The botched plug repair has done it's dirty work and the engine in my Blackwood truck is officially dead. Zero compression in #6, not even a whiff.

So it looks like I'm going engine shopping for a 5.4 long block with 4 valve heads, possibly a junkyard engine. My question is, which one? I'd like to stay away from the 4 thread (spark plug) heads that caused this whole mess in the first place. I understand they used those beyond '02 but would like to know, if anyone can tell me, what is the earliest safe year?

Secondly I would like to know what other vehicles these engines were used in? Since the Blackwood was only built in '02 it's pretty clear they all had the bad heads and since I want to avoid going through this whole thing over again I need to know what applications to tell the junkyards I'm looking for.

Thanks many times over. This board is the best resource around.

JB

 

Looking on Wikipedia, it appears the 5.4 4v was used in 99 through 04 Navigators.

 

Anybody know exactly the time period when the bad spark plug threads were sold?

 

I dunno about the 4v, but on the 2v 4.6 and 5.4, they went from 4 thread to 8 thread heads in mid-03.

Why don't you ask the guys at blownoutsparkplug.com? On the 2V's, they offer a high reliability service where they put their custom inserts in all 8 holes - in addition to their standard blowout repairs. They may have some good advice regarding the 4V's.

 

I've been looking for a wrecked '04 Navi nearby but it looks like my best bet may be to rebuild it. Unbelievable prices for these motors, just insane. Ten times what I'm used to paying for a junkyard engine.

I expect to have the head off in a couple days. I've got photos of damage in my public photo album now. Some fairly bizarre stuff.

JB

 

According to Ric Mahlmeister at BlownOutSparkPlug.com, the escaped cam follower sometime happens due to a stuck valve. This is consistent with the lack of compression in #6, as are the bits of spark plug electrode floating up into the intake manifold. It is just possible that a piece of electrode got trapped under the valve, allowing the cam follower to escape. At that point there would have been no more combustion in that cylinder, or what there was would have blown through the partially open valve, and cylinder charge would have been reduced due to lack of suction on the intake stroke. It is likely there would have even been reverse exhaust flow through the cylinder due to vacuum in the intake manifold.

So I plugged an air hose into the spark plug hole using the hose from my compression tester and had a large flow out the exhaust. I next attempted to open the valve a bit to dislodge the foreign object and was somewhat successful as I was able to get it closed enough to push the piston down and open the intakes. A subsequent compression test showed 70 psi and I'm still getting leakage through the exhaust valve.

The truck ran nearly 1000 miles this way (we were returning from a pick-up) so I'm hoping the problem now may be carbon on the valve and seat and that it will bed in once it's running again. Obviously once the cam follower escaped it was no longer cycling. I was driving when this happened and what seemed at first like the cowl shake we had been experiencing developed quickly into a change in the note of the engine and a persistent miss. So I'm hoping for none or minimal damage to the seat and valve sealing surface.

However this does not explain the mangled plugs. On the other hand, before I started tear down I did run a tap through the insert to clean up the threads, (meeting almost no resistance) after which I started the engine, observed the miss on #6, shut down and removed the plug for a compression test. No plug damage was visible at that time. Andy (my older brother) suggested that maybe the piston tagged either the plug or the insert. It seems possible that an overly long insert might have been used and gotten tagged and this could explain the damaged plugs. It could also explain why after running the tap through the insert the plug remained undamaged on the following start-up. It also could explain why I did not see any damage to the piston through the spark plug hole.

So at this point I would like to open the valve a few more times manually if I can find an effective way to do it, just to make sure the stem is riding freely in the guide. Does anyone know how much spring pressure they used on the 4V heads? It seems to take a good bit of force but I haven't managed to get a straight shot at it yet. Then if I can get good replacement valves for my compression tester I'll run another compression test. Then I will try a leakdown test if I'm getting it to hold any pressure. It seems at this point that the intakes and rings are good.

I'd still like to avoid pulling the head if I can. If I can get the compression up to around 120 with a corresponding reduction in leakage past the exhaust valve (and with a freely moving valve stem) I will reassemble and try to bed in the valve by running it. If subsequent compression and leak down tests show no improvement it will then be time to pull the head.

So just in case, I have two questions.

#1: Does the timing cover have to come off to pull the head?

#2: Does the front end have to come off the truck to remove the damper?

Oh, and a third I guess: is it easier to pull the engine before pulling the head or will it come off relatively easily given the confined space in which to work?

Thanks all,

JB

 

Ok You mention damaged sparkplugs so I assume you had several. What happens if a plug is damaged ( ceramic or metal debris) from the plug drops into the combustion chamber, it can bounce around for a few seconds or for a longer time hitting the cyl head, the piston and the sparkplug. This damages the plug. However that same debris will eventually escape through an open valve if its the exhaust the debris heads for the cat. if its the intake valve the debris enters the intake manifold. From there it starts a game of roulette. It can get pulled into any of the other combustion chambers from there and damage the sparkplugs, piston dome etc. The process will then start all over again. I have found engines with one tiny screw that dropped into one cyl and ended up doing damage in all 8 chambers. A bent valve stem or face will allow the follower to come off as it basicly shortens the valve stem and gives excessive clearance between the valve and follower. A lash adjuster cannot adjust far enough for that much clearance. I personally think you will have to pull the heads to make a repair here. You don't want to run the engine with the low compression as you will be dumping raw gas into your exhaust and damage the cats. A leakdown will give you more info on this than a compression test at least it can indicate which valve is the culprit. Another concern is that with the possibility of debris in the system (intake manifold) you will want to remove the intake and clean it out making sure no other debris is present to get sucked up into your repaired engine combustion chambers. You do have to remove the front cover to remove the heads and removing the radiator will make removing the damper and heads a little easier. Good luck.

 

I just had to replace my 5.4 because of my engine blowing plugs. I ordered mine from powertrain products. It was 2499 with a 4 yr unlimited mile warranty. It came with everything needed for install. Also came with Plugs already in the engine ! It drives better now then it ever did. I use to blow a plug about 1 time every two weeks. and i always had a misfire. usually in 1 or 3. I had helio coil kits in cylinder 1,2,and 3. lol it was horrible. put one in on the side of the interstate one day.

http://www.powertrainproducts.net/contact.html

 

Possibility of a partially siezed valve guide is my main concern right now. The intake is off, no problem there. The debris was from the #6 plug ground electrode which was destroyed twice following the installation of a thread repair insert. Pieces of electrode were found on the ledge just inside the gasket between the upper and lower intake. I don't think it went any farther up the runner. Photos of the plugs and the debris is here: https://www.f150online.com/forums/me...blackwood.html
I don't know of any reason for the valve to be bent, there were not any pieces larger than a ground electrode floating around in there. But it seems possible that sustained operation under a misfire condition could have caused the valve stem clearance to tighten up somehow and cause the valve to hang. Otherwise the only apparent reason for the cam follower to escape seems to be for a piece of ground electrode to have gotten under the valve. So I need to see if the valve moves freely. I was unable to do that today, I had to help a friend who's garage burned down.

I may very well have to remove the head. Even if I don't have to it may be advisable. Are there any locating pins between the timing cover and the head, or is it just bolted together? If just bolted I'm thinking suitable leverage may get the gasket to slip and allow the head to come off the deck pins. Does that sound possible?

I'll know more after I can mess with trying to move the valve some more, and get to run some more tests.

JB

 

You might want to take a look inside with a bore scope. I've seen debris imbeded in the piston or even the head (aluminum of course) and I would be worried about that breaking loose when the motor heated up. It's worth a look.

 

I sure would if I had one. My problem right now is keeping the engine from rotating when I'm pressurizing the cylinder. I'm not sure what the valve timing is on this engine but I don't seem to be able to find a spot where all four valves are closed and the piston is at the bottom, so as soon as I put pressure to it the piston goes down and the valves open up. I will try doing it with less pressure using the leak down tester I just bought yesterday. New tool, and I haven't ever used one of them before so that might be an adventure.

Also I'm pretty unhappy with the partial threads. My compression tester doesn't like them, only just barely gets a start and I blew it out of one of the unmodified spark plug holes yesterday on the first crank. That didn't entirely thrill me, the threads are long enough but it won't go in by hand and I'm a little hesitant to force it, even provided I could get a socket on it down that long hole which is very unlikely. Even better, the new leak down tester has threads that look like they will be too short to even engage. So I'm fighting that problem a little.

The good news is that the valve that lost it's cam follower seems to move easily enough. So I just need to get it to seal a little better and then get the cam follower back on it. I'm guessing that might be some fun. I figure if it will come up around 120 psi that's a pretty good indication that it's closing completely and may just have some foreign matter trapped in it. That may blow out or pound out or both as soon as the engine starts to run, probably better than even odds between that and burning the valve, especially if I don't put a load on it until it smooths out.

As far as the crap bouncing around in the cylinder, if the valves seal and the rings don't leak I think I'll leave it alone. I've seen stuff imbedded in pistons and heads before, bigger stuff like a broken lock washer and a check ball that punched dozens of pock-marks in the piston and the head. (and no, I wasn't the one responsible for either one of those) Nothing here is even close to that size. About the best I can do is run a slender pick-up magnet down in there and see if I can pick anything up, and then go on.

JB

 

OK the head is off. It dropped a valve seat. I sure never would have thought of that one, not with the spark plug issue. I still can't quite make the connection but I have no doubt there is a cause and effect relationship there somewhere.

Anyway the good news, piston is fine, bore is fine, spark plug location is slightly recessed away from the piston compared to original. Maybe that seat was popping out and swirling around enough in there to beat hell out of the tip of the plug but I doubt it, I think the plug is too deep for it to have done that without also beating up the combustion chamber much worse. It's probably a good thing the cam follower dropped out when it did.

Here are photos:
https://www.f150online.com/forums/me...blackwood.html

It doesn't show up in the shots but the seat is cracked. The other exhaust seat looks like it may be dropping out also.

So what are my options here? is this a repairable head? How expensive? etc.

Incidentally, no, you cannot remove the head without first removing the timing cover and a whole bunch of other stuff. That could very easily be the start of a huge rant so I'd probably better go now.

JB

 

There was a TSB on this: 06-5-13
It isn't really clear but either there was insufficient cooling or the metal was soft in the areas of #6 and possibly #7 and #8 chambers, which led to blown plugs and/or valve sealing problems (as in dropped seats and such things). It certainly is conceivable that the cause could have been a foundry mistake. I convinced my Ford service manager to submit a query to see if Ford would cover the parts cost. Long odds maybe, but why not?

In the meantime I've been looking around. '01 to '03 heads are pretty common at prices under $300 and reasonable mileage, but so far all the ones I've found had the short threads. Haven't seen an '04 yet. But a contact says he can get them. We'll talk this evening. After seeing this I don't think I want a repaired short thread head, even if all four holes are done.

I did a quick hardness test and the roof area of #6 looks to be a bit softer than the same area of #7 on this head. That could definitely account for the blown plug and the dropped seats. I'll check it against #5 just for comparison. Don't have numbers yet, just a comparative test but there was a measurable difference, so if I needed to I could definitely get the hardness numbers. Actually I've got the makings of a pretty decent case here if I wanted to pursue it. We'll see what Ford has to say about it.

JB

 

Talk to Ric about the short thread heads - maybe his inserts will fix them for good.

 

That's not what concerns me, I am quite sure they would. I want to avoid another dropped valve seat. One is quite enough. I figure my best bet is to get an 8 thread head and put on it.

JB