I did a forum search and can't seem to find anything on this topic so I'll start a new one. I have a '92 hi jet that keeps overheating after driving a few miles. A new thermostat makes no difference. When it gets hot, the fan only runs for 1 minute and then shuts off. The rad is clean and the coolant is topped up. Any suggestions?
it's probably one of three things fan motor fan relay engine temperature sensor honestly i would start by tracking down the fan relay. once you have found that there should be a little diagram on it. that will show the power coming in and going out and the "tickle" wire coming from the temp sensor. remove the relay and put a jumper wire in the plug to "hot-wire" the fan. if the fan runs for more than one minute you can rule the fan motor out. the single wire temperature sending units usually are a ground sensative sending unit. so if you pull the wire off the sender and touch it to a good ground that should also turn on the fan. if the engine is warm and the fan is not running, and you ground the wire to the temp sender and the fan kicks on that's your problem. if it's a two wire sender then you can connect the wires together to turn on the fan. if that doesn't do it, then you can just about bet on it being the realy not holding voltage. the abridged version of this would be to find a similar relay in your electrical panel and swap them to see if the fan kicks on. i have had luck a couple times taking apart a relay that isn't working well, cleaning up the contacts and bringing it back to life. good luck milt
Did you bleed the system ? They can get airbound if you don't. Theres a bleeder valve on the high jets of that year on the intake manifold that you loosen while you filling it up to burp the all system . .
Well... I finally figured it out. I first jumpered the sensor wire so that the fan ran full time but there was no change. Then I opened the bleeder valve on the coolant system to make sure it wasn't air-locked, but still no change. I was about ready to pull my hair out when TRAX and HORNS suggested I check to see if the bottom rad hose was collapsing with rpm... and sure enough! Every time I stepped on the gas, the rad hose would collapse and flatten out. I guess sometimes it's so simple that it's difficult. Thanks for all the help guys!
Good deal terik. This has happened to me 2 times on 2 different trucks. Integrity of the hoses fail because of age and heat. Make sure you get a high temp. hose when changing it out. Hoses will need be a commercial grade, high temp, good for 125 psi. Most upper end auto parts stores will have it in bulk. Nothing Ventured Nothing Gained.
Milt, Related question: My temp gauge doesn't work but the radiator fan comes on and goes off while the engine is running. Does this provide a clue on what is causing my gauge and warning lights problem? (Temp gauge, fuel gauge, and three warning lights do not work. Everything else electrical does work.) Since the non-working electricals are all located together and somewhat related, I have been thinking that there is a loose ground or a voltage regulator common to all that is the culprit. I cannot find a problem with a fuse that relates to these items. Thanks, Sam
sam, i'm not sure if the fan switch sender is also the one for the temp gauge. have you actually taken your gauge cluster out of the dash and looked at the back of it? i have seen them crack and break connections that will render one side of the cluster useless, and have seen a plug come loose on the back of the cluster as well... i would start there. trax, good call on the radiator hose! i didn't even think about that. i remember a lot of older cars having a large spring inside to support the hose for that exact reason.
trying to get BEHIND the dash will be harder than chinese arithmatic... i think it will come out from the front. i was under my dash one day putting speakers in and there wasn't much room to reach up if you aren't a contortionist. i did see a couple screws on the front of it... you may have to pull the sterring wheel worst case scenario... not sure though, hope someone else will chime in with more info... maybe start a new thread about it?
Milt, I didn't mean crawl up behind--my wording was poor. I meant look behind the gauges. I have read a number of messages about how to remove the fascia or trim and get to the wiring, but I am reluctant to try this. I am not a mechanic and tend to break things when I don't know what I am doing. I may wait until I take the Hijet to a garage for a general check-up. I do have the owner's manual on CD, although this is for the 550 cc model which was exported new to the U.S. It is loaded with information. Thanks, Sam
sam, a couple good pieces of advice when attemping things beyond your mechanical abilities; if it don't fit, FORCE IT! beat to fit, paint to match if you can't fix it with a hammer, the hammer ain't big enough. hope this helps you through. honestly though, it should come out easily enough, save your money from the mechanic, buy a 12 pack and invite a couple friends over and make a day of it... take it apart gently it's not that tough, i've done it before but not on my mini. good luck
temp switch for fan I'll check my hijet in the morning. But on a suzuki the single wire temp sender above #1 cylinder on the right side of the engine is for the dash guage only. The suzi has a 2 wire switch on the radiator that controls the fan. As I look at the wiring diagram (from James Danko) I see it too has a 2 wire thermo switch like the suzi. I would first short the two wires. They should be black/yellow and the other wire black only. While the manual shows a place to put a test jumper I was unable to find this very spot on a suzi that I was working on recently (so I just shorted the switch and verified the switch was working properly. hope this helps!
Thread revival here. I am tagging along in the hopes I can get some help and others may benefit from the additional information. My 1990 Hijet climber has been overheating. I plan to flush the coolant system but wanted to replace my lines first. I know I also have a leak or trapped air because I can hear bubbles moving around in the dash etc…. at times. But before I do a flush, I figured I would replace my lines in case I have a leak. Well I have found a few issues and I need advice from those who may have run into similar issues. #1. The upper return lines, both a 0.5” and 1” straight metal lines are heavily rusted. These are the lines above the valves and are supported by two of the intake manifold bolts. I cannot find OEM replacements for these metal tubes. Should I replace the metal with hoses or make some out of stainless? #2. Well my intake manifold water temperature control valve is toast. See pictures attached. Does anyone know where I can get another or has anyone just bypassed it? Below are the pictures . Also, what are the chances the passages in the carb are also clogged. Finally, currently other than overheating at high speeds, the truck works great. My idle and staring are fine. Initially after startup the truck idles a little fast and as it warms up the idle transitions to normal. I am worried the choke and setup is going to change when this is fixed.
I am pretty sure it is https://partsfan.com/partinfo/daihatsu/177808710100 177808710100 I have a few emails out to parts suppliers in Japan but no word back yet.
google search for 17780-87101-000 shows Monotaro in Japan had it , NLA, similar p/n's for Daihatsu 17780 Valve assembly. Thermostat are shown as 17780-97201-000 17780-87203-000 https://www.monotaro.com/g/03094563/ no idea if these could fit.
No joy so far. All current contacts have fallen through. I am wondering? The purpose of this valve is to prevent flow of coolant in the carb until it comes up to temp. Why not just setup the flow so it continuously flows regardless of temp. It would stand to reason the truck does not take long to come up to temp and this would a few minutes of cold coolant flowing in and around the carb be an issue. After all, from the looks of my valve, the carb has not seen any flow for years. any thoughts. To setup without the valve all I have to do is find a nipple with a NPT thread identical to the thread of the control valve and then I will have continuous flow.
I googled with the 2nd number and found a japanese site explaining the function, copied here with google translate: Daihatsu (genuine) hot water cut valve This valve was used in the EF-SE engine from October 2000 to June 2001 to limit the inflow of cooling water to the throttle body. The passage is closed at 70 ° C or higher and the passage is opened at 70 ° C or lower. It is said that this opening and closing operation limits the inflow of hot water, prevents overheating of the throttle body, and does not reduce the volumetric efficiency of intake air. t was found that the decrease in torque was clearly suppressed when running in the summer after mounting. Part number 17780-97201-000 hose 16337-97209-000 × 1, 16337-97208-000 × https://minkara.carview.co.jp/userid/243946/car/136573/1982920/parts.aspx thermostat valve installation notes Many engines introduce cooling water into the throttle valve. It circulates hot water, prevents the throttle body from freezing, and heats the intake air. Since there are two purposes, it is not good for the temperature to rise more than necessary. One day, I learned that the cooling water inlet of the JZ engine has a thermostat valve that opens and closes the cooling water passage so that the temperature does not rise more than necessary, so I bought it immediately. It was January 2005. The inner diameter of the hose and the outer diameter of the union in this part of the corona are 8 mm. The thermostat valve of the JZ engine is 8mm on one side and screwed on the other side, which is a different story if it is a lathe, but it is not very diversionable. I gave up immediately. Thermostat valve installation notes bout half a year later, one day, I found out that Daihatsu Hijet's EF-NS engine had a similar valve. It seems that one of them goes into the carburetor insulator, but you can't tell what the shape looks like until you order it.This is the one that came. One is 8mm and the other is 6mm, which is not straightforward either. This is because the 6mm side and the vehicle side cannot be connected as they are. The days passed while "examining the mounting method", and it was left as it was until the end of 2008. At the end of 2008, when I went to Tokyu Hands store, I remembered this thermostat valve and examined how to install it in the store. The problems with installing this are as follows. ・ Connecting the thermostat valve 6mm union and the vehicle side 8mm union ・ How to mount this valve The former is"Attach a silicon hose with an inner diameter of 6mm to the 6mm union" and "Make the outer diameter 8mm with a radiator repair putty" . It is expected that it will be almost resolved. However, there are still concerns, the former is the reduced effectiveness of the hose band due to the "brimmed" being covered, and the latter is the durability of the putty in water. The biggest problem is how to mount. This valve is made of brass and aluminum, but it is quite heavy. With a hose-shaped mount, it's easy to imagine it hanging loosely or hitting parts here and there with vibration. Well, in that area, I decided to bend Amon's stays in various ways and think while wearing them. Thermostat valve installation notes However, one day waiting for the execution, it was found that the thermostat valve was also used in Mira's EF-SE engine. Since it is a car from October 2000, I found out that it was supposed to be lighter and that it seems to be mounted in the air (?) With a hose, so I ordered the parts. Then, both unions are 6mm, but they are made of resin and are very light. This solved the mounting problem at once. The next issue is the inner diameter of the hose. The car side is 8mm at both the entrance and exit. And this valve needs to be converted at the entrance and exit with 6 mm on both sides. Now, I will consider again whether to wrap a silicon hose or use putty. At that time, at the SAB off party in Shonan, I discovered that a 6mm-8mm conversion union was on sale at the "Sekohan Market" and bought it immediately. Although it is said to be for vacuum hoses, it is temporarily installed because it was written that it also has heat resistance. Then, it will bite into the hose firmly. Water will be okay because no air leaks. Thermostat valve installation notes The quality of the hose band used there was better than the genuine one, so I decided to use it as much as possible, but I didn't have time to go buy it. At that time, I suddenly searched the Internet for "6mm 8mm conversion". Then I found out that there is a conversion joint for the fuel system of the motorcycle. Moreover, it is made of aluminum and seems to be short in length. I bought it immediately. perfect! I replaced the joint with this. Thermostat valve installation notes: it is wearing. The length is also perfect. Since the thermostat valve itself and the head cover may hit, we plan to wrap the cushioning material around here. The installation of the thermostat valve was finally completed four years after the plan. https://minkara.carview.co.jp/userid/243946/car/136573/710729/note.aspx maybe that gives you some ideas how to solve the problem.
here is a diagram for an BMW E36 throttle valve heating system, hot coolant comes from cylinder head >>>hose #15>>>thermostate>>thottle valve>>hose 9>>hose 7>>radiator easy to understand the system, Auxiliary Water Thermostat to Throttle Housing http://bmwfans.info/parts-catalog/E...1992/browse/engine/cooling_system_water_hoses
Ok so G&R came through with a used water temperature control valve. I also replaced all of the coolant lines. Now all fuel, vacuum and coolant lines have been replaced…what a pain! I also bypassed those metal tubes above the valve cover/manifold because mine are rusted so bad. I just ran continual green strip hose and used a three way where the smaller tube had a connection. Anyways, it was a beast to get all the air out when adding back in the coolant. The bleeder valve at the manifold would NOT bleed at all even with truck running, radiator cap off and front elevated. At first I tried with the truck level, then maybe about 8” and finally up about 20”. At first I just loosened it a little at a time for effect and kept going until it was almost completely unscrewed. Never bled a bit. So maybe when I run the radiator cleaner through I will back it out all the way and clean it. So back to the overheating condition. It still overheats when I am at 80km or higher. Basically temp gauge stays 3/4 to maxed out. >The heat blows hot air like lava >I don’t hear any trapped air in the heater coil like I used too. >All passages are clear as I flushed with a water hose all ports while I had the hoses off. >The thermostat is opening because all the hoses are hot when the engine is warmed up and I can see the flow in the radiator. >The fan does run but seems like for short periods of time. Longest time is like 30 sec to a minute. I would think the fan would run continuously when the temp gauge is up 3/4 or greater? How do I bypass the temp switch and does the Hijet have a relay other than the temp switch?
I forgot to mention the coolant did not appear to be contaminated with oil and the oil is not milky. I have also changed all the belts except the timing belt. I will replace the water pump at that time. >next I will attempt to bypass the radiator control switch and see if the fan will operate continuously and see if it brings the temperature down any running continuously etc… >the radiator cap appears to be on good shape, but I could replace it. >even though the thermostat is obviously opening, maybe it is not opening all the way? So I could replace it as well. >the radiator appears to be clean, but I could hose it off with some pressure and see if that helps. >I still need to do the radiator cleaning solution as well. Please let me know if anyone has other suggestions? thanks!
Has your truck actually boiled over and puked out coolant ? If not, you may be chasing a ghost. I am not sure about the Daihatsu temp gauge, but many older vehicles had gauges that requite 10 volts, not 12 - 14 volts like your battery. To achieve this, a voltage stabilizer was incorporated either within the gauge or externally. Also observe your fuel gauge, as it could be the same, and operation will also be erratic if this is the case. I chased the ghost with my Riley for 3 years before discovering this - always overheating at high revs, but never boiling over.
I too wonder if in part This is a ghost. Additionally are these trucks meant to travel at a sustained 60mph? but she has barfed a good bit of coolant. For one I notice hat sweet smell after A sustained 55mph plus ride and when I lift the seat I have coolant on the side of the overflow tank where the drain tube should be. I have since added a tube so it pukes under the truck and not all over the place. other than some of the basic stuff, I don’t plan on chasing it too much more. I rarely ride it at those speeds and my expectations for this 30-year old truck are getting closer to reality. I just wanted to make sure I am not missing something on the easy side.
60 mph is no problem at all, I drove this speed on highway with my old Honda Acty for hours and the temp gauge did not change at all.
I will keep searching. At some point I will run out of things to fix or replace and maybe she will run without getting hot. It always climbs to middle way give or take as it warms. Then up steady to 3/4 the max with speeds at 55mph plus. Comes right back down as when you stop or sustained speeds in the 30s. I think when I do the chem clean flush of the radiator I will remove that bleeder valve on the manifold and get it unclogged while I am at it. Might just replace the temp control as well, but that thing is not cheap.
The beheld valve not letting anything out, leaves me thinking you may have serious bunch of rust which is interfering with the ablility f the coolant to flow through the block.
a very good possibility as I have found rust throughout the coolant system. So much so I had to bypass those rusty metal coolant tubes above the engine as seen in my photos. When I flushed all of the ports I was able to connect my garden hose to the water pump inlet and water came out of the water outlet at the top of the engine, but that is not to say that the flow around all the jackets is uniform etc…. I don’t know how to confirm that. I hope doing the coolant flush with the coolant cleaner opens things up enough to remove some of the rust and increase flow. Though, hopefully not enough to cause any leaks in the radiator or heat exchanger…. Fingers crossed. I will get the bleed valve unclogged I hope as well and look for other reversible causes. Thank you all for your help so far. Reading this thread and many others is helping me work through this. Once all the boxes are checked and actions taken, if I cannot get her to stay cool at the higher speeds, she will just have to live a slower life. I still have hope though for now.
