86.5 nearing it's end - - - But maybe not yet

[Saudade]

Well, my 1986.5 D21 base may be finally headed for green pastures and white shores.

My son came home the other night complaining about hard starting, loss of power and a loud banging noise coming from the engine. It sounded pretty bad. Oil looks clean, coolant's a bit "muddy" but not oily.

A compression test showed about 175# on #1&2, with about 25# on #3&4. I could hear a "whooshing" sound when testing #3&4. I hoping it's a head gasket. If more than that, it will be time for us to part.

This has been in our family since day 1. Manufacture date is 12/85 so it's a fairly early unit too. Up until now, it has run great.

I'll pull the head this weekend and see what's going on.

[Q451990]

a loud banging noise coming from the engine

That part sounds especially not good...

[Rev_D21]

Hope it makes it.

[fattbottom]

I have an 86,5 that had the same issue, getting ready to work on it after it has been in the garage for about 1,5 yrs. I replaced the head gasket before at about 200k miles ago so expecting that is the issue. It has about 300k miles on it now..bought it new off the showroom floor. it is a long bed and is rust free. manual transmission.....it is still my baby. keep us posted on your find.......

[Saudade]

Did you pull the TC cover to do it? I'm trying to avoid that using a wedge but can't seem to make it fit right.

I started a new topic specifically on this.

[Saudade]

Well, after some band saw work, I managed to create a wedge that seems to work. Won't know for sure until I put it back together.

meanwhile head is off. Sure enough the HG blew between #3 & #4

[Rev_D21]

Typical. The head bolts should be retorqued after a while. That would help prevent this.

[Saudade]

Made no progress this week. Turns out one locator dowel between the head and block is missing. It must have stuck in the head and fallen out when I finally got the head off. It's not in the cam chain tunnel unless it fell all the way through. No sign of it on any other engine structure, the ground or my garage floor. So off with the pan to see if it's there. If it doesn't turn up, I hope I can find a replacement easily enough.

I need to post some pics too.

[Saudade]

Well, the pan's off. Not a terrible job but still pretty dirty. Looks like the gasket was "rubber" so it came off without too much trouble.

But no sign of the dowel. So guess I'll put it back together and hope for the best. Meanwhile a few pics.

[Rev_D21]

You should be able to order a dowel from the dealer if you are in too much of a hurry.

[Saudade]

Yeah, I'm off to the dealership tomorrow. I found some in my spare hardware bin that are just a tad off. I can likely grind one down if I get desperate.

[Saudade]

Alrighty!! Found the dowel at a local dealership. Cost a whopping $1.13 so I bought 2. I have no help and no time today to drop the head on but will pick up the pace with this tomorrow.

[Saudade]

The head is ON!! The cam sprocket is ON!!!

[Saudade]

It Lives!!! Ran a bit rough on 1st startup. Discovered I had crossed a pair of vac lines. Reseated all of the ignition wires too. Now runs pretty smoothly. Still need to add coolant, and a few exhaust clamps.

Will recheck head bolts after a few heat/cool cycles.

[boostedhardbody429]

You probably knew this, just incase you havent done it yet. You might want to get new head bolts, import head bolts tend to only last only 1 major torque sequence, or after you do your last torque sequence to finish off the head, at this point they are stretched and wont evenly tightened across the board if you try to use them again. Not always the case but usually. This is solely my experience. Just dont want you to have to do it again. Hope this helps, and if it works out for you, bravo on bringing the beast back to life.

[Saudade]

Thanks! It was a bit confusing if I had to have new head bolts. The FSM I have doesn't say to discard them when you remove the head, It also says to run them up to basically full torque, then loosen then re-torque when installing. Since they are not torque to yield and this is the first time the head is off, I reused them.

I have a small oil leak I think is coming from the pan back by the bell housing. Maybe I overlooked a piece of the old pan gasket. A local AZ has head bolts in stock so maybe I switch them out this weekend when I look at the leak.

However, so far so good.

[Rev_D21]

Good to hear it was salvageable.

[Saudade]

Thanks Rev. I haven't had a chance to look at the oil leak yet due to a brake problem on another truck However, it's running great.

Oh, and I found the dowel I thought I lost. Maybe it came out with the gasket, but I placed in on top of the header panel (for some strange reason!). I found it while reconnecting the harness and hoses. At least I know it's not rolling around inside.

[Rev_D21]

That's a good thing but it always irks me to find what I was missing after I went out and bought a new replacement.