Motor Rattle

[rocketscience]

My recently purchased Tercel has a rattling, clacking noise, it almost sounds squeaky like a belt when I'm driving. It gets better after a few minutes of driving and is only really evident from 2-2.5k or so. I never hear it at idle and only do hear it when I put it under load, ie pressing the accelerator. I recently bought this car and didn't notice the sound at all when I bought it, noticed it the next day. I first suspected the fuel pump cause I can hear it ticking away at idle but tried the screwdriver to my ear trick and couldn't say that was it, its hard to tell but I don't think so. Now I'm thinking piston slap, mostly because people here say it goes away when warm. Maybe even bearing or rod knock? I have the valve cover off right now (checking lash), everything is pretty close but a couple were a little loose and a couple a little tight, and I'll try pulling the spark plug wires one at a time when I get it back together.

The car is an 83 SR5 with 268k.

Here's a link to a sound recording of it. I was having a hard time with my ipod recorder and the car got too warm to hear the noise, to give you an idea of how long it takes for it to warm up too much to hear it (5 mins). Lemme know if you have any problems with the audio, I moved the mic around a little, about 2/3 of the way through it's closer to the back of the motor and the fuel pump.

https://soundcloud.com/rocketsciencesou ... se/s-vPGlk


Thank you!!!

[Gottolovem]

Have you done a compression check of that motor?
It sounds tierd

[rocketscience]

No but that's what I'm planning next.

I recently put some seafoam in the oil and then changed it hoping that would help clean it out a bit and have some MMO in with the current oil but was planning on going to 15w-40 delvac soon with some restore, if it is piston slap maybe that would help. The old oil was plenty dirty after I seafoamed it but there are no metal particles in it that I could detect.

Also, when I changed the PCV valve I realized that the old grommet was broken and found a piece of it under the valve cover, which I fished out. The piece that was still there and the piece I could see under the cover where not the full thing, but now with the cover off I haven't noticed any bits, but there is a pretty large amount of dirty oil pooled up on the head, is it possible an oil passage is blocked? The oil on the dipstick looks a lot cleaner than this.

[irowiki]

Might be valve adjustments.

Dirty oil in the head is normal, that is "sludge"

To clean the sludge, you can try the following:

few quarts of cheap ATF
several quarts of a cheap, high mileage oil
four quarts of whatever oil you want to end up with
Get a few good oil filters (like the fram tough guard)

Get oil HOT, like drive for 30-60 minutes.

Drain oil, change filter, put in 33/67% ATF/Oil

Get it hot again, drive a bit, easy on it

Drain it again ... change filter, more oil and atf, same story

Drain it again, filter, final oil in her

[rer233]

Typed a response to your first post last week, but somehow it got deleted before it posted (prob my screw-up.) Anyway, years ago, my former GF's '84 FWD wagon was making a similar noise (sounded EXACTLY like a rod knock.) I was ready to condemn the engine 'till I investigated further and found the crank pulley bolt was not tight. I removed the pulley and found the pulley, woodruff key, and crank timing belt gear were toast. Also, the keyway in the crankshaft was a little boogered-up.
Being the adventureous (and lazy) sort, I replaced the three shot parts with good used ones I had, and reassembled with plenty of loctite. That was probably 13 years and 60k miles ago, and the engine's still running good today.
Your noise, coupled with the discrepency of your crank timing marks sure indicates a similar problem. My advice is- pull the crank pulley and check it out.

Good luck, hope this helps, and let us know how it works out.

[rocketscience]

Oh yeaaah, I read a post you wrote about that a while back and was wondering if that could be it. Okay, I'll do it. I'm putting in a new radiator today or tomorrow (old one's cracked) and I'll do that while its out. And start looking for parts. Thanks!

[rocketscience]

I haven't quite gotten around to pulling off the crank pulley and checking it (hopefully tonight) it but I do have an update. I cleaned up the valve cover really well and tried to get as much of the old oil out of the top of the head. It was actually pretty clean, not really any gunk. Put the valve cover back on and idled it to get it warm for a compression test, it was a little more rattly at first start and then quieted down and seemed (could have imagined it) to be quieter when I reved it. I'm also think it still couuuuld maybe be the fuel pump, I tried listening for a while while revving and it could be.

Anyway I did the compression test and they came out as such:

1: 132/135 w/oil
2: 140/140 w/oil
3: 135/140 w/oil
4: 135/140 w/oil

Not great but not as low as they could be. I'm gonna seafoam again and change to some 15w-40 and try some restore before my next long distance drive (read that Petros says its better to use before a long trip so it can't settle out). Thanks y'all I'll keep you updated.

[irowiki]

In the end, it has 268k miles. I don't think you'll ever have it sounding like new.

[Petros]

that compression if fairly even, and the fact it hardly rises when you add oil indicates it likely could use a valve job. though it is not really bad enough to change it out now, but if for some reason you have to pull the head off, replacing the exahsut valves, and having the intakes and all seats reground, should bring the compression up much higher.

if it is piston slap, some oil thickener like STP should help. piston slap acts like a harmonic, it gets louder and than fades out as the rpm goes up. It could be ping or preignision, this is not rythmic sounding, but more a crackling noise when under load or hard acceleration. Switching to premium fuel might solve the problem.

Good luck.

[Petros]

I just listened to your sound clip, that actually sounds like an exhaust leak to me. when is up near the exhaust manifold it could sound like a ticking noise.

with it idling put your bare hand around the head pipe gasket (do not touch it!) and see if you can feel the warm puffs of exhaust gasses.

[irowiki]

Best to do that while it is cold, I've found.

[larry mcgrath]

Remove one plug wire at a time, if it is piston slap or a wrist pin you'll be able to isolate it to what cylinder it 's coming from Larry

[xirdneh]

also, a cracked piston will make noise untill engine warms up, i have had a couple of tercel engines that had cracked #3 pistons. drove one for 6 years like that before i pulled the engine and took it apart.

[rocketscience]

Finally get to mess around with the car today. I pulled the plug wires and the noise stopped when I pulled #4, I'm guessing some kind of piston slap or cracked piston, I'm guessing it's not worse than that because it stops doing it when warm. Didn't notice any air puffs around the exhaust but might could have been more thorough checking. I totally understand that this car has a lot of miles on it and it probably isn't gonna sound purrfect, I just like to try to diagnose possible problems. I'll probably let this ride for a while until it gets worse or I need to pull the motor for another reason, hopefully not anytime soon, and will use before mentioned oil thickener to try to mitigate it. I'll let you know how that goes when I do it. Also gonna pull the crank pulley today and I'll let you know what that looks like. Thanks for the advice y'all!

[rocketscience]

The crank pulley is fine, once I pulled it off I realized that the notch on the front of it that I thought was TDC did not line up with the tiny notch on the back which I couldn't see before but is what is pictured in the FSM as being the TDC notch. The key is fine and I'll swap the timing belt and oil seals, they look like they're both leaking.