90 degree coolant hose removal
 

I've just finished removing and installing my UIM for the first time, and that stupid 90 degree coolant hose is leaking (which means I need to redo everything). I read somewhere that with the throttle body mod, you can remove this coolant hose, since it's just for the accelerated warm-up. I don't have the throttle body mod, don't plan on doing it. How do I remove this hose? Just plug up both ends on the engine and UIM? Or should I rerout it or something?

I think you answered your own question. :) If you plan on keeping the Thermowax to your Throttle Body than you must keep the hose. Describing the removal of the hose Is self-explanatory.

When I did the TB mod I drilled/tapped/plugged the Rear Iron and Waterpump.

Oh...I think I get it now. The Thermowax is the name of the cold-start system. I'm looking at the fc3spro.com site now. So can I do just do half the throttle body mod, that is, just remove the cold-start assembly without touching the throttle plates? Then after that plug up both ends of that 90 degree coolant hose?

silverrotor: " When I did the TB mod I drilled/tapped/plugged the Rear Iron and Waterpump. "

you can do this?? you mean that once you've done the TB mod, you can simply remove this coolant line? It's not gonna affect cooling of something?

I'm really interested in this coolant line removal because my coolant nipple on my rear iron is kinda rusty! Is it also possible to to weld the hole shut instead of drilling/tapping it?

thanks for the hint!

Yes, you can just remove this hose (as long as you don't need any coolant to the throttle body).

As for plugging the hole, I wouldn't weld it. It's easy to just drill it out, tap it, then install a grub screw. By welding, you're going to concentrate a lot of heat in that area. Also, welding cast is difficult to do...

thanks Aaron

but how do i figure the lenght of the screw that I need?

can this drilling/tapping can be done with the motor assembled? i mean, no risk of getting metal deposits inside the cooling passenges?

I think Iam having this same problem. Ive removed the UIM like 3 times and I think that 90 deg hose still keeps leaking. After I put everything back together, the car runs fine but, until I drive it, everything gets fucked up all over again. The car starts to leak a lot when I shut it off.
Its a bitch trying to put it back on. The very first time I put that damn hose back on, I just thought I didnt put it on good enough, But I did... What can be going wrong?

If I jack up the car, it looks as if water is running down from the side of the housing when I look up at it from the ground. Where else could water be leaking? Can it leaking somewhere from the side of the housings???? I really doubt it. But I could be wrong...
Someone please help!!!!!!!!!!!!

Here's an easy way. get a hose compatible for coolant with a 90 degree bend on it.
Plug the coolant nipple on the throttle body. Run the 90 degree bend towards the back and up to the BAC. I did this YEARS ago and when I got tired of fucking with that coolant hose. Stupid Mazda engineers.
I disabled the excellerated warm up system. I don't like a cold engine revving to 3000 rpm . I let it idle a few mintues anyway before I drive off.

I used 3/8 inch fuel line. Works great for the 90 deg coolant hose. Oh....get GOOD hose clamps.

I've never understood the constant whinging about this little hose. Yes it's a little tricky to get to, but there are ways to improve that, and there are much harder jobs you can do on your car.

Apart from the first time (which required cutting) subsequent removals have been quite easy. The trick is to replace the stock squeeze clamps with screw clamps, as it's a helluva alot easier to lift the unbolted manifold and slide a screwdriver or small socket underneath than try to get in there with a pair of pliers. Another solution is to replace the hose with a longer one that has a join in it that's in a more accessible location.

It's silly to complain about Mazda's engineering and then rip off perfectly useful bits just because a hose is tricky to remove. How often should you really need to do this? A little simple engineering of your own makes this a non-issue.

Finally someone telling it how it is and should be! You don't have to do the TB mod!!! It is not a requirment of easy UIM removal.

Actually I did half of the TB mod. I removed the unwanted double-throttle system and left the thermowax in place for a nice idle when cold. I start my car from cold at least twice a day, so removing the thermowax just to make the occasional UIM removal 60 seconds quicker would be daft. :)

I believe we used a 1/2 grub screw. Length is unimportant.

Flush the cooling system afterwards.

I hate that 90 degree hose. I've had stuff go wrong where I need to fix it quickly and the 90 degree hose takes a lot of time and effort. Not to mention you can't get it immediately from Mazda, so it means your car is crippled for days. I always cut the shit out of my hands whenever I mess with it. I tried doing the DIY 90 degree bend and it ended up failing on me. I blocked it off in a rather ghetto manner, but it hasn't failed. It didn't hinder anything when starting the car in -20C, so why not do it?

Nice idle? I thought it raises the idle to like 3000 in the cold. On most of my cars, I leave the engine as close to 1000 as possible until it's warmed up. I suspect racing my engine while cold would damage it.

Also, I spent close to half an hour working at that coolant tube, until I eventually cut it. Then I had to go buy another one, and it's very hard to put it back with a good seal. No room down there to work. With the connection up by the BAC, I can ensure a good coolant seal. Also, it clears up the back of the UIM.

Can anybody help????

heater hose. right under the oil filter.

pat

on-topic, i was glad to get rid of that hose. I have worked on much harder things to get to, but hey one less little pain in my ass is never a bad thing. plus i have a standalone, so the thermowax doesnt help me much.

Then you must be doing it wrong. Once everything is disconnected and unbolted, I can simply lift the UIM up a bit, stick a screwdriver underneath, unscrew the clamp, reach under and pull the hose off. Very little time, very little effort.

You mean you get another one every time? That's just crazy! The only time it would need to be cut off and replaced is the first time. After that the new hose slides off and on easily. You're making this little job much harder than it needs to be.

It's not there to aid starting (the BAC valve does that); it's there to aid cold idling. Can your car idle completely unassisted when stone cold? I doubt it. For me that's way more important than the minor (and very occasional) inconvenience caused by one little hose.

The thermowax has nothing to do with the 3000rpm start. That's caused by the AWS solenoid on top of the UIM. The thermowax only raises the idle speed to ~1000rpm (it's adjustable).

See above...

I fail to see how it can be done "wrong", it's a hose. I replaced the hose more than once and each time it was a PITA to remove and did not slide off easily as suggested. What happends after you start it in the cold, it idles. :) Yes it idles fine in the cold, that's why I said that. If it stalled 2 seconds later I wouldn't consider that a "fine" circumstance. eg. I started in -5C last night and it idled perfectly @ ~750rpm.

A stone cold engine does not idle "perfectly" at 750rpm. It may idle, but it'll be far from perfect. I've never seem any engine do that so I'm certainly not going to believe yours can.

If my way allows me to remove and reinstall the hose with relative ease (it's not easy, but it's not hard either) and your way makes it a PITA, them I'd suggest your way is not the best way to do it. Pretty logical but whatever...

We're mincing words on "perfect", but it's an idle with little fault and certainly not "far from perfect". If you want to say that most FCs aren't going to have the same results because you don't want people to get the wrong idea, fine, I won't object, but to be frank I find it small of you to suggest that I am lying. What do I have to gain by doing so?

You say you've never seen an engine idle well when cold, I would point particularly to new, unmolested vehicles, while they may have a brief higher reving state, I fail to see what is major flaw their cold idle has.

No, I said I've never seen a stone cold engine idle well at 750rpm.

As you said, they rev higher. Which is the whole point of the thermowax. They also have the advantage of ECU technology and inlet manifold design 20 years ahead of ours, so new cars are pretty irrelevant to this discussion.