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My 86 6.9 popped a head gasket last night. Glanced at temp gauge while on the highway and it was very high. Shut it off and coasted as I was about a mile from an exit that would be a good spot to stop and see waht's up. Fired it up for the ramp and just went a block or so off the exit to park. Low coolant, blowing white smoke out the exhaust pulsing with firing, pressure in radiator. She's toast. I went to fire it up later to get it the few miles home and it cranked a very small amount and seized. Pulled some glow plugs and spun it over freely, put 'em in, along with more water and drove it home quickly at low RPM. Gauge got up just a bit over 200*, misfiring the whole time, and it was blowing lots of smoke.
For what it's worth this engine has a turbo and high output pump... It has seen a lot of time towing at 7-10 psi and has seen 13psi for a couple hours once. I knew I was on borrowed time without studs. It failed at a very bad time for me to have to deal with this though, but it's never a good time so time to dive in.
I'm going to try to pull the engine today to evaluate condition and damage. Hope I didn't bend a rod when it hydrolocked. Seemed to run alright aside from the misfire. The question is should I go through this engine to do a top end, do a full and proper rebuild, or pick up a 7.3 the do whatever that needs (studs and head gaskets at minimum). There is a 7.3 two hours away for $600/obo allegedly under 100k miles and "runs great".
If you have the engine out, I can't see the harm in rebuilding the whole thing. I'm currently rebuilding my 7.3 at the moment, and if you have the measuring tools, it's not that hard to do the bottom end.
But since you have a truck, you could just pull the heads off the engine with it in the vehicle and try to replace the HG's there. Save you lots of time. It's a hell of a lot easier to dothat in a truck than van.
You might want to order studs from Justin ASAP. He's always busy and getting that order in now will probably save you lots of waiting time.
I picked up a 91 7.3 today for $500, supposedly 77k miles it was in a plow truck with a rotted frame and allegedly ran great. Also got an extra oil cooler thrown in. I'd debating between dropping it in as-is with just changing the oil pan and oil cooler, a quick and dirty... Or do all bearings and gaskets along with head studs and maybe a cam. Or a full and proper rebuild. Of course tomorrow once I get it on the stand and check bearing condition that may dictate which route I take.
It was an interesting ride an hour and change to get it. Lots of closed or blocked roads from a storm the other day, trees and power lines down. A mouse was hanging on the hood of my 460 truck for some time before he lost his grip. Had some darn near death wobble at one point too. Reminds me that I need to stop neglecting the 460 truck, it sits for 6+ months at a time but faithfully fires up every time and does whatever is needed. Last time I drove it was last summer, it had sat for 9 months since it last ran and I just hopped in and drove it on a 12+ hour round trip to Virginia to get a ZF5 for the diesel truck. It's such a good reliable truck, and I was considering selling it just the other day. It reminds me I need to go over everything on it though as it has been severely neglected. Definitely needs track bar bushings and a wheel bearing repacking.
Pretty tight. The exhaust manifolds on your trucks are very different than the vans.
Nice score. The extra oil cooler is worth a third of the cost of that whole engine. Extra icing on the cake is the spare IP, spare injectors, spare GP relay, spare....
As for the OP's claims, I'd expect them to be bull****. Almost every OP's "this engine is X and has X and does X" never pans out. You won't know anything until you can pull the pan and inspect the oil. And while you have it off, might as well check the oil pump, and check the bearings, and check the crank, and check the......
Off to a great start. 3 bellhousing bolt holes are stripped. They thread in but won't tighten sufficiently that I'm comfortable putting it on the stand. I stripped the wiring and accessories and did a quick degreasing to get the worst of it off. In typical fashion my pressure washer wouldn't start so not as deep a cleaning as I hoped for.
In any event, the seller said the clutch was nearly new. It appears that way. One very minor hot spot on the flywheel, the pressure plate looks great, and plenty of meat on the disc. It's a LUK SMF kit, same as I put in my truck last year. I will likely sell it for cheap. The flywheel and pressure plate bolts were regular grade 5 hardware store parts, no washers on some. Flywheel bolts had RTV on them. Some hackjob stuff going on with that, and likely gunned down the bellhousing bolts with all the ugga duggas. The threads appear to be 7/16-14 and approx 1" deep. I'm thinking time-sert rather than helicoil, more so for hanging it on the stand than holding the trans to the engine.
Although she's a bit crusty on the outside I found several things that support the low mile 77k claim. Radiator and heater hoses all appear original with original style clamps that could well be 27 years old. The glow plug harness and wiring, specifically the bullet connector boots, are in excellent condition. Both ground cables and the positive cable are likely original, FORD lettering and such. All fasteners aside from the flywheel and pressure plate appear original, all factory clamps, clips, etc. are original and appear undisturbed.
Who knows, I'm almost out of time tonight but I'll try to do more with it tomorrow, maybe pull the manifolds and heads off. The time-serts will be here Tuesday and head studs by the end of the week. I may order gaskets and everything to reseal assuming bearings and bores are good. I wanted to do this real quick but at this rate I'm thinking I may as well check cylinder condition and taper on a cylinder or two if not all of them and do it proper in general. Terrible timing for me with everything else I have going on at the moment but if I'm going through an engine and have these delays even getting it on the stand, I may as well do the upgrades I want for more performance and to avoid this type of failure in the future.
Nice score on the engine. I know the feeling too. My 94 has a leaky head gasket, out of the corner of the head unforunately, hasnt stopped me from driving it yet thou.
The Time-serts were fairly easy to install. I did the two in the adapter plate and one at the lower left hole. The middle left bellhousing hole is all prepped but the insert is a hair too long. I only have 1" and .600" inserts, so I ordered some .870 inserts that should fit the blind hole at full available thread depth. I only need a small amount but I don't want to risk making the hole deeper and I read something about the Timesert taps being proprietary in some way, so I don't think I can find a bottoming tap in that size to get the small amount more I need. Also, the insert is tightened by the installer, a triangular bolt, going all the way through it to expand it to a press fit with the repaired item, though I'm using Loctite 271 on the outer threads. In any event, I'll have the shorter inserts Friday and get this repaired and on the stand.
Aside from that no real progress so far. I need to get to the point to check bearings and measure the taper, probably Saturday I'll be there and know if I need to order anything else.
Also worth noting was the other day when I took the glow plugs out 5 were expended at the tip and difficult to remove. They are Autolites. Decision is whether to use the DieselRX glow plugs in my 6.9 that all tested good some time ago and were not expended, or use new Motorcraft glow plugs I think I have somewhere in 6.9 spade style, or get new bullet style 7.3 plugs and use the good 7.3 harness either with or without the glow plug controller. I'm somewhat partial to manual glow plugs, and I don't know where I'd put the controller with the turbo occupying the space it came from.
Also, anyone know a source for new exhaust manifold bolts? These were really bad, as in they're a 9/16" head but I used 13mm, 1/2", and 12mm sockets to remove them.So glad IDI exhaust bolts don't tend to break.
Also, anyone know a source for new exhaust manifold bolts? These were really bad, as in they're a 9/16" head but I used 13mm, 1/2", and 12mm sockets to remove them.So glad IDI exhaust bolts don't tend to break.
If I had to replace mine with non-IDI bolts (Lucky for me, I have a jar of them from tearing down engines and I keep everything labeled and boxed up), I would use Grade 8 or Stainless alternatives, with plenty of Anti-Seize. The last thing you need is regular grade steel that will just corrode and break under the heat of the EM.
No progress tonight. Head studs arrived though. Lots of money for a small box. Says torque to 125 ft/lbs with ARP lube instead of oil. I know Justin has tested these to failure in both 6.9 and 7.3 applications, I believe in the 6.9 the block failed and 7.3 the fastener failed but there was appreciably more torque before the ARP studs yielded at plastic deformation. I should probably try to find that thread and decide if additional torque is warranted.
Aside from that, my 460 truck had some pretty major exhaust leaks after the drive to pick up this 7.3. This is the third pair of Dynomax Super Turbos on the truck in maybe 7 years of the over a decade I've owned it. I like the design and how they sound but they really could stand to use thicker or better quality metal. I ordered a new pair of mufflers and some pipe to get that sorted. One muffler arrive today so I installed that. I was able to remove the old muffler by hand, it was hanging on by a thread. Much quieter now. I'll do the other side tomorrow or Friday when it arrives. Getting under the 460 truck I see what a toll letting it sit unused on dirt for 6+ months at a time has taken, everything is crusty and rotten. The rear portion of the SuperCab needs to be replaced, again. The patch panels I welded in have rusted out well beyond where the rust was several years ago. Shame I had no room to store a cab or time to do a swap when I got a rust free AZ rad support and the seller had a cab from AZ he wanted to unload for cheap. In any event, I was sick of breathing exhaust driving this truck around. We're halfway to having that problem solved and I'm sure the neighbors appreciate it!
I put the last time-sert in and got it on the stand, removed a few small parts. Probably about done for tonight, I'm tired with the time change today. At least it's ready to tear into now.
03-03-2018, 11:22 AM
3 bellhousing bolt holes are stripped. They thread in but won't tighten sufficiently that I'm comfortable putting it on the stand. I stripped the wiring and accessories and did a quick degreasing to get the worst of it off. In typical fashion my pressure washer wouldn't start so not as deep a cleaning as I hoped for.
