Hey all,
New member, lurked a few times before. I don't actually own a MM but my friend is way into them and I am his go-to for repairs. He has a 1983 4d55-t mighty max 2wd that unfortunately developed a wicked oil leak en route somewhere and ran long enough to develop some rod knock. Found an '85 4wd 4d55 (56?)-t mechanics special on craigslist that had most of the rocker arms snapped and general rust and disrepair on the head from sitting for a long time. Story was that PO adjusted the valves too tight. Might have been a red flag there.
So, the plan. we are assuming for right now that the block on the '85 is fine and we are swapping the head from the '83 over and will work from there to get the engine running and then go over everything else. No idea what is going on with the injector pump so we will probably swap the '83 over as well. Pulled the head from the '83, it is perfectly flat, some cracks on the swirl cups but having trouble sourcing those. Both turbos are shot, leaking oil, and need repaired/replaced.
Here are my questions:
What places in the 4d55 can develop a leak that's fast enough to run dry on a 20 mile trip? My friend unfortunately put stop-leak in there before I got to look at it and we can't make it leak to diagnose. He said it was a heavy drip on the passenger side though. Engine runs fine but you can hear the knock in the higher rpms.
For temporary use only, and only if it won't hurt anything, can we block off turbo and run without until we get to repairs or replacement? Do they rebuild well or is a modern upgrade a better option?
Do the swirl cups in the head bust up and rattle in the combustion chambers? Are small cracks in them worrisome or just usual wear?
Thanks for any replies, These forums are amazing.
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