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Posted

I'd like to hear everyone's opinion on this ticking type of sound on my 2008 GMC Sierra Z71 1500 (iron block). It has 58,000 miles, and I purchased it used with 5,000 miles. I have used Mobil1 5w30 with a Mobil1 filter since I purchased it. No oil consumption and no other none problems, and I always use top tier fuel. I change the oil every 6,000-6,500 miles (35-40% oil life). The engine is warm. The sound cannot be heard inside with the radio and AC off, but it can be heard outside. The sound also doesn't appear to be present if the RPMs are increased. I've always considered the noise to be normal injector or valve train noise. What do you think?

 

http://vid1027.photobucket.com/albums/y338/awhendricks/Mobile%20Uploads/trim897DCE24-339E-4501-B508-F1A6D87A9B3F_zps86b23b66.mp4

 

http://vid1027.photobucket.com/albums/y338/awhendricks/Mobile%20Uploads/trimA7185A48-2357-4CA4-A76F-7C9AFFAB0FCD_zps337a59d7.mp4

Posted

I wouldn't trust it.... how long has it gone on? You say it comes and goes with rpm but how about with gear changes? For example, can you hear it more distinctly when it's in park versus drive or reverse. Also, try to locate the sounds origin as best as possible. Top end, bottom, back or front.

Posted

I had a noise similar to what you described. I took it back to the dealer because it was still under warranty. The dealer told me it was the belt tensioner. I was skeptical but sound went away after the new tensioner was installed.

  • Like 1
Posted

Hi Austin02,

 

I understand that you are reaching out to you fellow forum members to figure out if the sound you are hearing is normal. Were you able to figure this out? Are you continuing to experience this sound? Please feel free to contact me via private message if you have any lingering questions or concerns.

 

Jennifer T.

GM Customer Care

  • Like 1
Posted

My 4.8 makes that exact sound occasionally. If it makes it this week maybe I'll take it to the dealer. For my sake, will you keep me apprised of what they tell you?

  • Like 1
Posted

I'd like to hear everyone's opinion on this ticking type of sound on my 2008 GMC Sierra Z71 1500 (iron block). It has 58,000 miles, and I purchased it used with 5,000 miles. I have used Mobil1 5w30 with a Mobil1 filter since I purchased it. No oil consumption and no other none problems, and I always use top tier fuel. I change the oil every 6,000-6,500 miles (35-40% oil life). The engine is warm. The sound cannot be heard inside with the radio and AC off, but it can be heard outside. The sound also doesn't appear to be present if the RPMs are increased. I've always considered the noise to be normal injector or valve train noise. What do you think?

 

http://vid1027.photobucket.com/albums/y338/awhendricks/Mobile%20Uploads/trim897DCE24-339E-4501-B508-F1A6D87A9B3F_zps86b23b66.mp4

 

http://vid1027.photobucket.com/albums/y338/awhendricks/Mobile%20Uploads/trimA7185A48-2357-4CA4-A76F-7C9AFFAB0FCD_zps337a59d7.mp4

To me, it sounds like a cracked flexplate. I say that because I had a similar sound coming from my 6.0 and that's what it was. In the video, it seemed to be louder when you were down low. Crawl under there when it's running and listen right around the bell housing on the tranny and if it's real loud and a very sharp, metalic sound, it's a flexplate.

 

Also, if the sound goes away or quiets when put into gear, that could be another indicator because as you apply load to the plate, the force is enough to push the Crack back together, making it quiet again.

Posted (edited)

Thanks for the replies everyone, here is what I've figured out. The sound only starts happening after the engine heats up. The ticking increases with rpms, but it's hard to distinguish at faster rpms. The sound is present in all gears. The sound also appears to be more pronounced on the underside above the driver side catalytic converter. I first thought it was the bell housing until I got closer to the front driver side wheel. I'll do some more inspecting under the truck tomorrow. I'll keep everyone updated.

Edited by Austin02
Posted

I have seen a lot of posts on here about broken exhaust manifold bolts. If it only happens when the engine heats up, perhaps you have a broken manifold bolt and the leak only occurs when things heat up. It's an easy enough thing to check of your under the truck anyway.

Posted

I'm pretty sure that "chunk" of manifold was always that way. If that is where I think it is, then it's perfectly normal. When I first saw that on my engine I thought the same thing. Then I looked at several other engines and saw the same thing. Now as far as bolts being broken/missing, those definitely will need to get fixed if the manifold is starting to leak.

Posted (edited)

You're right, I looked at another Sierra this morning with the same missing section. The local dealership said they need $120 to investigate it, and that there are known lifter problems. I expressed my displeasure at having a 58,000 mile truck that has potential problems. I was also told GM might be able to help with the costs. I am not however interested in paying thousands of dollars for a tick that might be a non issue for years. I'll probably just live with it.

Edited by Austin02
  • Like 1
Posted

I feel that pain brother. My truck had the flexplate crack at 80,000 miles. Dealer wanted a grand to fix it. Now I have a truck in my driveway on stands with no transmission, transfer case or drive shafts.

  • Like 1
  • 2 weeks later...
Posted

The mighty vortec tic!

It used to drive me nuts. I don't even notice it anymore,

If it comes and goes. Louder some days?! Try looking at the Pcv valve, if it does it all the time do an oil flush with ATF then run Lucas valvoline 5-30

(I'm not a fan of synthetics in trucks!! They free up power but are noisy) also look at your climate? It's about 105 in the summer where I live so I run a little Heavy and lighter weight in the winter. Plus I'm always pulling a boat.

Posted (edited)

Can't get the link to work....I see it's Photobucket...can't upload from mine, otherwise I'd add the video clip of the "Knock" from my '13 Silverado I've been dealing with for the past year.....dealer cannot duplicate (did once), but when I get it home...Knock, Knock, Knock.....dealer sez "Your warranty is good to 100,000...I wouldn't worry about it". Mine seems to also come from the rear of the engine....the foreman heard it once, and checked the flywheel, no problem found. It goes back in on the 9th (third visit for this), they told me it may be the timing chain....but from the rear of the engine ??

Edited by Beer Belly
  • 5 years later...
Posted

I have an 05 Yukon and I have been dealing with the exact same issue  I wasn't able to see the video but from what I have read it's the same only I call it a chirping sound, and guys I have to say its completely consumed me I some times come home from work and pull valve covers and break out my long screwdriver and spend over half the night probing and listening. I even stayed up all night changing the rocker arms this is the first time I herd anything about the flex plate, looks like its gonna be a long night. Whish me luck. Oh and it's not anything to do with the AFM mine is an 05 with a 5.3L it doesnt have it.

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