I get spills too, not as bad though. Did you replace the cap with a new one? I think thats my problem, just forgot about it.

 

Yes he did.



Edit: Oops...I thought rad cap, but its not specified.

 

Do you fill it when the engine is warm or when its cold? Coolant will leak out if you fill it to the line when its cold.

 

When you say you replaced the cap, do you mean the reservoir cap, or the radiator cap?

If you did replace the radiator cap, are you sure it was the correct part with the right psi rating? Most people here seem to recommend only an OEM radiator cap.

BTW, it could just be the lighting in the photo, but your coolant looks dark, on the brownish side. It should be vibrant red and crystal clear. If you've ever thawed frozen strawberries and they oozed juice, that juice is the bright red color it should be.

 

When you say you replaced the cap, do you mean the reservoir cap, or the radiator cap?

If you did replace the radiator cap, are you sure it was the correct part with the right psi rating? Most people here seem to recommend only an OEM radiator cap.

BTW, it could just be the lighting in the photo, but your coolant looks dark, on the brownish side. It should be vibrant red and crystal clear. If you've ever thawed frozen strawberries and they oozed juice, that juice is the bright red color it should be.

The radiator cap is OEM and and I replaced the reservoir cap. The coolant is a nice clear red color and only topped off with distilled water. Never overheated.

I think during a long drive, the coolant in the reservoir slosh around and leaks pass the cap.

 

Did you replace the reservoir cap with a new one or from the junkyard? I think the spills happen coolant moves around too much and spills out the overflow port.

 

I replaced the cap with two different junkyard caps, even from a Gen 3. They all snap on tightly.

I would try replacing the entire tank and cap, and also the overflow hoses. I was having a similar leak but not near as bad on my '93, replaced the cap but still saw some coolant on the outside of the bottle. I replaced the tank and hoses (new ones), problem went away. BTW, check to make sure there is a rubber gasket in the cap and it is lined up correctly.

I haven't replaced the tank yet. I believe it's a faulty cap but I don't recall any of the caps having a rubber gasket. Maybe that is the problem.

 

I would try replacing the entire tank and cap, and also the overflow hoses. I was having a similar leak but not near as bad on my '93, replaced the cap but still saw some coolant on the outside of the bottle. I replaced the tank and hoses (new ones), problem went away. BTW, check to make sure there is a rubber gasket in the cap and it is lined up correctly.

 

I would get a new one from the dealer. They are about $3-4.

 

This has annoyed me forever and I finally decided to do something about it.

The problem is the cap itself. It's a crummy, cheap design, and when the coolant sloshes around it leaks out of the top. Then there's the drain tube to vent pressure. It just pukes coolant on the top of the tank, and it drains down and makes a mess in the engine compartment. What were they thinking?

I looked around to see if I could come up with a fix. I found some rubber stoppers that I had used for feet on another project, and much to my surprise they fit perfectly.

Plugging the hole is one thing, keeping the plug in place was another thing all together. I tried various things, all came up short and looked real ugly. I needed some way to remove the plug, so I thought of attaching a knob of some sort, and then I got the idea to use an eye bolt. This would give me something to grab onto, and I could fasten it securely by drilling the rubber stopper, and fastening it with a nut. Here's what I came up with.

Now I had to figure out a way to keep the plug in place. I thought about zip ties, bungie cords, all were lame. Then noticed that the plug with the bolt in it, stuck out farther in the hole that without the bolt. Hmmm, seems that the plug expanded when I inserted the bolt in the rubber. Taking advantage of this, I removed the washer that I had on the bottom of the plug and let the nut bind into the rubber. Then I could insert the plug into the hole with no threads engaged on the bolt. After it was in the hole, I just had to turn the eye bolt clockwise and the plug would expand and lock it in place in the tank. And as an added bonus, by tightening up the bolt, it would also secure the nut tightly so it wouldn't come loose, and drop in the tank.

Here's the before and after picture.

And finally to address the pressure vent. This was pretty simple I just used some plastic tubing that I had left over from the PowerBleeder and jammed it inside the hole of the vent. It's not a straight shot, and has a little bend so by jamming the plastic tubing into the hole in the tank as far as I could, it seemed to be pretty secure. Then I routed the plastic tubing through the ABS tubes, under the wiring loom, and then through the hole where the Windshield Washer fluid goes. And finally, I had to check the clearances between the top of the eye bolt and the hood. Fortunately there is a recess in the hood lining for the stock tank, and there were no clearance problems between the top of the eye bolt and the hood. I'm pretty sure that this will solve the leaking problem.

Here's what it all looks like when it's finished.

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^I wound have not thought about that and will get it a try. I got to stop by Home Depot later to get some Drano Max and I'll see what I can find as a rubber stopper.

 

I don't think you can create a sealed system like that, unless I'm not understanding exactly what you did. But good innovation.

The system normally has a pressure valve, it opens to allow air to be drawn into the tank as coolant is drawn from the tank and back into the engine/radiator during the cooling cycle. When the engine warms up, the opposite happens, the valve opens to allow air to escape as coolant expands and is pushed into the tank.

 

It's not sealed any more than the original system was. The "Puke Port" as I like to call it, is vented to the atmosphere. Adding the plastic tubing to the Puke Port doesn't change anything. It's still vented to the atmosphere, but when the tank decides to puke, the mess drains away under the car, not in the engine compartment.


.

 

Here's mine, not as bad but still. I will probably try ajkalian's solution next week. Or maybe a new cap should fix it?

Off topic, how can I clean those black stains above the full line? I think I tried before, but it didn't work.

 

The port is not designed to expel coolant normally, only to allow air to move in and out. If coolant does come out then something is wrong with the system.

For the 1MZ, you can get a whole new unit with hoses for about $50, part number is 16470-20040. This is for the Japan produced, NA could be different.

 

re: Off topic, how can I clean those black stains above the full line?

If they have stained the plastic, probably can't. You'd need to buy a new reservoir. If they can be scrubbed off, some type of bottle brush might work. I've had good luck ordering various odd-ball brushes from thse guys before:
http://www.torringtonbrushes.com/

For stoppers, spouts, plugs, etc, I've had good luck ordering from this place:
http://www.widgetco.com/

 

Did any of you check your rad cap? This happened to me while on a road trip. I found out the rad cap was broken. Since then, no spills.

 

Okay, so $3 later at Lowe's; I got a rubber stopper and some rubber hose to "mod" the reservoir as ajkalian suggested. The stopper goes in 1/2" and I can still pull it out but quite tight. Then cut and route the hose out to the fender. Looks close to stock :thumbsup:

As for the radiator cap, I'll pick up a new one at the dealership tomorrow. It's 10 years old anyways.

 

Okay, so $3 later at Lowe's; I got a rubber stopper and some rubber hose to "mod" the reservoir as ajkalian suggested. The stopper goes in 1/2" and I can still pull it out but quite tight. Then cut and route the hose out to the fender. Looks close to stock :thumbsup:

I like your black tubing much better than the clear tubing I used. I'll have to pick up some black stuff next time I'm at Loew's.

In your picture it shows on the right hand side of the tank, a hose going across the top and is held in place by a plastic U-shaped bracket cast into the tank. I have the same bracket cast into the top of my tank, but the hose goes to the engine, where the radiator cap is and the U-shaped bracket just sits there with nothing in it, and I always wondered why.

The radiator on my 2000 6-cyl doesn't have a radiator cap, it's on top of the motor. You can kinda see where the hose goes in the pic I posted in the upper right hand corner of the picture. So that means that the 2000 6-cyl, and the 2001 4-cyl tanks are interchangable ?? Looks like it.

I wonder if the part numbers are the same. Mine shows part #16470-03062. I'd be curious to see what the part number for your car is.


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Looks OEM, I'm definitely doing this tomorrow. What area was it in, plumbing?

 

The rubber stopper was over at the hardware section with the pull-out bins. The package reads "rubber stopper #7" but the 1/4" rubber hose was back in pumping on rolls.

 

The coolant reservoir is the same for the 2.2 and 3.0 but there might be a different between the US and Japan built models. The 2.2 uses the little bracket to keep the hose away from the drive belts as it travels to the radiator.

EDIT: I took a look and I'm not sure why there's a backet on the reservoir as there one holding the hose on the rad support. Maybe to make it look nicer? Also, I had to wrap some black tape on the new hose to make it fit better.

 

Where is the check valve on this system? I though it was in the cap, is it part of the tank? And you should never lose coolant like this, something is not right. Also keep in mind that coolant is very toxic, so it should not be allowed to spill on the ground if you can help it.

 

The radiator cap acts as the check valve and the reservoir is just there for the ride, a non-pressurized tank. It's just poorly seal, a hard plastic cap that snaps over a plastic tank doesn’t seal as good as a rubber stopper. We’re losing coolant from it splashing around and leaking pass the vent and cap. Now it shouldn't and air is the only thing that should enter and exit from the vent. The other problem is when air vent out of the tank, it carries some coolant vapor and stain the reservoir. Now it should stain wherever the hose ends on the vent. But if coolant is blowing out of the tank, then I know the rad cap is not holding pressure.

 

There is usually a check valve in the reservoir cap. The valve only opens when there is pressure from the rad, or when the rad is drawing coolant back from the tank, otherwise the system is sealed. So with no check valve, the tank is always exposed to air. Don't think that is a big deal, but I would think the valve is there for a reason.

Seems pretty lame that the tank leaks like that, poor design? It does look like the NA produced cars have a different tank than Japan made. Wonder why? I know on my '93 I had to specify where it was produced. Different tank supplier I guess.

 

Yeah, you're talking about J-vin cars, I have no check valve on my cap.