Anyone got an 8.1 liter?

[Petrou]

Hello all,

I have a 2002 Chevy 2500hd with an 8.1 liter. Does anone else with an 8.1 have a a lifter tick when using certain oils, its seems that when i changed the oil this last time with Quaker QHP after the engine is good and hot it has a lifter tick, it doesent really do it much with conventional or high mileage M1. any way i was just curious if anyone else had this problem

 

[bretfraz]

The 8.1 is part of the GM Vortec modular V8 family, along with the 4.8, 5.3 and 6.0L. Are you sure the tick is not piston slap or cold start knocking? Those are well known issues with the Vortec V8's.

Anyway, in my 5.3 I use GC as its a fairly high viscosity 0W-30, almost a 40W. The ticking sound is pretty well muted using GC compared to Mobil One or a few other synths.

I've driven GM trucks with all these motors in them, some used almost 100% for towing with 100K miles on them. Most had the ticking sound but all ran well and pulled hard. So, yeah, I'll say lots of people have had this problem but how its manifested itself is another issue.

 

[Chris142]

Originally Posted By: bretfraz
The 8.1 is part of the GM Vortec modular V8 family, along with the 4.8, 5.3 and 6.0L. Are you sure the tick is not piston slap or cold start knocking? Those are well known issues with the Vortec V8's.

Wrong. It's based on the old BB Chevy.

 

[cronk]

8.1 is a big block engine but is a newer design and different from the old big blocks. The 4.8, 5.3 and 6.0 are all small blocks.

People try to compare these to the old chevy v-8 engines , but they are a whole new design and no parts are shared with the old engines.
Most of these engines seem to like a more thick oil.
Try Valvoline, Mobil or Amsoil.

 

[typ901]

I thought the 8.1 was a stroked 7.4?

 

[bretfraz]

Straight from GM.com

Introduced in 2001, the Vortec 8.1L was essentially a new engine. Nearly 90 percent of its parts were completely redesigned. While it shares its valve centers, bore centers and bore diameter with the previous 7.4L big block, stroke was increased 9.4 mm (0.37 inch) to increase displacement 700 cc. The latest math-based engineering tools were used to improve the flow and distribution of oil and coolant, to refine castings and to improve production quality and efficiency.

 

[bretfraz]

I misspoke regarding the 8.1L. I've always assumed it was part of the same family as the smaller displacement engines but its not:

The Gen IV Vortec V-8 truck engines are built in a variety displacement and power combinations, including versions with aluminum cylinder blocks. All engines share a basic architecture that includes 4.400-inch bore centers – the same design foundation on which the original small-block V-8 was developed in the early 1950s. Initial Gen IV engine offerings include:

* 4.8L iron block (RPO LY2), rated at approximately 290 horsepower*
* 5.3L iron block (RPO LY5) with Active Fuel Management technology, SAE Certified at 320 horsepower (including E85-capable version – RPO LMG)
* 5.3L aluminum block (RPO LC9) with Active Fuel Management technology and E85 capability, rated at approximately 310 horsepower*
* 6.0L iron block (LY6) heavy-duty engine with variable valve timing, rated at approximately 350 horsepower*
* 6.0L aluminum block (L76) with Active Fuel Management technology and variable valve timing, rated at approximately 355 horsepower*
* 6.2L aluminum block (L92) with variable valve timing, capable of 380 to 403*

All Gen IV Vortec engines are designed to provide improved fuel economy and reduced emissions, compared to previous-generation small-block V-8s. The 5.3L engines with Active Fuel Management technology, for example, provide up to 7 percent increased fuel efficiency when measured against a comparable non-equipped 5.3L engine.

The new engines also meet more stringent emissions standards. In fact, compared to truck engines of a decade ago, the Gen IV Vortec engine family is approximately 90 percent cleaner. Cast iron exhaust manifolds matched with dual close-coupled catalytic converters help reduce cold-start emissions, which is the largest source of vehicle emissions.

http://media.gm.com/servlet/GatewayServl...=39&docid=21579

 

[Petrou]

ya i know its not the piston slap that comes with these motors, its only when its well warmed up. if i use different oils i get different results. so i was just curious

 

[LordAbbett]

I have a 2006 8.1 I don't think the valvetrain is excessively noisy; in fact on the quite side. U think it's all the lifters' noisy or perhaps just one?
using 5W30? they do seem to shear more than 10W30.

This engine is more like than unlike the old big block chevys. Firing order is changed though. coolant comes out the front of the heads no longer thru the intake. 8coils like the LS based V8s. 4.25B X 4.38S

I know of a 2000 tahoe w/5.3 and a loud lifter or 2
It's been that way for the last 150,000 miles.

 

[Petrou]

well at around 1200-about 1600 rpm is when i hear it. its never at idle, the idle is sound is the piston slap, its coming from around the left bank, but like i said its a valve train issue. but only really there when i use quaker state QHP. it is 5-30. i get the best MPG with this oil but i think i may need to run lucas additive or something. (which i dont like)

oh and yes i do tow with it, up to 11000 lbs before. its pretty regular that it gets at least a 4000 lb load once a month and the 11000 lb load once or twice a year. plus any other load when i want to take four of the six horses out.

 

[crazycrak]

Ive heard some of the 6.0s with a tick.. sounds like lifters/ injectors or maybe even exhaust. not sure tho

 

[el_zorro]

I rented a brand new U-Haul last summer to move some household goods and was surprised at this engine. It had power to spare even in a 28ft truck and the gas mileage was better than expected, at $4.25 gas last summer it cost me $200 to drive from SE Wisconsin to SE Michigan. Not bad. I didnt notice any piston slap and I have a 4.8L in a Sierra that has a little slap. I am going to use GC on the next fill and will report back. It will be a ashame if GM discontinues this engine. I heard it is not an option in a pickup anymore, hopefully it will be retained for medium duty trucks.

 

[mechtech2]

From bretfaz post quoting GM.com -
"The latest math based engineering tools were used"
Is this a special gift or extra burden that needs to be identified?


Aw c'mon now... let's just round off Pi to 3.25!

 

[cronk]

Originally Posted By: Petrou
well at around 1200-about 1600 rpm is when i hear it. its never at idle, the idle is sound is the piston slap, its coming from around the left bank, but like i said its a valve train issue. but only really there when i use quaker state QHP. it is 5-30. i get the best MPG with this oil but i think i may need to run lucas additive or something. (which i dont like)

oh and yes i do tow with it, up to 11000 lbs before. its pretty regular that it gets at least a 4000 lb load once a month and the 11000 lb load once or twice a year. plus any other load when i want to take four of the six horses out.


If you only get the noise with qs, don't use qs.
Adding Lucas to it will only degrade the quality of the oil further and cause foaming.
Try some Valvoline, their 5w30 tends to run on the thicker side.
If your doing regular towing I would just stick with a 10w30 as your oil will run hotter and tend to shear faster.

 

[bretfraz]

Originally Posted By: mechtech2
From bretfaz post quoting GM.com -
"The latest math based engineering tools were used"
Is this a special gift or extra burden that needs to be identified?


Aw c'mon now... let's just round off Pi to 3.25!


haha.... I guess it depends on what engineering tools you are used to. Those non-math based ones can be a little confusing, I'd imagine.

 

[LordAbbett]

Originally Posted By: Petrou
well at around 1200-about 1600 rpm is when i hear it. its never at idle, the idle is sound is the piston slap, its coming from around the left bank, but like i said its a valve train issue. but only really there when i use quaker state QHP. it is 5-30. i get the best MPG with this oil but i think i may need to run lucas additive or something. (which i dont like)

oh and yes i do tow with it, up to 11000 lbs before. its pretty regular that it gets at least a 4000 lb load once a month and the 11000 lb load once or twice a year. plus any other load when i want to take four of the six horses out.


Last summer I towed 4 horses for my brother from Georgia to NW arkansas(allmost missouri) in his old steel horse trailer which is pretty heavy empty. For a gas motor the 8.1 will pull like nothing I've had. I was surprised what grade it would pull in 6th gear. 6speed manual.

 

[Petrou]

Originally Posted By: LordAbbett
Originally Posted By: Petrou
well at around 1200-about 1600 rpm is when i hear it. its never at idle, the idle is sound is the piston slap, its coming from around the left bank, but like i said its a valve train issue. but only really there when i use quaker state QHP. it is 5-30. i get the best MPG with this oil but i think i may need to run lucas additive or something. (which i dont like)

oh and yes i do tow with it, up to 11000 lbs before. its pretty regular that it gets at least a 4000 lb load once a month and the 11000 lb load once or twice a year. plus any other load when i want to take four of the six horses out.


Last summer I towed 4 horses for my brother from Georgia to NW arkansas(allmost missouri) in his old steel horse trailer which is pretty heavy empty. For a gas motor the 8.1 will pull like nothing I've had. I was surprised what grade it would pull in 6th gear. 6speed manual.


i know that was the main reason for me getting this engine/ truck. it pulls great in sixth gear, around here i have to go to fifth and fourth but thats only cuz six percent grades that go on for two-three miles has that effect sometimes.

 

[Petrou]

Originally Posted By: cronk
Originally Posted By: Petrou
well at around 1200-about 1600 rpm is when i hear it. its never at idle, the idle is sound is the piston slap, its coming from around the left bank, but like i said its a valve train issue. but only really there when i use quaker state QHP. it is 5-30. i get the best MPG with this oil but i think i may need to run lucas additive or something. (which i dont like)

oh and yes i do tow with it, up to 11000 lbs before. its pretty regular that it gets at least a 4000 lb load once a month and the 11000 lb load once or twice a year. plus any other load when i want to take four of the six horses out.


If you only get the noise with qs, don't use qs.
Adding Lucas to it will only degrade the quality of the oil further and cause foaming.
Try some Valvoline, their 5w30 tends to run on the thicker side.
If your doing regular towing I would just stick with a 10w30 as your oil will run hotter and tend to shear faster.


ill give it a try this next oil change, i was short on cash so i was wally world and got qs.