Replaced timing components.....still didn't fix it.

Well yeah that's what I mean. It's already ran like that for 15k and hasn't stopped yet so....

The reason I say a new motor is because I don't really have the convenience or time to take the motor out again and being able to search for the problem and work on it like I did with the timing chains. It was basically a one shot deal, but we didn't get it right the first time so yea...

 

Run it till it blows, then get new motor...LOL

 

That's probably what I'll do.

It sucks when you throw a bunch of money at something and it still doesn't get fixed

 

Issue like this would mostly likely require, pulling the engine, tearing it apart and checking every single bearing, every single clearance in the head and block. Checking every part of the timing chain, etc...

It could also be the balance shafts. The balance shafts is essentially a rotating assembly, rotating opposite way than the engine rotates and rotating twice the speed of the engine.

I have heard of a guy with Nissan 2.5L which also has balance shafts who sheared the gears inside the shafts completely...LOL

 

That's part of the problem, I don't have the convenience to do all that another time. Which I should've when I had it out, but we were so convinced it was the chains. Basically, anything that requires more work than a set of lifters is pretty much out of the question now, it's my only truck and I drive it every day

A new motor and I would practically have a brand new truck and i'd also be able to tear the current one down to find the source of the problem.

 

I was reading another post you made about overheating and I think post #16 has confirmed my own diagnosis that the timing needs to be checked see here: http://www.tacomaworld.com/forum/1st-gen-tacomas/104501-water-pump-2-7l-tacoma.html

"too much heat for the cooling system to remove caused by timing too advanced".......too advanced timing can also cause the "dieseling" sound you have. I think we've found the answer.

 

Yeah I understand where you are coming from, but when I got the truck it ran fine, the truck was cherry.

Eventually, after I downshifted in too low of a gear and. The noise you hear in that video slowly became more present. From not very loud you wouldn't think anything of it...........to so damn loud you want to rip your head off.

Then it started overheating, replaced fan clutch/water pump. Problem fixed. It hasn't overheated since. (This was replaced when the ticking was "so damn loud you want to rip your head off.)

All of that was with no changes to the timing. So it essentially was a perfect truck, then SOMETHING mysterious happened, and then started sounding like s***.

After about a month or so I finally get the OK to tear it down and replace all chains/guides/tensioners. Start it up and runs just like it did before. Literally no change from before we tore it apart. With the balance shaft MAYBE off by a tooth, if that.

I understand that the timing being off could produce a sound such as a diesel. I do not understand how my truck went from running SO unbelievably smooth (with no changes to timing from running smooth/s***ty).... and now (somehow?) maybe the timing is slightly off, producing such a sound like you heard in that video. It just doesn't make sense to me. I strongly believe the tick has nothing to do with the timing/type of fuel/crack in the header/ or any of that jank...? I do however, strongly believe I completely F***ED something inside of the motor. Something that is so obnoxiously loud it makes me want to punch the screen of my laptop repeatedly till there is nothing left, but also something that isn't effecting "how" the motor runs. Maybe I'm wrong? Who knows..

X1000000

 

After reading the posts in this thread, there are still several things I would check. I am not a mechanic for a living, I like to save money and fix my own stuff, but I am in no way a professional, so anything you try in this list is at your own personal risk.

An old timer I know gave me a suggestion that has save me lots of money over the years. "Make a list of the possible problems, why you think it could be a problem, Then start with the cheapest thing first".

The cheapest thing is your labor. Here's where I would start.
detail the engine compartment/engine (clean makes it easy to see any new fluid leaks, or build up)
Make sure all mounts are tight. Motor, transmission. (Low RPM stuff shakes)
Check for any excessive play/slop in the rotating parts. Cam Shaft, does it slide front to back, rock side to side, top to bottom. (Goes back to the floating valves, instead of a valve bending, maybe you bent a cam shaft, or bearing race)
Visual inspection for out of balance pulleys. (was it put on dead center)
Do a leak down test, record the numbers. (would reveal compression issues if any)
Hook up an oil pressure gauge and see what the numbers are at idle vs low rev. (Worn oil pump doesn't produce enough pressure at low RPM)
remove belts and free spin pulleys.
Stethoscope the under side of the block and the corners.

now time to spend some money.
Exhaust manifold gaskets.
Belts
Water Pump
Any tension pulleys.
Oil Pump

Since you have to have your truck, the following will keep you on the road.
Go to a junk yard and pull a head, have it reworked by a machine shop, then swap out. (new gaskets!)

If it still makes the noise, you will already have a ready to go head. Unless you buy a crate motor, I don't think they come with heads.

if you do all that, and it still sounds like a diesel, buy some ear plugs and drive it till (or if) the motor it grenades!

Good luck.

 

Awesome Advice here.

OP, You probably know this already but it is possible for the timing chain to jump time without you knowing it, my mom's old 4 runner did it once and started running terrible all the sudden.

 

Ok, I continue to understand your frustration. Humor me and check the timing. It will only take 10 minutes. Absolutely nothing else makes sense. Plus the noise changes as RPM increase (so does the amount of timing advance controlled by the control module). It's the ignition timing!

 

Check out the videos at the bottom of this post.
http://www.tacomaworld.com/forum/1st-gen-tacomas/87881-engine-noise-knock-ping.html#post1670480

Similar knock on a V-6 and it was timing.

 

@jdtemple, thank you for the advice. However, all of the things listed have already been done except for a leak down test (did compression test)....and checked good.

I have in fact thought about getting an assembled head, just haven't gone through with it yet.

@thombiz, I understand...and once I get around to figuring out how to check it I will. Although something to maybe consider is that before we touched the timing it made that sound. Then, after we reset the timing back to spec completely it still made that sound.

After watching those videos from the link Whitfield posted, I noticed the noise increases as rpms increase. On my truck, as the rpms increase the noise goes away.

Maybe i'm just being close-minded about it not being the timing. I know you guys are smarter than I am when it comes to diagnosing a problem and I appreciate the free advice more than anything. If I have time tomorrow morning I will try to get a video of the sound after a night of letting it sit. I think it might change your mind about the noise.

 

Okay I'm a little late on the video, but here it is:

http://www.youtube.com/watch?v=Dvu0Ek5fQEw

This is after it has sat overnight. You can hear about mid 50 seconds it starts a small rattle....then it goes away. then it comes back. goes away.

Then it gets more consistent as the idle starts to settle, but up to that mid 50 seconds the truck sounds fine? It's usually longer as the temp. is colder.

My theory (although probably wrong) is at these temps the oil is thick at startup and takes up the slack in between whatever is making the noise. Then as the oil gets thin causing more slack .. And as it gets up to operating temp. the sound starts to dissipate as the metal parts heat up and expand causing less slack.

 

Anyone have any ideas on the video above....?

 

welll.... i have read this entire thing.. and i cant think of sh**

 

or.. maybe go to a couple dealerships tell them everything you have done and ask them what could cause this problem

 

OK that sound like diesel. diesel sound = rod knock... I would pull the oil pan and see if there are any metal pieces in there...

 

There aren't metal pieces in there. I've pulled the pan and there weren't. Every time I change the oil there aren't either.

 

When you pulled the pan, and had the battery disconnected, did you rotate the motor over by hand and check for excessive play at the Connecting Rod and Crank, as well as connecting Rod and piston for each cylinder? Also, get a firm grip on the crank and try to move it front to back, side to side, and top to bottom.

Theory : Everything is nice and tight when its cold, as it warms up and expands, the tolerances go out of spec.


I had a motor swapped out of an honda, I picked the car up in the morning, drove it it 15 miles on the freeway, and the next stoplight I was at, I heard a rattle at idle up to 2500rpms. Turns out the shop the did the engine swap left a 10mm wrench sitting on a nut.