Engine Refresh

[jdavis]

Some of you might know from FB that I slipped the timing belt on my 95 SR the weekend before last while playing at Tahuya ORV. Long story short, I have a great bunch of friends that gave up half of their Sunday to come tow my rig and 16 ft camper back to Seattle.

Anyway dug into the engine and found the timing belt tensioner gave up the ghost. Causing the timing belt to shred the plastic covering and itself

Anyway figure it is time to refresh the engine a bit. Obviously, going to replace water pump, timing belt, tensioner, crankshaft and camshaft sensor and appropriate seals in there.

Assuming the valves are shot, the rear main is leaking a bit and think there is slight head gasket leak. Had a bit of an overheating issue last summer. So, going to pull the engine this week and dig a little deeper. This will be the deepest I've dug into an engine, so will be leaning heavily on the experts here and RockAuto.

Once the engine is out planning on pulling heads, replacing seals, seats. HVA's and valves. Will replace head gaskets, exhaust manifold gaskets, camshaft seals, rear main seal.

While the engine is out what else should I do? Are their any Montero specific engine guides?

Thanks,
~ Jon

First Draft Parts List:

• Water Pump + seals + O-rings
• Timing Belt, actuator, tensioner Bearings, idler Bearings, etc.... thinking about this kit for the timing belt.
  
• Timing belt cover and seals - Think I have spare cover somewhere,d anyone know where to find the seals?
• Crankshaft bolt
• Crankshaft Position Sensor
• Camshaft Position Sensor
• Head bolts
• Engine gasket rebuild kit, something like this
• Intake & Exhaust valve seals 12 each
• HVL's 12 each
• Valve Cover Gaskets
• Cam Shaft Seals

 

[RyanY]

I wouldn't replace the cam and crank sensors unless you've had a problem with them or they were damaged by the timing belt failure.

The updated crank bolt may need an updated washer to go along with it.

Take the bare heads to a machine shop and have them surfaced, removing the minimum necessary to get the head gasket surface completely straight. The valves themselves shouldn't need to be replaced unless they're bent, just have the machine shop do a 3-angle valve job on the valves and seats.

If you're dealing with a DOHC check your lower intake for the typical butterfly shaft bushing failure, and repair or replace the lower intake if there's any slop in the shaft.

Replace the plugs and wires with good quality parts if they haven't been done recently.

If you don't know the maintenance history of your radiator, now would be a good time to have it rodded out at a radiator shop. Replace the thermostat and radiator cap with OEM parts (Stant is garbage, and the cost difference isn't worth the risk), and replace any radiator and heater hoses that you don't know the age of.

 

[evomaki]

jdavis, it sounds like your are pulling the engine out of the vehicle. Is that right? then you are talking a fairly comprehensive re-fresh, which depending on the mileage might be the thing to do, particularly if the rear main is leaking. That must be an awful repair on any big vehicle. If you have not rebuilt an engine before, I'd start by reading a book or two on the topic. Amazon has many to choose from. Most feature domestic v8's, but much is the same. The next thing is to find a good auto machine shop. One of those is gold. They will help walk you through the process, and tell you how they want to see the engine, when you bring it in. Heads off pistons and rods out, bearings in, that sort of thing. Label everything, including direction (front). Get a copy of the factory service manual. You need torque spec's. I think Mitsu cylinder numbering is different than domestic v8's. Make sure your number matches what the machine shop thinks. I get the machine shop to do as much as possible. Definitely get them to assemble the head. They will replace valves and springs as needed. Frankly, getting the lump out and back in is more than half the battle. Take pictures and keep good records of all you remove, so you put it back. Always install a new oil pump (use oem). OEM gasket set probably worth the money. I hear OEM tensioner the way to go on these too. Good luck.

 

[mudraider]

jdavis, it sounds like your are pulling the engine out of the vehicle. Is that right? then you are talking a fairly comprehensive re-fresh, which depending on the mileage might be the thing to do, particularly if the rear main is leaking. That must be an awful repair on any big vehicle. If you have not rebuilt an engine before, I'd start by reading a book or two on the topic. Amazon has many to choose from. Most feature domestic v8's, but much is the same. The next thing is to find a good auto machine shop. One of those is gold. They will help walk you through the process, and tell you how they want to see the engine, when you bring it in. Heads off pistons and rods out, bearings in, that sort of thing. Label everything, including direction (front). Get a copy of the factory service manual. You need torque spec's. I think Mitsu cylinder numbering is different than domestic v8's. Make sure your number matches what the machine shop thinks. I get the machine shop to do as much as possible. Definitely get them to assemble the head. They will replace valves and springs as needed. Frankly, getting the lump out and back in is more than half the battle. Take pictures and keep good records of all you remove, so you put it back. Always install a new oil pump (use oem). OEM gasket set probably worth the money. I hear OEM tensioner the way to go on these too. Good luck.

You know to go to mitsubishilinks.com for the FSM. Don't understand what a V-8 book from Amazon will do for you.

sent from my pretty good Android phone

 

[JohnnyBfromPeoria]

Listen to RyanY. Get that radiator rodded. Pay attention to the cooling system, as in fan clutch, thermostat, hoses (ALL of them) and a complete Aisin water pump. Make sure your coolant-to-water ratio is 50/50 and no higher unless you're traveling to Antarctica or some places in Illinois, where I'm from (J.K.), because anti-freeze does not transfer heat well at all and a too-high ratio will cause overheating. Es muy importante!

John B.

 

[jdavis]

Hey guys!!

Thanks for the responses!! They have helped me determine a plan to get the truck back on the trail.

The engine was pulled this weekend. After putting it on a stand, reattaching the timing belt (after busting a couple knuckles aligning the cams .... grrrrr....) found the engine has little compression and there is knocking in both heads when spinning the engine.

I have a spare engine that ran fine when pulled out of my old '94 SR - "May she rest in peace". It did have the classic ticking and smoking habits but outside of that ran smooth.

After reading the posts above, realized I should really rebuild the engine I just pulled instead of just swapping parts. But as evomaki mentions, I have not rebuilt an engine before so will be in a little over my head.

The plan now is to run with the spare engine. I'll address the smoking and ticking by replace the valve seals, HLAs, the head cover gaskets on the spare engine and anything else I notice then drop it into the rig.

Then as time and money allows will fully rebuild the other motor. There are couple good machine shops close by I'll go talk to about rebuilding before starting.

Thanks,
~ Jon

 

[evomaki]

Well, in my book, you have done the nastiest part of the re-build process, getting the thing out and back in, so you are already an expert in breaking and making a boatload of connections from fuel lines, grounds, mounts, etc. Re-building will not be so tough. I did my first engine many years ago after reading a couple of books. These aren't race motors and you aren't doing anything funky like messing with cam timing, building a stroker, clearancing a block, knife edging a crank, porting heads, etc. Reading a book familiarizes you with the process, everything from replacing freeze plugs, plastigauging rods and mains, sizing rings, etc. That is all the same whether domestic V8 or 6G74. That also helps you have an idea when talking to the machine shop so you aren't clueless. You do a bit first to make the relationship with the machine shop good. Building the engine itself is kind of a Zen deal. I find that peaceful and clean, and you aren't all contorted as you often might be working on the vehicle itself.

 

[evomaki]

Oh, and one more thing. If the FSM covers all the engine building stuff I talked about, still get an additional reference resource. They are cheap and it will build some context for you at the least. Sure the FSM will govern on so many points from torque settings to bleeding lash adjusters and the timing assembly, but another reference resource is worth the $.

 

[Salonika]

I know it is expensive, but the peace of mind you get by having a rebuild done by a professional is priceless when you consider the work involved in pulling an engine, especially for a daily driver that you plan on keeping around for the long term. A trained machinist is practicing a skilled trade and they have my respect. I'll rebuild my lawn mower engine instead.