cleaned and fluxed for cracks and damage u cant visually see. You are going to def going to need to atleast have your crank cut and micro polished, and you may also need to replace your rods. If you replace the crank, you will need to line bore the engine. If you cut and polish the crank you need oversized bearings based on how much material has to be removed, but that extent of the damage is likely a new crank and new main caps. Sorry to see the damage, and its def going to not be a cheap fix. Good luck

 

[gixrman]

Since you have '99 split thrush bearing 63 I would not get rid of that block. Check the crank journal for scoring and specs.do not cut the crank they never turn out right. Replace it with a evo8,9 crank if you have to.

 

[jukematt]

Wow lots of good information I hadn't thought of.

richard33, How do I find out why this happened? By inspecting my bottom end or what?

doubleclutch99, thanks I hadn't thought of the oil cooler in this mix.

CrawlinZX14, I am still learning as far as anything under the car or inside the engine. That's why I didn't know what the "green thing" was and I wasn't expecting that tube coming down since I had never removed my oil pan before or the windage tray. I wasn't racing, I did do a couple of logging runs. She was fine after the run but the noise started a couple of days later the first time I drove her again.

What is "tanked", and "fluxed"? From searching, I found I'm most likely going to need to remove my crank to have it inspected and all that. I also don't know what "line bore" means. When you say, "cut the crank" do you mean have any grooves smoothed out? And yeah, I haven't bought new bearings yet due to not knowing what size yet.

gixrman, Yeah I didn't want to get rid of the block either for that reason. The journal actually doesn't seem that bad. A few lines but I can't feel them with my finger. I also didn't know we could use an Evo 8 or 9 crank. That will probably be expensive. I'm running on a very tight budget which is why I'm doing all the work myself with a friend nearby if I need help.

 

[CrawlinZX14]

Tanked is hot tanking. Fluxed is magna fluxing, which finds cracks and damage you cannot see with your naked eye.

If you are running a very tight budget you would likely be better off picking up a good used engine.

 

[Ghost_92TSi]

Check the turbo for shaft play. I destroyed mine after spinning a bearing

 

[g4ebguy90]

Yea looks like a oil pressure, starvation problem to me. Kinda sucks, cause when my car lost oil pressure, it only affected cyl 3, but it only knocked for about 10 seconds before I shut it off. The other rods were affected but mainly 3 took the hit.

 

[jukematt]

I have a friend who has a '96 block in their storage with about 50,000 miles. I didn't really want to get rid of my '99 but that would be a last resort. If I need it, they also have a '99 head with ~220k miles as well. I assume hot tanking and fluxing must be done by a shop? I do have some connections through some friends so maybe I can get a good deal.

Chris_92TSi, I heard of people doing that with spun bearings, I will check.

There was also a guy in the classifieds with a '99 crank but I wasn't sure if I needed it and if that would be all I need (aside from bearings).

*EDIT: What really stinks is I know a guy who has a 2G Talon TSI AWD which had rod knock. He drove around, raced, autocrossed, etc. for a year and a half before taking it apart! He said he reached in and sanded the crank like crazy and bought new bearings and hasn't had a problem since. He's going on 50,000 miles now since he did that!

 

[gixrman]

gixrman, Yeah I didn't want to get rid of the block either for that reason. The journal actually doesn't seem that bad. A few lines but I can't feel them with my finger. I also didn't know we could use an Evo 8 or 9 crank. That will probably be expensive. I'm running on a very tight budget which is why I'm doing all the work myself with a friend nearby if I need help.

You can pick up a crank used from an Evo guy doing the 2.4 crank swap. Also the Evo cranks are supposedly 5lbs lighter.

 

[jukematt]

You can pick up a crank used from an Evo guy doing the 2.4 crank swap. Also the Evo cranks are supposedly 5lbs lighter.

And they are a direct fit? Where would you find one? Evolutionm?

 

[gixrman]

I've seen them listed on eBay but I'm sure you can find other sources. Yes they are a direct fit into a DSM seven bolt motor. I'm collecting parts for de-stroked 2.4 (2.1) build and this is the route I'm going with the Evo crank.