thar she blows

[egchewy79]

for those following my most recent saga of tracking down a slow loss of coolant, this next story will be ironic.

I'm sitting at a stop light on my way home from work today, ready to turn left into a plaza for gas.
All of a sudden, a ton of steam is coming out of my hood scoop. I immediately turn the car off and notice a growing puddle of coolant under my car.
A nice guy and his friend behind me in the turn lane get out of their 350z and one guy helps me push it across the busy intersection into a parking lot while the other guy is in the car helping deflect traffic.
Once in the lot, I open the hood and coolant is everywhere. Looking at hose clamps but nothing that seems obvious.
Once situated, I give my wife a call to tell her I'll be late and then call AAA which has a 1.5hr wait time.
While waiting, and fighting dwindling daylight (damn daylight savings!) I still can't see exactly where the leak is from, not to mention that the sh!t is still very hot under there.
Fortunately, I'm in a plaza w/ a grocery store, so I hike to the store to buy a gallon of distilled water.
I get back and start filling it up from the upper radiator T piece and about 3/4 gallon down, I hear fluid hitting the asphalt.
I grab my cell phone for a flashlight and pour more in, to discover that the lower hose blew off the water pump. It was sitting close enough that I didn't notice the gap.
I get a screwdriver from my trunk tool bag and undo the clamp, stick the hose back on, and tighten up the clamp.
Then I'm off for more water, buying 2 gallons. After putting these in, I'm back to the store to buy 2 more gallons. Clerk at the u-scan gives me a funny look after seeing me 3 times, buying distilled water.
Ended up using just shy of 4 gallons, which means almost the entire volume of the coolant had puked out when the hose blew.
Cancelled the tow, fired her up and made it home after sunset, helped finish dishes and put the kids to bed. Then went outside to rinse the coolant off my pain and under the hood.
Time to research better hose clamps.
I'm just glad I didn't need to take a pic of a tow of shame.

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[Jeff Kleiner]

But she sure looked good while sitting there ;)

Sounds like an easy fix. May have been seeping all along...not so much as to show drips or leave a puddle but just enough to show a loss which burned off while driving.

Jeff

[Nigel Allen]

Excellent save!

[JohnK]

That's a bummer. Thankfully it was a relatively easy fix and didn't end up requiring a tow. Check out the Gates Powergrip hose clamps. I love those things.

[D Stand]

Thanks for sharing. Glad you didn't need a tow. I used the hose clamps from breeze, they looked much nicer quality than standard clamps. I am sure others will chime as well.

[maclonchas]

Glad you found the fix. I am just starting the hoses now before first start. Will use better hose clamps.

Thanks
Bill

[egchewy79]

hmmm...interesting finding tonight as well.
my manual fan override switch that should automatically turn of my fan, doesn't appear to be working after the incident.
is it possible the steam bath damaged the fan electronics? I'll need to dig a bit deeper, perhaps unplugging the fan harness and hooking it up directly to a 12v source.
also discovered that I should have been using silicone specific clamps and not the standard worm drive ones.

[Al_C]

Glad you had a "relatively" happy ending! Don't forget to replace the water with coolant (i.e. antifreeze). Winter's coming!

[maclonchas]

Well I am not sure how you wired your fan, but I had a devil of time trying to figure out the problem until I went back and dug into the overall fan system electronics. I did your approach and wired my fan directly to a 12V portable source as you said and eliminated that as a possible issue. I checked the fuse for the cooling an in the RF box (0r whatever you used) and all looked good. Since your manual override just bypasses the pin 85 relay and completes the ground circuit via the three position SPDT switch, you check that part of the circuit is good. I first added power at pin 87 to ensure that the RF blue wire was good from the relay to the fan and closed the ground at the fan. If all is good there, you can check the relay with a multimeter across pin 85 and 86 and ensure the coil is good ( a number of 70-80 ohms is good). If that all checks out, then the switch or ground circuit is probable bad. Coolant could have damaged the lines. For me the culprit was the blue wire had an intermittent short somewhere in the DS footbox. I just laid a new wire from the fan connection to PIN 87 since my body was still off. I hope this helps. Wiring gremlins can be a real PITA to chase down.

Thanks

Bill

[egchewy79]

Well I am not sure how you wired your fan, but I had a devil of time trying to figure out the problem until I went back and dug into the overall fan system electronics. I did your approach and wired my fan directly to a 12V portable source as you said and eliminated that as a possible issue. I checked the fuse for the cooling an in the RF box (0r whatever you used) and all looked good. Since your manual override just bypasses the pin 85 relay and completes the ground circuit via the three position SPDT switch, you check that part of the circuit is good. I first added power at pin 87 to ensure that the RF blue wire was good from the relay to the fan and closed the ground at the fan. If all is good there, you can check the relay with a multimeter across pin 85 and 86 and ensure the coil is good ( a number of 70-80 ohms is good). If that all checks out, then the switch or ground circuit is probable bad. Coolant could have damaged the lines. For me the culprit was the blue wire had an intermittent short somewhere in the DS footbox. I just laid a new wire from the fan connection to PIN 87 since my body was still off. I hope this helps. Wiring gremlins can be a real PITA to chase down.

Thanks

Bill

yes, fuse is probably the first thing to check. then the fan itself. then the relay. the wiring will be checked last.

[egchewy79]

Glad you had a "relatively" happy ending! Don't forget to replace the water with coolant (i.e. antifreeze). Winter's coming!
Plan on doing this as soon as new hose clamps arrive.

[Hoooper]

also discovered that I should have been using silicone specific clamps and not the standard worm drive ones.

Yeah, get yourself some t-bolt clamps so you dont have to worry about this again

[UpNorth]

It happened to me this spring during shakedown.
No harm but when it happens...Gasp!...You shure do wonder what the problem is.
It was the clamp on the hose on top of the engine going to the rad that was the problem.
I secured it and added another one for good measure.
Since then I'm a happy camper.

[Rdone585]

Just a thought... it could be there is still air in the system and it's floating around where your sensor is. Make sure your system is fully burped.

[scrubs]

I am just staring at that dash...

[Dave 53]

I have a friend that used worm gear clamps on silicon hoses on his boat and also found out the hard way. You might want to consider replacing all the hoses with the new clamps. The other hose might / probably are damaged too, just not yet to the point of failure.

I went down the coolant Google wormhole a few months ago. While I can't explain why, I recall using distilled water was discouraged. It would be better to use the pre-mixed coolant. If you want to go first class, VP Racing Stay Frosty.

[JohnK]

One of my personal pet peeves is worm-gear clamps. IMO, they don't belong anywhere on a car. On hoses that heat-cycle like coolant hoses, it's not a matter of if they will fail, but when. There's a reason why no OEM uses them. Plus, I think they just cheapen the look of the car. Use anything other than worm gear clamps and you'll be better off.

[weendoggy]

One of my personal pet peeves is worm-gear clamps. IMO, they don't belong anywhere on a car. On hoses that heat-cycle like coolant hoses, it's not a matter of if they will fail, but when. There's a reason why no OEM uses them. Plus, I think they just cheapen the look of the car. Use anything other than worm gear clamps and you'll be better off.

In my 40+ yrs. of working and managing a heavy duty fleet including off-road construction equipment, we never lost a hose due to a worm-drive clamp. That goes for intake hoses as well. Not sure what happened after I left, but feel good it never happened on my watch. I also don't think someone looks at your car and say's "oh, you have a cheap looking car because you use worm-drive clamps". OMG!

[egchewy79]

I think one of my issues is not using clamps specific for silicone tubes. Looking at some of the other clamps, it does appear that the silicone is walking itself back from underneath the clamp. I'm assuming that over many heat/cool cycles, the silicone is slick enough that it slowly works itself back. I've got some T style clamps on the way. Hope to drain the system today, remove all the existing clamps, and replace them once the new ones get here. I had to replace almost the entire volume of the system w/ distilled water for the moment and will replace w/ antifreeze and adjust freeze temp using a hygrometer I received.

[MB750]

I had a worm clamp let go during a heat cycle test on my car once. Blew 170F coolant all over the passenger side of the car and all over the back wall of my garage. Fortunately, I wasn't in the car at the time.

I replaced every clamp on my cooling system with T-bolt clamps.

[J R Jones]

In my 40+ yrs. of working and managing a heavy duty fleet including off-road construction equipment, we never lost a hose due to a worm-drive clamp. That goes for intake hoses as well. Not sure what happened after I left, but feel good it never happened on my watch. I also don't think someone looks at your car and say's "oh, you have a cheap looking car because you use worm-drive clamps". OMG!

OEMs prioritize fast assembly on the production line and the majority of original clamps I encounter are spring clamps. Replacing the water pump recently on my 500ci Chevy Workhorse RV chassis I found heavy duty] spring clamps that required me to buy appropriate ratcheting pliers. I do not love the spring clamps, they are out there.

With the silicone hoses, the thick soft material will creap-out under the clamp and the worm gear clamp load loosens. The irony is a spring clamp continues to squeeze the hose over time even if the material squeezes out.
Another approach is periodic retightening clamps as the hose material creaps.
BTW marine fuel systems use double/reversed worm gear clamps.
jim

[EZ$]

Chewy, I had an issue a while back where the car ran perfectly cool when cruising along, but if I got caught in traffic or idled for a bit the temp would creep up to levels that I was uncomfortable with. Tried using my manual switch, but it didn't help. Tested the fan, and that was OK. Someone mentioned to check the relay by switching it with the other relay to see if it worked. Everything worked fine with the other relay, so it was the relay that was bad. At the time I was really surprised since those things are supposed to be good for a couple hundred thousand operations. I thought they never went bad!

[egchewy79]

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I have the day off today (thank you veterans!) so I decided to drain the coolant and remove all the hoses. I will be replacing all the worm drive clamps with T style clamps. Also tested the fan. The fan appears to be working when hooked up to a 12 V source. I also checked the fuse which looked OK. Assume the problem now is the Relay? I’m pretty sure I wired the manual switch to run with the ignition off

[egchewy79]

Chewy, I had an issue a while back where the car ran perfectly cool when cruising along, but if I got caught in traffic or idled for a bit the temp would creep up to levels that I was uncomfortable with. Tried using my manual switch, but it didn't help. Tested the fan, and that was OK. Someone mentioned to check the relay by switching it with the other relay to see if it worked. Everything worked fine with the other relay, so it was the relay that was bad. At the time I was really surprised since those things are supposed to be good for a couple hundred thousand operations. I thought they never went bad!

thanks EZ. my thoughts exactly. didn't think about swapping the relays to see if it would start working. I was also researching how to check the relay w/ a multimeter tool

[egchewy79]

Ok. Bad relay confirmed. Safe to say that the fan didn’t kick on in traffic, temps got too high and blew off the hose? Any suggestions on better replacement relay, and should I go ahead and replace both?

edit: ordered 2 Bosch relays. Figure I'll keep the other good one in the trunk for a rainy day.

[EZ$]

I did the same thing. I figured if I bought two it would never go bad again, but if I only bought one it was a guarantee that it would!

[AC Bill]

Once you mentioned an issue with the fan I kind of figured that overheating may have been the problem as to why the hose blew off. The coolant temp gauge should have registered that though.

[J R Jones]

Once you mentioned an issue with the fan I kind of figured that overheating may have been the problem as to why the hose blew off. The coolant temp gauge should have registered that though.

Overheating or not, the cooling system pressure is controlled by the pressure cap. IF the cooling system is beyond cap pressure threshold, it vents, and you likely would see that. By design, hose connection retention is well beyond cap pressure.
jim

[egchewy79]

Once you mentioned an issue with the fan I kind of figured that overheating may have been the problem as to why the hose blew off. The coolant temp gauge should have registered that though.

Happened so quickly so I didn’t have a chance to look at the coolant temp. Relay is definitely bad though

In hindsight , when I put the key on Acc after the incident, temp needle did spike to 120C before going back to 0

[egchewy79]

Overheating or not, the cooling system pressure is controlled by the pressure cap. IF the cooling system is beyond cap pressure threshold, it vents, and you likely would see that. By design, hose connection retention is well beyond cap pressure.
jim
Wondering if pressure/temp rose so acutely the cap wasn’t able to keep up

[Nigel Allen]

Wondering if pressure/temp rose so acutely the cap wasn’t able to keep up

Pressure cap reacts instantly. It's basically a spring loaded relief valve, with no relationship to coolant temperature. Besides, temp wont rise too quickly in the engine whilst cruising, as there is quite a bit of steel mass and coolant to be heated. It will take minutes, not seconds.

My hypothesis is that the relay had failed first, then when you pulled up at the interesction, temperature and pressure began to rise due to lack of air flow. Before the radiator cap could reach relief pressure, the weak hose connection failed under the higher than normal pressure.
You mentioned in a related post that there had been unusual smells when parking up in the garage. It is possible that the smell is from the relay, or the fan motor windings. A bad fan could take out your relay. So certainly worth checking the fan as well.

The best part is your engine is not cooked. As said on the Simpsons "Your potential Chernobyl is but a mere Three Mile Island"

Cheers,

Nige

[egchewy79]

Pressure cap reacts instantly. It's basically a spring loaded relief valve, with no relationship to coolant temperature. Besides, temp wont rise too quickly in the engine whilst cruising, as there is quite a bit of steel mass and coolant to be heated. It will take minutes, not seconds.

My hypothesis is that the relay had failed first, then when you pulled up at the interesction, temperature and pressure began to rise due to lack of air flow. Before the radiator cap could reach relief pressure, the weak hose connection failed under the higher than normal pressure.
You mentioned in a related post that there had been unusual smells when parking up in the garage. It is possible that the smell is from the relay, or the fan motor windings. A bad fan could take out your relay. So certainly worth checking the fan as well.

The best part is your engine is not cooked. As said on the Simpsons "Your potential Chernobyl is but a mere Three Mile Island"

Cheers,

Nige

Yes, the relay failing first was also my hypothesis. I tested the fan and it appears to be running fine when hooked up to a 12v source

[egchewy79]

Installed all new t bolt clamps, filled fluids, let fluids circulate. No obvious leaks. Replaced both relays. Also swapped air cleaner lid for a filter style one. Also changed the hose from the t filler to the rad with a solid hose.
Case closed, problem solved…for now
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[BRRT]

If the smaller hoses are silicone you could have the same problem again. It looks like the bypass and heater hoses are still worm-gear. I think most silicone hose vendors recommend lined worm-gear clamps at a minimum.

[egchewy79]

If the smaller hoses are silicone you could have the same problem again. It looks like the bypass and heater hoses are still worm-gear. I think most silicone hose vendors recommend lined worm-gear clamps at a minimum.

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