Timing chains, Pcv/Catchcan issues.

[Ck1984]

SO theres a consensus that Direct injection leads to caked up valves and poor PCV function leads to crud in the oil that wrecks timing chains.

what is the priority;

1. to do the catchcan fix Asap

2. OR drill out the PCV first
7/64s on top hole & 5/64s on both bottom holes

3. OR should we all do both if we want our LFX engines to last 200,000 miles

Also being second owner at 40,000 miles, should i also do some kind of engine oil flushes to clean out some of the crud deposited already, or pull off passenger valve cover first to see if there is crud built up first?
assuming passenger side is the dirty offending one?

[gtstorey]

I don't know that DI does anything but cause problems in the intake track leading to the intake valves. I don't think that crud buildup under the valve covers is a problem.

[Ck1984]

Originally Posted by gtstorey

I don't know that DI does anything but cause problems in the intake track leading to the intake valves. I don't think that crud buildup under the valve covers is a problem.

the timing chain tensioners depend on spring pressure AS WELL AS oil pressure.

SO, some of that crud build up will eventually make its way back into the oilpan/oilpump and be circulated and it builds up in the small orifices of the oil pressure activated chain tensioners
leading to loose chains and excessive wear that eventually sets off alot of OBD2 codes OR even skips a beat and the engine probly has a catastrophic failure soon after that.

at least thats what lotsa youtube mechancis are saying, like this guy

[Ck1984]

Originally Posted by gtstorey

I don't know that DI does anything but cause problems in the intake track leading to the intake valves. I don't think that crud buildup under the valve covers is a problem.

THANKS man;
your questioning my premises made me see the flaw in my questions, that being DI causes cruddy valves and poor PCV function causes crud buildup in oil leading to poor timing chain tension.

SO now my own question has been edited and the answer is;

BOTH are neccessary cuz its 2 seperate problems!

[KillboyPowerhead]

I'd get yourself a catch can and then once it's installed clean the intake valves (I walnut blasted them myself).

As far as I know the PCV outlet was made larger on the LFX compared to the LLT and there's no need to drill out the LFX, but I could be wrong...

Other than that, regular oil changes ought to keep the engine as clean as it's going to be. Not sure if it's build-up on the valvetrain and timing chains that's an issue, but more so not keeping an eye on the oil level. I've heard of some LLT's burning a quart every 1000 miles (at that rate you'd be topping up so often you wouldn't even need a conventional oil change...), and with a lack of oil/lube/heat dissipation the chains get hot and stretch.

I change my oil every 6 months (5 to 6000 km) with Mobil 1 full synthetic and check the level once a month or so, never seen the level drop much nor have had any issues; installed cams recently and the timing chains were still taut, about 80,000 km (50,000 miles).

[redcoats1976]

have 86,000 miles on my LFX with no problems and very rarely have to add any oil between changes.maybe if you are an aggressive driver theres more likelihood that a catch can is needed.

[Ck1984]

Originally Posted by KillboyPowerhead

I'd get yourself a catch can and then once it's installed clean the intake valves (I walnut blasted them myself).

As far as I know the PCV outlet was made larger on the LFX compared to the LLT and there's no need to drill out the LFX, but I could be wrong...

Other than that, regular oil changes ought to keep the engine as clean as it's going to be. Not sure if it's build-up on the valvetrain and timing chains that's an issue, but more so not keeping an eye on the oil level. I've heard of some LLT's burning a quart every 1000 miles (at that rate you'd be topping up so often you wouldn't even need a conventional oil change...), and with a lack of oil/lube/heat dissipation the chains get hot and stretch.

I change my oil every 6 months (5 to 6000 km) with Mobil 1 full synthetic and check the level once a month or so, never seen the level drop much nor have had any issues; installed cams recently and the timing chains were still taut, about 80,000 km (50,000 miles).

You could be right about LFX already fixed, most the mechanic videos i watched just stated 3.6 L chevy but at least one had LFX listed.
i will check it out myself

[Ck1984]

i checked my PCV valve if thats it on back of passenger valve cover and it does have a fairly large top hole, like 1/8 ish

SO i guess i just need a decent catchcan

whats most popular decent priced model?

[JAFWF]

Originally Posted by Ck1984

i checked my PCV valve if thats it on back of passenger valve cover and it does have a fairly large top hole, like 1/8 ish

SO i guess i just need a decent catchcan

whats most popular decent priced model?

You are asking two questions, probably not going to like my answer. Firm believer in you get what you pay for, so if you are going to do something be prepared to pay the price. Elite E2-X Dual Outlet System is one of the best, not cheap.

[Ck1984]

Originally Posted by JAFWF

You are asking two questions, probably not going to like my answer. Firm believer in you get what you pay for, so if you are going to do something be prepared to pay the price. Elite E2-X Dual Outlet System is one of the best, not cheap.

you are right, i dont wanna pay 354 usd plus shipping, taxes, customs, duty and conversion to cdn$
especially when i could probly swap in a entire used engine for price of 5 of those elites ;-)

im thinking under 100 usd and if it doesnt work i will put it on my PUNISHER THEMED LS swapped 85 Cutlass that i have for sale, as a selling point

[PaulsSS]

I never put a catch can on my v6 and at 90k the valves had minimal carbon on them. I walnut blasted them and it made absolutely no difference in any way. I do 3 things, I only use premium fuel, I only use Pennzoil plat changed every 6k and I use Lucas fuel treatment 6ozs every tank fill up. Its at 145k now and doesn't run any different than it did at 45k. I just checked the valves and the little bit of carbon on them it not worth the effort to clean off. We also mostly do highway driving with very little stop and go. The stop, turn off the engine then 1/2 hr later restarts are the "CARBON BUILDERS" carbon does not form on the intake valves while the car is running YES I said CARBON DOES NOT FORM ON THE INTAKE VALVES WHILE THE CAR IS RUNNING> it forms after the engine is shut off hot. The oil from the PCV system and valve guides vaporizes after the engine is shut down hot and causes this carbon build up on the very hot intake valves. So if you don't do alot of stop get out come back later drives carbon build up isn't a big problem. Trust me on this I have a 160 IQ and wrote all the Rolling Stones songs...well not really, I didn't write the stones song but I wish I did!

[Badbubba]

The previous V6 engine, LLT, had the timing chain stretch issue. DI engines tend to dilute the oil with fuel. This would cause pin wear with the chain. Issue was to be corrected with the LFX. We have an Equinox with the LFX and 140k miles. Slightly different intake because of the transverse mounted engine, but oil does get into the intake on the clean side do to reversion and the dirty side. Original front plugs still looked at 140k, still replaced. Need to pull the intake to get the back plugs, remember mine's transverse mounted. Will replace plugs/coils and inspect valves after the new coils arrive. I use CRC intake/valve cleaner for DI engines, starting at around 80k miles. And then at every 7.5k mile oil change. After I inspect it, I'll decide if I should install 1 or 2 catch cans.