coolant hoses keep popping off

[russthedude]

any ideas what the cause might be? I've got a 1mz which has been running fine for about 6 years now I guess. a few months ago a hose popped off round near the alternator. then a different one came loose between filler cap section and some rubber hose, and today a hose going into the engine block (above the gear shifter linkages) came off and caused more havoc on my way home.

the car hasn't been running hotter than normal, and no sign of coolant in oil a few weeks ago when I changed it. I had to remove the large core alloy rad recently as it was leaking both ends near the hoses, but now I'm starting to think maybe the leak was between the rad and hose rather than through the fins. I chucked an OEM rad on and temps have been fine (warns up a lot quicker that's all).

[cdwood2010]

Rad cap or coolant expansion bottle might be your first suspects.

Chris.

[cdwood2010]

And by rad cap in mean the one on the top of the filler neck, whichever one you ended up with!

:)

[russthedude]

I've got one with a trd sticker on it and 1.5 stamped in, so assume it's 1.5bar? what am I looking for in the expansion bottle or rad cap? I've got a spare cap in the shed that came with the car, I'll go and dig it out and see what it is.

[russthedude]

ok, so the cap on the car currently is 1.5bar. I've got a 1.3 and a 0.9 in my spares box, as well as a thermostat I didn't know I had!

[cdwood2010]

Swap out the cap for the 1.3, see how you get on with that.

Check that the filler neck and expansion pipe and bottle are not blocked too.

C.

[Torero]

Yes, agree Chris 1.5 bar is far too high, I even ran with the stock one of 1.1 on my 3VZ for a while.

I am only surmising but if it's not a genuine TRD cap then feck knows what the exact rating is and how accurate it is. If it's a genuine Toyota 1.3 bar that would be far better.

[russthedude]

looks like a genuine trd 1.5 but who knows. I put a new blitz 1.3 cap on today, but had try same pipe pop off on my way work as last night. probably not done up tight enough, I was being cautious not to squash the metal pipe work. Euro car parts will start to wonder wtf I'm doing with all this coolant! I noticed some sludge in the bottom of the expansion bottle earlier so I'll get it off tonight for a clean and check the connecting hose/pipe isn't blocked.

[cdwood2010]

A bit odd. If you've got sludge present you might need to flush.

It lives in the long metal pipes under the car usually. The way to get it out (and you will probably get wet and brown) is to disconnect the two pipes in the engine bay and shove a hose down one or both until it runs clear. That will flush the pipes and rad without getting it in the engine etc. Prob do the same with the heater hoses, the two 19mm pipes that duck behind the heat shield in the engine bay.

Chris.

[russthedude]

OK sounds doable thanks, heater hoses sound trickier to get to. I made it home last night and back in to work this morning OK, but spent a lot of time looking in the mirror waiting for steam! I've got a set of coilovers waiting to go on the car so I'll do it then while it's up on stands. do you think it's worth sourcing a 1.1bar filler cap?

[cdwood2010]

I think a 0.9 would do for now, it should be expanding into the bottle, not on the floor. It will not do your engine any good having the coolant eject.

What juby clips you using? I either use really decent ones (not cheap pressed rubbish), or the Totty spring clips, theyre pretty damn tight.

This type:-

http://www.twobrutal.co.uk/forum/images/recovered/2016/05/66.jpg

Not this type:-

http://www.twobrutal.co.uk/forum/images/recovered/2016/05/67.jpg

[Deadly_Smell]

check how much engine movement you have, could be soft torque mounts giving excess engine rock pulling the hoses off, just an idea.

[sketchy]

heater hoses are easy to get to without the OEM air box...both above the starter motor

as for the main coolant lines, I tend to undo them from the top, and stuff the end of the garden hose into the rubber hose I take off the water pump, and the hockey stick that bolts to the firewall under the air box as well, just remember to flush it in both directions a couple of times...the first time each way wont get it all.

[russthedude]

the clip that came off last week was a chunky sturdy thing, looked more like a scaffold clamp. I haven't got any of the poundland specials on there (that I know of!). I'm going ot get the Koyo rad tested and if it's actually OK and not leaking like I thought, I'll stick that back on when I flush the system through. I had the expansion bottle off the weekend for a good clean out, and ran the hose through to clean the line between the bottle and the filler cap.

[russthedude]

this is the clip that keeps coming off.. I did it up nice and tight the other day, but the hose came off again today sat in traffic.

http://www.twobrutal.co.uk/forum/images/recovered/2016/05/87.jpg (http://s86.photobucket.com/user/russthedude/media/172AF234-BF94-47BC-A772-0E1CBD6CAAED_zpsk7gy7ka6.jpg.html)

[cdwood2010]

Bloody hell. Ok you need to check for blockages, because that's just not right.

Isolate and check the rad, fat pipes front back and the engine / thermostat itself.

C.

[russthedude]

how much of a pain is it to change the thermostat? I've got a new one sat in a box that I could pop in while I'm flushing the pipes. the first time this happened I had the koyo rad on, so the smaller OEM one on at the moment can't be solely to blame, but I wonder if it's not helping. I need to get the Koyo leak and flow tested and back on the car assuming it's all OK.

[cdwood2010]

1mz in a mk3, dunno to be honest. Pretty sure it's above the starter motor, so fairly accessible.

[russthedude]

wasn't too much faff to get to it. whipped it out and tested it and it started to open at the time time as the new one, so I guess that's ruled out. gave the system a blast through with the hose. it all came out nice and pink, no horrible brown crap. I'll pop it all back together and just fill with water for now and see how it goes for a few days before wasting more coolant. I'll also stick the 0.9 bar cap on and see what happens. if all goes well for a week or so, I'll drain the system and chuck coolant in, and assuming the test on the koyo she is its fine, lob that back on. now, is there enough time before sunset to put my new coilovers and droplinks in? :D

[cdwood2010]

When did it start doing this? I'm assuming it was fine at some point then wasn't.

Have you checked compression / leak down etc?

C.

[russthedude]

it's been fine for almost four years, then one day a hose popped off behind the firewall. I just put it down to a clip working loose. then a few months later the rad started leaking, swapped that and all was good for a couple of months and then a hose popped off next to the filler cap, which I thought was odd. popped it back on nice and tight and then a while went by until last week, when it started popping the hose off that goes into the thermostat housing. that one has come off four times now. haven't checked compression, have no idea how to check leak down? but I do almost have one coilover on lol

[D2W]

Am far from expert here. Please forgive me if this sounds naive. No-one seems to have mentioned the water pump yet.

Assuming there is no obstruction to the flow of water around the system and through the rad when warm, have you confirmed that the water pump is actually pumping water?


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[russthedude]

I did think water pump, then I looked at how much of a pain in the arse it is to change so buried that idea in the sand lol

I managed a couple of 20 mile trips today without any issues, but hate the nervous drive!

How can I check the pump is doing its job?

[cdwood2010]

The water pump is driven by the timing belt, you would probably have other indications if it wasn't working correctly.

If you remove the filler cap and rev the engine, the water level should pull down. Although given your issues, you might just get really wet.

:)

[Phaeton]

Do you have a flange on the outlet the pipe is on? I had some pipes running front to back on the buggy & they would come off until it put a flange on there.

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[cdwood2010]

Russ has had various pipes pop off, not just one. It's a puzzler.

[cdwood2010]

haven't checked compression, have no idea how to check leak down?

Probably needs to be done by a garage, or well kitted out friend.

Compression test will show psi when the engine is cranking. If there's a leak (compression into water for example) it should show up.

Leak down test is where you pressurise a cylinder then see if it holds or leaks out.

Between these two tests you should be able to establish if any cylinders are adding to the water pressure ) hose pop off issue.

C.

[russthedude]

so I made it to work without giving anyone a steam bath on the way in. But when I was parking noticed the rad fan was on, which I've never ever heard kick in before, so at least I know that works! I took the coolant cap off this morning before I left to see what happened, if I gave the revs a blip the coolant foamed up a bit and then got sucked down as the revs dropped.

I'll start enquiring about a compression test at my local garage. I'm guess low compression or a leak = something along the lines of head gasket failure or other big bills?

second rear coilover is one at least, and while I was outside last night a chap stopped by to have a chat with my car, he recognized the plate from the woodsport site, his old man is toying with the idea of a 2zz or V6. as soon as I fired it up to let him hear it he looked like he was about to go and tell his old man to take a trip up to durham for a V6 :D

[Torero]

At least get the compression test done and that way you'll know how serious it is.

You gotta love the V6 the sound is absolutely breathtaking.

[russthedude]

took the rad for a leak test, it had four of them so he's fixed it up using some glue form nasa or something. He reckons that I need to ditch the crappy eBay rad I've got on there and get the Koyo back on and see if that sorts the issue out. I'm not sure how long the repair will last so he said I should start looking out for another big rad sooner rather than later.

maybe, just maybe, the first hose to pop off was because coolant had slowly leaked and air found its way in, and the subsequent hose problem caused by the piddly little OEM rad?

so.... any tips for a replacement radiator which isn't going to break the bank if possible? or des everyone pay the £300+ for the Koyos?

Really appreciate the pointers by the way, thank you! I'll still get a compression test done too asap.

[cdwood2010]

I wouldn't. I've owned a butt load of Mk2's, and swapped most of them to V6, and only ever done two rads.

The fact that its blowing hoses / rads is a symptom of it over pressurising. I would shove the bodged one back on (i love to bodge) and resolve the issue with the hoses popping off, then fit a half decent one. I bought this type off of the eBay, works just fine.

http://www.twobrutal.co.uk/forum/images/recovered/2015/03/263.jpg

http://www.twobrutal.co.uk/forum/images/recovered/2015/03/269.jpg

c.

[Phaeton]

Shame you are so far darn sarf, I have both compression & leakdown testers here

[russthedude]

I stuck the Koyo back on but the last person to bleed it kindly mashed the bleed valve for me, so I've had to fudge it for now with an o-ring from my scuba spares box.

Got it refilled and bled and left it idling for a while, took about 15/20 mins of idling on the driveway before the fan kicked in for 30 seconds. Kept an eye out for leaks and signs of hoses coming loose, but everything seemed to be behaving, which is good because I'm eager to give these coil overs a good blast.

Been looking fit another rad, does anyone know if a celica rad will slot straight in? Not much around on the eBay in terms of roadster rads.

[cdwood2010]

I dug about for a bit, looks like £30 will see you a decent enough one.

https://www.amazon.co.uk/gp/aw/d/B01876SE42/ref=mp_s_a_1_8?qid=1464597744&sr=8-8&pi=AC_SX236_SY340_QL65&keywords=mr2+radiator&dpPl=1&dpID=411gVrfbUyL&ref=plSrch

http://www.fastrads.co.uk/radiators/toyota/mr2/mr2-roadster/index.html

http://www.adrad.co.uk/prices/prices.php?id=TO840&model=MR2&make=TOYOTA

[russthedude]

The £30 one looks the same as the one I put on a couple of months ago, it was only 15mm thick. In my search I found an old thread by the previous owner who said he put the Koyo on because the standard rad wasn't up to the job, so I think a larger rad is definitely needed on it.

[russthedude]

So I've had the Koyo back on for a couple of weeks and haven't had any hose issues. Coolant temp is 100C after my drive in to work. I noticed the fans are still kicking in, which is odd because that never used to happen. I'm wondering if that was because maybe they weren't plugged in properly before I swapped rads over?

I haven't had chance to get compression test done yet, but it's on my list of jobs to do.

[cdwood2010]

I would call that a win. :)

[D2W]

Glad to read you're sorted.


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[Torero]

Sounds like you've nailed it.

[russthedude]

I picked up a cheap (£100) large alloy rad off the eBay. I couldn't find an MR2 one so took a punt on a celica one. only things I had to dick around with was to blank off the outlet for the expansion bottle, and do some hose jiggery pokery because one hose outlet is about 100mm lower than on the MR2 rad, and points downwards. I've managed to get those hose on just about, but I'll be getting some new hose asap for that bit. probably use a couple of 90 degree bends to solve that one. other than that, it slotted straight in.

[cdwood2010]

Um, might want to keep a close eye on it. I've done similar before and it changed the behaviour a bit.

[russthedude]

what changed? I've ordered a couple of 90 bends and some pipe so that I can get that hose off that's currently bodged on.

[cdwood2010]

You might find it runs cooler or hotter than before, or struggles in traffic. Even the number of vanes on the water pump can make a difference (as proved by Paul Woods).

It's probably fine, but considering the fun you have had with the hoses etc, just keep a close eye on it.

c.

[russthedude]

I won't mind if it runs cooler. after I'd bled the system (as much as I think it needed bloody bleeding) I let it run for a while so I could check the temp and for leaks. No leaks or fans kicking in which was a good start, but I did notice the expansion bottle was full, so maybe once I've got those new pieces of hose on I'll stick my 1.5 or the 1.3 bar cap back on. I won't be going too far with it until that's done, and I've got a big bottle of coolant in the frunk ready to use if something goes tits up before the postie arrives. I tried all the motor factors around here at the weekend and none of them stock large coolant hoses!