toyotatom93

So I am getting this really intense rattle from somewhere under the hood when the truck has been running for a while. When I start it in the morning it is fine, drives fine to work. When I get to work or stop at a light it rattles like crazy, but still drives fine. I think it might be the TC but not sure...hoping to find some info here?

It did always rattle for a few seconds on startup before, but now I would say the rattle sounds like that but continuous and kind of gets louder and quieter. Not too sure but it sounds like it goes away once I start to drive, or gets drowned out??? I had a few mechanics look at the guides around the begining of winter and the both said not to worry.

Um if the guides are worn would it make the rattle sound all the time? Like when it is started cold?

Are there any other symptoms of a timing chain on it's last leg besides the sound?

The other half of the problem is that the truck is about 800 Km's from home and my trusted mechanic. So do I risk the drive, or pay for towing not covered by CAA. Or risk a shotty mechanic, or pay a stealership. May as well rebuild the motor instead of doing a TC thru the dealership me thinks

Matt16

Start up is hardest on the timing chain really, if its going to break, likely its going to snap on startup. This is because the chain tensioner applies pressure using oil pressure so at startup, when the oil pressure is low, the chain has more slack. Where is the truck right now, not Vancouver by chance?

toyotatom93

Hmmm, oil pressure seems to be acting normal. Think it might be a really loose valve or something? It gets hot and loosens some more maybe???

So are you saying it would rattle on startup it is was the tensioner or guides?
And if I do risk the drive, the chain should be ok as long as the oil pressure is up?

The truck is in the opposite end of BC, Fernie.

AH64ID

I had a rattle on mine... stethoscope pointed to the throw-out bearing... changed it with a new clutch... no more rattle...

toyotatom93

Ya dont say, I noticed the rattle got worse when I put it into reverse but thought it was a coincidence.
And I have been told by a mechanic that my throwout bearing was going to go at some point.

That rattle you had did it sound like it was coming from the engine, and make you think it could be a timing chain? (Although I have never heard a TC rattle I would imagine it sounds similar to what I am hearing)

AH64ID

I feared timing chain... but could never narrow it down until the stethoscope...

HelliphinoN8

It's the timing chain & tentioner. Stop driving it asap or it'll wear thru to the coolant and then you'll really be screwed. If you haven't changed it since you've owned it, or don't know if the last owner did, do it.

toyotatom93

When I did take it in to do the chain on two seperate ocasions the mechanic said not to worry about the guides, there were no signs of wearing out.

I'm not ruling it out, but it still is not clear to me if the rattle would be constant if it was the TC. But since it ony happens when it has been warmed up from driving (I started it up and let it idle for about 20 minutes with no rattle.) And since I was told my throw out was on it's way out (it squeals sometimes) I guess I am just hoping it is clutch related rather then TC related.

I guess I should also mention that I am mechanically challenged, and just because I think it sounds like how I imagine how a loose chain would sound; definetly doesent mean I know what I'm talking about.

Thanks for all the help so far by the way.

toyotatom93

So the rattle is definetly not there all the time. Yesturday I let it idle untill the heat guage was in the middle and then drove it like a grandma into town and it dident rattle....I dont know what that means, but seems like it is not the timing set??? can anyone concur?

84sr5yoty

Yeah, you could have a pinging issue. Check your timing.

toyotatom93

Does pinging have to do with the rings? Checking the timing will tell me if thats the issue?
Does pinging sound like a rattle?

ovrrdrive

Another really popular thing to fail that's hard to diagnose are the idler pully's. Next time it's rattling get out and pop the hood and listen to the tensioner pully's and see if they're making the noise...

It does not sound like the timing chain to me based on what you've described, but anything is possible.

toyotatom93

Forgive my ignorance but where is the idler pulley. I am taking a break at work and dont have time to search around.

ovrrdrive

There are 2. It's the pully that is for tensioning the belts. They don't serve any other purpose. There's a bolt behind them you turn to move the pulley. That's what tensions the belts.

toyotatom93

If someone could help me one last time it would be greatly appreciated...

So I seem to be able to make the rattle start by down shifting and using the engine to help the brake, when the rpm's go up the rattle starts.
The only thing I have found to make it go away again is to turn it off for a while, or better yet let it sit overnight. Although there was one time I had to drive with the rattle and it went away on it's own...like I said it happend once.

In the meantime I can avoid the rattle by putting it in neutral when I need to slow down and using 100% of the brakes power.

This just makes me think it is the throw out bearing as AH64ID had suggested, but would love to hear what the people who know about these things have to say about it.

And for people wondering why I dont take it to a mechanic or try to do anything my self it's because I an working out of town 700 Km's from my house with no tools and no friends in the area and no mechanic I trust here.
I also have to get it home...I can get it towed halfway with CAA, but it will still cost me $650 to get it towed the rest of the way; wich is about all I can afford for repairs.

HelliphinoN8

All you need is some masking tape, a sharpie, and a 12mm wrench or socket. Remove the valve cover and use a flashlight to look down the timing cover. If there are two grooves wore into the cover on the driver's side it's your t chain guides and tentioner. Pullin the valve cover will take 30 min. max. Just mark all of your vacuum lines.

toyotatom93

So this morning I looked at my hoses and I was able to push one on the egr down a little further along with maybe another one. Went for a test drive, and I thought I had fixed it. Unfortunatly about 25 minutes into it it happend again when I down shifted.

So far it looks like for the rattle to happen the truck has to be warm, it never happens for a little while, and turning it off and letting it cool down is the only way I can make it stop. It runs awesome in the morning, but when it only has an hour or so of sitting that rattle comes faster.

The sound has me thinking there is some metal to metal contact somewhere, seems to be coming from the driver side near the front of the engine...but sound bounces and I havent been able to get a stethoscope on it yet.
The sound also kind of comes and goes in a random cycle and gets louder as it goes on. At first it will happen when I down shift stay around for a few seconds and go away, then maybe not come back next down shift, but when idling at a stop sigh it will come on again on it's own. Once this has gone on for a couple of minutes it will get way louder and not stop but still have cycles of louder and quieter rattle.

toyotatom93

Is it really that simple? I obviously have never taken it off and to tell you the truth I am kind of scared to do it here in a parking lot.

toytech76

check your timing chain guides before you drive it any further. You can wear through the tcover into a water jacket and scatter your motor

AH64ID

To pull the valve cover, yes... very simple... I would say 30 minutes is about 27 more than needed... after you have done it a time or two...

I would pull it and look....

To change the TC is a lot more involved thou, to do it right you need to pull the head, and really should have it looked at by a machine shop to make sure its true.