Blown coolant hose, how screwed am I? (Turns out, not at all!) -- Update: I'm most likely screwed :(

ryushe

ryushe

Member
 Rotterdam
As I was driving home today on the motorway what appears to be the lower coolant hose suffered catastrophic failure. I heard a muffled bang/plop/sound, and immediately as this happened, my temperature indicator shot up in the red and the engine shut down. Luckily I was able to coast into a very conveniently placed roadside gas station and park it.

Things I noticed:
  • White smoke briefly came from under the bonnet and disappeared, and the ground underneath the car was instantly wet.
  • No coolant fluid at all in the tank under the filler cap.
  • Opened up the oil cap and smoke came out of that as well.
I let the car cool off for 30 minutes and even though I know I wouldn't be able to go anywhere I tried to start it briefly. The engine turned over very roughly and immediately shut down again.

Now seeing as it's roadside, not much I can do mechanically. I can't reach the hose from above, and the car is way too low to reach it from below (besides the fact that I couldn't even get the undertray off). So the car is still sitting at the gas station at the moment.

In short what I'd like to get an idea of, is how screwed am I?
 
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It's not unusual to get smoke/steam out of the filler cap when the engine is still very hot.
If you really did manage to get it stopped that fast then I would like to think it's not as bad as you fear.
Did the whole engine bay get wet? Maybe it's upset some electrics which may dry out and be ok.
Obviously the best thing to do is going to be get a code reader on it as that may give you a better idea why the engine died.
Whern you say it's running rough, could it be missing on one or more cylinders?
 
I wonder if the electric water pump packed up, causing a sudden pressure surge which blew the pipe?
 
enuff_zed said:
I wonder if the electric water pump packed up, causing a sudden pressure surge which blew the pipe?
Click to expand...
That’s what I was thinking.

I’d be cautiously optimistic that once sorted you won’t have done any damage- a short time with coolant loss isn’t the end of the world

Fingers crossed
 
enuff_zed said:
It's not unusual to get smoke/steam out of the filler cap when the engine is still very hot.
If you really did manage to get it stopped that fast then I would like to think it's not as bad as you fear.
Did the whole engine bay get wet? Maybe it's upset some electrics which may dry out and be ok.
Obviously the best thing to do is going to be get a code reader on it as that may give you a better idea why the engine died.
Whern you say it's running rough, could it be missing on one or more cylinders?
Click to expand...
Good to hear on the smoke/steam from filler cap!
The engine died pretty much immediately as I was getting beeps about high temperature and coolant issue. I coasted into a parking spot with no power. So hopefully major damage prevented?
Engine bay is generally pretty dry, just soaking wet on the try underneath the lower coolant hose, and obviously the puddle underneath the car itself.
I actually did read codes with ignition on. The following codes appeared:
  • 2E68 (knock sensor)
  • 2E69 (knock sensor)
  • 2E83 (water pump related code, probably due to no coolant?)
  • P0328 (knock sensor)
  • P1328 (knock sensor)
On the missing cylinders, maybe. Engine didn't run long enough for me to notice that, just that it was quite rough.


Waterpump, thermostat and expansion tank were replaced about 6000 KM ago.
 
ryushe said:
Good to hear on the smoke/steam from filler cap!
The engine died pretty much immediately as I was getting beeps about high temperature and coolant issue. I coasted into a parking spot with no power. So hopefully major damage prevented?
Engine bay is generally pretty dry, just soaking wet on the try underneath the lower coolant hose, and obviously the puddle underneath the car itself.
I actually did read codes with ignition on. The following codes appeared:
  • 2E68 (knock sensor)
  • 2E69 (knock sensor)
  • 2E83 (water pump related code, probably due to no coolant?)
  • P0328 (knock sensor)
  • P1328 (knock sensor)
On the missing cylinders, maybe. Engine didn't run long enough for me to notice that, just that it was quite rough.


Waterpump, thermostat and expansion tank were replaced about 6000 KM ago.
Click to expand...
Well the 2E83 code does suggest it could be an internal pump fault. However it also mentions a short circuit in the power plug to it. Possible if water has poured over it.
 
I've also been reading up about the knock sensors. You have simultaneous faults on sensor 1 and 2. Highly unlikely everything has failed at once. However, one of the things it says to check is that there is a good earth. So again, potentially it is the water spraying onto electrical connections that may have caused all your codes?
 
Well, our friendly roadside assistance person showed up this morning, and confirmed it was indeed a blown hose. He was able to repair it roadside, and after filling up with coolant everything seems to be back to normal!
 
ryushe said:
Well, our friendly roadside assistance person showed up this morning, and confirmed it was indeed a blown hose. He was able to repair it roadside, and after filling up with coolant everything seems to be back to normal!
Click to expand...
Phew!
How did he repair it? Replacement hose?
They have those push on fittings with the metal clip that holds them in place. I have seen people bodge them with locking wire if the clip has disappeared.
 
Late reply, been a (very) busy week!

enuff_zed said:
How did he repair it? Replacement hose?
Click to expand...
Yes, replacement hose. I happened to have a replacement lower radiator hose in the boot, as I was already planning on replacing it that weekend, for no reason other than preventative maintenance. Scary timing though.

Since then there's a related new problem. The car was able to drive after replacing the hose and refilling / bleeding the coolant system. However I drove it last Sunday, and it took more time than I'm used to to get up to temp. The needle did stay perfectly centered after that for quite some time, but it did suddenly jump up towards the red again quite quickly (not instant). I slowed down, let off the gas, and within 10 seconds the temperature dropped again, the needle centered, and stayed there. I drove off again, but 10 minutes later it did the same thing.
Checked as soon as I parked it again, and saw no leak, nor any loss of coolant.

I suspect either the pump or the thermostat, even though they're relatively brand new. Are these symptoms of a broken thermostat?

Since I parked the car on Sunday, I haven't driven it, and right now I'm a bit worried driving the car at all.
 
Sometimes need to run the automatic bleeding sequence more than once to shift any airlocks.
Could be an airlock which every now and then passes the temp sensor and makes it read too hot.
 
The saga sadly continues. Again didn't have too much time this week, so left things until yesterday.

I tried the bleed process again, but it no longer seems to activate. Did the activation procedure, but I don't hear anything run.
The coolant level looked OK, so took it for a careful drive locally. The car is slow to get to temperature, and the cabin heater never got hot. The engine temperature indicator settled dead center and never wavered. I checked live data with a scan tool, and the temperature was pretty stable at 100 degrees, +/- 2 to 3 degrees.
Based on some things I've been reading, this seems to point towards the thermostat?

Just to confirm I'm doing the bleed procedure right for an N52 engine;
  • Ignition on, no running engine.
  • Filler cap and bleed screw closed.
  • Cabin heat to max.
  • Cabin fan to lowest (running) setting.
  • Press and hold gas pedal for 10-11 seconds.
That should be it correct? Battery seems fine, no blown fuses.
 
Since Saturday things have gone downhill.
The car overheated again on Monday morning on my way to work. Roadside service did a vacuum refill of the coolant system, and everything seemed fine after that. The waterpump is definitely working, and the thermostat seems to be working as well, as I got heat in the cabin. After the refill did a complete full bleed cycle, and this seemed to show that there was no air trapped in the system anymore, which the friendly roadside service guy thought was the issue. Drove off to work and parked it.

When I left work later that day, I noticed a small (tiny) puddle of fresh coolant fluid underneath the car, but wrote it off to some minor spilling. So drove back home, and lo and behold, the car overheated again and the cabin vents started blowing cold instead of warm air. Parked it, called roadside service again, and this time they decided after looking at it that the best course of action was to have it towed to a shop. The guy also said that as the system was refilled and bled correctly that morning, that the only other reason I would suddenly have air in the system again is a blown head gasket. As the shop is busy, I'm currently waiting on an initial diagnosis.

So yeah, now I'm sad and worried. Also the first time I've ever had to have a car towed :(

IMG_5148.jpeg
 
Diagnosis done (took a while). Leak detected in cylinder #4, cause seems to be a leaky head gasket, which explains all my recent coolant problems. For you folks in the UK, you'll be shocked to hear what they charge to replace the gasket (and the other seals required), resurfacing/machining the head, new bolts, and refill with new oil +& coolant. All of it, including labor and tax comes down to approx 3.000,00 GBP :oops:
Hopefully it's still worth it here in NL seeing used car prices ...
 
So....would it seem that your initial hose blowing caused the engine to get hot enough to damage the head gasket??
 
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