(6G72) Going… going… hopefully not gone..

[RossOtero]

Hey gents, hope all has been well with you during the holidays. Im in need of help. The mighty max is showing signs of extreme wear. Loud ticking till warmed up, White smoke barreling out the exhaust pipe at take off; burning 1qt of oil every 200miles, loss of power… list goes on. What are my options? Rebuild? Crate? Swap? Most mechanics in my area say no when I bring up the word rebuild and others say their vendors don’t offer the 6G72… I’m lost. What I have is a v6 4x4 with the 6G72 and the V5MT1 five speed manual transmission. Cost this is currently my daily driver

[xboxrox]

Maybe try additives @ O'Reilly's into gas tank & engine oil ~ RISLONE stopped my G54B ticking & CATACLEAN gave butt O meter 2 HP (?) gotta check valve & ignition timing & perform compression test & test radiator for combustion gas ~ change oil & oil filter & change air filter ~ best of luck to you

[FMS88]

If it's your daily driver, has a lot of miles and you need quick turn-around, a crate or good used engine may be the quickest option, assuming they're available. If the miles are reasonable and you have a bit more time, try to determine the state of the rings with compression, leak-down or other tests. If those produce positive results, you may only need to do a top-end rebuild. Of the signs you mentioned, rebuilt heads and new lifters should eliminate the ticking and reduce the smoking and oil consumption caused by worn valve stem seals. Also, check the catalytic converter. The high oil consumption may have plugged it causing the loss of power.
Some on this site have swapped engines, but that's more time and complexity, especially if it necessitates upgrades of the engine wiring and management systems.

[geezer101]

#1 cause of oil consumption is bad valve stem seals. You 'can' replace the stem seals without removing the heads but I would consider giving the heads a once over (hot tank, pressure test, check for valve run out and lap the valves if everything checks ok) An oil flush will help with hydraulic noise but while it's siphoning oil through the valve stem seals it's going to run like a dog (oil consumption, lots of smoke, loss of power)

[Chargerx3]

Questions to ask yourself:

1)Are you also consuming coolant? If yes, then its likely head gaskets. Not a terrible job to do.

2)As mentioned valve stem seals are a very common culprit. New Viton seals would fix that issue if its the main one.

3)Does your truck smoke worse on decel and when first taking off from a stop, or constant throughout?

4)If you are noticing power getting low in conjunction with burning more oil then that is a stronger indicator of blowby and needing a rebuild.

5)When was the last time you did a tuneup (Cap, rotor, plugs)?

6)Also are you certain there are no oil leaks on your motor? No puddle marks after sitting in parking spaces?

[RossOtero]

Questions to ask yourself:

1)Are you also consuming coolant? If yes, then its likely head gaskets. Not a terrible job to do.

2)As mentioned valve stem seals are a very common culprit. New Viton seals would fix that issue if its the main one.

3)Does your truck smoke worse on decel and when first taking off from a stop, or constant throughout?

4)If you are noticing power getting low in conjunction with burning more oil then that is a stronger indicator of blowby and needing a rebuild.

5)When was the last time you did a tuneup (Cap, rotor, plugs)?

6)Also are you certain there are no oil leaks on your motor? No puddle marks after sitting in parking spaces?

@Chargerx3
1)No coolant is being consumed, it is still at the correct level in the resevior and the radiator itself.
2)Never considered this, its the first time im dealing with a smokin motor so this is new territory but i love learning all i can, its become my hobby to fix things and go "picking" at estate sales or junkyards for dads old truck haha sure mor of you guys can relate.
3)It smokes upon acceleration from a stop or a slow roll, i have noticed if i rev higher while shifting the smoke cloud is a bit smaller. There is a small trail of smoke behind me during travel and small amount during idle.
4)This was my inital thought.. Also i did some horse trading this weekend and got another dependble daily while i work on MAX. Thats why Ive really been thinking some sort of swap or upgrade.
5)I did a full full tune up about 7000 miles ago new cap, plugs, battery cables, flushed tranny and diffs.. the works and change the oil every 3000.
6)I set large pieces of fresh cardboard under her for a couple weekends because my parking spot is impossible to tell if they are fresh.. anyway there were no drips on the cardboard over a course of a week i parked on top of them.

@geezer101
I admit my first thought was that id be rebuilding the entire engine. Its just at 196000 miles so if the top half is worn out i figured so was the bottom half... my train of thought anyway lol do you agree?

@FMS88
I was able to get my hands on a new daily so its not a quick turn around thing anymore. I dont have much else going on at the moment though so most of my free time will be into it. Looking to upgrade the motor hopefully if its pretty much plug and play.

@xboxrox
Thanks for the info, I was thinkng of putting a liquimoly brand engine cleaner that i used on my old VW Diesel.. the name esacpes me at the moment but i think it was diesel clean or something like that.


If someone can educate me on hoe to tag yall in my responces that would be appreciated.

[Chargerx3]

@Chargerx3
1)No coolant is being consumed, it is still at the correct level in the resevior and the radiator itself.
2)Never considered this, its the first time im dealing with a smokin motor so this is new territory but i love learning all i can, its become my hobby to fix things and go "picking" at estate sales or junkyards for dads old truck haha sure mor of you guys can relate.
3)It smokes upon acceleration from a stop or a slow roll, i have noticed if i rev higher while shifting the smoke cloud is a bit smaller. There is a small trail of smoke behind me during travel and small amount during idle.
4)This was my inital thought.. Also i did some horse trading this weekend and got another dependble daily while i work on MAX. Thats why Ive really been thinking some sort of swap or upgrade.
5)I did a full full tune up about 7000 miles ago new cap, plugs, battery cables, flushed tranny and diffs.. the works and change the oil every 3000.
6)I set large pieces of fresh cardboard under her for a couple weekends because my parking spot is impossible to tell if they are fresh.. anyway there were no drips on the cardboard over a course of a week i parked on top of them.

Ok so it appears you are not consuming any coolant and its oil being consumed. Valve stem seals are very common on Mitsubishi's, but you should perform a cylinder pressure test, or better yet a leak down test if you have all the tools. Most of which can be found cheap at places like Harbor Freight. Watch some youtube vids to know what you are getting into. This will let you know what cylinder pressures are and where the leaks are.

Dont go putting additives in your oil. They will only further complicate your testing. They are also just band aids. Get it fixed right.

[geezer101]

The vast majority of the time it will only need the head (or in your case, heads...) freshened up and it'll easily go another 100,000 miles without any grief. It's not strictly a Mitsubishi thing with valve stem seals. You'd expect valve stem seals to last maybe 10+ years with daily driving as long as it's getting an oil change. But this is subjective and you won't really know what you're getting yourself into until you can see the condition of the internals like the cylinder bore walls and bearing surfaces. Luckily you are working on a RWD truck and not a FWD car or van. The V6 in that configuration is the stuff of nightmares and is definitely an engine-out job. Even if the bores are looking a little glazed, a quick bore hone and some fresh standard size rings will make it like new without having to go through a complete tear down and the block going through a machine shop.

[Geoff]

My first thought was valve stem seals. Changed mine a couple years ago and it solved my smoking problem. Personally, I wouldn’t recommend anything like seafoam or marvel mystery oil. I went down the YouTube rabbit hole and watched people pulling the spark plugs and soaking cylinders overnight with one or the other. I did that and the oil treatment too. In my case, it knocked all the sludge loose and clogged the oil pickup tube which lead to other problems. I cleaned the pickup and my engine’s been running great. I did the usual tune up stuff too including a home built fuel injector cleaner rig. Unfortunately, I recently sprung an oil leak driving over the Rockies on I70. Looks like valve cover gasket blew out. I recently changed it so that’s a bummer. Looks like I’ll be pulling everything off the top of the engine for a third time in as many years. Meh. I still love the truck. I have fun.

[RossOtero]

My first thought was valve stem seals. Changed mine a couple years ago and it solved my smoking problem. Personally, I wouldn’t recommend anything like seafoam or marvel mystery oil. I went down the YouTube rabbit hole and watched people pulling the spark plugs and soaking cylinders overnight with one or the other. I did that and the oil treatment too. In my case, it knocked all the sludge loose and clogged the oil pickup tube which lead to other problems. I cleaned the pickup and my engine’s been running great. I did the usual tune up stuff too including a home built fuel injector cleaner rig. Unfortunately, I recently sprung an oil leak driving over the Rockies on I70. Looks like valve cover gasket blew out. I recently changed it so that’s a bummer. Looks like I’ll be pulling everything off the top of the engine for a third time in as many years. Meh. I still love the truck. I have fun.

What needs to be done to access the oil pickup tube? Having the top end worked on and wondering if the tube will be cleaned during that process.

[geezer101]

Running diesel/oil blend to flush it out will break all of the gunk and lamination up in the crankcase and oil journals etc. As it'll dissolve it gradually it won't just knock a big chunk of it out and lodge it somewhere else to cause grief. The problem with additives like seafoam or mystery oil is it won't clean the backs of valves like people expect it to (oil flush won't either but it won't turn your engine into a smoke machine while running) If the pick up screen is clogged - I mean really clogged, it'll need to be removed and mechanically cleaned. If you think your combustion chambers are carboned up you can take the throttle body intake pipe off and spray water into the throttle body while the engine is running with a trigger pump sprayer (water has to be atomised and not shot into the intake in a stream) When you hear a 'crackling' sound, the carbon is swelling up and lifting off and getting burnt in the process. Has to be done when the engine is at operating temps.

[FMS88]

What needs to be done to access the oil pickup tube? Having the top end worked on and wondering if the tube will be cleaned during that process.

Access to the oil pickup requires removal of the oil pan - not a fun task and not part of a top-end re-work. If the engine has had regular oil changes, it's unlikely the oil screen will be clogged. You can also ask whoever is working on the top end, how much buildup of gunk or sludge they found inside the valve cover and on the valve train. Hopefully they can give you they're educated guestimate of whether you should be concerned about the rest of the engine and the oil pickup in particular. If you're still concerned about a buildup, geezer101's suggestions are very good in that they're effective and easy to perform. They're worth a try before taking on the time and expense of removing the oil pan.

[Chargerx3]

Don't pull the pan. Run Motor Flush through your oil and it will clean up all the gunk.