Timing belt slipped 5 notches... What to do?

[Maui Cruiser]

Hey everyone!

I'm a first timer, so please excuse any amateur or naive questions!
I bought a 1995 with a V6 3.0L EFI and auto transmission at 200k miles.

The idle was always lower than it felt like she wanted, averaging around 500 revolutions, and the overall power of the engine seemed to be sub-par for a V6 at the low end of 2-3k revs... but she fired up and drove smooth so I kept driving. Then recently when starting up: a high pitched squeal with a self shut off. Then started, squealed and she shut off again. Then started, ran in idle but with a sound as if something was going around and around in the timing belt case... but she kept running so I took my chances of avoiding a tow truck and drove home. Pulled out some wrenches.

Investigating further I began pulling apart the front end to look behind the timing belt cover where all the noise was coming from. It seems that the timing belt is actually new. So seems is the water pump. The water intake, not so much. The engine when in "stroke compression" with all the notches of the left and right cam and major center pulley all lined up to zero and the distributer pointed to the #1 spark, the timing belt is five notches behind where it should be. My guess is a faulty hydraulic tensioner (in the fan bracket) which gave some slack and now there is five notches of slack somewhere in the line. I am at the point where the fan bracket just came off.

What to do? Do I need to take the whole belt off and just turn it five spaces or can I somehow reset the belt with its original placement and tension? I think a new tensioner is due, and think taking a look into the idler would smooth things out but first how to get this delayed belt in order?

I have attached a photo for reference of one of the cams.
Any help is much appreciated.

Thanks!!

 

[Ahlem]

It's the pulley orientation that's critical to avoiding catastrophic failure.
My experience is with BMW timing belts that don't have any markings on them other than a directional arrow. I would think you could align all your pulleys to the right marks, release belt tension and put it back on with the marks on the belt lined up. That being said, the recommendation from other manufacturers, BMW e30 M20 motor, is to replace the timing belt any time you relieve tension on it. Others with more specific experience will weigh in I hope. We have to do the same project shortly.

 

[Hyde802]

Forget what the belt says, are the cams and harmonic balancer lined up with each other?

If it did in fact slip, I think your on the correct path with a new tensioner. If the belt looked good, I would run it.

It's the pulley orientation that's critical to avoiding catastrophic failure.

Its a non interference motor. So if the timings off, it will just run poor. Valves and pistons are safe.

 

[Maui Cruiser]

New info---

Thank you for your replies!!

Ok so today I got back under the hood and tested out the situation a bit further.
Feeling the fan pulley I noticed it had some bearing tension and is likely to blame for the initial high pitch squeals, assuming it locked up and then broke something inside... I also noticed a spark plug had somehow backed itself out and was hissing as I turned the engine by hand so I tightened this back up and compression seems normal again.

As I turned the main bottom pulley (is this the harmonic balancer?) and the engine rotated, my L+R cam pulleys stayed in time with the zero marks, but the timing belt would end up one notch behind (to the left) from the previous rotation. Again: When pulleys are in TDC, then rotates once over, back to TDC the belt has skipped a notch each time. As if the belt was goin slower than the pulleys by a single notch each rotation somehow...

Is this negative or normal?
Is the timing belt one tooth too big/long?
Is the tensioner to blame?
Is this problematic, given that the cams and main pulley remain lined up in TDC?
I'm still looking for an explanation for hearing a rotating sound as if the (fairly new) timing belt had a fray tooth the last time I heard it running ....

I'm temped to just replace the fan bracket, tensioner, button it up and turn it on to see what happens. My friend thinks I should put a whole new kit on. Thoughts?

Any help and advice much appreciated by this amateur backyard mechanic who is currently riding his bike to work, haha!

 

[Ahlem]

Cams and crank don't turn at a 1:1 ratio. Check the diameter of the pulleys. Therefore your timing marks are there to make sure you are at TDC when you need to take things apart and put them back together and check the timing. If you turn the crank in the direction the motor runs and then back again and then forward to take up the timing belt tension, you should end up where you started. If you keep going around and around in the same direction, you will notice a different orientation and you will be able to amaze your friends with your knowledge of the four stroke cycle.

 

[02SE]

The marks on the timing belt are for installation ONLY. After installation, and the engine having been run, they are irrelevant.

 

[Maui Cruiser]

Another update!

First off- thank you to those who have responded so far, your advice was awesome!

So here's what happened:
I replaced the fan bracket and tensioner. Tightened up all loose sparks.
Buttoned it up and she fired up, but still rough running.
After fiddling with spark wires, learned #6 cylinder is getting spark but not firing.
Fuel injection must be clogged tight?
I wiggled the electric connector I could access, nothing happened. Other than additive solvent into the gas- what should I do?

How do I investigate further? Can I pull open and look at my fuel injectors?

Thanks in advance y'all!!
Maui Cruiser

 

[Howitzer]

After fiddling with spark wires, learned #6 cylinder is getting spark but not firing.
Fuel injection must be clogged tight?
I wiggled the electric connector I could access, nothing happened. Other than additive solvent into the gas- what should I do?

How do I investigate further? Can I pull open and look at my fuel injectors?

Thanks in advance y'all!!
Maui Cruiser

Three main products of combustion: air, fuel and spark. If you've determined that it's sparking, and it's a good clean spark, it's probably either in the fuel or air portion, my guess being fuel, but internet diagnosing is always tricky

 

[Ahlem]

See my running on 3 cylinders post from January. I just went through this.

 

[Maui Cruiser]

Runnin on less than 6 V6

Ahlem,

Do you have a link to a step by step for what I have to do? To get to those injectors? I can't even see the 1,3,5...

As an amateur I really don't know what's going on but want to fix it myself. I heard I need to get an air intake gasket because they rip often on de-install of the 2,4,6's. Did you experience this?

Thanks!
Parker

 

[Maui Cruiser]

Flipped out all six for upgraded 4-hole injectors...
Seems like I'm burning way more gas than necessary now...
Still have low torque at 2-3.5K RPM...
Any way to reset the computer system and try to get new ratios?

 

[Ahlem]

Try pushing the OD off button when you accelerate on an on ramp to see if this helps your "torque" situation. Push it again when you reach speed. These machines are not known to be very big on acceleration, hence the name 3.slo. If your timing is off you can also see a loss of power. If you are getting in the 15 MPG range, welcome to the club for gas consumption.