Cooling system Mods

[Gunflint]

Hi all.

I have been doing some research recently and have stumbled across the issues the 2CT engine has with potential overheating and the repercussions that has on the little diesel engine in our vans. I have also learned that the stock temp gauge is notoriously unreliable, and will generally give no warning of overheating until it suddenly blasts into the red. Yikes.

I ran into a simple mod called the 'mason alarm' which improves the accuracy of the temp gauge and also lets you know, via an audio alarm, when you are in the danger zone. I got a hold of the creator/manufacturer Dave Mason and he said demand faded away about 3 years ago and he no longer makes the device.

So I am trying to figure out how I can be proactive. I have heard that aftermarket temp gauges can difficult to install, and you still need to watch them like a hawk to be sure you are in range. Does anyone know of an alternative solution I could look into?

I have also heard of folks adding a second auxiliary radiator in the front where the air intakes is (specifically a toyota van people user 'lwiniarski'.) Even better, he may be in Portland! Does anyone here know of a way to get a hold of him? I would be willing to invest sometime and money into this! Any other suggestions welcome!

Thanks all!

Matt

[timsrv]

I have built and installed overheating alarms on all my vans. I have also installed a large heater core behind the front bumper on my work van to enhance cooling. I use a digital temp gauge with big numbers. These are inexpensive and easy to install. For the alarm I use a super bright LED in my dash cluster along with a doorbell chime (like what's used with electric eye systems that alert store employees when somebody walks into their establishment). In my case I wired the system so it will alert me if the coolant exceeds 220 deg F or if oil pressure drops below 4 psi. On my work van I also installed an extra loud back-up alarm (like what garbage trucks use while backing) and have that set to alert me if one of these problems occur while using my alternator driven welder (engine RPMs must be around 2,500 while I'm welding). I have posted these mods in various places on the forum. I don't have time to look them up at the moment, but if you're interested in learning more, let me know and I'll post links along with more information (when I have a little more time). Tim

[Gunflint]

Thanks Tim!

Yea I would love to learn more. If you get a chance to post links and more information, that would be very much appreciated. Of course take your time. Next time youre out and about in Portland I'll get ya a beer.

Matt

[llamavan]

I have also heard of folks adding a second auxiliary radiator in the front where the air intakes is (specifically a toyota van people user 'lwiniarski'.) Even better, he may be in Portland! Does anyone here know of a way to get a hold of him?

My understanding is that Larry hasn't been driving his "french-fry oil" van for quite some time now that his electric vehicle is up and running. He's closer to Corvallis (ie, south of) than Portland. I know someone who periodically runs into him, but that's the best I can do for contact info. You'll find it most expedient to get started using Tim's excellent existing write-ups.

Gwen

[Gunflint]

Thanks Gwen!

[timsrv]

Got home late and still have stuff to do. I'll post more details on the alarm mods later. In the mean time, I discovered I never did post my Previa heater core mode on TVT, so here's a quick copy/paste from my post over on TVP. Enjoy



As some of you know, I use my 89 cargo van as a service vehicle for my RV business. Due to the heavy fixed load (about 3k lbs), the hot weather, and my desire for air conditioning, my engine was having problems staying cool. At ambient temps over 80 deg it did okay up to 30 mph, but any faster & I needed to turn off the AC (or risk overheating). I was considering having a 2nd custom radiator built to incorporate into my cooling system, but then decided to go the cheap route.
In another thread, Wonderwagon suggested using an extra heater core and plumbing into existing heater hoses. Since I had most of the stuff already on hand, that's exactly what I did. I pulled the heater core, hoses, and control valve of my wrecked 92 Previa, then mounted the core directly behind the front bumper.


This is a great location because of the direct air flow and the close proximity of the heater hoses.


I had some aluminum angle laying around left over from another project, so I used it to fab the mounts.

Here's some pictures of the core mounted in it's new home.


Here's the part I spent money on. Napa had this all in stock. Total cost of parts = $25

Teeing off this heater hose was easy.

If I wanted the new core to have constant coolant flow available, I needed to tee off the other hose on the inlet side of the existing heater valve. Unfortunately, the AC condenser was in the way, so I had to remove it for access. Fortunately there are flex lines attached to the condenser, so I didn't need to open my AC system. I just took the mounts loose and let it hang.

Okay, 2nd hose was teed into the system (that 90 deg bend heater hose I pulled off the Previa came in handy at that location). Sorry, but I forgot to take a picture before I reinstalled condenser.
Okay, here's where I mounted the control cable in dash. "In" position is closed (normal flow for winter driving). "Out" position is open (full flow of coolant through core for summer driving).


Fed the cable though floor and hooked it up to the valve taken from Previa.

Topped off cooling system, reinstalled bumper and went for a test drive. This mod took 6 hrs from start to finish. As you can see, the heater core is now directly exposed to good air flow. Today only got up to about 80 deg, but I ran the van hard and used the AC constantly. Several times I closed the valve and watched the temp needle rise. When I opened the valve, within seconds I could see it begin to fall. Like I said earlier, before the mod, the temp of the van was stable up to around 30mph. I believe the higher speeds where a problem due to lack of airflow through the radiator. At the lower speeds, the electric fans do an adequate job moving the slow moving air up and through the radiator. At higher speeds, the air tends to move by quickly underneath, missing the radiator. Now I can take advantage of this passing air and dissipate more heat. I believe this has solved my problem, but I'll have to wait for another 100 deg day to know for sure. I'll keep you posted. Tim

[Gunflint]

Man. Really great work Tim! I would love to try to work something like that out!

[timsrv]

Here's some pics of the scoop I made to direct more air up through the big radiator:

[Gunflint]

Nice! I may even be able to pull that off

Matt

[timsrv]

FYI, I determined the valve and the cable are not necessary. I put that on thinking the van would take too long to warm up in the winter and/or maybe run too cold. Turns out I just leave it open all the time anyhow and van warms up fine. Heater works good too. Tim

[JDM VANMAN]

Tim,

thats awesome work!!!! Would a supercooler be similar to what you've created?


http://www.carid.com/bm/bm-engine-an...ct-details-tab

I've seen something like this mounted to the front bumper of a few sports cars- Mitsubishi EVO, Nissan 240 and even a older 500 series BMW.

thank you

[originalkwyjibo]

The B&M Supercoolers are intended for engine oil or automatic transmission fluid and the coolers you see in the front bumpers of those types of cars are generally air to air intercoolers for their turbo.

[timsrv]

On the temperature monitoring/alarm side of things I'm using a Koso temperature gauge. This comes with a temperature sender that has 1/8" pipe threads. Since there are no 1/8" pipe threaded ports on the van's cooling system, I'm using a 1/8" FPT to M16 X 1.5 adapter bushing found in this adapter kit (M16 X 1.5 is the size Toyota uses for it's cooling system sensor ports). I removed the threaded plug in the front of the head (marked below as "Extra / unused port") and installed it there. Note: Another potentially good spot would be in place of the "Overdrive water thermo switch" (if so equipped) as this switch (IMO) is a silly waste of a sensor port and serves no valuable purpose. If your van has a manual transmission, there will be a plug here.



I'm not familiar with the diesel version, so for those of you with diesels, you will need to check your engine for a suitable place.

here's a picture of my temp gauge installed in my 86 van (blue digits saying 90 deg)



As to the alarm, I'm using a Radio Shack #273-071 12VDC chime. It's pretty loud (80 DB), but somewhat pleasant sounding (not super annoying like some of those piezo buzzers). Anything loud enough to catch your attention will work here though. If for some strange reason I can't hear the chime, I'm also using a super bright LED light. I installed it into my dash cluster:





To trigger these I'm using an OEM factory fan switch used in 84 - 89 Nissan Maximas (AIRTEX 1S1536). I selected this unit based on activation temperature and the thread size (M16 X 1.5). This is a normally open temperature switch that's designed to close contacts @ 220 deg F. Since I'm using the extra port in the front of my head for the gauge, I mounted this switch in place of my water temperature switch on the top radiator hose outlet housing. Note: This switch is found on gasoline powered vans with factory AC only. If you have a gas van without factory AC, there will be a plug here. As discussed in the heat soak thread, this switch's function is pointless. If your van is equipped with this switch, take the wire that used to go to it and attach it to ground. Here's a picture of my 220 deg switch mounted in the housing:



Of course you diesel van owners will need to find a suitable spot to mount the switch (sorry).

As to powering up the warning light and the chime, Unless you're using an incandescent bulb or an LED designed to run off 12VDC, you'll need to use a resistor in series with the LED (or it will quickly burn out). In my case I'm using a 680 ohm 1/2 watt resistor. Depending on the light you choose, you may need something different, or perhaps nothing at all. When you purchase the LED, it should give you the information you need to select the correct resistor. Once the correct resistor is found install it between the anode (long leg) of the LED and an ignition switched 12 VDC power source. Connect the positive wire of the chime/buzzer to the same power source. The cathode (short leg) of the LED and the neg wire of the chime or buzzer will go to one wire of the 220 deg temperature switch (doesn't matter which one) note: If you're chime/buzzer has a trigger wire, put this together with the negative wire. Now take the other wire from the temperature switch and attach it to ground. Your done!

Now if the engine temp ever exceeds 220 deg, the contact points inside the temperature switch will close and supply ground to the LED and the chime/buzzer. The LED light will illuminate and the chime/buzzer will sound.

On my cargo van, I'm using this same alarm system to alert me of low oil pressure. I'm using a low oil pressure warning switch (supplies ground if oil pressure drops below 4 psi). I simply wired this directly to the negative side of my alarm system and if my oil pressure drops below 4 psi the same alarm will sound. When I'm running my alternator driven welder (on the cargo van) I'm not behind the wheel (usually about 15 feet or so away from the van). The engine is running and set at around 2,500 rpm (I've rigged up a throttle lock), so I need to know if a problem comes up. For this reason I also installed a super loud back-up alarm aimed towards where the welding leads come out of my van. Since it is extremely loud, I wired it to be enabled only when my welder is on (otherwise I'd probably piss myself if it ever went off while I was driving) . Tim

PS: Almost forgot, Since I like AC, I have my AC amplifiers on my vans cranked down to allow my AC to run at an idle. I've wired my compressor stators (magnetic clutches) in series with the "normally closed" side of a Bosch relay. I wired the coil side of the relay to the switched side of my 220 deg temperature switch. Due to the resistance of the relay coil, to avoid potential feedback, I wired it through a diode (prevents false alarms). If engine temperature exceeds 220 deg, the relay is triggered and the AC compressor shuts down. Since my "Idle-up" VSV is still activated, when the load of the compressor is dropped the engine RPMs increase to around 1k. This makes the engine cooling fan move more air (my 86 still has the fan clutch set-up), and this helps cool the engine. As soon as the engine cools down below 220 deg, the relay closes and AC operation resumes. This prevents accidental overheating in the event I leave my engine running with the AC on (if I run into a store for something) . Due to my habits, an event such as this is rare for me, but due to Murphy's law, I actually had such a thing happen about a week after overhauling the engine in my 86. As luck would have it, I came back to the van just as my overheat alarm was starting to go off. I made the "AC limit mod" shortly after that.

PPS: The above description of the A/C cut-off/Idle-up mod is the simple explanation. The actual circuit is slightly more complicated as I needed to incorporate a 10 second timer and a capacitor to get it to function correctly. If anybody is interested in this mod, let me know and I'll identify actual components and I'll draw/post a sketch of the completed circuit.

[Gunflint]

Thanks Tim!

[adamh]

is your van 4wd auto 2ct? if so It may already have extra horizontal rad at front+fans, just the fans might not come on until it gets above 217f. I have not investigated mine yet, need to confirm its operation at high temps... there is a sensor on the water outlet pipe just infront of head which should switch those fans on.

[Gunflint]

Hey Adam.

It is a 4wd auto, 2ct. Thanks for the heads up! It does have a front horizontal radiator, with fans. Let me know what you find out.....I wonder if it would be worth figuring out a way for the fans to come on at a lower temperature?

Matt

[timsrv]

Finally hot enough to test the warning system. Sat in driveway with AC running. Here's a video:

[Gunflint]

Cool Tim!

I ended up installing the http://enginewatchdog.com/ TM2. Quite a but more expensive than your set up, but really, really easy to install.

Seems to be doing the trick thus far!

IMG_0325.jpg

IMG_0324.jpg

IMG_0323.jpg

Matt

[highwind]

tim, is there much difference in an oil cooler / coolant cooler like you did?

[timsrv]

Anything that cools engine fluids is beneficial. Oil coolers need to be tougher (higher pressures) and are more critical when it comes to rigging (requires special high pressure hoses and fittings). Then there's availability and cost. Heater cores are cheap and easy to find, operate on less pressure, and if you spring a leak, you're less likely to destroy your engine. For these reasons I prefer to improve the cooling system (more bang for your buck). Everybody has a different situation though, so cooling the oil might make more sense to some. Tim