Aluminum heads need decked every time, they never stay straight once torqued and heat cycled, then removed. Cast iron blocks usually don't need surface if they were decked correctly when originally built.

 

ive only decked the head side. the main concern is that it hasnt gone soft. if its overheated then id be worried but if youve kept the temp under control probably okay still. but the aluminium does go soft over time anyway.

If you dont have time then maybe just throw a gasket in and hope for the best but id say it will pop again. and i wouldnt run it with a popped gasket your just asking for trouble. if the water tracks in the wrong direction it can **** the block

 

I thought the same the first time my head warped. Within 3 track days it blew out the head gasket again. Decked both head and block the next time and no more head gasket issues. Surface finish is critical when you're using an MLS gasket. If the surface finish isn't there it won't seal no matter what the material is.

 

Figured. Glad you got it sorted.

I was *told* I got the last one available. I assumed it was a sales tactic, but.....

Though it came new, from Mitsu, it was still basically a "rebuild" according to the labeling. I thought that was weird. Maybe a factory reman?

 

Myles did the same to me, "it's the last two short blocks eveeeeerrrrr!" only to find dozens everywhere lol. I struggle with the same thought though - pay almost 700 bucks for "new" but is it really 99% the same as a name brand reman from the parts store.

 

My thing was that a warranty is great, unless you are swapping out parts as often as you do oil changes.
My alternator has been a champ for the past ? years. So far, so worth it, IMO.
But yeah.....I always wonder.

 

Exactly why I paid for the $$$ OEM PS Pump. Its lasted 15 years so hopefully the next will do just as well. I dont want a unknown quality but lifetime warranty to be a reason I cant finish an event.

 

I work in parts and sell Denso. I called them about our alternator and they said nah lol. Maybe a group buy situation. Their stuff is made in Japan and is quality.

 

Tells me the block was not surfaced right/well the first time and you had an ongoing issue because it.

The fire ring in the head gasket dents the deck surface of the head when it bites into it. You can't not surface the head. The block doesn't always need it if it's still flat and the finish is good.

 

Myles relays the info he gets from whatever dealer they buy their mitsu parts from. My car needed an alternator last month, and I was told the OEM's are NLA/disco by the dealer I use here in Vegas. I got an AC Delco off rock auto. See how it holds up. I may see if a local rebuilder can rebuild/fix mine; all the case bolts fell out lol.

 

The alternator components still seem to be available. Should be no problem to rebuild one.

https://partsouq.com/en/catalog/genu...&uid=117827&q=


Common Fail items are Brushes

https://www.mitsubishidirectparts.co...lator-md618689

Voltage Regulator

https://www.mitsubishidirectparts.co...lator-md619268

Rectifier

https://www.mitsubishidirectparts.co...ifier-md619663

 

The block had never been surfaced. It was a completely original longblock. Unless you're saying the factory finish is subpar.

I measured the deck on the block, it wasn't warped at all, which is why I didn't get it decked. The head was warped around .002" so I only got the head decked. Head gasket leaked shortly after rebuild. Tore it down again, got head and block decked .001", no more issues. Both times fairly high end CBN decking mills were used.

 

Thanks for this. I still have my old, flakey alternator sitting around. Couldn't find anyone local to rebuild it but I may give it a shot myself.

Although the combined price of those replacement parts adds up to more than 2X a remanufactured alternator, so maybe I'll be getting some aftermarket replacement parts.

Also, the alternator replacement job isn't as easy as it looks. It's not exactly hard, but I greatly underestimated how much time and effort it was going to require because it looks like it should be a quick job.

I got a similar story from another vendor. I get the impression that parts routinely are out of stock in the United States until another surprise shipment shows up from Japan and suddenly they're available again for a little while. Hard to know when NLA is really NLA.

 

If you have the head o-ringed, do you still need to deck it every time you pull it? Also, thoughts on re-using ARP head studs?

 

Studs are meant to be reused. That's why we swap to them any time the head is off.