Timing chain guides??

I just bought a beat up 2002 2.7L 184kmile taco, and a few days in it started making a new noise.

https://youtu.be/cOVxAP1_BmI

(this is with the engine warmed up)

I stuck a sawed-in-half ski pole against my ear and probed around, and it seemed pretty loud right in front near the water pump. I'm guessing (hoping, praying) that its just the timing chain guides and not rod knock, but I wanted some more opinions.

Is there a way that someone could make the noise go away just long enough to sell it? I heard the timing chain was a semi-common issue when I bought it, so I specifically listened for it. This is new. Its not impossible that I just missed it, there's some other stuff I missed when I checked it out, but I was specifically looking for this.

If it is the chain, is this on the far end of the spectrum where I shouldn't drive it too much until I fix it? I heard that if its left unchecked it can cut through a coolant passage and kill the whole engine. Ive got of other stuff on this thing to fix, so I've got to see where this fits in the triage.

What other stuff should I replace while I'm in there? My search hasn't turned up a 1st gen tutorial yet, but I bet there's one out there somewhere.

Thanks in advance.

 

Timing chains rarely go bad but will rattle before they go out and The 2.7l is a interferance engine. So its probably not a good idea to drive it if you think thats the cause of the noise and have another option.

 

Hard to really tell from a video but it might be the chain.

There are ways to quiet things I won`t mention.

It is not just the guides it is the chain the tensioners the gears.

It is possible that engine was treated poor causing the tensioners and guides to wear.

 

Good on ya for not mentioning the quieting methods, I suppose that's not information that needs to be floating around...

I wouldn't be surprised if the engine was treated poorly. And if I am going in, I'm throwing the whole timing chain kit in.

I think I'll pop the valve cover after work and see what I can see

 

I'll try premium gas at my next fill up. It doesn't sound like pre-ignition ping to me, but its such an easy thing to test I might as well try it.

 

It is a full weekend fight and a half to do the timing kit on these motors. I did it when I rebuilt the motor and everything looked fine when I took it apart. But to get the front cover off you have to take the pan out... to do that while it's in the truck you have to drop the front differential to get the pan out

 

I haven't sold my old car yet, so I can deal with the truck being out of commission for a bit. It seems like its going to be a real pain but if it needs to happen it needs to happen. I'd rather do it now, while the weather's good and I have other forms of transportation. Did you pull the engine for a full rebuild or did you leave it in the bay?

 

I pulled the engine for a full rebuild, the cylinder head was cracked and it had 220k on it so I did everything.. good thing cause the PO ran it so low on oil so frequently the oil pump journal in the timing cover was egged out.

 

Good to know, Ill be sure to inspect the oil pump while I'm in there. I'm kinda afraid of what I'm going to see when I open this thing up. I'm not really prepared to do a full rebuild on this thing, but its probably got other issues from being abused. There's also an oil leak from the oil pan seal, so I'm not sure if someone was in there before...

 

How long have you had it? If it's clacked like that the whole time, there's a chance PO tried to do the timing kit and realized how much has to come off to get the pan outta the way... then tried to just seal it and tighten it back up

 

I just bought it last week . That certainly could be it. It seems like they didn't do their own work though, It's got a stack of repair receipts saying they've always brought it to the same local mechanic. He could have been a little bit of a hack though...

 

Wouldn't be the first time I've seen it

Do you wrench yourself? You mentioned other things on the list.. have you got any CEL? I honestly don't know what kinda limit you can expect with the chain but you should be able to see the guides if you take the valve cover off.

There's a hydraulic tensioner on the passenger side of the timing cover.. might want to look into testing to see if that's not stuck?

 

I do wrench, and part of the reason I got this is because I heard they are easy to work on. I guess I'm going to see how true that is lol. Replacing the timing chain would be my biggest job yet, which is why I was listening for chain noise when I bought it. I didn't want to deal with it, but here we are. There is a CEL, but its an evap code.

I'm going to scope out that tensioner when I pop the cover. It looks like it can be replaced without pulling the timing cover, so I'm kinda hoping that's the problem

 

Update: the chain and tensioner are fine, so I think its a balance shaft bearing. Supposedly this is a semi-common problem, and I can just remove the balancer chain. It can be cut and removed without pulling the timing chain case. There may be a little more vibration at certain RPM's, but id rather have a little more vibration than a ruined bearing spewing flakes into the oil. I'm going to check the oil for flakes and do some more probing around before I get cutting, though.

 

What exactly have you done and checked out so far? Was there heavy sludge buildup? Might help to make a longer video with different angle shots. Id start with the basics if you havent already. Look at the plugs for impact marks and make sure it didnt break apart. Compression test. Make sure nothing is just loose and rattling ex.

 

The plugs look good, although they aren't oem so I'm not sure how long they've been in there. I dont have the numbers in front of me but IIRC the compressions were 185, 175, 160, 200 from front to back. I tested it a couple times but I'm still not so sure I trust the number for the rear cyl, 200psi seems pretty unrealistic. The cylinder with the 160psi reading had an exhaust valve that was a couple thou tight, but I'm hoping that the low number is from the valve being open for too long and not a burnt valve/cracked head. I'm doing a HF run after work and Ill pick up a leakdown tester to check that out, and I'm going to adjust the valves before putting it back on the road. I think that's a separate problem though.

I haven't drained the oil yet, but the oil pooled up in the valve compartment looked a little old (but not glittery). When probing with a metal rod to my ear, the sound seemed the loudest right in the front near where the power steering pump is mounted, which is where the front bearing for one of the balance shafts is. The ps pump itself didn't seem to be making any weird noises.

In the process of taking the valve cover off I noticed that the part of the plastic intake that is supposed to bolt to the pass. side of the valve cover via a metal bracket wasn't actually bolted in, so that could be be loose and making noise, but the noise didn't seem to be coming from there. Once I get the valve cover back on (I sheared a couple bolts, so I need to deal with that first) I'm going to see if messing with that unbolted connection stops/changes the noise, along with my other probing.

 

another random bit of information I just remembered: the knocking seemed a lot slower (lower frequency) when I was engine breaking

 

So I finally got around to stethoscope-probing some more, and now I'm pretty sure its just the water pump bearing. The sound goes away when I take off the alternator/water pump/fan belt and comes back with a vengeance when I tighten it up. There also didn't seem to be any flakes or glitter in the oil when I changed it.

When I bought it the belt was loose enough to squeal for a couple seconds on start up, so maybe the PO loosened it because a squeal doesn't sound as damning as a knock. Either way, I'm just happy I don't need to drop the front diff and oil pan