Long time since i posted here, so let’s recap salient highlights of my van’s history:

• 1981 Dodge B-150 225 Sl 6 727 AT California emissions, registered in California
• 1987, June: New engine installed under previous ownership at 55,056 miles on the odometer. I surmise that this was related to an undeclared collision (see below). P.O. documented new manifold, fuel pump, motor mounts, and shocks at this time.
• No date specified, 59,555 miles on odometer: new fan, new water pump.
• 1989, May: Purchased used by me. I am the second owner. First vehicle i ever purchased, and i missed some obvious issues the seller did not declare, such as that the vehicle had been in a front passenger side collision then fixed up. (This is likely relevant to my current issue. Please keep reading.)
• 1989-early 1990s: did not pass emissions when i bought it. Under previous ownership, vacuum hoses had been scrambled and routed places they did not belong, likely to get the van running better. Rerouted vacuum hoses correctly, then years of working with a carburetor/fuel injection expert at a shop to get it running decently and passing emissions.
• 1989-1995: driven once a week or less, recreationally. Majority of mileage was highway miles. Catalytic converter replaced.
• 1996-’97: commute vehicle. 110 nearly all highway miles each work day.
• 1998-2003: back to recreational and long trip driving.
• 2003-2005: sat outside, not run, due to near-death illness and long-term recovery.
• 2008-2014: had not been running well. I’d been in denial regarding how many years and miles were on it under my ownership. All vacuum hoses replaced (many had been cracked). Was not running at all most of these years. Sat in garage as i gradually, occasionally worked on it. Rebuilt distributor successfully and did a bunch of other work that might distract us from my current question.
• 2014: once road-worthy, did not pass emissions when time to reactivate registration. Took it to a supposedly-good shop, who caused some significant unnecessary interior damage and (eventually) fixed the problem(s). (Outsourced) carb rebuild ran much better than my 1989 first-ever rebuild: better fuel economy along with good running.
• 2018: Paid too much/got too little for suspension work. More emissions problems, requiring catalytic converter replacement.
• 2020, 2022: ever-more difficult and expensive emissions tests, as fewer shops are equipped to test pre-OBD II vehicles, and State of California requirements makes doing so extremely costly. But Vanglorious passes.
• 2020-2022: had been noticing stronger fuel smell after parking van, and jingling sound coasting at certain speeds. Oil and transmission leaks.

Recent History
• The van last moved sometime prior to 28 June 2022 at (1)34361 miles on the odometer.
• When timing chain cover was off for front seal replacement, found timing chain loose. Replaced timing set. Set timing to match existing—did not degree in cam.
• Checked alternator brushes: almost down to the springs(!). Replaced.
• Running engine with Evans prep fluid, as part of conversion to Evans waterless coolant. Discovered fuel pump leaking gasoline out of weep hole. This led to a whole extended long time diversion of life distractions and seeking a good replacement fuel pump. Note that i likely ran for about 5 years with this leaking fuel pump diluting the oil.
• Next problem: horrible noise that hadn’t been there before. Eventually traced to a bad bearing in the idler pulley i installed new in January 1990 as part of the missing A/C. (Pulley is A/C compressor delete.) Another delay and life going on searching for and eventually finding a replacement pulley. Since then the engine sounds like it always has when running well.

Here things get interesting. For most of the late 20-teens into the 2020s, the dash gauge showed that the engine was taking longer and longer to warm up. Whilst doing this other work and prepping for the waterless coolant conversion, for the first time ever since i’ve owned this van, took the thermostat out. It was a 180° unit. This van is supposed to run with a 195° thermostat.

Once again, my inexperience and failure to think things through led me to ignore obvious evidence right in front of me. Ever since i bought the van, the temperature gauge never went more than 1/4 from Cold, other than almost to the halfway mark very briefly for hot restarts on hot days. Not until this discovery did the clue-by-four hit me that most automotive engineers would have designed the dash temperature gauge to be near the middle of scale during normal operation—like pretty much every other vehicle i’ve seen.

Obtained the correct 195° thermostat and installed it (more than once: dealing with leaks from the new t-stat gasket not sealing fully).

Attempted to resume the Evans Waterless Coolant installation, a year and a half after starting it. Everything was peachy until the engine warmed up and white smoke emerged from the rear of the engine along the head block/cylinder block seam. The temperature gauge was just slightly above halfway.

I shut down the engine and have not run it since. This was this past September (2023).

The white wispy smoke i saw emerging from the rear of the engine along the seam looked exactly like similar smoke at the thermostat before i solved the leaks there, so it seems to me likely that it’s the Evans coolant, else water that did not get purged or got back in over all the many months between starting the Evans conversion process and almost finishing it.

Did a cold engine compression test a few days ago. Ignition killed, all spark plugs removed, throttle and choke wide open, 2 min. between cranks to allow starter to cool:

Dry compression (PSI):
1: 155
2: 154
3: 176
4: 169
5: 164
6: 160

Wet compression (PSI, Blaster Chain & Cable spray Lubricant):
1: 157
2: 156
3: 183
4: 174
5: 171
6: 165

The Question: Can the white smoke from that seam be anything other than a blown head gasket?

The Big Picture: Is further repair worthwhile to me, given my skills, resources, and goals?
I have never been into any engine deeper than having the valve cover off or the timing set change (whichever of those is considered a deeper dive). This engine has about 79,000 miles on it, and most of the rest of the vehicle 134,361, for what i understand was a vehicle designed to last 100,000 miles. Despite my conservative, mellow driving style, the engine may be tired, as may be the transmission and other major assemblies.

Further, given that under previous ownership someone scrambled the vacuum hoses and installed a 180° thermostat, perhaps maybe the white smoke is related to something they were trying to cover up with that lower-temperature thermostat? Likely something else that cannot be known without an engine rebuild.

Removing an engine seems daunting—especially from a van, which is why these last couple of years i tried to Mickey Mouse re-sealing the engine to cure leaks rather than pulling it and rebuilding.

Let’s say i do manage to find a knowledgeable person to help with rebuilding the engine and do all that work. In a best-case scenario, i get a nice fresh stock Slant 6 in a body which as far as i know is working, but may soon have other age + mileage-related major failures. More than that, California really wants internal-combustion vehicles off the road, and they really seem to hate 1975 to 1998 (or thereabouts) vehicles that had emission controls that kinda sorta worked, but predate OBD-II. Registration every year is not in the $130 range and only going up, and emissions tests every other year for this vehicle are now about $165 or more—if i can even still find a shop willing to do the test.

I have time (mostly), but not many $$. It would be great to keep my first and, until this past August, only motor vehicle on the road, in particular for hauling materials for home maintenance and the like, but i’m not sure it’s worth it. The severity of this white smoke issue and what will be necessary to fix it are likely to tip the scale one way or the other. If it’s something easy, it’s likely worth it to me to keep the van. Otherwise, it may be time for me to say goodbye to it.

I very much look forward to your informed thoughts and suggestions.

Appreciatively,

))Sonic((

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1981 B-150 short Van, stock 225, California emissions package, Electronic Spark Advance (digital Lean Burn), Non-feedback Holley 1945, AT
Driven for economy, not for speed.

It is possible to have an external water leak without having a head gasket bad between cylinders ( that is what a compression test would show). I would go to an auto parts store and using their "tool loaner" program, get a cooling system pressure tester. Pressurize the cooling system and check for leaks. With compression readings like you have, I would not be concerned about needing a rebuild. Might need a head gasket to repair a coolant leak. Time to check it out

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 225 nitrous
64 Valiant Signet
64 Valiant 4dr 170

Those compression readings are great, so I would say no rebuild as well. Charlie has the right strategy.

It is conceivable one of the casting plugs ("freeze plugs") on the head is bad (rusted or not sealed) and is leaking. It might require head removal to get at it, but in a van maybe not, since the back of the engine may be exposed with the doghouse off.

Keep on vannin!
Lou

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Home of Slant6-powered fun machines

I don't get where you say it was "designed to last (only) 100,000 miles". Many many of those same vans went several times that distance over their lifetime without near as much major work as you have done to yours, many not even getting what would be considered normal maintenance. Most of the similar age vehicles I've had I haven't even come to own until they were at much higher mileage than yours has now.
But yeah, a lot of times sitting is harder on a vehicle than being run the snot out of.
On the heat gauge comments about being "1/2 gauge being normal"
A lot of times even between one and of another of the same vehicle the gauges won't read identical due to gauge or sending unit calibration, or something in the wiring, grounds that aren't what they should be etc.
But I will add that the "dead in the middle of the range" wasn't always true. Until at least the mid 80s models, especially concerning the heat gauge, most of them that I have owned (every single one a chrysler product) seemed to run about 1/4-1/3 of the range as "usual normal". And I've always run 195 thermostats.
But then again many times I've verified that within the middle half of a given gauge range sometimes a few degrees of change can mean a big change in gauge position.
Ever noticed that on factory gauges that show numbers vs those that just say "C..........H" that the numbered scale will show (something like) low range 100, mid, 210 and pegged high 260?
The higher half of the needle sweep covers 1/2 the number of degrees as the lower half of the needle sweep range.
That never really made sense to me.

Just another thought. It is possible you have water seepage at one of the rear manifold studs into the head. I have seen that on occasion.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 225 nitrous
64 Valiant Signet
64 Valiant 4dr 170

The Evans prep fluid is meant to be in the engine for 15 minutes, to take out the last remnants of water. I don't know in detail what its chemistry is; the MSDS says it's a "blend of hygroscopic diols" (fancy way of saying more than one kind of alcohol) "and sequestering agents". Perhaps letting that brew steep for 18 months dissolved a leak path through a gasket or coat of sealant.

Charlie has a good suggestion; check for seepage at one or more of the rear manifold studs—that's a very likely source of this leak, because in order for coolant to produce white smoke (and not just steam) it has to burn, and the block and head aren't hot enough for that, but the exhaust manifold is.

Hardcore defenders of the glory of their favourite car brand will squawk—some have squawked already—but that is more or less correct. Take a look at the average age of cars and trucks on US roads over the years and decades and see for yourself; figure about 10,000 miles per year (or use 15,000 if you like; it doesn't change things) and do the math, then confirm it by remembering that your van has a 5-figure odometer. Yes, a lot of these vans went significantly more than 100,000 miles…no, they didn't do it without a lot of repairs and replacement parts. If we're honest with ourselves, they were not super-well built by the standards of that time, and theyre decades old now. A lot of the body hardware and fittings were cheap and sloppy—good enough to stand a pretty good chance of surviving the warranty in good shape. A lot of the parts are no longer available.

Given what you've found so far—slack timing chain, etc—that is surely the case.

This van is never going to give you the kind of never-have-to-think-about-it, hop-in-and-drive-anywhere dependability you might have in mind, the kind we easily get used to with modern cars. You will pretty much always be in one of three positions: replacing parts, just replaced parts, about to replace parts. I'm not saying you should take the van out behind the barn and shoot it between the headlamps, just that you should base your decisions on realistic expectations.

Probably not.

True and correct.

Totally get that. When I had the chance to buy back my first (running) car after a bunch of years, I had to sit on my hands hard. "No" was the correct answer, but it still hurt.

It almost certainly isn't, unless you're doing a big renovation and hauling every day for weeks and months on end. You can rent a van or truck for $25 for a single job's worth of use at Home Despot.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

tl;dr: did the cooling system pressure test. Unsure how to interpret result. Ran engine to full operating temperature then 10 min. at full temperature with heater on full to complete the Evans Waterless Coolant installation process. No smoke nor steam nor similar beyond maybe a very brief faint wisp. But i did find a leak as advertised.

Coolant Pressure Test One—External Leaks
Loaner tool EverTough Radiator and Cap Tester 67085 from O' Reilly was difficult to get to fit on the radiator filler neck in place of the cap. Pumped up to 15 PSI per factory service manual. Pressure dropped 1 PSI after about 20 minutes, 1.5 PSI after half an hour. 2.5 PSI after an hour and 10 min.

Question 1: Is that degree of drop considered a leak, or allowable? In other words, how perfectly sealed is a real-world cooling system of this nature supposed to be?

I looked all over for leaks: thermostat, radiator, hoses, freeze plugs, and most particularly around the back of the engine where i’d seen the white smoke. Absolutely no leaks found at all with a cold engine under pressure.

Coolant Pressure Test Two—Internal Leaks
The factory service manual has the following:

Then a strong warning about pressure building up fast and keeping it under 20 lbs. (138 kPa). I had no issue with anywhere this level of buildup, completing the test with a helper within a minute or two from pressurization.

I was in the cab monitoring the gauges, looking for smoke/steam/etc., and fluttering the accelerator. My assistant had pumped up the pressure and monitored the gauge. She reported barely a needle’s width of movement with vigorous acceleration.

Question 2: Is a needle’s width close enough to zero for this test to be OK, or should it have been absolute zero fluctuation?

The test continues with a warning about not disabling any cylinders (catalytic converter damage) as item (4), then:

I admit i forgot about this part of the test, but there certainly wasn’t anything enough to draw attention.

The test ends with:

Not sure whether this dipstick check would be valid with waterless coolant. Did it anyway. The oil still looks brand-new, with no visible anomalies.

Visual finding: Bubbling At Exhaust Manifold Stud
First, we need to jump back in time for some corrections and additional information.

I have the good fortune of having a new (as of 2022) Love in my life. Amongst her many positive attributes, she has automotive repair skills on a level similar to my own: just about anything other than going deep inside an engine. She was present when the engine was last run, which my records show as early February 2023—about a year ago now—not this past September. She also saw what i have been describing as white smoke. She is not certain that it may not instead have been steam. I just know that it was white, wispy, started when the engine reached full operating temperature.

Back to the present. This time as the engine was warming up in step (3) above for the hot under pressure acceleration bursts needle flutter test, both of us were very closely monitoring the back of the engine (and me the dash gauges and checking the tailpipe visual output). I thought i might have very, very briefly seen a faint wisp of white smoke or vapor, but unlike a year ago it was very faint and brief, if indeed it existed at all. At another point she thought she briefly saw something away from the manifolds on the passenger side at the block/head seam near the back. I didn’t see anything there, multiple videos didn’t capture anything, and she’s not entirely sure. Also there likely was some residual oil over there from my recent compression test.

What i did see (and captured on video) was slight bubbling on the back side (or edge) of the gasket for the exhaust manifold #6 runner at the head. This seems to correlate with:



As noted there was no smoke this time (else only about a second or two of it, very light, and not near the manifolds). The bubbling looked highly localized to a small point, but did keep going a few minutes before it stopped. It was slow, maybe 2 to 3 bubbles/minute. I had noticed during the cold off engine pressurization test whilst looking for leaks that there was no active leaking at that manifold gasket edge, but there was old dried gummy “yuck” around that gasket several places. I surmise that this leak may have been present for some time, back when i was running regular coolant/water, and last time i had the engine cover off was too small to notice or i didn’t run the engine to full operating temperature and look there. Only saw bubbles, not running liquid nor visible vapor of any sort.



Excellent point, and my error based upon faulty memories. Re-reading my records shows that at worst the prep fluid was in for a month or two, but i’m pretty sure from the re-reading that it was not in for more than an hour. When i was at that stage, i had what would turn out to be the bad idler bearing noise, which went away, and then i noticed the fuel pump leak. Despite the leak, i was close enough to the 15 min. mark to take the chance and keep running the prep to completion. What most likely happened then is i drained the prep fluid and left the system dry until sorting out the fuel pump issue. Then i would have filled with the actual Evans coolant and tried to follow those steps, but that’s when the bad noise issue came up and i was uncomfortable running the engine until that was sorted out. The noise issue was resolved with a new pulley not quite a year ago, and that was the white smoke (or vapor) incident currently being worked through.

So if having the system “dry” between the prep fluid and the coolant, and/or from getting part-way through the coolant adding procedure but not all the way, until today, is in any way problematic, there could have been issues related to the over-extended coolant installation procedure. The system has been mostly full of Evans Waterless Coolant and the coolant did have time to circulate (including the heater core) over a year ago, but might not have been fully topped off as a year ago with the smoke i did not run it the full 10 min. after reaching operating temperature, having no idea how benign/severe the white smoke (or vapor) was.


****** Current Concerns/Questions/Thoughts *******
Two questions repeated from above (see above for context if necessary):

Q1) What amount of cooling system pressure drop is OK? Zero only? 1.5 PSI over half an hour? Something else?

Q2) For the rev the hot engine and see if coolant pressure needle moves under 7 PSI pressure, is a very slight needle’s width movement a Pass or Fail?

New questions:
Q3) How serious a problem is a very slight, possibly intermittent, bubbling coolant leak? If it’s too much work to correct, i might consider running it as it is.

Q4) What sort of work would be most likely to re-seal the bubbling leak? Exhaust or both manifolds come off, i’m sure, and i’m aware that there are very specific ways reinstallation needs to be done to avoid manifold cracking, and if i get into this will assuredly review the good material on that here. Does the stud need to come out? Is it reusable? Is the other manifold hardware reusable? Does the repair go beyond the manifold and stud?

Q5) Anyone with a Slant 6 van had the manifold(s) off with the engine in place in the van?

Feel free/encouraged to suggest to me search terms or direct post links if any of these have been covered already, and i’ll go do my homework.

I’d like to comment further on some of the other aspects of my post and the responses, such as the Big Picture stuff/longevity/fuel gauge indications, but not right now. This is plenty long and i don’t want to make things even more confusing/tedious to read.

~ Thanks All! ~

))Sonic((

_________________
1981 B-150 short Van, stock 225, California emissions package, Electronic Spark Advance (digital Lean Burn), Non-feedback Holley 1945, AT
Driven for economy, not for speed.

This raises suspicion as to whether it sealed 100 per cent properly.

Depends how well the tester sealed to the radiator, but on its face I'd call this a good enough result.

Yes.

Probably no coolant-into-oil leak.

Probably.

Not really, no.

It'll stink (=you're breathing stuff you shouldn't ought to), and it'll slowly drain off your costly coolant.

Both.

Yes.

If it's in good condition, yes, but it's subject to extreme thermal cycling, which weakens it, so best to just install new. Only if the stud breaks off (not very likely in a case like yours) or you discover other problems (hidden manifold crack, etc).

Could I put in a vote for just using regular-size, regular-font, black type? The multiple sizes and colours and stuff don't make your question easier to read, they do the opposite. And they make an unnecessary markup mess for those trying to help you by replying.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.