TB: resolved? didn't jump time and starts

I know I have seen threads about the crank sensor harness being chewed up and where the timing belt jumped a cog or was off a cog but I can't for the life of me find them now

any and all help greatly appreciated

Had an issue with a coolant leak after first run at TB change, but corrected that. Everything was definitely aligned correctly when I was finished today.

I let it idle until normal running temp for testing and to ensure it was full of coolant.

Shut if off for a few minutes and Took it for a 2 mile test drive. Everything was fine.

came back outside and tried to crank it again and it didn't want to crank. It acted like it wanted to catch but the automatic starting feature kept going. By that I mean, the engine was turning over and it sounded like it was about to start immediately as it usually would, but it didn't.

I immediately cut it off. Not about to try it again until I confirm there is not an issue with the timing belt tensioner

Checked OBD but no codes


Could it have jumped one cog?

Timing was done correctly and it ran fine for my test drive

I did have an issue with a stripped bolt hole for the timing belt tensioner pulley while replacing the TB. Repaired with a heli-coil and everything seemed fine

Also, videos with audio showing how much quieter my engine was since replacing the timing belt. It had a lot to do with the fan and fan bracket - stud broken off and one of the other 3 nuts wasnt even finger tight. Could've also have been issues with some of the pulleys that were replaced.

At any rate it was much quieter until this issue reared it's ugly head.

 

Man, that stinks! Did you get the crank position sensor/wire tucked back out of the way? If in the wrong spot it could have gotten rubbed through on your test drive....

 

I routed it correctly. I should've triple checked it before I finished assembly

 

Engine sound before timing belt change:
https://youtube.com/shorts/rzO7by-pRCQ?si=zz1GEN37cHIttGh1


Engine sound after timing belt change:

https://youtu.be/jyiRW5Tl1Tk?feature=shared

With hood open for better comparison with orig video. Excuse the wind noise

https://youtu.be/mwRwWRZxO70?si=x-__XhcW9tODz6oO

 

I finally made a video with sound of the DirtyDeeds full racing exhaust with 16 inch BAM mufflers and long tube headers

this is fully warmed at idle, then a rev 2000 RPM's then a couple of revs to 4000 RPMs then once more to 2000.

very quiet when idling. And if you drive gently, it remains pretty tame, but it lets you know if you get on it.

I didn't have my tripod and the phone fell off the bumper during recording

https://youtu.be/NLg2tPO3t5o?si=urp-sAxsXDx1pfba

 

Wow, I never knew it made that much of a difference. I’m obviously in the before category.

 

Now the hood was open in the older video and it was not after the timing belt change. But still, the difference is very dramatic.

if I ever start hearing noises like that again, I will not hesitate to change the timing belt. The timing belt itself was visually fine, but there were several problems at least some of it due to whatever mechanic did the timing belt 100,000 miles ago

 

So there are no wires rubbing like this on the drivers side

 

I tried looking, but it was getting late and I couldn't see it very well.

that's my first order of business tomorrow

i'm about as sure as I can be that it is either that crank sensor wire/harness or it has jumped a cog due to the issue with the timing belt tensioner

 

Do you think that was just the belt alone? I thought most of that noise was worn out tensioners and pulleys?

 

I don't think it was the belt at all. Visually the belt looked to still be in great shape as it should.

I know for a fact some of it was the fan because of the broken stud and loose nuts. But some of that noise had to have been pulleys and/or tensioners. That was a lot of noise.

 

I added one with the hood open for an apples to apples comparison. You can still tell an amazing difference.
https://youtu.be/mwRwWRZxO70?si=x-__XhcW9tODz6oO

 

yes sounds much better, mine is not as loud as your "Before" video. But I suspect when P.O did timing belt about 30k ago that was all that is done, not rollers etc, sticker says asian timing belt ....where I thought on my 4runner it came with a sticker that said asian timing belt kit.....anyway...plan to tear into one of these days and redo it, but its not my daily driver

 

This is not easy to see in this picture with the lighting and camera angle, but the crank harness feels like it is connected fully and appears to go directly behind the fan bracket as it should.



i'm pretty convinced it jumped time - a cog But I don't believe enough for it to brick the engine


I remembered the first crank after the TB change and it was so quiet that I could hear the very slightest soft chirping noise coming from the passenger side front which is where the timing belt tensioner is located. Which not coincidentally had the stripped bolt hole repaired with a heli coil. It concerned me but then it went away and I forgot about it

and I also remember how it sounded when I tried to crank it for the 2nd test drive. There was a bump or pop noise immediately, and then it didn't start immediately as it always has and just kept turning over even though I released the key due to the auto start feature (unsure of the correct term but where you can release the key and it keeps trying to start).

that heli coil seem to be installed correctly but if that is the culprit, I guess a time sert is all that is left to correct the problem

 

You saw the thread that shows the trick for jumping the timing belt forward or backward a tooth at a time, right? Verify timing. If needed, use that tip to jump the belt back. But weird it happened. Why was it able to?

 

Yes, I did. But I wouldn't trust it at all. Like you said why was it able to?

That's why I'm worried that heli coil didn't take properly for whatever reason

Since it ran fine for a good 20 or 30 minutes, there's just no way I could trust it without correcting the underlying issue

 

agree it needs to be fixed to be trusted. A helicoil can strip too

 

I'm about to start digging back into this to diagnose. Had to get it moved before I could start and it was in a tight location - not where a tow truck could move it

I don't know yet if it is the timing belt tensioner whose bolt hole was stripped and we repaired with a heli coil but I'm just looking ahead to consider my options

I had a long conversation with the service department at a local dealership that I trust more than the others First mechanic was a PITA and wouldn't just answer my question and had to go into the "we would have to diagnose." But the second mechanic was really good and thorough with me.

All this to say, if it is stripped, then the heli coil failed I believe my only option is a big sert which is a larger time sert to repair a threaded bolt hole that has already been repaired one time

The dealership told me yeah if you do have to use a time sert and it fails, then You have no option other than to replace the engine. They were not the only ones to tell me that

That just didn't sit well with me. I thought surely someone makes a double side threaded hardened steel sleeve where you could just tap the hole out bigger and put in the sleeve with the inner threads being the same size as the tensioner bolt.

and then I found these





I know I'm getting the cart way before the horse but I guess I'm just terrified that I'm potentially one step away from the engine being worthless.

Is this a viable option for the timing belt tensioner? Seems like it would be. And some Loctite thread locker red on the outer threads of the sleeve

I'm not sure this grade is strong enough, but surely there is one stronger. I think 8.8 is not as strong as 8 and is more like a 5. Or maybe 8.8/5 is strong enough since I believe the original hole is aluminum

 

Pretty sure that mounts to the oil pump housing and will NOT require a new engine.

Our blocks are iron. Your tensioner mounts to aluminum.


Just FYI.

 

thanks much! The stealership should've known that.

but that does confirm that the tensioner mounts to aluminum so there are multiple options, including replacing the oil pump housing

 

how hard is that to do....maybe that is your best option now

 

OK, I'm finally digging in to the issue. I've got both of the top belt covers loose enough to see the belt.

if it jumped time, then my issue should most likely be the timing belt tensioner pulley whose boot hole was stripped and repaired with a heli coil. Timing belt seems reasonably tight, even though I can only check for tension a couple of inches away from the cam pulleys. For comparison, I would estimate that it is slightly tighter than the serpentine belt is about that same distance from one of its pulleys.



My question is if I rotate the crank until the cam pulley timing markers are on their mark, will the crankshaft be at TDC?


I'm hoping to confirm before I have to drain the coolant and tear the whole front off again. Without taking the harmonic balancer off so I can take off the bottom timing belt cover My only other point of reference is the TDC mark

 

Where was our coolant leak you mentioned?

 

I say this very cautiously, but I just confirmed some great news. It does not appear to have jumped time and thereby bricking the engine.

also, I rechecked the crank sensor wiring harness while I was down there and it does appear intact and to immediately go behind the fan bracket. So now what? What a coincidence that it would happen within 30 minutes of running my truck for the first time after a timing belt change unless it is indirectly related



Ignore the timing alignment marks on the belt. It has already been running and is purely coincidental that they happen to in the pics

The first three are of my truck. At the bottom are pictures from an article shifty linked in another thread about aligning these without the harmonic balancer/damperener removed.




My crankshaft mark is at an awkward angle and difficult to see because I didn't remove the fan, fan shroud, radiator etc. it's a little easier to tell in person that it appears to be on the mark



Driver side cam timing mark:


Passenger side cam timing mark:

A

A little concerned about how far the timing beltshifted forward on passenger side, but it appears to be within the ridge on the pulley (not pictured)







From the article @shifty` linked:

 

So now I'm back to diagnosing the problem. I just don't think it is a coincidence that it happened right after I changed the timing belt

even though the crank sensor wiring harness appears to be intact, it as always cranked immediately so I'm really suspicious of the crank sensor

I see where this poster had a similar issue, although he had some other problems as well. He used a loaner Noid light from autozone to confirm that the fuel injectors were not receiving the power and switching signals.

He got no light when trying to crank, so then he replaced the crank sensor and it started right up. I guess this would be an easiest way to confirm that it is related to the crank sensor and or wiring harness.

 

No, the easiest way to confirm if it’s a fuel delivery issue is to buy a $8 can of ether/starting fluid, and spray it into the TB, behind the plate, and turn it over. If it fires up, you have a fuel delivery issue and would want to check the CPS.

 

What he did in a roundabout way was confirmed that the crank sensor was causing the power to be shut off to the fuel injectors


I'm not trying to confirm it's fuel because I don't believe that's it. I'm trying to confirm if the cranksensor and harness are functioning

 

Found the source of the bump that shook the hood and made me think it had jumped time



Not sure where it came from, but I knew I found another one loose on reassembly the first go round




Still don't know why it didn't crank. Crank sensor wire and harness seems to be OK I guess I should test it before I put everything back together

 

Given I haven't done TB/WP yet I'm not sure what I'm looking at, but that appears to be a standoff/spacer you'd find to hold, like, an accessory bracket in place.

Is it possible you missed a spacer on one of the accessory brackets, and that's why the belt is sitting so far off? Maybe someone who's done their TB already would know.

That's pretty stout, too, any dents inside the hood?

 

no dents - it was still within the lower timing belt cover


It's possible that pushed the timing belt out a little bit. The timing belt is still Within the acceptable range but not what I would have expected

I Think that is exactly what happened I just went to take a picture of all of the pulleys and the timing belt is back in position. I did the bump start method to loosen and then remove the harmonic balancer/damper. That's the first time the motor has taken a turn other than me lining up the timing marks since the incident




I'm still going to take the timing belt off and fully inspect to be sure there is no damage to any of the pulleys and the tb


I believe it is something like these that are on the old water pump