Engine trouble. Need help.

[C-ya]

In the good ole days, you just popped the intake manifold off, pull the valve cover(s), loosen the rockers, pull the push rods and reach in and just grab them old lifters right outta their hole.

What changed to require a head removal for a lifter? Something to do with them being controllable? Granted, I haven't seen inside these DOD engines. Just seems odd to have to pull the head to change a lifter. I'll have to get my Haynes manual out when I get home.

 

[NJTB]

Make sure you have a lobe left on the cam to lift the pushrod.
$900 seems excessive but I've never been inside a v8 Blazer.

 

[Sparky]

In the good ole days, you just popped the intake manifold off, pull the valve cover(s), loosen the rockers, pull the push rods and reach in and just grab them old lifters right outta their hole.

What changed to require a head removal for a lifter? Something to do with them being controllable? Granted, I haven't seen inside these DOD engines. Just seems odd to have to pull the head to change a lifter. I'll have to get my Haynes manual out when I get home.

Dunno, I'm just guessing that may be the reason. But now that I'm home I am looking at my haynes and it says:

"Remove the intake manifold, valve covers, rocker arms, pushrods, valley cover (2002 - 2004) or valve lifter oil manifold (2005 - 2009), timing chain, and the cylinder heads. Also remove the radiator and air conditioning condenser and the camshaft position sensor)."

So apparently the heads do have to come off. Also it says:

"On 2005 and later 5.3L Displacement on Demand models, these specific lifters are installed in the notched areas of the retainer. DO NOT attempt to withdraw the camshaft with the lifters in place."

Now I'm starting to see why the shop is wanting to charge so much. They probably want to pull the camshaft to inspect it for damage, and to do so they have to remove BOTH heads to get all the lifters out, which also means they need all those extra gaskets and seals.

Honestly if I was going through all that I'd be tempted to replace all the lifters since everything is already apart, although I know that adds a fair amount of cost. At least inspect each lifter very well to be sure it isn't worn too badly.

 

[C-ya]

Yep, the heads have to come off since they cover the lifter retainers. Gotta make things more complicated, huh?

 

[ch41]

I just figured I would publish the final result of my engine trouble. I had the work performed at a local shop. They confirmed a collapsed lifter on cyl 4. They replaced both lifters on that cylinder, ($65 per lifter), new head gasket ($183), two other gaskets one was intake
Gasket for a price I can't recall, $79 to resurface the head to prep for new gasket I'm assuming, $46 for six quarts of oil, $10 for a filter, $26 for a gallon of antifreeze, and $600 for labor. Plus tax of course grand total was $1107.43. I wasn't happy with the price, but the envoy seems to be running great again, so for that I am happy. The job took about 2 days once they started it. I'm not sure what caused it, but I have the bad lifter in my hand and no matter what I do, I can't get it to pop back up. I hope nobody else has this problem but maybe this thread can help someone with a diognosis. Again, thank you to all for the input!

 

[gmcman]

Good to hear it's all back together, sux they bored a howitzer sized round through your wallet.

You mentioned that you are using the Autolite plugs...I know the 4.2 only likes the AC-Delco plugs but maybe someone can chime in on the 5.3. Something you may want to consider if you're not using synthetic oil already is to use it on a regular basis and not the dino oil, again I'm just throwing this out there...not sure what oil you use. I feel it's a safe assumption that any type of residue or varnish inside a lifter bore could cause an erratic operation. Synthetic generally dissolves any varnish or sludge and overall keeps a motor cleaner inside, could be some easy preventive maintenance.

 

[ch41]

I'm not sure if this issue is at all related to my original post but here's my problem.

The temp here has been around 5-10 degrees for the past few days. I now have little oil pressure when I start the engine. If I let it idle I have zero pressure according to the guage on the cluster. If I feather the throttle I can keep the pressure up at about 20 lbs until the engine warm up. My oil level is good. I never noticed much variation in the oil pressure guage in the past however since I had the lifter replace I see much more variations in the pressure now. If I stop at a traffi light the pressure drop to about 30 and then when I throttle up it hits somewhere around 50-60. It always seemed to be right around 40 all the time before with slight boost with acceleration from a dead stop. I did run the engine flush through when I was figuring out the lifter issue. Could I have cleaned out to much that it's now lacking oil pressure? Or could my pump be going? I heard something about a oil pick up tube o-ring going bad? Anyone have any advice or suggestions?
Thanks in advance!

 

[BRomanJr]

I'm not sure if this issue is at all related to my original post but here's my problem.

The temp here has been around 5-10 degrees for the past few days. I now have little oil pressure when I start the engine. If I let it idle I have zero pressure according to the guage on the cluster. If I feather the throttle I can keep the pressure up at about 20 lbs until the engine warm up. My oil level is good. I never noticed much variation in the oil pressure guage in the past however since I had the lifter replace I see much more variations in the pressure now. If I stop at a traffi light the pressure drop to about 30 and then when I throttle up it hits somewhere around 50-60. It always seemed to be right around 40 all the time before with slight boost with acceleration from a dead stop. I did run the engine flush through when I was figuring out the lifter issue. Could I have cleaned out to much that it's now lacking oil pressure? Or could my pump be going? I heard something about a oil pick up tube o-ring going bad? Anyone have any advice or suggestions?
Thanks in advance!

Sorry to hear you are still having issues.
That does sound like poor oil pressure when cold, but after warmed up you get 30 at idle sounds ok. It sounds more like your sender is messing up badly when cold and working better after warmed up.
The best diagnosis is to attach a mechanical oil pressure gauge to see what is actually going on. Could be a bad sender, possibly a loose/damaged wire harness or connector from your previous repair.

The oil pump pickup o-ring is unlikely since you get good oil pressure when warm. Usually leaky oil systems and worn out bearings have higher pressure when cold and drop off as temperature increases.

 

[Jkust]

Do you hear any ticking with the low oil pressure symptom when you start it in the cold?

 

[ch41]

Do you hear any ticking with the low oil pressure symptom when you start it in the cold?

I do not hear any ticking noise or anything out of ordinary. I had my pressure sensor go bad about two years ago and replaced it. However when it went bad it was showing pegged high pressure. Could I attach a oil pressure guage where that sensor is threaded in?

 

[BRomanJr]

I do not hear any ticking noise or anything out of ordinary. I had my pressure sensor go bad about two years ago and replaced it. However when it went bad it was showing pegged high pressure. Could I attach a oil pressure guage where that sensor is threaded in?

Yes, That is the best spot, if readings seem normal, replace the sender of course.

Check out the wiring and check that the connector is plugged onto the sensor properly as you are taking it apart.

 

[ch41]

Yes, That is the best spot, if readings seem normal, replace the sender of course.

Check out the wiring and check that the connector is plugged onto the sensor properly as you are taking it apart.

I will try those suggestions. Is the sender the same thing as what we might also call a oil pump? Also am I just checking wiring from the pressure sensor? I'm not sure what other wires or where they would be. Just a side note, when I left work today at 3:00pm the temp outside was 16 according to my read out. When I started the engine I didn't have the zero pressure and check gauges light like I did yesterday. (8 degrees @ 5:30 pm.). Now today the guage was fluctuating between about 10-30 psi. Once the engine warmed up it held a constant 35-45psi all the way home. About 15 miles. I did check the oil level again today before I started it, and it was about a half inch above the hash marks. And thanks again for the responses!

 

[Sparky]

Check the pressure with a mechanical gauge first, but it does sound like a sensor issue to me. Usually cold startup has higher oil pressure because the oil is thicker, then it drops a bit as the oil warms up. Every car that I've had with a real oil pressure gauge has done this.

 

[Jkust]

So this is a long shot but i've had this similar situation happen one time before on another car I owned. Turned out the oil change place put the wrong oil filter on the car. New filter instantly corrected.

 

[ch41]

So this is a long shot but i've had this similar situation happen one time before on another car I owned. Turned out the oil change place put the wrong oil filter on the car. New filter instantly corrected.

Now that is thinking outside the box. I've always changed my own oil and filter but this oil and filter were done at the shop that did the lifter repair. Having the wrong filter on could be possible. It's due to be changed so I'll see how that turns out. I never noticed any oil pressure fluctuation at all until I had the lifter replaced.

 

[Old Coot]

I will try those suggestions. Is the sender the same thing as what we might also call a oil pump? Also am I just checking wiring from the pressure sensor? was about a half inch above the hash marks.

Most will consider the sending unit and pressure sensor as one and the same.

Just for curiousity sake, I would pull of the wire off the sending unit and plug it back in a few times, just be sure you have good electrical contact.

The oil filter is a good idea ... +1 for thinking outside the box!

 

[daniel944turbo]

I just figured I would publish the final result of my engine trouble. I had the work performed at a local shop. They confirmed a collapsed lifter on cyl 4. They replaced both lifters on that cylinder, ($65 per lifter), new head gasket ($183), two other gaskets one was intake
Gasket for a price I can't recall, $79 to resurface the head to prep for new gasket I'm assuming, $46 for six quarts of oil, $10 for a filter, $26 for a gallon of antifreeze, and $600 for labor. Plus tax of course grand total was $1107.43. I wasn't happy with the price, but the envoy seems to be running great again, so for that I am happy. The job took about 2 days once they started it. I'm not sure what caused it, but I have the bad lifter in my hand and no matter what I do, I can't get it to pop back up. I hope nobody else has this problem but maybe this thread can help someone with a diognosis. Again, thank you to all for the input!

I'm glad you got your problems solved. I was one of the lucky ones that had the same exact problem. After replacing the bad lifter about 3 months later i had another one failed that was part of the DOD system. The second time i had them replace all 8 of them that ties to the DOD to be on the safe side because forking out that kind of money is no fun. My oil pressure sensor went bad also so that got fixed too. About 4 months after problem free now i'm having more problems with vehicle but different problem that i plan on posting a new a thread to get help.

 

[mrphoenix80]

If you have the oil pressure sensor out there is a filter under it you should be able to pick it out and clean it. Maybe some crap got knocked loose and is restricting that filter?
Also how often do you do your oil changes? I dont like the oil life monitor system as it seems the change interval is too long. Most engines I see that have the oil changed @3k miles dont have issues that the 6k and above ones do. We are asking the oil to do more like cam timing and cylinder deactivation and yet we think it can last longer? For my money an oil change @3k is cheap insurance.
The bank 1(left) valve cover was redesigned to prevent oil consumption through the PCV system. The old ones did not allow splash oil to drain out of the PCV baffle. So that oil got ingested and burned.