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Discussion Starter #1 (Edited)
Hey all, sad day I have to post this, I've had my 05 2.8L canyon for about a month and a half now, and the other day I noticed I was low on power, and when
I turned down my radio I heard an unhealthy ticking/rattling noise (not rod knock) it tends to only happen when you start revving the engine up, and it is resulting in low power. I pulled off the belts to see if it was a pulley/tensioner/alt. etc. but the sound persisted, I took a peak in the bell housing and the clutch looks fine and isn't slipping. The sound seems to be coming from the valve train.

I did a search but didn't come up with anything.

So recap, symptoms are

-low power
-rattling/ticking noise, usually only above 1200rpm, and only sometimes at idle.
-I'm not getting any engine codes
-oil has no shavings in it.

I have a feeling it could be timing chain/lifter related, but
I have no idea how those engines are built, are they interference engines? Are they OHC, or pushrod/lifter type? Any help or any common issues would be helpful, I'll be
Honest I was driving truck pretty hard previous to the issue, but
I wasn't bouncing it off the rev limiter.


Thank you guys so much.
 

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Discussion Starter #2
Nothing? :( valve cover is coming off tonight to look at it, I don't think I've ever seen a valve cover this dumb to take off.
 

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Check the heat shields on the exhaust manifold. They're notorious for breaking lose and causing rattling and ticking noises.






Maybe, but that doesn't explain the low power and crappy
Idle :$ I'll check it though. Thanks.

I'll second the heat shield on the bottom of the manifold it's around the curve it probably won't look like it but there is most likely a broken weld there. I'll see if I can find the thread about it. Mine rattled bad in between 1200 rpm and around 3000. I would think if there were issues with the valvetrain you would have a code but stranger things have happened


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the guy that always on
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Hey all, sad day I have to post this, I've had my 05 2.8L canyon for about a month and a half now, and the other day I noticed I was low on power, and when
I turned down my radio I heard an unhealthy ticking/rattling noise (not rod knock) it tends to only happen when you start revving the engine up, and it is resulting in low power. I pulled off the belts to see if it was a pulley/tensioner/alt. etc. but the sound persisted, I took a peak in the bell housing and the clutch looks fine and isn't slipping. The sound seems to be coming from the valve train.

I did a search but didn't come up with anything.

So recap, symptoms are

-low power
-rattling/ticking noise, usually only above 1200rpm, and only sometimes at idle.
-I'm not getting any engine codes
-oil has no shavings in it.

I have a feeling it could be timing chain/lifter related, but
I have no idea how those engines are built, are they interference engines? Are they OHC, or pushrod/lifter type? Any help or any common issues would be helpful, I'll be
Honest I was driving truck pretty hard previous to the issue, but
I wasn't bouncing it off the rev limiter.


Thank you guys so much.

These motors are dohc with vvt.
Have you cleaned the MAF, throttle body lately? That's a known idle issue on these trucks. The lack of power could be caused by a bad fan clutch. I've heard of that causing it to feel sluggish.

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Good call about the fan clutch.

Has it been really hot lately? Do you know what the fan sounds like when it is locking up?

Since you're willing to pull the valve cover and look for (I don't know what) something, I will assume you are confident you aren't being robbed of power because of A/C and the fan engaged due to heat.

Not trying to question your mechanical ability, but I don't know you and just the other day somebody asked why the truck felt sluggish to drive when the A/C was turned on.
 

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Discussion Starter #9
I haven't checked the cats but I pulled the belt and ran the truck with the clutch pedal in (eliminate transmission) so I can rule out all the fan/alternator/AC/idler/pulley noises. And the low power symptom came very suddenly with the noise, but I'll check all that stuff when I get home after work around 9:30.

And yeah it always had a little bit of an idle issue and I planned on cleaning/seafoaming it when I did my first oil change (only had the truck for about two months or less), however the truck will barely stay running at idle now. It hangs around 500rpm and is very rough.

I almost had the valve cover off this morning before work, but I'll check the other stuff first as a new gasket is in Vancouver. Maybe I blew out the cat out or something and it's clogging stuff up? I planned on gutting it anyway.

Thanks guys, I'll keep you posted.

Ps. Is there a write up on removing the valve cover? I couldn't find one and I'll make one if I have to take the valve cover off.

Thanks again
 

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Pull the heat shield off the Exhaust manifold, check it out all over, likely it is a broken bolt on the mani, or the mani has self destructed. It will probably have cracks in it, and when you rev the engine and it torques under a load it opens up the hole and power goes down due to no back pressure, but it will not throw a code. I have been there and done this twice. Some of the cast iron mani's do not like that aluminum they are connected to. The difference in heat levels and cooling times between some of the mani's and the aluminum heads create stress on the mani and it cracks. My last one, before I got a header, fell apart in 4 pieces when we unbolted it to take it out.
 

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Discussion Starter #11 (Edited)
Thanks guys, I'll be off work in two hours, I'll keep you posted.

EDIT: I checked the exhaust manifold and it's fine, pulled out the sensor and looked at the car and it doesn't look clogged. So I think I can rule that out.
 

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Discussion Starter #12
Anyone that can point me to a write up on taking off the intake
Manifold, seems ridicouslg difficult to get the bolts off.
 

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Thanks guys, I'll be off work in two hours, I'll keep you posted.

EDIT: I checked the exhaust manifold and it's fine, pulled out the sensor and looked at the car and it doesn't look clogged. So I think I can rule that out.
I'm not saying this is for sure the case but when my mani heat shield was making racket there was no visible damage. I didn't want to pull it but finally I did and no more noise

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Discussion Starter #14
Yeah first thing I pulled the shield and used a "stethoscope" (really long screwdriver) and the sound definitely seems to be coming from the valve train somewhere, still woorking on it as we speak. I can't believe how much extra bull **** you have to pull to get that stupid valve cover off. I checked Mitchell on demand at work and the intake, battery box, left front wheel and fender lining have to come off. Makes me miss my crappy
Old tercel, 2 bolts, 45 seconds and a prying screw driver and I would have already had the valve cover off.

Thanks for the help though guys, even though it wasn't the issue I'm glad you guys got me to check it first, cause if it was I woulda been p***sed with myself haha
 

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Does the ticking sound like it is coming from the front of the motor? Could be the timing chain guides wearing out. Just a thought.
 

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Discussion Starter #16
Hey, just an update, so after all this it's a spin main bearing :'(

Pulled the oil pan, and the 4th piston had quite a bit of play on the crankshaft.

I figured this might be the case when I pulled spark plugs as it was running and only the 4th cylinder made a difference in noise when I unplugged it. New engine is on it's way from a wrecker. So cross my fingers there's nothing a rong with it haha. Planning on having this done by mid next week or this weekend.
 
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