HELP Timing belt (Disaster?)

derekdevasia

derekdevasia

New member
Hey guys, well I have a 2004 4runner v8, and I finished the timing belt and water pump job on my 4runner this weekend. I filled her up with fluid, and yes, i made sure that the timing was right on, the crank was at the two notches when you take the crank pulley off, and the two cams were lined up with the lines on the block and i rotated twice to make sure everything was in alignment. The belt arrows pointed me and everything. Now here comes the good part. Or for me, horrible.

I started her up and she ran like a champ, smooth, nothing noticeable except a small pulley noise which i assume is one of the idlers. Then I went to rev her up about 5 minutes later and she did find and then on the 5th rev up, she sputtered and died. Now all she'll do is crank and she won't start up. Is this disaster? All the hoses and everything are as they should be, MAF is connected and cleaned, and so is the throttle body. What do I do.

Also I checked the engine with tech stream and there are no codes.
 
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If you're talking about the serpentine belt, then no I did check and everything is on the pulley and aligned still, thanks for the suggestion
 
derekdevasia said:
If you're talking about the serpentine belt, then no I did check and everything is on the pulley and aligned still, thanks for the suggestion
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I'm fairly certain he was referring to the timing belt...

Was that pulley noise always there before you swapped belts? I have to ask why didn't you replace the idlers when you were in there too?

Also, did you use a new tensioner or did you just reset the old one?
 
[MENTION=70523]derekdevasia[/MENTION]

You need to check the timing on the Timing Belt to make sure it hasn't slipped. Its not too bad to do as all you need to do is take the two plastic camshaft covers off for now (You may need to dig deeper if the timing is off, but we're just checking at the moment.)

Just manually turn the engine over a couple of times until the crank pulley matches the timing mark on the front cover, the camshaft notches should match up with the lines next to the "T's" if you do this.

Post Note-

Did you put the belt one with the arrows facing AWAY from the engine or towards? Common mistake is to do it facing towards the timing marks which will set the vehicle up with incorrect timing.
 
can someone explain to me why having the mark line up correctly on the belt vs cams causes it to be off timing?

Everytime, i did a TB i line up the cams/crank and if the belt marking line up, then fine, if not then i don't worry about it, i just turn the motor by hand 2 revolutions and double check the marks again.
 
pc1p said:
I'm fairly certain he was referring to the timing belt...

Was that pulley noise always there before you swapped belts? I have to ask why didn't you replace the idlers when you were in there too?

Also, did you use a new tensioner or did you just reset the old one?
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Yes the noise was always there, but i did replace the timing belt tensioner and idlers
 
I'll do that first thing tomorrow blackworks, but yes I did know to put the arrows facing away from the engine thanks for the insight
 
I'm new to the 4Runners and Yota, however I'm wondering if there's any data stream when you try to crank that might show you the cam sensors or maybe a crank sensor (if there is one)?

I'm totally with the other guys, but don't know enough about the motor yet. I'd also check any bolt holding a gear on that you may have to pull during the job. Hopefully Yota used keys and not just press on like Dodge did on the V10 motor. (Their HB's rotate at high rpm because they are press on and the bolt loosens).
 
I'm going against the grain here, I'm not convinced the timing belt slipped.

Pull the #1 plug and check for compression. If you have good compression then chances are the belt is fine. Belts usually don't slip. They break. If it did slip, then it wasn't installed correctly. What was the procedure on getting the right belt tension?

On the pathfinders with timing belts, there's an upper cover that takes you about 10 minutes to take off and look at the belt. Does the Toyota V8 have something like that? If so, do that and look at the belt. Check to see if it's loose.

Now the bad news. If the belt slipped...there's a chance the piston could have hit a valve and done some internal damage...this is an a interference engine.
 
riverider said:
I feel sadly he did none of the above I am betting,this is the reason many times it's best to take these belt changes to the dealer or a really good repair shop.

When I found the Toyota V8s had belts and the V6s had a chain. I went with the V6.
Been down the belt road with another Auto,and don't care for them.
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I kept my Man-Card intact and went with the V8 :flamewar:

Just kidding - the belt is a quality belt and plenty wide. Toyota wouldn't put a flimsy thing inside their beefy SUV engines. I changed my own belt at 120k miles and it looked damn new. With the belt, pulleys, water pump, etc I only spent $300. I'll gladly spend the $300 and 6 hours to do it again at 240k miles :)
 
I feel sadly he did none of the above I am betting,this is the reason many times it's best to take these belt changes to the dealer or a really good repair shop.

When I found the Toyota V8s had belts and the V6s had a chain. I went with the V6.
Been down the belt road with another Auto,and don't care for them.
Click to expand...

Replacing a timing belt isn't rocket science. Any decent backyard mechanic can do it. I've done many over the years - starting with my 73 Vega up to my 98 Pathfinder....and several in-between. Having a belt or chain never influenced my buying decision.

If you're like me and keep you vehicles for 300k+ miles then you'll have to replace that timing chain. Over time chains will stretch and could slip. And since the V6 is an interference engine if the chain slips it could cause serious damage (mainly valve damage). If you think replacing a timing belt is expensive then wait til you replace a chain....$2000+ at the dealer. I'll replace mine when the time comes...it's a lot more complicated the a timing belt.
 
MikeInNH said:
I'm going against the grain here, I'm not convinced the timing belt slipped.

Pull the #1 plug and check for compression. If you have good compression then chances are the belt is fine. Belts usually don't slip. They break. If it did slip, then it wasn't installed correctly. What was the procedure on getting the right belt tension?

On the pathfinders with timing belts, there's an upper cover that takes you about 10 minutes to take off and look at the belt. Does the Toyota V8 have something like that? If so, do that and look at the belt. Check to see if it's loose.

Now the bad news. If the belt slipped...there's a chance the piston could have hit a valve and done some internal damage...this is an a interference engine.
Click to expand...

There is an automatic tensioner that needs to either be reset or replaced. If this wasn't done, failed, or was incorrectly reset, it is totally possible that the timing belt skipped over a few cogs (typically on the lagging end, so the passenger side cam gear). It is also possible that the belt was incorrectly installed (backwards as some people mentioned) but was close enough for the initial startup.
 
my92t4r said:
can someone explain to me why having the mark line up correctly on the belt vs cams causes it to be off timing?

Everytime, i did a TB i line up the cams/crank and if the belt marking line up, then fine, if not then i don't worry about it, i just turn the motor by hand 2 revolutions and double check the marks again.
Click to expand...

The belt markings make life easy and provide a nice double check after tension is applied and everything is snugged up. Since there are two idlers and some slack, the marks give a visual from the cam face to the reference marks while you're actually putting the belt on too.
 
Sadly today and tomorrow here in Virginia Beach it's raining with temps in the low 30's. I'm going to have it towed to a friends shop tomorrow morning so I can dig deeper.
 
Check the crank position sensor. I had mine come apart at the connection and the truck would not start. Sometimes it's easy to pinch the wire when putting things back together. That is an easy thing to check and is a good possibility.
 
BlackWorksInc said:
Did you put the belt one with the arrows facing AWAY from the engine or towards? Common mistake is to do it facing towards the timing marks which will set the vehicle up with incorrect timing.
Click to expand...

pc1p said:
It is also possible that the belt was incorrectly installed (backwards as some people mentioned) but was close enough for the initial startup.
Click to expand...

Can either of you elaborate on this...I've done a few Subaru timing belt changes. 99.9% sure I put the arrows towards the timing marks and haven't had issues yet. Heck for the first one I followed a well regarded DIY thread from a Subaru forum and there was no mention of which way to put the marks. If the belt is symmetrical, I don't why it would make a difference.

EDIT: I guess Subaru uses a line to mark the belt as opposed to an arrow. Still curious tho, are Toyota belts not symmetrical?
 
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