Lost the Timing Belt....

Hexus · **Posted:** Sat Nov 10, 2012 8:45 pm

Pretty sure it's a timing issue...

I replaced the turbo, and put in the 2nd Gen Fuel pump/filter/head. Engine is still running exactly the same except the turbo works now and I can hear it.

You think I could've destroyed a weak (Past due honestly) timing belt when the Turbo crapped out? I know they fail for no reason, entirely reasonable to think one might crap out during something as brutal as a turbo failure...

Anyways, I'll post a video of a startup and very short run tomorrow so you all can tell me what I already fear.

$402 for Rockers and $700 for timing belt/water pump crap and not to mention renting/buying the tools etc.

What a pain in my rear......

rotordriver · **Joined:** Mon Mar 28, 2011 8:35 pm **Posts:** 44

Did you check your IC hoses? How many miles?

turbobike · **Posted:** Sun Nov 11, 2012 10:21 am

correct me if I am wrong......but if you "lost" the timing belt......the engine would NOT run

geordi · **Posted:** Sun Nov 11, 2012 12:36 pm

Turbobike, you are not wrong. If the timing belt is broken or slipped severely enough, the cams will not be held in alignment with the crank - it will no workee. No correct spin, no vroom... Just metal crunchy noises (if anything) from the crank spinning freely and destroying the rockers, and then the starter will spin it VERY VERY fast and easily because there is no compression to fight and most of the stuff the starter turns... isn't.

If it runs, the timing belt is not broken. It *could* be slipped a tooth, but not broken.. Verify timing mechanically, at least as far as the two cams in relation to each other: Remove the two caps (You will find it beneficial to remove the alternator and just unbolt-to-move the heater line on the turbo side of the valve cover)... And check the position of the holes in the cams.

I would pull the engine fan and shroud to help with this, so you can rotate the engine by hand and see the crankshaft bolt holes - they are important. You could use drill bits or allen keys for this, the ultimate goal is to verify that when you can feel the cam holes feel "centered" toward their respective caps, the bolt holes in the crankshaft are perfectly vertical / horizontal and not off at some angle. If everything checks out, your timing is good.

Sir Sam · **Posted:** Sun Nov 11, 2012 11:28 pm

geordi wrote:

Verify timing mechanically, at least as far as the two cams in relation to each other: Remove the two caps (You will find it beneficial to remove the alternator and just unbolt-to-move the heater line on the turbo side of the valve cover)... And check the position of the holes in the cams.

I would pull the engine fan and shroud to help with this, so you can rotate the engine by hand and see the crankshaft bolt holes - they are important. You could use drill bits or allen keys for this, the ultimate goal is to verify that when you can feel the cam holes feel "centered" toward their respective caps, the bolt holes in the crankshaft are perfectly vertical / horizontal and not off at some angle. If everything checks out, your timing is good.

I've worked on two engines now that both mechanically timed out correctly. Cam to cam to flywheel/flexplate. Rockers were both trashed. It is possible for a belt to slip, hit rockers, then jump back(or be one tooth off at the crank).

If your engine runs and sounds anything like this:
http://www.youtube.com/watch?v=95x7NiozPB0&feature=plcp

Or sounds like this with backfiring out the intake:
http://www.youtube.com/watch?v=F5v4mJb31sA

Then you probably have a slightly slipped timing belt.

-Sam

Hexus · **Posted:** Sun Nov 11, 2012 11:46 pm

It sounds just like the second one. It is difficult to start and when it does start it sounds a lot like the second video. Where is it pumping that air out from that is moving the glove?

ChooChooman74 · **Posted:** Sun Nov 11, 2012 11:55 pm

1/2 my rockers were trashed on mine. Mine was due to the PO lack of oil changes and probably egr and wrong oil.

Sent from my DROID BIONIC using Tapatalk 2

geordi · **Posted:** Mon Nov 12, 2012 12:52 am

Wow - I wouldn't have thought that it could jump back INTO time after a belt event like that, and killing the rockers. Learn something new every day.

At least you have those example videos. Maybe we should create a sticky thread with some video links - first a happy engine, then each of the bad engine videos people have posted? I still have mine where it was tapping, which I now know to have been a rod bottom coming apart... AGAIN. I haven't gotten confirmation yet, but I strongly suspect the rod bearing melted out again, for reasons I don't know. I could see both sides of the bottom of the rod, and it didn't look like the bolt holes were damaged or the bolts had sheared off... Is it possible they somehow backed themselves out from the vibration after the bearing melted?

Hexus · **Posted:** Mon Nov 12, 2012 3:03 am

You ever make any trips to Nashville Geordi?

Heh...

Sir Sam · **Posted:** Mon Nov 12, 2012 3:27 am

Hexus wrote:

It sounds just like the second one. It is difficult to start and when it does start it sounds a lot like the second video. Where is it pumping that air out from that is moving the glove?

That air is air being blown out the intake, seriously, it should be sucking air in constantly, but instead there is a noticeable "backfire" of air back out the intake, I think it is exhaust residual from the cylinders that are not venting correctly(normally this exhaust residual is what drives the turbo).

Those videos are actually both of the same Jeep, the second video is just what it sounds like with the boost hose off of the intake.

geordi wrote:

Wow - I wouldn't have thought that it could jump back INTO time after a belt event like that, and killing the rockers. Learn something new every day.

the nearest I can figure is that the stretch of the belt causes the jump to happen where the belt has the longest untensioned section, which means the crank. there are so few teeth and distance between the cam gears that it would be very hard for it to slip there, but at the crank, mush easier.

So now that the crank slips something has to hit, I've noticed that in these cases the exhaust rockers always seem a little worse than the intake rockers, now they are all bad mind you, but the exhaust is just a bit worse, so I think that what happens is the crank slips a tooth, or maybe more valves hit, the rockers fail like they are supposed to, and during the process the belt gets pushed back where it should be.

Its the only reason I can see that otherwise well maintained vehicles, 15-20k miles overdue for a belt change, can have mostly trashed rockers, suddenly, and still have the engine in time.

geordi · **Posted:** Mon Nov 12, 2012 4:46 am

Hexus wrote:

You ever make any trips to Nashville Geordi?

Heh...

I haven't recently... But I could.

Hit me with a PM if you are interested, and we can talk.

Lost the Timing Belt....

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