EyeInTheSky's Gen 3 Budget Build Thread

[coffeegoat]

My manifold had a ton of carbon in it when I pulled it all apart. How did the throttle body look? I had gunk from the throttle body all the way down to the cylinders and chocked it up to a bad PCB valve and/or EGR valve - I replaced both.

The spark plugs may be causing some of the problem, I remember trying to run platinums on my old truck and it never quite worked correctly, when I switched to the correct ones it ran much better. Mitsus might be the opposite.

 

[EyeInTheSky]

How is your PCB Valve and air filter?

I just changed my plugs last week and removed my manifold also was a PITA. But my manifold didn't have no carbon build up likes yours interesting.

Air filter is fine, PCV is pretty gunked up. Cleaned it out with some throttle body cleaner, seems to be OK.

My manifold had a ton of carbon in it when I pulled it all apart. How did the throttle body look? I had gunk from the throttle body all the way down to the cylinders and chocked it up to a bad PCB valve and/or EGR valve - I replaced both.

The spark plugs may be causing some of the problem, I remember trying to run platinums on my old truck and it never quite worked correctly, when I switched to the correct ones it ran much better. Mitsus might be the opposite.

Throttle body is pretty clean, just some streaked carbon deposits around the edges. EGR valve seems ok; not visibly nasty, and when I put suction on the end, the valve actuates.

 

[EyeInTheSky]

Done. My aching back. Seems to be ok. Going to do a longer shakedown drive tomorrow.

 

[EyeInTheSky]

Done. My aching back. Seems to be ok. Going to do a longer shakedown drive tomorrow.

Nothing like a roadside update for a build thread. Ran fine around town, but when I took it up a nearby grade, I caught a P0300 multiple misfire code almost all the way up. Pulled over, reset ECU, started again. Rough idle, won't stay alive without my help on the throttle, P0306, short term fuel trims all at 25. Looks like my wife may not be taking it this weekend....

AAA is on the way.

So what are your guesses? Coil packs maybe?

 

[BOPOH]

so, from my understanding - you getting misfires under load? in my case it were spark plugs. Could be bad ground to engine block, could be faulty MAF, could be clogged fuel system

 

[coffeegoat]

To check coil packs you can just move them around and see if the error moves with it - though from my quick check cylinder 2 and 6 are not on the same ignition coil which makes it seem unlikely.

 

[EyeInTheSky]

so, from my understanding - you getting misfires under load? in my case it were spark plugs. Could be bad ground to engine block, could be faulty MAF, could be clogged fuel system

Yep, misfires started under load (up a long grade at highway speeds, approx. 60mph), though I was getting on it pretty hard around town with no issues. I was keeping Torque up on my phone showing me fuel trims and timing advance. I was pushing 40 on T/A under acceleration, but all my trims were fine.

Spark plugs and wires changed yesterday, MAF looked ok, though I didn't clean it, fuel system clog is a possibility.

To check coil packs you can just move them around and see if the error moves with it - though from my quick check cylinder 2 and 6 are not on the same ignition coil which makes it seem unlikely.

It's at the shop currently so we'll see what happens. The problem with trying to diagnose it is that the misfires only seem to happen under heavy engine load. At idle it was fine. If I had it here I'd run through the FSM and test the coils. I received a P0300 multiple at first, then P0306 after an ECU reset, so maybe the coil pack for 5+6 is bad? Let's hope it's just a cracked vacuum hose that costs $3...

 

[EyeInTheSky]

Preliminary info is that cylinder 6 has no compression and another cylinder is low. He's guessing valves.

 

[BOPOH]

i'm not an expert at this, but i dont see how low compression would cause misfire especially if valves are leaking and how would they start leaking out of nowhere(your wife wasnt racing, right?) i still think it's something less dramatic. Low compression would be bad piston rings, scratched/cracked walls, bad valve seals or spark plug issue, bad head gasket. Check your oil for milkyness (milky mess ), check exhaust under load for color of smoke (blue=oil, white=water/coolant).

Either way go to walmart buy a can of SeaFoam, run Premium fuel until you fuel tank 1/4 low and dump entire can in it. Drive normally until fuel is low, at that time you can also run another can of seafoam through you intake manifold or brake booster hose. Let it sit for several hours/day, that will give Seafoam time to soak into build up carbon. Refill enough 1/4-1/2 of premium, warm up and run it hard to burn/blow crap out it.

 

[EyeInTheSky]

The verdict is in regarding the shop: Using another AAA tow to get it pulled back to my house.


Owner of the shop checked with all the local machine shops he uses and out of 5, only 2 would even agree to look at the heads. Total cost for valve job from where it sits currently, to running and back in my hands is $2,255. With a complete engine overhaul while he's already in there, $5,775.


He told me book labor was $1,900 on the valve job (removal, re-installation, timing belt, etc.), leaving $355 for machine shop and any parts needed. Granted, book and real life are different, but it's a good benchmark.


He hasn't even removed the heads since he wanted to find a shop that can do the job before going to that trouble, so I don't know what the damage looks like.


FYI this is a very reputable shop recommended by my normal mechanic who is completely swamped right now. I already balked at the price before a hard quote, so if he's inflating the estimate it's probably to get the Montero out of his shop, not to screw me. No negotiation offered on the phone either, so I'm thinking he either wants to free up that bay ASAP, or that's really the price and that's all he can do.


I've been looking at rebuilt heads, like HeadsOnly.com and others, and they seem to run around $800/pair with shipping. If I were to find damage to the head, and have no local shop to do the work, then that would be my best bet. If I find damage to the block, well, junkyard block? Complete engines for these are quite expensive, with used running around $2500 with little to no warranty, and rebuilt running around $3500+shipping.


I'm faced with a hard choice. At this point, here's what I see as my options:

Pay through the nose (2x KBB value) for the shop to fix what's there. <- No
A complete engine swap with a used or rebuilt. <- Probably not
Bring it home and attempt to fix it myself. <- Possible.
Cut my losses and sell it. <- Possible.


Any input? I feel like throwing up. Five months of use, and here we are.

 

[nwoods]

I'm faced with a hard choice. At this point, here's what I see as my options:

Pay through the nose (2x KBB value) for the shop to fix what's there. <- No
A complete engine swap with a used or rebuilt. <- Probably not
Bring it home and attempt to fix it myself. <- Possible.
Cut my losses and sell it. <- Possible.


Any input? I feel like throwing up. Five months of use, and here we are.

I have no advice to give. I'm in the same boat. I've personally decided to cut my losses and recycle the Monty to the junkyard.

 

[normal_dave]

"Never give up...never surrender".

Late to the party, so I may have missed something. So many shops seem not to be able to properly speak Mitsubishi. You pulled the intake and changed plugs and wires. Looked like normal build up to me. It might be worth your time to run the compression test yourself. Shops often run the computer load test for compression, I'm always optimistic, you seem pretty handy with the tools, take another shot and check it yourself.

Read through this thread all the way (twice) and pay attention to the links before you throw in the towel.
http://forum.expeditionportal.com/threads/159696-Replacing-Gen-3-Heads-(Like-a-Virgin)-Any-Recommendation?p=2110222#post2110222

The coil pack issue has 'burned' many a Montero owner or mechanic. Also failing ignition modules cause fun as well. It may well be that you've lost a valve or two, but I'd sure want to know for sure. Air compressor handy? rig up a fitting and charge #6 with air and see if it leaks out and where. Intake port or exhaust = valve(s), crankcase=piston and/or rings. Cylinder that holds pressure=electrical issue?

Edit: As others have mentioned, the most interesting tidbit I've learned is the coil pack setup. Each pack fires two paired cylinders at the same time. One cylinder on the compression (firing) stroke, the other is wasted on the exhaust stroke of the paired cylinder. If the truck will still run, swap # 6 wire at the coil with # 3 (paired) and see if the cylinder misfire moves to #3 (or not). Cylinder #2 is paired with #5, which also makes me curious.

Apologies if I missed important prior information, and good luck, nice truck, I'd hate to see it go away.

David

 

[Toasty]

I'm not offering a diagnosis however...

On the idea of coil packs, If the boot(s) (the ones under the coil pack) are bad weird problems will happen. I had a Montero that would run fantastic until about 45min of driving or less with "spirited" use. Shut it off, wait 30min and it was like new again for 45min. The boots were old and when they would heat up they would allow spark to escape to an easier ground, took a while to figure this one out.

 

[BOPOH]

you can do what i did, you can find engine at junk yard from sport 3.5L, here in ohio they sell around $500-800 - and replace it yourself(nothing hard)

OR

you can find used montero sport with 3.5L for cheap, in my case it was $500 with leaking rusted fuel pump. I bought it as a project for spare engine and 4.9 diffs but after replacing fuel pump i loaned it to my friends for a year and end up selling it for $1500

I still think your engine is fine, if it runs fine under normal conditions and doesn't overheat and doesn't burn(loose) oil or coolant something insignificant is probably the case. by the way replacing just heads is not bad either

 

[coffeegoat]

I wouldn't be so hasty to assume a valve is totally shot and even if a valve is burnt the head might be OK.

Normal_Dave's advice is where I'd go with this, it's been my experience that shops, even really good ones, will assume worst case scenario because no one wants that to make that call "yeah we thought it was just a $25 part, turns out your engine is entirely ruined..." If you need a vehicle asap that can certainly color your experience, but if you have some time to cool off and think about the direction forward I'd do that. To me it seems pretty unlikely that you've had all the success you've had with the truck and then it randomly burns a valve up, that sounds more like electrical gremlin to me.

Good luck buddy