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Old 03-09-2008, 03:12 PM   #1
double07
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Default bad timing belt tensioner?

Just redid my timing belt and the car started and then ran really ****ty and all of a sudden started knocking...so i turned it off and checked the timing belt...it slipped a teeth so i redid the belt again. started it up again...same results..but now the belt slipped like 7 teeths...also when i try starting it there are loud pops from the throttle body and smoke coming out then it will crank ut not start anymore...could it be a bad tensioner? any advice will be great..o yea the car is my00rs...thanks...
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Old 03-09-2008, 03:53 PM   #2
flstffxe
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The tensioner could be bad, but that up to the guy who has it at his disposal to look at.

As for it not starting now, it may be getting expensive for you. The 2.5L is an interference engine. Meaning if the timing belt breaks or jumps teeth the valves may hit the pistons, resulting in bent valves. Bent valve can result in your symptoms to a tee.
Quote:
when i try starting it there are loud pops from the throttle body and smoke coming out then it will crank but not start
The smoke and popping back through the intake could be the result of the cam timing being off, if your lucky. Otherwise it is the result of a intake valve being bent and not closing all the way. If it is the later, the minimum you are looking at is pulling the heads and installing new valves with a valve job. If there is significant damage to the piston from contacting the valve they should also be replaced.
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Old 03-09-2008, 04:16 PM   #3
double07
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dammit...before the engine went in a valve job was just done and the exhaust valves were replaced with brand new hot grind cams and dual valve springs and titanium retainers....i just put the engine in on friday and started it up on saturday...can you elaborate on the cam timing being off b/c when i brought the heads home from the machine shop, i had to set the lash and noticed that the cam gears were not tightened at all and had to tighten it...now i am suspecting that the machine shop guy just kind of threw the cam gears on there...is there a specific way they are suppose to be installed so that the timing marks line up correctly or can they just be slapped on?
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Old 03-09-2008, 04:43 PM   #4
flstffxe
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The pulley are basically slapped on, you just have to line up the tab on the pulley with the notch in the cam. The shop most likely didn't have a good way to hold the cam gear and tighten the pulley bolt. It is best done on the engine with the belt run around it, you can get more leverage.

By cam timing I am referring to if the belt slipped. If the belt slipped on either the crank sprocket or a cam sprocket the valves are no longer opening at the proper point which may or may not put them in contact with a piston as they open/close as the piston moves.

The cams and the rest of the valve train will be savable, only the valves that hit the piston/s will be bad and maybe the said piston/s too.
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Old 03-09-2008, 08:38 PM   #5
double07
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ouch that sucks i may have to pull my motor again...will have another go at it with the timing belt....
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Old 03-09-2008, 11:36 PM   #6
double07
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hmmmmm....with more agressive cams and stiffer valve springs i think no matter what i need a new tensioner...
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Old 03-10-2008, 09:46 AM   #7
eb1888
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You might consider also using the blue PE belt. The kevlar PE belt does not stretch like the standard. My tensioner didn't even move when I installed it, I thought it was bad. The tensioner also has to be compressed vertically, I use a large c clamp.
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Old 03-10-2008, 07:19 PM   #8
flstffxe
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Quote:
Originally Posted by eb1888 View Post
The tensioner also has to be compressed vertically, I use a large c clamp.
Subaru actually has a process for this, it is supposed to be done slowly over a period of 3 minutes so you can bleed the pressure down as you collapse the tensioner. If done to fast you can pop the seal out....
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Old 03-10-2008, 10:56 PM   #9
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Quote:
Originally Posted by flstffxe View Post
Subaru actually has a process for this, it is supposed to be done slowly over a period of 3 minutes so you can bleed the pressure down as you collapse the tensioner. If done to fast you can pop the seal out....
^^yes.
http://endwrench.com/images/pdfs/StepEWAug07.pdf
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Old 03-10-2008, 11:00 PM   #10
double07
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what do you guys think is causing a knock? It does not sound like a spun rod bearing or ticking valve...the knock actually sounds like a low oil knock but the thing is that it is filled with oil but with synthetic this time instead of the usual syn blend...could it just be a timing issue?
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Old 03-11-2008, 02:18 AM   #11
my4isflat
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Tensioners on your 2.5 SOHC are known to fail, especially after a timing belt. It will sound like a piston knock as the tensioner just flaps around under the timing cover. If I was you I would reset the cam timing and do a leakdown to see if there is any damage in the valvetrain or pistons. If no damage, then go out and get a new tensioner, put it in and you should be ok. But, with the problems you describe above it sounds like you've got some work ahead of you.
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Old 03-11-2008, 11:46 AM   #12
double07
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ill be doing that this weekend...i hope all is good though..no valves are ticking or anything just a small knock like oil not being there...we will see though...
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Old 03-30-2008, 01:59 AM   #13
02 Scoob-TN
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Default These may help too.

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