3-AC Rod knock/Other possible causes for rattle noise

Jts · Post by **Jts** » Tue Nov 21, 2006 6:36 pm

Hi everyone.

I'm a new member and picked up a 83 4wd wagon a few days ago. Cost 150 bucks with 316k miles on it. I have been fixing all the minor problems it has (stuck doors, windows, leaking sunroof, cracked radiator, etc) However, now that the cooling system is fixed, i fear i have a rod knock

Car will idle with no apparent noise, but when rev'd to about 2k rpm and above, has a very loud and nasty metallic rattle. Its louder from the drivers side, so i dont think it has to do with exhaust leaks. Is there anything else that you guys can recommend to check? Is the fuel pump in that area and known to make rattle noises? I will have to check all the possible causes, but i wanted to know if anyone thought they had a rod knock and turned out to me something else

Worst case is i swap it out for a 4ac, which would be easy and cheap enough for me. But not something i really want to do if necessary. Has anyone had any luck with changing a single rod bearing?

Anyways, thanks for the help in advance. I'm in the portland metro area, and ive noticed there are a few people from oregon. Just wanted to say hello to those in OR

Typrus · Post by **Typrus** » Tue Nov 21, 2006 7:42 pm

Whats your oil level at?
Check your cat heat shield. Its deceptive in how it sounds. i.e. louder on drivers side. Check to make sure all exhaust bolts are secure and tight. Any exhaust leaks will be evident by black carbon on things in the area of.

A good way to see if the sound is in the block is with an automotive stethoscope. I just use a screwdriver pressed against the block with my ear to the handle, but they make purpose-built auto stethoscopes.

Jts · Post by **Jts** » Tue Nov 21, 2006 7:45 pm

Oil level is full, as i just changed it. Oil level was fairly full before i changed it, but im sure it was abused before i got it.

Thanks for the reply.

takza · Post by **takza** » Tue Nov 21, 2006 8:11 pm

A rod knock will usually sound solid...& like it's low in the engine.

If you could get the pan off....you could look at the bearings...and use plastigage to fit a stock or undersized bearing and maybe take most of the slop out. Then use some 15W50 oil and drive it.

Think the fuel pump sounds more like a loose valve.

With that kind of mileage...that's the way I'd go about it.

Jts · Post by **Jts** » Tue Nov 21, 2006 8:11 pm

can you pull the pan with the engine in the car, or does the crossmember get in the way on this car?

Typrus · Post by **Typrus** » Tue Nov 21, 2006 8:25 pm

I think its possible, it just takes finess, and preparation for a lot of mess.
Hope you have a lift.

Gasoline Fumes · Post by **Gasoline Fumes** » Tue Nov 21, 2006 9:06 pm

I've seen a spun rod bearing in these engines make the piston smack into the head. That was hard to diagnose. I kept wondering "why is the head knocking?"

keith · Post by **keith** » Wed Nov 22, 2006 4:32 am

You can pull the pan without pulling the engine, but the differential gets in the way. You will need a couple of 1/4" drive flex extensions, the kind where the whole extension can be bent, and you are working blind. 3/8" drive will not fit. Figure in several hours of pure frustration to get at one bolt.

I did this to get at the oil pump to replace the front seal in accordance with the FSM. It is a lot easier to just pry out the front seal and pop the new one in.

xirdneh · Post by **xirdneh** » Wed Nov 22, 2006 8:31 am

I will have to check all the possible causes, but i wanted to know if anyone thought they had a rod knock and turned out to me something else

a worn timing belt can sound like a metallic knock. that happend on my first tercel.

a cracked piston will knock when engine is warming up and quiet down somewhat after engine warms up. drove one tercel for three years like that.
til i re-ringed engine.

coltarms · Post by **coltarms** » Wed Nov 22, 2006 4:58 pm

Good to have another in the PDX area. I'm in Hillsboro....

Would love to compare car issues some time. Perhaps we have an answer or two for each other...

Jts · Post by **Jts** » Wed Nov 22, 2006 6:39 pm

I just wanted to thank everyone for their replies. As it turns out, the bottom nut on the alternator was missing, causing the bolt to rattle at higher rpms. So i grabbed one from a parts bin i have when i parted out an mr2 and the rattle is now gone. I feel dumb for jumping to conclusions, but there you go. No rod knock, just loose alternator.

I am currently working on my vacuum advance, as it is non functioning. I took it apart, and have repaired it with rtv and cling wrap. I have pictures of the disassembly process that i will post onto the vacuum advance thread soon.

Nice to meet you coltarms. I've been reading the forum for a week before i bought this tercel. Let me know if you ever need to swap parts to trouble shoot something. I live in beaverton off of murrey, so we're quite close. Thanks again everyone

takza · Post by **takza** » Thu Nov 23, 2006 4:25 am

Jts wrote:I just wanted to thank everyone for their replies. As it turns out, the bottom nut on the alternator was missing, causing the bolt to rattle at higher rpms. So i grabbed one from a parts bin i have when i parted out an mr2 and the rattle is now gone. I feel dumb for jumping to conclusions, but there you go. No rod knock, just loose alternator.

I am currently working on my vacuum advance, as it is non functioning. I took it apart, and have repaired it with rtv and cling wrap. I have pictures of the disassembly process that i will post onto the vacuum advance thread soon.

It's easy to imagine the worst.

That would be a good writeup..can't seem to buy the vac part of the dist...just a complete rebuilt dist.

Post by **ARCHINSTL** » Thu Nov 23, 2006 10:14 am

Actually, the vac advance is still available from Toyota (at least the 3-pipe version was last November). I bought it from Butler Toy in Indy for $120. Advance also shows the advance (heh) on its site, but Autozone does not.

When I got the rebuilt Cardone distributor this Summer (I fried the old one-my bad), I subbed the OE Toy advance, as it was new. I mentioned at the time that I had the rebuilt Cardone advance available, but there were no takers. I called Cardone on this before offering it, and was told that it disassembles the advance, puts in a new diaphragm, recrimps it and tests it - so it is "remanufactured" as well.
Tom M.

Typrus · Post by **Typrus** » Fri Nov 24, 2006 10:10 am

$120 or more is what Advance, NAPA, and Autozone in my area wanted. They all said it was available, but I dunno how much to trust the Zone boys. They've been letting me down of parts tracking recently.
Never checked Carquest, but they are usually a good $$$ above even NAPA.

Jts · Post by **Jts** » Sat Nov 25, 2006 3:08 am

i went to a junk yard today. I pulled 4 vacuum advance cans and 3 were bad. They would not hold the slightest vacuum. I did find one though, from a corolla or tercel. It was smaller than all the other vacuum advances, which were the same size as my 83 tercel. It held vacuum, and i snagged it for 5 bucks, so i might be in luck. My attempts to repair my last one did not last once on the car. It involved cutting slits around the can and uncrimping it. I dont really recommend it as it does not seem to hold up. Anyways, my question is this

I unplugged the 2 vac hoses to my vac advance. Mine only has 2 hoses. Which hose is the one you disconnect to check while timing. The fsm shows u leave the end one connected and disconnect the middle one. Isnt the end one more important, which the middle acting as a booster for it? Ive seen single hose advances that just have the end cap hose. Can anyone shed some light on this. Also, my hose labels fell off. Can anyone tell me what hoses should trace back to what? Thanks

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3-AC Rod knock/Other possible causes for rattle noise

3-AC Rod knock/Other possible causes for rattle noise

Re: 3-AC Rod knock/Other possible causes for rattle noise