Page 2 of 3 FirstFirst 123 LastLast
Results 21 to 40 of 52

Thread: Possible thermostat issues.

  1. #21
    Van Fan
    My Van(s):
    1984 Toyota Van
    Join Date
    Jun 2013
    Location
    California
    Posts
    24
    Rep Power
    1

    Thumbs up Re: Possible thermostat issues.

    Quote Originally Posted by timsrv View Post
    Replacing the thermostat is a good 1st step when chasing cooling issues. It's a moving part & one of the most likely to fail. It's also cheap and fairly easy to change. It may not solve the problem but if nothing else you can rule it out and feel confident with it for at least a few more years.

    Were you running AC when this happened?
    No, the A/C was off. The dealership said the Tmstat will get here this afternoon. I've been driving around today, but then again the temp is a lot cooler today 'cause it's cloudy.

    I'll keep you posted. I'm planning of flushing the raditor really good, putting that new tstat on and filling it up with coolant vie water.

    Thanks!

  2. #22
    Van Enthusiast joegri's Avatar
    My Van(s):
    87 4wd cargo 88 4wd cargo
    Join Date
    Apr 2011
    Location
    narragansett,rhode island
    Posts
    112
    Rep Power
    1

    Re: Possible thermostat issues.

    after all this talk about t stats and radiators and having much of the same problems and symptoms that we all are having i went ahead and ordered a new t stat from the toyota dealer today. i had to think long and hard about this and i remember putting in an aftermarket t stat a long time ago like 7 years.but i didnt drive this van cuz it was under construction so i put a new aftermarket t stat in it like feb and still the same symptoms continued to this day.and my previous van had a toyota t stat in it that opperated perfectly normal with no problems. so long story short i,m guessing in the case of t stats ya gotta use original equipment .i,m sorry for jumping in on this thread but, i had to let you guys know i have many of the same situations that you do and i will report back back my findings after i put the new one in! i just gotta make some time(thankfully i,ve been real busy with the carpenter work these days.
    Attached Images Attached Images  

  3. #23
    Administrator timsrv's Avatar
    My Van(s):
    Lots of them
    Join Date
    Jun 2010
    Location
    SW WA ST
    Posts
    6,173
    Rep Power
    10

    Re: Possible thermostat issues.

    Quote Originally Posted by MonTex View Post
    Who reading this has placed a 4-row core into their van? If so, was it beneficial? My radiator shop can retrofit a high-efficiency 4-row core onto my original radiator tanks, but I was told (cautioned) that a larger 4-row core would accommodate less solder at the tanks than the original 3-row core
    has. This may result in the radiator being less reliable over time.

    Thoughts?
    Over the years I have had several high efficiency extra core radiators custom built. I have never had a problem with any of them. I have however noticed a marked improvement regarding cooling problems. I used to build hot rods and in many cases the extra rows were the only solution that actually worked. I have never heard before from any radiator shop that there was a down-side. In fact, quite the opposite. When brainstorming with radiator shops on how to address cooling system problems I have had multiple radiator guys recommend this as the best solution.

    I'm not disagreeing, I'm just very skeptical. If that turns out to be true it will be news to me. As for putting one in a van, I had a custom high efficiency 4 row radiator built for my 89 van in 2005. There was an immediate marked improvement with cooling & I'm still running that same radiator 8 years later (hasn't sprung a leak yet)..........knock on wood Tim

  4. #24
    Van Fan
    My Van(s):
    88 Cargo
    Join Date
    Nov 2012
    Location
    United States
    Posts
    50
    Rep Power
    1

    Re: Possible thermostat issues.

    I had some overheating issues a few years ago. The van would run just a little hot but only occasionally. After parking it I could hear overflow gurgling into the overflow tank. So I did what I would always do in that situation and ordered a new tstat from the dealer. While I was waiting for it to arrive I happened to talk to a buddy of mine who's a pretty damn good mechanic. He suggested first replacing the radiator cap for any and all cooling issues with any vehicle. So I went to Napa(or some such) and picked up a new radiator cap. I put it in and haven't had a single overheating or overflow issue since. I actually still have the tstat sitting in the glove box for the day it's actually needed. Obviously, your mileage may vary.

    On a side note, this new server is fast. Me likey. Thanks Tim.

  5. #25
    Administrator timsrv's Avatar
    My Van(s):
    Lots of them
    Join Date
    Jun 2010
    Location
    SW WA ST
    Posts
    6,173
    Rep Power
    10

    Re: Possible thermostat issues.

    Good point. Sometimes the best solutions are also the simplest. Every time you pull the radiator cap you should inspect the rubber gasket & check the seal surface inside the filler neck. Sometimes the seal surface gets divots or bumps from corrosion. The cap is designed to keep pressure at around 13 psi, but if the seal to the cap is compromised it won't hold any pressure. Tim

    PS: Yes, the new host is awesome! Although I don't deserve credit. Gwen (llamavan) did all the real work. Tim

  6. #26
    Van Fan
    My Van(s):
    1989 4WD LE Van w/Auto with custom 4-row core radiator
    Join Date
    Nov 2011
    Location
    Portland, OR
    Posts
    47
    Rep Power
    1

    Re: Possible thermostat issues.

    Thanks for weighing-in on this, Tim.

  7. #27
    Van Fan
    My Van(s):
    1984 Toyota Van
    Join Date
    Jun 2013
    Location
    California
    Posts
    24
    Rep Power
    1

    Re: Possible thermostat issues.

    ..update. I got my new thermostat from Toyota. I drained my radiator. Put the new tstat on and now the temperature gauge hangs around the 50%, 55% neighborhood when I drive, which has me worried because the weather has been a lot cooler since I put the new tstat on.

    Now, I noticed I made the mistake of not draining the engine block like I did with the radiator and since there was water in the system before instead of coolant I guess now I have a mix of coolant and old water. No wonder, I was reading the manual for the van today and it says you need about eight quarts of coolant and I could only fit four quarts .

    So my questions now are: should I do the complete coolant drain this time, and then refill with 100% coolant?

    ..and also, after driving a little today, maybe 15 minutes or so, I checked my radiator hoses. The upper one was really hot (could not keep a hold on it), and the bottom one was hot, but definitely not as hot as the upper one. Is that normal? I read somewhere it's a sign of a shut closed thermostat.. but I just replaced it! No bubbling coolant or leakege anywhere.

    Like I mentioned before, it has been a lot cooler these last two days, but I'm worried that when it gets hot again the temp gauge will go up again.

    Any thoughts or suggestions will definitely help.

    Again, Thanks!

  8. #28
    Van Fan
    My Van(s):
    1984 Toyota Van
    Join Date
    Jun 2013
    Location
    California
    Posts
    24
    Rep Power
    1

    Re: Possible thermostat issues.

    Oh, forgot to mention I replaced the radiator cap as well.

  9. #29
    Administrator timsrv's Avatar
    My Van(s):
    Lots of them
    Join Date
    Jun 2010
    Location
    SW WA ST
    Posts
    6,173
    Rep Power
    10

    Re: Possible thermostat issues.

    50 - 55% on the gauge can be normal. If it stays below the 75% mark I wouldn't worry about it. If you want to know the exact temp get a meat thermometer & check the temp in the filler neck (warning, removing the radiator cap from a hot engine can be dangerous). Normal operating temp is 180-200. It's typical to see it on the higher side when the weather is hot. Yes, it's normal to have the hoses hot like you observed. The upper hose has ~200 deg coolant flowing inside of it when the van is at normal temp. The lower hose represents the temp of the coolant AFTER it's been cooled by the radiator. Actual temps will vary depending on weather conditions & how hard the engine has been working..........but should be noticeably cooler than the top hose.

    As for the ratios of coolant to water, the only way to get it right on initial fill-up is to completely drain the system then put the correct mix ratio in. If your ratios are off, you can use an ethylene glycol refractometer like THIS ONE to determine correct ratios & adjust. Most auto parts stores have cheap ones LIKE THIS that aren't as accurate, but will get the job done. Just remember that water cools better than antifreeze, so don't go above 50% (-34 deg) mix ratio. This could also be reason you are seeing the temp gauge reading higher. Of course the down side of 100% water is it will create corrosion issues & will freeze-up/break your block in the winter (assuming it gets cold enough where you live). Tim

  10. #30
    Van Fan
    My Van(s):
    1984 Toyota Van
    Join Date
    Jun 2013
    Location
    California
    Posts
    24
    Rep Power
    1

    Re: Possible thermostat issues.

    .. Just remember that water cools better than antifreeze, so don't go above 50% (-34 deg) mix ratio. This could also be reason you are seeing the temp gauge reading higher. Of course the down side of 100% water is it will create corrosion issues & will freeze-up/break your block in the winter (assuming it gets cold enough where you live). Tim


    Thanksagain for replying Tim. I hear that water also boils faster during a hot day, while the coolant don't and eventually water evaporates, what do you think? Do you think I should drain the whole thing and fill it with the already mix 50/50 coolant?

    Thanks again! the progress has definitely gone for the better

  11. #31
    Administrator timsrv's Avatar
    My Van(s):
    Lots of them
    Join Date
    Jun 2010
    Location
    SW WA ST
    Posts
    6,173
    Rep Power
    10

    Re: Possible thermostat issues.

    The pre-mix is all I use anymore. I used to scoff thinking it was a waste of money.........until I lived in a place that had acidic water. Unaware of the water's destructive properties I used hose water (as I always had) to mix my own coolant ratios. We lived there for 8 years & that water found it's way into every one of my vehicles. I only discovered this a few months before we moved. As a result I have had to flush my systems, have my radiators rodded out, and have switched to the pre-mix. An alternative could be mixing with demineralized water. Tim

    PS: Yes, water will boil faster than ethylene glycol, but for this application that is typically not a concern. If you have a sealed system water won't boil unless it's severely overheated. At atmospheric pressure water boils at 212 deg but at 13 psi it boils at around 245 deg.

  12. #32
    Van Fan
    My Van(s):
    1984 Toyota Van
    Join Date
    Jun 2013
    Location
    California
    Posts
    24
    Rep Power
    1

    Re: Possible thermostat issues.

    Quote Originally Posted by timsrv View Post
    The pre-mix is all I use anymore. I used to scoff thinking it was a waste of money.........until I lived in a place that had acidic water. Unaware of the water's destructive properties I used hose water (as I always had) to mix my own coolant ratios. We lived there for 8 years & that water found it's way into every one of my vehicles. I only discovered this a few months before we moved. As a result I have had to flush my systems, have my radiators rodded out, and have switched to the pre-mix. An alternative could be mixing with demineralized water. Tim

    PS: Yes, water will boil faster than ethylene glycol, but for this application that is typically not a concern. If you have a sealed system water won't boil unless it's severely overheated. At atmospheric pressure water boils at 212 deg but at 13 psi it boils at around 245 deg.

    Woow, that is a pretty good lesson to learn from, thanks for sharing it Tim . I'm flushing everything out and refilling w/ the coolant-antifeeze all in one, all the way to the top. Better be on the safe side since we still have the hotter days of the summer still ahead.


    Thanks again Tim and everyone that has been commenting and sharing their experiences, I've aponged a lot of knowledge and gotten to know my van better than any other car I've owned

  13. #33
    Van Enthusiast
    My Van(s):
    '86 2wdAuto made it to 490k,now in van 'heaven' '88 panel 4x4 standard,,stolen in Tijuana jan 2012 '87 4x4 auto...new paint, now on th'road! '86 2wd auto 360k,,mint condition,had some fun, needs engi
    Join Date
    Jan 2012
    Location
    vancouver canada
    Posts
    266
    Rep Power
    1

    Re: Possible thermostat issues.

    Quote Originally Posted by timsrv View Post
    I can confirm it was definitely the thermostat. My 86 van was having an issue with super long warm-up times so I pulled the thermostat & found it stuck open. After looking through my boxes of parts I couldn't find my extra Toyota thermostats (6 months after moving finding stuff still sucks). Anyhow, after about an hr of looking I gave up and called Napa. I asked for their most premium thermostat and got a Tama Enterprises Co. Part #154-2403 "made in Japan". It looked pretty good & even had a jiggle valve. I compared to the Toyota thermostat and although a bit different it looked to be the same depth & travel. Long story short I installed it and immediately started having the same problem as Scott. My new fan clutch (which I know to be adjusted correctly) would only run sometimes even though the gauge was getting up to 3/4 (this means the radiator temp was already cool but the system was lacking circulation).

    This weekend I picked up a Toyota thermostat part #90916-03046 (was actually a couple bucks cheaper than the Napa one) and that completely solved the problem. Now my temperature gauge stays rock solid at 1/4 - 3/8 of the scale. It was warm today and I even ran my AC for a while. Tim

    ....fan clutches have an adjustment?

    ..I'm on my 3rd installation of a brand new fan-clutch,, the most recent is an Aisin,, still doesn't seem to be fully engaging as seen on TV (your vid)

    ...is there something I'm doing wrong with my fan clutches?...seems like an easy installation.
    Last edited by micah202; 05-24-2016 at 11:25 PM.

  14. #34
    Administrator timsrv's Avatar
    My Van(s):
    Lots of them
    Join Date
    Jun 2010
    Location
    SW WA ST
    Posts
    6,173
    Rep Power
    10

    Re: Possible thermostat issues.

    Quote Originally Posted by micah202 View Post
    ....fan clutches have an adjustment?
    Not really something I'd recommend just anybody try, but I've adjusted them before. Back when I was experimenting with AM fan clutches I did this on a premium Napa brand (TRW I think?). If opened up there's screw slots inside that allow for adjustment (to make fan engage at a different temp), but this one was riveted together. The fan was engaging late, and I didn't want to drill rivets and/or mess around in the silicone goo, so I adjusted externally by relocating outer side of the bimetal coil. There wasn't a groove in the right spot so I cut a new one and dialed it in that way. It's the one I was running in this video, and I had it dialed in right where I wanted it. Sadly it failed after only a few thousand miles so I got a Hayden AM fan clutch. That one was adjusted correctly out of the box, but it leaked out all the silicone and failed after only a few thousand miles too. At that point I had enough of the AM clutches and went with the Aisin. That was 20 something thousand miles ago and it's still performing well. Here's some pics of that riveted one I adjusted:






  15. #35
    Administrator timsrv's Avatar
    My Van(s):
    Lots of them
    Join Date
    Jun 2010
    Location
    SW WA ST
    Posts
    6,173
    Rep Power
    10

    Re: Possible thermostat issues.

    Quote Originally Posted by micah202 View Post
    ..............I'm on my 3rd installation of a brand new fan-clutch,, the most recent is an Aisin,, still doesn't seem to be fully engaging as seen on TV (your vid)

    ...is there something I'm doing wrong with my fan clutches?...seems like an easy installation.
    I guess it depends on operating temperature. With the van shut-off, put a temperature probe in the proximity of the front of the fan clutch and put a meat thermometer in the filler port. If you don't have or can't afford a professional grade "remote probe" thermometer, they make them for cooking roasts and things and the range is perfect for automotive use. Anyhow, secure it in the area between the fan clutch and the radiator and hold your van at a high idle. As the temperature rises the bimetal coil on the front of the clutch rotates (changes valving inside the clutch). At some point the clutch fan will begin to engage (probably around 180 F). If the clutch fan is working correctly it will only engage as much as needed to stabilize temperature between radiator and fan. If temp in this area continues to rise, but the clutch continues to slip, then it's a defective clutch. If the temperature stabilizes, then the clutch is doing it's job (it's designed to regulate air flow based on temperature)

    If the engine coolant temperature continues to rise beyond a normal range (205+), but the temp in front of the fan remains low & stable, then there is a circulation problem (coolant and/or air). Coolant circulation problems can be caused by a plugged-up radiator, an aftermarket t-stat, a stuck thermostat, or excessive rust/scale build-up inside the block (foreign material). If you've recently replaced the t-stat with an OE, then you can probably rule that out. If the coolant is nice and clean, then you can probably rule out rust/scale. You can get an indication of radiator condition by removing the top radiator hose & inspecting the visible core/tube openings for solder bloom.

    Air circulation problems can be debris or anything preventing air flow through the radiator. If air cannot flow through the radiator, the fan will suck cooler air from surrounding areas. Since the clutch is regulated by temperature, it will never engage if the bimetal coil stays cool. One common cause of air flow restriction is road debris stuck to the front of the radiator/condenser. Since air will follow the path of least resistance, if you have a fan shroud that's missing parts or that's missing altogether, this will allow the fan to suck air from everywhere except through the radiator (make sure your shroud is there and intact). Note: These vans have 2 piece fan shrouds, both pieces MUST be there. Tim

  16. #36
    Van Enthusiast
    My Van(s):
    '86 2wdAuto made it to 490k,now in van 'heaven' '88 panel 4x4 standard,,stolen in Tijuana jan 2012 '87 4x4 auto...new paint, now on th'road! '86 2wd auto 360k,,mint condition,had some fun, needs engi
    Join Date
    Jan 2012
    Location
    vancouver canada
    Posts
    266
    Rep Power
    1

    Re: Possible thermostat issues.

    ...thanks Tim,, got the remote thermo today,, it'll be good to get to the bottom of all this


    ....I thought I was done and dusted when I got the Aisin ,, what you've given above should help.
    ....then again, I also thought fan clutches transferred the engine heat through their mount with the engine.

    ..prolly should be in a 'cooling system' thread, lotsa valuable deets beyond thermostats!
    Last edited by micah202; 05-25-2016 at 06:58 PM.

  17. #37
    Van Enthusiast
    My Van(s):
    '86 2wdAuto made it to 490k,now in van 'heaven' '88 panel 4x4 standard,,stolen in Tijuana jan 2012 '87 4x4 auto...new paint, now on th'road! '86 2wd auto 360k,,mint condition,had some fun, needs engi
    Join Date
    Jan 2012
    Location
    vancouver canada
    Posts
    266
    Rep Power
    1

    Re: Possible thermostat issues.

    ,

    ,,the remote thermo was an interesting and informative experiment.
    I drilled a small hole in the cowling, so the sensor was ~3-4'' from the center of the fan. I had already calibrated my thermostat and temp guage to know where 180 deg is, so did most of my observations in driving.
    I've been starting and running ~180 usually,, but on a longer drive, 40 min or more, temps would rise but the fanclutch wouldn't engage.As this happened I could now see that the front heat was only ~125deg or so.... I've returned 2 fan clutches in error! I recall once stopping by my parts dealer when the car was very hot, but the clutch wasn't engaging,, the car sat a few minutes,, and the clutch worked- only time! Now I see that temp rises enough when the van's stopped,, enough that the fan clutch engages

    So now, a new radiator's in place,,, and I believe a HUGE BONUS! I was quietly concerned about a small but steady loss of coolant,,, concerned it was head gasket issues, but not seeing typical telltale white smoke, and no water in the oil. In changing the radiator, I found a cracked bleeder hose ,between filler and top of radiator....here's hoping that's the end of fluid loss!


    Tim,, thanks for all you helpful direction. Without you, I'd be totally lost as to where to bring some very thilly questions, necessary to ask in order to bumble through. Thanks for your patience!


    .....now if only I could figure out why I've stopped being able to post pictures,, I'd document the projects I've done,, bumper rebuild,, and doubling rear springs.
    Last edited by micah202; 05-29-2016 at 05:13 PM.

  18. #38
    Van Enthusiast
    My Van(s):
    '86 2wdAuto made it to 490k,now in van 'heaven' '88 panel 4x4 standard,,stolen in Tijuana jan 2012 '87 4x4 auto...new paint, now on th'road! '86 2wd auto 360k,,mint condition,had some fun, needs engi
    Join Date
    Jan 2012
    Location
    vancouver canada
    Posts
    266
    Rep Power
    1

    Re: Possible thermostat issues.

    .

    ...again, not the right thread for this question,, but a continuation of sorting my cooling system.

    ..it's been great to continue driving with the remote thermometer just ahead of the fan clutch,, really gives me a read on what's going on. It's amazing how fast the compartment temperature rises at idle, or especially when the engine's stopped!

    ........A concern,,,, I might be over-worrying things, when filling the cooling system,, I run the heaters, let the thermostat open,, then top off the coolant. Most of the first time I encounter some stronger heating,, highway, heat or both,, the 2nd half of the reservoir fills up,, but never a drop more!
    . I refill the cooling system as above, and exactly the same fluid goes back as came out.

    Is it customary that the cooling system purges this amount?....
    I'm very worried about anything that resembles signs of head gasket damage,, wondering if this is it!?


    Is it possible that the times that I find the reservoir filled, I'm checking the system before it's had a chance to cool enough that the fluid is drawn back into the engine?




    ......an amusement....
    ....from a boat forum,, but makes me wonder if I'm doing the same with mah baby....

    "Whazzat sound?"
    "Something smells odd"
    "Did that light just flicker? Why??"
    "The tiller didn't feel this way 5 minutes ago..."
    "Why did the bilge pump just cycle?" (ice melt running into the bilge)
    I was so uptight during my first year of ownership, that I could make coffee nervous.

  19. #39
    Administrator timsrv's Avatar
    My Van(s):
    Lots of them
    Join Date
    Jun 2010
    Location
    SW WA ST
    Posts
    6,173
    Rep Power
    10

    Re: Possible thermostat issues.

    As you already know, when you heat fluid, volume increases. When you cool it down, volume decreases. This is the reason for the recovery tank. As the engine heats up, there becomes more coolant than can fit in the system, so it overflows into the recovery tank. When the engine cools, the coolant volume decreases. When it decreases, it creates a vacuum, and that's what sucks the coolant back from the recovery tank.

    In the old days we didn't worry about that. We just filled up our radiators and when the engine heated, it spit out the extra coolant on the ground. After the 1st couple heating cycles, the excess coolant was gone and the radiator stopped spitting it out (when cold it was normal for coolant level to be a couple inches below fill cap).

    The advantage to the recovery tank is we can see levels without removing radiator cap, and our cars don't drip as much coolant as they used to. The down side can be a false sense of security. If there's a breach in the cooling system (can be a leaking hose or perhaps a failing head gasket), the engine might not suck the coolant from the recovery tank on cool-down. This is because vacuum is required for that to happen. If a breach prevents vacuum the system will not suck from the recovery tank. This means your radiator warning light will not illuminate, and you may run dangerously low on coolant, even though the recovery tank is full.

    If you think that might be happening, check the fluid level in the coolant fill port and keep the system topped off there. If that level is always full, and the recovery tank level varies with engine temperature, then you're good (assuming it doesn't lose coolant). If there is an unexplained loss of coolant (coolant goes away but there's no signs of external leakage), then you may be having an issue with your head gasket. If that's the case, there would likely be the sweet smell of coolant present at your exhaust and perhaps some steam there. Usually head gaskets leak more when cold, but may slow down/stop when hot.

    Another thing you can do is pull your spark plugs and check condition. If you have one that's super clean, then the head gasket may have a breach to that cylinder. Breaches to cylinders are a 2-way street. If you have coolant going into a cylinder, then you have combustion gasses entering your cooling system. Since combustion pressures are so much higher than cooling system pressures, depending on size of breach, it could force coolant out of your system and into the recovery tank (more than what would happen due to heat expansion). If this is happening, the recovery tank will likely overflow and you will lose engine coolant.

    There are block tester kits you can purchase that detect combustion gasses in coolant. If you think this is happening I'd recommend getting one and doing the test. If it detects combustion gas, then it's time for a head gasket job. Tim

    PS: We have talked about this on other threads, so for more information, search the site. Tim

  20. #40
    Van Enthusiast
    My Van(s):
    '86 2wdAuto made it to 490k,now in van 'heaven' '88 panel 4x4 standard,,stolen in Tijuana jan 2012 '87 4x4 auto...new paint, now on th'road! '86 2wd auto 360k,,mint condition,had some fun, needs engi
    Join Date
    Jan 2012
    Location
    vancouver canada
    Posts
    266
    Rep Power
    1

    Re: Possible thermostat issues.

    ....thanks Tim,, a lot of information there, thanks for your effort.

    That's a very useful hint to check the plugs to allay my concerns... something to do while I actually give the system a chance to prove itself!

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •