Picture of my Unimog for attention

 

Mike, before ordering parts, take a mechanics stethoscope, hose, or a long handle screwdriver from your ear to the valve cover to try to isolate the tick sound. Also to the exhaust system. It can be an exhaust manifold with a crack or loose bolt too.

 

Mike, GM engines tick, the lifters have done this from day 1 in 1955 when the chev V8 was made.
I wouldn't open the engine yet, it mat get worse, it may go away; I would wait until it becomes a lot louder.

Unlike the old V8 built in 1955 you can't change just one lifter, they are changed in pairs; and, as again unlike the old V8 you need to pull the head to remove the lifters.
To me, it isn't worth the cost and the possibility of future problems to fix at this time.

 

Thank you very much for your replies.
The noise has gotten louder,then sometimes softer and at times nothing at all.

Would it be alright to upload a video and ask for opinions?

I have to go to Sweden next month,I certainly do not want a breakdown 700 miles from home

 

Oil pressure at idle with engine Hot.
After towing 2 tonne 7 miles

 

Not sure on the smaller 4.8l, but I know the 5.3 blocks had some serious issues with the knock sensors. my '03 had completely rusted away on the back sensor. Anyone know if they fixed that in the 900 series?

 

The sound fluctuates in intensity,I held a stethoscope to the valve cover and could not hear it.

I guess I might need a head and manifold gasket,pair of lifters and a Manuel when I choose to fix this.I would hate for it to chew up the cam.

 

Chevy Silverado 2007,4.8 liter V8,90,000 miles

Recently I have noticed a ticking sound getting a bit worse,I have followed the service intervals religiously and always used Castrol 5W-30 Synthetic Oil.

Oil pressure is good and if the engine is hot or has run along time it sounds fine,start up it is noticeable outside the car but not once inside and it does not make the noise with each and every cold start.I have looked for exhaust leaks too.

I have to order all my parts from the States because I live in Norway,I want to get all the parts the first time.

Should I replace all the lifters on the one side that is making noise?
What other parts might I need to order?

I will also buy the Haynes manual,I hope it covers lifter replacement,do I need to remover the head in order to change the lifter?

Thank you in advance

Mike

 

Some years ago my 2001 5.3 started ticking, only when cold, so some days later while I was at the parts counter I asked one of the parts guys about the sound. He sent me to the most experienced service manager and he told me , “most of those tick after they get some miles and it might not be lifters.” He countinued telling me that at some point Chevy stopped putting piston skirts on those engines. As a result what you may be hearing is a little piston slap until it warms up. Mine always quits after it warms up a little.

 

I could not hear any tapping sound from the video but I’m more inclined to think it is one lifter hanging up because it is not getting enough oil. Though synthetic oil hardly thickens in cold weather and you do use good oil, on the next oil change try a different brand of synthetic oil but DO NOT use “High Mileage” oil. Check the owners manual if a lighter oil can be used such as 5w-20 for extreme cold weather. It could be a push rod worn just enough that when cold is maybe a few thousands of an inch shorter resulting in a tapping sound.

As noted by others, the knock sensor can detect this tapping as knock and the timing is retarded so a little engine performance might be noticed. I believe your engine has VVT. Look in the RPO plate, usually inside the glove box, for the engine code. You can find a lot of information on you engine.

When a lifter starts to fail or with some normal wear, tapping noise comes from the rocker arms because of too much play. Sometimes just a little turn on the rocker arm adjustment would be all that is needed. But since it goes away once warmed up, don’t fix what’s not broke. The 4.8 is a sold engine and should easily go 200,000 miles.

 

I have a 2000 GMC Yukon with 225000 miles on it & it has had the tick almost from day 1. I just let it warm up & disappear then go, to me not worth the effort to fix.

 

I suggest you use an engine oil cleaner. One of the best ways to clean lifters, oil galleries and even piston rings is to add a quart of regular old style ATF to your engine oil. Don't over fill the oil level in engine. If need be drain a quart out of engine before adding the ATF. Drive the truck for a few days to let the ATF do its job cleaning deposits off engine parts and out of oil galleries. I don't suggest any high rpm driving though. Change the oil and filter and check the drained oil for how black or dirty it is. If you have been using Fram oil filters then forget that junk and buy a Wix or good quality filter. I suggest also using a fully synthetic oil. I use Mobil 1 in all my engines. The rumor has it that using synthetic oil in a high mileage engine is bad is from my experience wrong. My Ranger had over 100,000 on it before I started using Mobil 1 in it. I had a very tiny bit of seepage from the front seal afterward but that was it for the synthetic oil causing seals to start leaking.
I had a Ford Ranger with a 3.0 V-6 that I used Castrol oil and changed oil every 3,000 miles. When I would start the engine it had a slight ticking sound that went away as it warmed up. I replaced the junk Fram filter with a Wix and put Mobil 1 fully synthetic oil in it. Guess what? The engine ticking at start up was never heard again.
I run Mobil 1 and I often go 8-9 thousand miles before changing oil. I have over 200,000 miles on my 04 Silverado 5.3 V-8 and it doesn't use or burn any oil. Same as my 06 Impala with a 3.9 V-6. The engines are as quiet as a brand new engine. I swear by fully synthetic oil.
Do an engine oil cleaning and see if that does away with the ticking. You can replace lifters but if the oil galleries are clogged up then the new lifters will probably start making noise also. Been there done that.

 

I suggest you use an engine oil cleaner. One of the best ways to clean lifters, oil galleries and even piston rings is to add a quart of regular old style ATF to your engine oil. Don't over fill the oil level in engine. If need be drain a quart out of engine before adding the ATF. Drive the truck for a few days to let the ATF do its job cleaning deposits off engine parts and out of oil galleries. I don't suggest any high rpm driving though. Change the oil and filter and check the drained oil for how black or dirty it is. If you have been using Fram oil filters then forget that junk and buy a Wix or good quality filter. I suggest also using a fully synthetic oil. I use Mobil 1 in all my engines. The rumor has it that using synthetic oil in a high mileage engine is bad is from my experience wrong. My Ranger had over 100,000 on it before I started using Mobil 1 in it. I had a very tiny bit of seepage from the front seal afterward but that was it for the synthetic oil causing seals to start leaking.
I had a Ford Ranger with a 3.0 V-6 that I used Castrol oil and changed oil every 3,000 miles. When I would start the engine it had a slight ticking sound that went away as it warmed up. I replaced the junk Fram filter with a Wix and put Mobil 1 fully synthetic oil in it. Guess what? The engine ticking at start up was never heard again.
I run Mobil 1 and I often go 8-9 thousand miles before changing oil. I have over 200,000 miles on my 04 Silverado 5.3 V-8 and it doesn't use or burn any oil. Same as my 06 Impala with a 3.9 V-6. The engines are as quiet as a brand new engine. I swear by fully synthetic oil.
Do an engine oil cleaning and see if that does away with the ticking. You can replace lifters but if the oil galleries are clogged up then the new lifters will probably start making noise also. Been there done that.

Loudpipes
I'm with you on Mobil1, bought this truck in 2004 & have ran Mobil1 till this day. At about 215000 rear main seal as a little drip & that's it, I attest the oil has kept this engine running great other than my lifter tick on cold starts.

 

Also having to remove the head to replace lifters is news to me. From my experience remove the intake manifold and pan. Remove the valve, lifter rockers and push tunes. You might need a expander tool to grab into the lifter top to remove them. Maybe the newer engine like the 5.3 are different though.

 

Also note, that the LS engines also have an oil filter just for the lifters.
It's in one of the passages from the main oil filter.
Hard to get at, but cheap to buy.

There are a couple of threads on here talking about it.

 

Very interesting replies gentlemen! Engine flush/cleaner is pretty much unheard of here,I have read about adding ATF to the engine oil but I thought that was largely redundant due to ATF no longer having detergents in it?

I think I will order the following in case I need them.

All the lifters down one side of the engine
Head gasket
Manofold gasket
rockercover gasket

Workshop manuel

Anything else you think I need for the job?

 

Chevy Silverado 2007,4.8 liter V8,90,000 miles

Recently I have noticed a ticking sound getting a bit worse,I have followed the service intervals religiously and always used Castrol 5W-30 Synthetic Oil.

Oil pressure is good and if the engine is hot or has run along time it sounds fine,start up it is noticeable outside the car but not once inside and it does not make the noise with each and every cold start.I have looked for exhaust leaks too.

I have to order all my parts from the States because I live in Norway,I want to get all the parts the first time.

Should I replace all the lifters on the one side that is making noise?
What other parts might I need to order?

I will also buy the Haynes manual,I hope it covers lifter replacement,do I need to remover the head in order to change the lifter?

Thank you in advance

Mike

Mike, before doing anything, I'd change the oil and replace one quart of oil with one quart of transmission fluid and run it for about 500 miles and then change the oil again. I just don't know if you can do that, because I'm not totally familiar with the 2007 engine. If it has variable valve timing, you will get cam codes due to the difference in weight of the lubricants.

 

I have a ticklng noise in the back of my motor just started 2days ago. Sounds like a rod,but my friend says not ablown motor yet.he thinks it's a loose fly wheel,maybe a nut bouncing around.i still drive my 99gmc 5.3litre short distances.thinking about dropping the transmission check flywheel.oris there something else I should do? Markabsolon44@gmail.com

 

Does it stop if you park with the nose down hill?

 

Haven't tried that yet!will get back to you on that. Thanks
Markabsolon44@gmail.com

 

Haven't tried that yet!will get back to you on that. Thanks
Markabsolon44@gmail.com