Need Help Identifying Engine "Tick"

[jrobie79]

2011 Escalade 6.2 v8- 140K

The 1st video below makes the noise much more pronounced almost like a diesel. In person it's not that loud/aggressive, and can't be heard inside the vehicle with the windows and stuff closed. This happens at idle, no matter engine temp - cold start, at temp, etc... I couldn't tell if it was RPM related - revved engine from inside car with my head out the window and couldn't tell if it increased. My phone was in the front driver side wheel well, where I could hear it the loudest, didn't check passenger side or with the hood up, I'll do that when I'm out of work.

Is this normal? Could it be lifter tick? Would GM Top Engine Cleaner help?

I have an old BMW that has notorious lifter tick, sounds similar. I added an engine cleaner to the oil and changed oil and the sound went away. It happens when it's low on oil as well, and goes away after topping up.

I just put brand new Mobil 1 5w30 extended performance about 200 miles ago with brand new filter (P48E). The oil life monitor said 9% when I changed it old oil looked pretty filthy, and there was a generic oil filter on it - from previous owner. Just had it inspected in Massachusetts and no engine codes popped up, no light on, etc.

2nd Video taken the day after the first: The sound isn't nearly as audible with the hood open and my phone above the engine, but seems to be more noticeable along the passenger side exhaust manifold area. It also seems to be louder from underneath the truck. I'm gonna put it on my lift this week and listen more closely.

Could it be an exhaust leak even though it's still audible after 1/2 hour worth of driving at idle? I know these engines have a problem with broken exhaust manifold studs, but there are no broken bolts, and small gaps should close as the metal expands right?

 

[mobilaltima]

My buddies 2011 Chevy 1500 with the 4.8 vortec has made that same noise for as long as I can remember, still runs fine with 120k miles. Might just be my head but it seems a tad bit quieter with a Fram Ultra filter

 

[LeakySeals]

My Escalade 6.0 had the exact same thing on the same side. The exhaust manifold bolts can rust and pop off. check and verify every bolt is accounted for. I had to put a aftermarket exhaust clamp on mine. That helped. Also found out my knock sensor harness had popped off exposing the sensors to moisture. That also helped quiet the ticks. And thirdly was a internal sludge/varnish cleanup and running a good oil. its quiet now, knock on wood.

 

[bigjl]

Injector perhaps?

 

[Phishin]

Originally Posted By: LeakySeals
My Escalade 6.0 had the exact same thing on the same side. The exhaust manifold bolts can rust and pop off. check and verify every bolt is accounted for. I had to put a aftermarket exhaust clamp on mine. That helped. Also found out my knock sensor harness had popped off exposing the sensors to moisture. That also helped quiet the ticks. And thirdly was a internal sludge/varnish cleanup and running a good oil. its quiet now, knock on wood.


I second the notion that it might be the exhaust manifold. It could also be a cracked flexplate.

 

[UltrafanUK]

Hard to say if the noise is a leaking exhaust or not. I would spray some oil (Or Seafoam) directly into the intake whilst a friend checks to see if the white smoke is coming out some place God did not intend. Also check the manifold bolts and downpipe clamp.

If it's not the exhaust, then try a can of major brand fuel additive designed for cleaning the injectors. Even if it's not them, it might help improve the fuel economy figures slightly.

If that fails, try a can of Liqui Moly lifter tick additive, or use an idle flush just before changing to a slightly thicker oil. Moving up one grade from an Xw20 to an Xw30 should help reduce the hot rattle, but I would also try using a certified OEM standard oil filter, as a bad over pressure valve can cause cold start rattles if it fails to open.

 

[jrobie79]

There's no bolts missing, they are rusty as [censored], perhaps they are compromised allowing a slight gap, but still attached enough to give the illusion they are in place. Shouldn't this be louder at startup when the metal is cold vs after 1/2 hour of driving and it's expanded?

Has anyone ever converted these 6.2's to a stud/nut setup vs a bolt on the exhaust manifolds?

 

[Ohle_Manezzini]

Try a ucl like MMO or Zmaxx and if it quiets down, than the culprit is injectors, but could be a very light faint piston slap at initial phase, too.

 

[UltrafanUK]

Originally Posted By: Ohle_Manezzini
Try a ucl like MMO or Zmaxx and if it quiets down, than the culprit is injectors, but could be a very light faint piston slap at initial phase, too.


MMO is not much good as a UCL, Bio diesel is far better. It's just a thin oil used by some as an oil scourer.

Too much Zinc will reduce the life of the CAT and kill a DPF if fitted. LM Ceratec is a far better oil additive, but works best after an idle flush.

The OP is using a 5w30, so it would be interesting to see if an 0w40 helps.

 

[aquariuscsm]

I can hear two noises,the perfectly normal injectors firing and a louder,slower paced "tap tap tap tap" coming from the bottom end it seems.

 

[PeterPolyol]

Exhaust manifold ticks respond to throttle and load, they're quietest at idle.

 

[LeakySeals]

Yes the exhaust tick diminishes with expansion but never fully goes away if the bolt has sheared.

Here was mine.

You state they are all there so moving on..

How many insulated plastic covers do you have? I have 3 on the 6.0. Assume you have something similar on your 6.2? not sure I see anything covering your valve covers. As you can see in my pic the valve covers are covered with insulation. They cut down a lot of top end noise coming from the plastic intake manifold.

 

[LeakySeals]

Resolving knock sensor issues also made a HUGE difference for ticking. I was totally unaware that my knock sensors were exposed until I sprayed the engine and got a CEL. I took the intake manifold off and this was what i saw (in this pic visible to the left and right of where you add the oil).

The rubber grommets should be flat into the oil galley. Instead, rusted and full of crud. Can't set the timing correctly like that.. Once I replaced and performed the RTV fix the ticking was way down, nearly gone.

And lastly, stick with a good oil with good cleaning power. you have no history so maybe its just neglected and dirty and after a couple short oil changes the gunk will clear, no more sticky lifters.

 

[Ohle_Manezzini]

Originally Posted By: UltrafanUK
Originally Posted By: Ohle_Manezzini
Try a ucl like MMO or Zmaxx and if it quiets down, than the culprit is injectors, but could be a very light faint piston slap at initial phase, too.


MMO is not much good as a UCL, Bio diesel is far better. It's just a thin oil used by some as an oil scourer.

Too much Zinc will reduce the life of the CAT and kill a DPF if fitted. LM Ceratec is a far better oil additive, but works best after an idle flush.

The OP is using a 5w30, so it would be interesting to see if an 0w40 helps.


Controversy? No.

A diesel fuel less than 1 cst is a better uclube than MMO that's 2.7 cst @ 100C? And Zn kills cat? Nono it is too much P of ZDDP that does it, and MMO doesn't have any zddp.

I would't go 0w to quiet down a clicking engine with 5w, JMO.

 

[askani79705]

Dose your gas with TCW-3, 1 oz per 5 gallons. If it's the injectors they'll quite down.

 

[jrobie79]

Last video until I can get it up on the lift. I put my phone on the lines going into the firewall on the passenger side, then revved the engine. Definitely associated with engine RPM...also sounds like its the top end rather than bottom, and I'm starting to think it could be the exhaust bolts. I'll get the truck up on the lift this weekend and see if I can diagnose anything further.

On a side note, is it wise to convert the exhaust manifold to a stud/nut configuration vs the OEM bolt design? Every other car I've had has been studs and nuts.