My cold start tick

[gmcman]

So back in Feb I posted a vid of the cold start tick I was experiencing. I haven't been inside the valve cover so I don't really know what could be taking up the gap causing the tick. Fast forward to October and I ran a can of BG 44K and then some Quick Clean then changed the oil and still using M1.

The tick before the treatment was happening almost every day or every other day, always varied in duration and was routinely about 10-20 sec but this is about the longest it would go. Since the treatment I still get a cold-start tick but the intensity is reduced by about half and the other deeper noise I was hearing which sounded like a piston-slap is almost non-existent but only very faintly heard and it's muffled by the injector noise. The cold-start tick is very infrequent now, this is the first time it has gone for over a couple seconds since the treatment but it lasted longer in duration which makes me question the oil pump. I wanted to post a vid of a longer duration noise earlier but it wouldn't do it.

I drove it around for awhile and took another short vid, motor is very quiet but generally is when warm.

I imagine most people have very quiet motors but my question is, can these oil pumps lose their efficiency or overall performance at around 175K? I haven't seen these pumps yet so I don't know.

Either case, whatever my issue is has been greatly reduced but I would like to know what may be casuing it. I was thinking maybe I could get it to tick then shut it off then pull the valve cover and see if anything is a miss but that's a longshot and takes awhile.....still an option.

[video=youtube;lp5YZ5ko33Y]http://www.youtube.com/watch?v=lp5YZ5ko33Y&feature=youtu.be[/video]

 

[Voymom]

Lifter?

 

[gmcman]

Im not sure what type of lifter is used in these, not like the 5.3 since this is is an overhead cam design.

 

[CaptainXL]

Im not sure what type of lifter is used in these, not like the 5.3 since this is is an overhead cam design.

Yes i believe there are hydraulic lifters in the i6. How else does the engine expand? A kerosene flush fixed this for me.

 

[Ed H]

Lifter. Pretty common (on many vehicles).

She purrs like a kitten when warm though.

 

[gmcman]

Yes i believe there are hydraulic lifters in the i6. How else does the engine expand? A kerosene flush fixed this for me.

Please elaborate on the kerosene.

Engine expand, mine is still 4.2.

Just playin, I figured it was hydraulic of somesort but I don't know about the design, never seen one on this motor. I would like to know the mechanics of it to understand what could be hanging up.

 

[CaptainXL]

Please elaborate on the kerosene.

I meant to say to do an engine flush. Engine flush products are basically just kerosene.

Also might want to try Gunk Valve-Medic. It's a detergent made up of 85-95% diesel fuel. Diesel has a flash point of 144 deg F but Kerosene can be lower at 100 deg F. So since diesel has a higher flash point it is safer to run in the engine for long periods of time. Which is what you do with Valve-medic. You just leave it in the engine and hope it helps with the tapping noise.

When I had my 1999 GMC Sonoma a while back I had this constant ticking noise from the 4.3 v6 lifters straight from the factory. So I just added a bottle of this stuff whenever the noise came back. Worked pretty good.

Now I don't use it anymore since I found out that flushes every other oil change help in that regard.

Engine expand, mine is still 4.2.

Just playin, I figured it was hydraulic of somesort but I don't know about the design, never seen one on this motor. I would like to know the mechanics of it to understand what could be hanging up.

I will look it up and confirm to be exact what they are called. But its my understanding that OHC engines usually have lifters, tappets or hydraulic lash adjusters.

 

[WarGawd]

I meant to say to do an engine flush. Engine flush products are basically just kerosene.

Also might want to try Gunk Valve-Medic. It's a detergent made up of 85-95% diesel fuel. Diesel has a flash point of 144 deg F but Kerosene can be lower at 100 deg F. So since diesel has a higher flash point it is safer to run in the engine for long periods of time. Which is what you do with Valve-medic. You just leave it in the engine and hope it helps with the tapping noise.

When I had my 1999 GMC Sonoma a while back I had this constant ticking noise from the 4.3 v6 lifters straight from the factory. So I just added a bottle of this stuff whenever the noise came back. Worked pretty good.

Now I don't use it anymore since I found out that flushes every other oil change help in that regard.



I will look it up and confirm to be exact what they are called. But its my understanding that OHC engines usually have lifters, tappets or hydraulic lash adjusters.

There are no lifters in the I6, but Capn has it correct there are hydraulic actuated valve lash adjusters. I think roadie on the OS is just making a minor error in his use of the term "lifter"

 

[WarGawd]

So back in Feb I posted a vid of the cold start tick I was experiencing. I haven't been inside the valve cover so I don't really know what could be taking up the gap causing the tick. Fast forward to October and I ran a can of BG 44K and then some Quick Clean then changed the oil and still using M1.

The tick before the treatment was happening almost every day or every other day, always varied in duration and was routinely about 10-20 sec but this is about the longest it would go. Since the treatment I still get a cold-start tick but the intensity is reduced by about half and the other deeper noise I was hearing which sounded like a piston-slap is almost non-existent but only very faintly heard and it's muffled by the injector noise. The cold-start tick is very infrequent now, this is the first time it has gone for over a couple seconds since the treatment but it lasted longer in duration which makes me question the oil pump. I wanted to post a vid of a longer duration noise earlier but it wouldn't do it.

I drove it around for awhile and took another short vid, motor is very quiet but generally is when warm.

I imagine most people have very quiet motors but my question is, can these oil pumps lose their efficiency or overall performance at around 175K? I haven't seen these pumps yet so I don't know.

Either case, whatever my issue is has been greatly reduced but I would like to know what may be casuing it. I was thinking maybe I could get it to tick then shut it off then pull the valve cover and see if anything is a miss but that's a longshot and takes awhile.....still an option.

Damn Youtube - I always find something to distract me at the end of each video.

Thx for posting those gmcman. Not really sure what comments to make at this point, I've watched it several times, still trying to absorb the differences from one to the next. I have some pics to take in the morning for meerschm's tranny fluid thread, so when I do, I'll make some comparative vids to post here for you. Since I bought mine in July I've always been a bit suspicious that the cold start noise levels aren't "normal". When you posted in CapXL's big thread that BG44K helped a lot, I was def intrigued.

As for your question on oil pressure related possibilities, I can say that the GM Service Info has fairly extensive references on the subject, some of which reference the possibility of a broken valve lash adjuster. I'll put a brief blurb here, but I think both you and CapXL would really like to have the full GMSI....great thanx again to blckshdw for his post, which led me to a source for it.

Blurb:

Spoiler

With the vehicle on a level surface, run the vehicle for a few minutes, allow adequate drain down time (2-3 minutes) and measure for a low oil level.
If required, add the recommended grade engine oil and fill the crankcase until the oil level measures full on the oil level indicator.
Run the engine briefly (10-15 seconds) and verify low or no oil pressure on the vehicle gage or light.
Listen for a noisy valve train or a knocking noise.
Inspect for the following:
• Oil diluted by water or glycol (anti freeze)

• Foamy oil

Remove the oil filter and install the J 42907 (1) .
Install J 21867 (2) or equivalent to the J 42907 .
Run the engine and measure the engine oil pressure.
Compare the readings to Engine Mechanical Specifications . {Oddly this link in GMSI leads to a pile of specs that DON'T include oil pressure!??
If the engine oil pressure is below specifications, inspect the engine for one or more of the following:
• Oil pump worn or dirty

• Refer to Oil Pump Cleaning and Inspection .

• Oil pump screen loose, plugged, or damaged

• Oil pump screen O-ring seal missing or damaged

• Malfunctioning oil pump pressure regulator valve

• Excessive bearing clearance

• Cracked, porous, or restricted oil galleries

• Oil gallery plugs missing or incorrectly installed

• Refer to Engine Block Plug Installation .

• Broken valve lash adjusters

• Repair as necessary

If the reading on J 21867 or equivalent is within specifications, inspect for the following:
• Plugged or incorrect oil filter and/or malfunctioning oil bypass valve

• Malfunctioning vehicle oil pressure gage or sensor

• Repair as necessary

 

[CaptainXL]

There are no lifters in the I6, but Capn has it correct there are hydraulic actuated valve lash adjusters. I think roadie on the OS is just making a minor error in his use of the term "lifter"

I don' think Bill made any error if thats what he said. The terms are used interchangeably. A hydraulic valve lifter is also known as a hydraulic tappet or a hydraulic lash adjuster.

 

[WarGawd]

I don' think Bill made any error if thats what he said. The terms are used interchangeably. A hydraulic valve lifter is also known as a hydraulic tappet or a hydraulic lash adjuster.

It's not a huge deal, and the terms may be used interchangeably, but I believe it's incorrect to do so. The lifter used to be what rode the cam lobe, and the pushrod sat atop that to actuate the rocker arm. Back in the days of solid lifters, there was an additional valve lash adjustment possible by (IIRC) adjusting the rocker arm height. In the I6 the thing that follows and rides on the cam lobes is no longer a lifter, it's a roller, directly attached to the rocker arm. I haven't found a good pic that shows where the lash adjuster is situated in the valvetrain.

From The Lifter/Cam Relationship: Engine Builder “The primary difference between a lifter and lash adjuster is that unlike a lifter, the lash adjuster does not contact the camshaft lobe.”

 

[CaptainXL]

From The Lifter/Cam Relationship: Engine Builder “The primary difference between a lifter and lash adjuster is that unlike a lifter, the lash adjuster does not contact the camshaft lobe.”

That's right. The cam is on top which contacts the rocker arm underneath. One half of the rocker arm contacts the top of the valve. The other half of the rocker arm is pressed against the lash adjuster. The camshaft lobe contacts the roller in the middle of the rocker arm.

As the camshaft lobe rotates downward it forces the rocker arm down which in turn simultaneously pushed the plunger in the lash adjuster and valve down. In this downward direction the lash adjuster is stiff and will not move down. Only the valve can move down. At this point it is now adjusted or "pumped up". It is now taking up the slack where the rocker arm contacts the tip of the valve stem.

It's an interesting arrangment. Instead of the cam pushing the lifter in a OHV engine the cam pushes the rocker arm. If the valve lash adusters are not working correctly (collapsed) then it appears the valves won't open as much as they should. Excessive valve train noise might mean there is a problem which would require inspection. Here is a picture.

View attachment 24036

View attachment 24037

 

[dfc739]

Are you smelling any exhaust up there? It sounds a little like an exhaust manifold leak. You might pull the heat shield and check since these exhaust manifolds and bolts are notorious for cracking and breaking.

Have you ever pulled the valve cover before? If not, then get ready for a fight with the intake. Once the intake is off then it's easy... until you get ready to put it back on. If you have pulled the intake before, then I would reserve a weekend to pull the valve cover and check the cam followers and hydraulic valve lash adjusters. If you PM me your address I can send you some of the parts I took out of my old engine that burned a valve.

 

[gmcman]

Are you smelling any exhaust up there? It sounds a little like an exhaust manifold leak.

Have you ever pulled the valve cover before? If not, then get ready for a fight with the intake. Once the intake is off then it's easy... until you get ready to put it back on. If you have pulled the intake before, then I would reserve a weekend to pull the valve cover and check the cam followers and hydraulic valve lash adjusters. If you PM me your address I can send you some of the parts I took out of my old engine that burned a valve.

I haven't gone through and checked the bolts, but I'm fairly confident there is no exhaust leak. The ticking stops abruptly and sometimes it's not even there.

I haven't pulled the valve cover yet, but if I do I may make it into a day-long project and check everything as well as replace anything I can that doesn't require a matched surface or machining. For example, if I can replace a lash adjster without harming the cam lobe then I may but doubtful....need to check on that.

I may give it one more flush and see what happens, so far something is working as the tick has decreased substantially.

 

[CaptainXL]

I may give it one more flush and see what happens, so far something is working as the tick has decreased substantially.

Sounds like it's working. I am on my 4th flush since buying my truck a couple years ago. Last winter the ticking was really noticeable from the bottom end at the oil pan but now even in this 30 degree weather my ticking is gone. The flushing and also using the BG 44K seem to work good. Just keep at it. If your engine is anything like mine it will go away. It seems to be just stuck lash adjusters.