Project Hazey

[DintDobbs]

Welp, the leak does appear to be on the thermostat housing. No build-up, but it looks like there's coolant on the outside after leaving it parked all night. Might as well replace the thermostat while I'm in there, just for funsies (have reason to suspect it's stuck open; will plan on playing with the old one after replacement).

@410Fortune Thanks for the pointer, I wouldn't have checked there before, and wouldn't have thought any thing of the coolant on the housing after, replacing the thermostat.

 

[DintDobbs]

The thermostat O-ring was the guilty party. Opened up the TH and saw the problem written on the thermostat: CHINA. Replaced with Motorcraft thermostat and O-ring, and the leak has vanished.

Suspect the old thermostat was faulty. Boiled it on the stove and observed no change.

Next, spacers and tires!

 

[DintDobbs]

Welp, she was playing tricks on me... Checked today again, coolant reservoir was empty again. Hrmm, back to the drawing board, and the parts store, to buy more coolant.

But the engine temp gauge works again, so at least the thermostat issues have been resolved.

It's also possible that fixing that introduced a new weakest link elsewhere.

 

[DintDobbs]

Old parts, new parts, same issue.

Assuming the engine is COLD when I begin:

I fill the coolant reservoir and it stays full, for a day, for a week, for ever, unless the engine has been warmed up and cooled down.

The coolant stays full when the engine is running, as long as the engine is running and when it is off IF it is not allowed to cool down.

Drove it for about an hour on a trip out of town, let it sit for about 2 hours, and drove it for about another hour back home. Checked on arrival at destination and again when home, full. Let it cool down overnight and checked the level this morning, and the slow leaking has returned.

So the leak begins after being warmed up completely, and cooled down completely. Once it ALL drains out, it can be refilled and won't leak out until being warmed up and cooled down again.

If I refill it before it is empty, it will all leak out.

 

[DintDobbs]

Well, I finally had some time off the other day and took ol' Hazey to get a proper look over and have a cooling system pressure test. The results weren't altogether surprising: there was a miniscule leak in the back side of the thermostat housing. Tossed in a new thermostat housing the other day, and noticed that the hose fittings on the old one were very extremely eroded.

The new thermostat housing and sensors rectified the issue causing the coolant temperature to read low. Not sure if that issue was caused by a bad sensor, or by air from the leak getting close to the sensor, but in any case, it's no longer an issue.

There are only two non-cosmetic issues remaining on this truck - the windshield washer fluid level sensor and the factory-installed subwoofer do not function consistently.

Besides that, there are two holes in the driver's seat, the "Limited" badges on the doors are damaged, the radio face doesn't work consistently; there are a few scratches and dings on the bumpers, rear driver side door, and hood; and the hood and roof have surface rust in places where they could use to be repainted. All can be rectified in due time.

I consider Hazey a restomod project, with a moderate lift, two additional roof bars, and a matching spare wheel being the only mods, and the rest being period-correct repairs. Hazey is a freeze-frame of what luxury looked like during my childhood, and if I ever father kids, it is Hazey that I want to pass down to the next generation as a preservation of life as we knew it at the change of the millennium.

If a 1955 Chevrolet Nomad was a cool classic in 1980, then a 2000 Ford Explorer is a cool classic in 2025.

 

[CDW6212R]

Good update, that sounds like the best old SUV a person could have. Keep enjoying it, the age takes a toll on certain parts that people don't think of worrying about.

That spare Limited wheel, if it look nice you should keep wax on the outer finish all the time. Mine was eaten up by a few years of minor yearly snows and the salt solution they spray here most times before it hits. I think wax should protect nice aluminum wheels from most corrosion. I have 13 of those BTW, I love them.

 

[DintDobbs]

Well, Hazey turned 230,000 miles this week. It's been a good ride. That's more than nine times around the circumference of the planet Earth.

Last week, however, I noticed that there has been an increasingly loud rattle coming from the underbody, seemingly resonating with the engine noise between about 1500-2500 RPM. My guess is a loose heat shield. Can't think of any thing else that should sound like that without impacting performance.

With my daily driver waiting for parts, I've been using Hazey as my run-around vehicle; work hasn't allowed much free time, but I'll plan to follow up once I get the other things in order and have time to check it out.

 

[CDW6212R]

Bought some needle nose vise grips and kicked the spring's butt in a second, went over to the other side and threw the whole assembly together in like 15 minutes... and noticed what made the first side so difficult.

My little scissors lever is seized up, partially open. Whacked on it from a few different sides with a few different tools, after drenching it with WD-40 overnight, and it still won't move. I've seen other threads with this issue, and will probably junkyard a replacement or just order new.

Also observed that the left rear brake caliper is floppy, anybody know what's up with that? The right side caliper is stiff.

How are your rear brakes now, and the parking brakes? I had to swap the entire rear from one of my 98's to my main truck. The parking brake scissor levers were a source of cussing. One pair was very rough and sticking a lot, but they are two piece assemblies, easy to clean apart.

The B#### was that they are unique left and right, all are stamped yes, but they are very easy to mix up. I did that while having them all out and cleaning them, adding anti-seize too. They can be installed on either side, but only one way will allow the rotor to go onto the parking brake linings. I fought that for a while, and then looked at the pictures I had taken before taking it apart. I had R&R the parking brake parts, including the scissor levers, with the axles in place. I figured it out, but it is much easier with the axles out.

So you can reuse your scissors levers, take them out and carefully clean them with a wire brush etc. They are tough steal, they will work once cleaned and lubricated.

 

[DintDobbs]

@CDW6212R My scissors levers were a lost cause. Replacing them was cheap and easy, cleaning them required time and energy. I have money.

It's been quite a while since I replaced them, so I might be missing details, but as I recall I managed to permanently deform one of the new springs during installation on the driver side, and elected to re-use one of the old ones. After replacement, one of the driver side shoe springs scraped against the wheel or hub assembly a bit, so I had to take it apart and put it back together more carefully to rectify that.

I don't recall having any issues with getting them onto the correct sides. I may or may not have looked them over carefully, or may be I knew that they were different going in and paid attention, or may be I took a shot in the dark and got it right the first time. I have no memory of that part of the process.

I did not service the floppy caliper, but the brakes are still strong as they are. It'll still stop all four wheels on dry pavement, but I'm planning to replace the pads and rotors on all four within the next few years, and likely the calipers too, just for funsies.

 

[DintDobbs]

Welp, there's yer problem.

I don't have the smallest idea of how this got here, but it is definitely not the smallest of holes. I have no cause to think somebody did this on purpose, but I haven't taken it off road or run over any thing big or sharp... the mufflers on these 2nd-gens are pretty close midboard and very high up. You'd get hung up on any obstacles long before they got to the muffler. What gives?

 

[CDW6212R]

Interesting muffler. I don't know either, maybe lack of driving caused extra rusting from the inside, and some minor object like a tree branch got run over. I have rarely run over anything that does real harm. I had a right CV boot torn this past January that I caught while doing suspension rebuilding. The high ground clearance keeps most objects from hurting anything, while on road.

 

[DintDobbs]

@CDW6212R Unironically, the muffler appears to have been the only part of the exhaust system replaced before I purchased the vehicle. Can't speak for its internal condition at that time. The rest of the pipe appears to be original. Might be time for an upgrade... Thrush? Flowmaster? Dual side exit with twin Cherry Bombs? I'll push it around for a while and decide what to do.

As far as driving goes, I've been regularly driving this between 1 and 3 times a week since I bought it. It gets used plenty, and even more so over the summer, with places to go and things to see. Definitely sees more action than the Vulture, although the latter is driven much harder.

Need to measure the inlet/outlet sizes to confirm, but I'm pretty sure the inlets are 2.25". Outlet size is less important... since the pipe behind the muffler might be getting gone.

 

[CDW6212R]

It's great that you drive it a lot, it saves many headaches of a hardly driven car. Do you like loud exhaust or not, since most aftermarket are a good bit louder than stock? I like the OEM in general but I'd like it a little deeper with just a little more volume.

I've got plans to use Cherry Bomb Vortex mufflers, which are flat top and bottom, easy to stack or weld together. I want two tail pipes, but since you might make those real short, how about two right where the stock one is. The Vortex are under 4" thick and I think the typical 14" length. I wonder if two would not make it too loud, if the pipes ended just at the outside edge of the rocker. Making two run to the bumper is much harder, space for two around the suspension is not great.

 

[410Fortune]

Flowmaster makes a good dual inlet single outlet muffler that will fit right in there

That part of the muffler is the lowest spot in the exhaust so that is where water collects
If trips are too short the exhaust never gets hot enough to burn up the water and well you end up with a rusted out el cheapo muffler

I’d replace it with another el cheapo muffler, the flowmaster is like $60 flowmaster flowfx 72198

A fully loaded limited like that back in 2001 was almost $35,000 a real luxury suv!!

 

[DintDobbs]

@CDW6212R Exhaust sound/volume isn't really a concern for me, as long as it flows well. It's a machine doing work, it's going to make noise. I did notice during the test drives and for all of my ownership that whatever muffler is on this Limited was a lot noisier than the one on my Sport, which as far as I can tell is the factory muffler. There are no visible cuts or welds on the Sport's pipes, and the muffler has the exact same surface rust as the rest of the exhaust system. It even still has the little skid plate thingy. I may never replace that one. Hazey's exhaust system however has already been violated.

While I know there are certain advantages to true duals, I'm fairly set on a dual inlet / single outlet, as a single pipe will be easier to route similarly to the factory location. If the factory tail pipe has to go, I'm absolutely going for a side exit, either in front of or behind the rear passenger wheel well. Being mindful of entering and exiting occupants, though, I think the civil thing to do would be to route it behind the wheel well.

@410Fortune I saw a thread from like 20 years ago, you had mentioned the Flowmaster 50 Series SUV for 5.0L Explorers, which seems to be Summit Racing's favorite suggestion for Explorers to this day. It's available with dual inlets and they're the right size. Cost isn't really a major factor in my decision making process, but functionality and reliability are. I can't confirm the factory tail pipe diameter for the SOHC, though. Based on my rough measurements without proper tools, it appears to be either 2" or 2.25". The 50 Series has a 3" exit as I recall, which would mean a new tail pipe is in order.

As far as trip length goes, my regular path takes almost exactly 38 minutes, mixed city and highway with no stops. She gets plenty of time to warm up.

And, I just got my registration renewal notice in the mail today, so there is a timer on this project.

 

[CDW6212R]

My 99 with the SOHC I put in an Edelbrock muffler and the shop made a 2.5" tail pipe for it, plus an aftermarket resonator. It worked great and was louder than stock, most people liked it.

The stock pipes are 2.25" on almost all of the older Explorers, V6 or V8. The V8 cat pipes the shop I had change them said they were smaller than 2.25", but they were wrong, the OEM pipes are a thicker wall tubing though.

A lot of mufflers you get with dual 2.25" inlets, will have a 2.5" outlet. I'm sure there are plenty that will have all three openings the same size. The Vortex I mentioned I got years ago to see them in hand. So I was glad to see they are slightly thinner than the 4" they describe, instead of thicker(harder to stack together). The pair I bought have 2.25" inlet pipes with one 2.5" outlet, it would replace the stock muffler easily. Flowmasters are almost always on the much louder side, their chamber design is well known. I wanted less volume, and as power goes up, it's harder to hide it. So I guessed at the Cherry Bomb's last design, supposed to be a hair quieter(but I doubt it).

 

[GRNMACHINE]

I had a Flowmaster Force II catback system, muffler developed a rust hole, nothing like your pic. That does seem odd. I will say I buy Magnaflow now as their warranty is lifetime. I had a muffler replaced by them already on a different SUV(they are also stainless). They wanted me to work with the shop and there was zero chance I was going there again. Sent them pics, explained why I would not return to the independent dishonest muffler place and they sent replacement directly to me, no charge. I try to stick with companies that do things like that. Flowmaster warranty was 3 years, granted system was put on Many Years ago and I have no issues with their product, the catback was and is great, mandrel bent pipe so far still solid. But when a product is cheaper, made of stainless, and has a lifetime replacement, Im in. You can order directly thru them and they will help out finding a replacement with similar dimensions.

 

[DintDobbs]

@GRNMACHINE MagnaFlow, forgot to check out their lineup. Thanks for the suggestion and recommendation, that sets high expectations for doing business with the company. Will definitely add that to the list of options to explore.

Ultimately I'd like to run a dual inlet, with either single or dual outlet, and have one or both pipes exit behind the passenger rear wheel well. In my fairly uneducated mind, on such a low-power application, a true dual would serve extremely little benefit and create unnecessary inconveniences; any benefit to a true dual that could be offered by a crossover pipe on a high-power engine could be effectively replicated on a low-power engine by simply merging the exhaust flow inside the muffler, and as long as you're not stifling the exhaust flow behind the muffler, it basically shouldn't matter whether you have one pipe or two. Still leaning toward dual 2.25" inlet, single outlet. Working on some math that will help me to decide which outlet size might theoretically make the most sense.

 

[DintDobbs]

All right, so based on the "area of a circle" formula

Pi x Square of Radius = Area

it seems that for a dual 2.25" inlet, a 3" outlet would make the most sense for this application, since it is mathematically the closest to the same area.

2.25" diameter means 1.125" radius, so plugging that into the formula, we get

3.14 x 1.125 x 1.125 = 3.974

Multiply that by two, because we have two inlets, so the total inlet area is 7.948 square inches.

A 2.25" dual outlet would make zero difference, but what diameter should we use for a single outlet?

A 3" outlet would give us 7.065 square inches of area. Outlet area is 12.4% smaller than inlet area. Ford's single outlet was smaller and it worked fine.

Out with the old tail pipe it is.

 

[DintDobbs]

A local shop with good reputation quoted me $160 for installation if I can get a dual 2.25" inlet / single 2.25" outlet. He also said that if I go that route, he'll bend the existing pipe into a side exit. The price is favorable, but I wonder what he'd charge to bend a custom 3" pipe. I caught him like 5 minutes before closing, so to day wasn't the day to have theoretical discussions. I was grateful that he bothered to look at it at all.

Anybody have further suggestions? I'm still somewhat more inclined to move for the 3" single exit, but there isn't any thing wrong with the factory pipe.