Just blew a cooling system hose!

[pundit]

I just arrived home tonight (45 mins before posting this thread) and as I pulled into the drive I could smell steam. Anyway I pulled the bonnet and realised that the short 90 degree hose between water pump and thermostat housing had well & truly exploded! Aye carumba!

Fortunately it had just only occured as the temperature gauge had not even shifted above normal and the bonnet insulator was covered in water when I opened the bonnet. In fact the hose appears to have expired just as I stopped in the drive. The low coolant level warning didn't occur until after I switched the motor off & inspected the engine before briefly restarting it to check for anything abnormal.

Apart from the smell of coolant still evaporating off the motor nothing smelt 'terminally' hot and overcooked. Believe it or not I just did a coolant flush yesterday to prepare for a coolant change and had ordered that very hose and a new thermostat today - which will be delivered tomorrow. Now I'm going to order the rest of the hoses as well. Lucky I still have my Toyota van, so I can get to work tomorrow.

A word of advice for anyone buying a 2nd hand vehicle. If you aren't absolutely certain that all hoses, thermostat, belts etc. have either recently been replaced, or are in good condition (not always easy to determine with some hoses & of course the thermostat) then 'bite the bullet' and replace them. Cause you'll definately have to after you've forked out $1000+ to fix the damage one $10.00 hose can cause!

[Russell]

My car, is 10 years old and I do not believe any hose has ever been replaced. Of course, nothing looks bad or leaks. However, I am of the the opinion I should replace them all. Of course some of the hoses are not visible or even touchable. If you look at the ETK, there are some rather "unique" looking hoses involving the secondary water pump and I think involving heating the throttle body area. It just looks rather difficult and expensive even if you do it DIY.

TIA

I just arrived home tonight (45 mins before posting this thread) and as I pulled into the drive I could smell steam. Anyway I pulled the bonnet and realised that the short 90 degree hose between water pump and thermostat housing had well & truly exploded! Aye carumba!

Fortunately it had just only occured as the temperature gauge had not even shifted above normal and the bonnet insulator was covered in water when I opened the bonnet. In fact the hose appears to have expired just as I stopped in the drive. The low coolant level warning didn't occur until after I switched the motor off & inspected the engine before briefly restarting it to check for anything abnormal.

Apart from the smell of coolant still evaporating off the motor nothing smelt 'terminally' hot and overcooked. Believe it or not I just did a coolant flush yesterday to prepare for a coolant change and had ordered that very hose and a new thermostat today - which will be delivered tomorrow. Now I'm going to order the rest of the hoses as well. Lucky I still have my Toyota van, so I can get to work tomorrow.

A word of advice for anyone buying a 2nd hand vehicle. If you aren't absolutely certain that all hoses, thermostat, belts etc. have either recently been replaced, or are in good condition (not always easy to determine with some hoses & of course the thermostat) then 'bite the bullet' and replace them. Cause you'll definately have to after you've forked out $1000+ to fix the damage one $10.00 hose can cause!

[TC535i]

Keep an eye on that.

I blew that same hose twice... because of overpressurizing, caused by a blown head gasket.

Not saying that's definitely what's happening here... just keep that in mind.

[Kalevera]

Guys - I just rebuilt the coolant system in my car this weekend, minus the water pump and radiator. Do the Aux water pump while you're at it - it's was the most expensive part for me at $100+/each.

Cost was less than $300 in parts from BMA (actually, I did buy a GEBA WP, but didn't install it as the one currently in the car looks new and has no play or noise in the bearings).

That little half circle pipe is ~ $4. Since I don't know the service history of my car for the past ~ 100k, I thought it wise to just replace them all, although I had slow leaks on the expansion tank pipe and in the heater valve/aux pump area.

It's a saturday afternoon job, assuming nothing else breaks (I cracked my TSTAT housing - yes, the aluminum one - and had to have one overnighted to get it done) and you've got some Cool Blue on tap.

I also hylomar'd every hose or flange connection in the system. Bled it and now there are no more leaks and the car is much happier

Best, whit

[George Davis]

We bought our '94 525i with 100k miles on it. After doing the mandatory water pump, t-stat, and radiator replacements, I wanted to do all the hoses and eventually got it done. It's not a real entertaining job, but in my opinion worth it when you don't know the service history of the car.

One hose in particular looked very challenging. It's the 4-ended hose that runs under the intake manifold. Luckily (?) for me, the starter began going bad and I had to remove the intake to replace it. That gave me access to the 4-end hose, so I did that one, all the heater hoses and the small throttle body hoses at the same time. Dealer price on these hoses is pretty high, so order them from one of the aftermarket guys.

It might be possible to replace the 4-end hose without pulling the intake, but I think you'd want to at least remove the air filter box and throttle body to improve access below the intake. You'll need one gasket for the throttle body to manifold joint, and one for the ASC extra throttle if you have ASC.

[632 Regal]

I replaced everything on mine this past fall as I didnt know if anything was ever replaced...everything didnt look old but you never know. waterpump, thermo & housing, all them looking hoses. I know I dont have to worry about anything bursting or leaving me stranded far away from home and being at someones mercy especially since I'm pretty sure I can do a better job of whatever than some half assed mechanic.

[DueyT]

Pundit, was it just the hose, or the plastic inlet fitting to the aux pump...like the one that blew on mine?

See bottom of this page of mine...

Cheers,
Duey

[Paul in NZ]

that same hose(little 90 deg fella) hose was cut or split at the clamp slightly,i had the low coolant level warning twice but couldnt find the leak.Finally spotted some bright GREEN antifreeze sitting in a puddle near the altenator clamp,found the split,repositioned the clamp drove quietly to the dealer and replaced,i check the hoses regularly now ....................

[pundit]

Pundit, was it just the hose, or the plastic inlet fitting to the aux pump...like the one that blew on mine?

See bottom of this page of mine...

Cheers,
Duey

1990 535iA (M30) not plastic, the hose itself burst.

[pundit]

that same hose(little 90 deg fella) hose was cut or split at the clamp slightly,i had the low coolant level warning twice but couldnt find the leak.Finally spotted some bright GREEN antifreeze sitting in a puddle near the altenator clamp,found the split,repositioned the clamp drove quietly to the dealer and replaced,i check the hoses regularly now ....................

That's where mine let go - right at the clamp. I think most likely because I removed it the day before to flush the system and the retightening was probably too much for a several year old hose. It seemed quite okay when I had it off but I decided to order a replacement anyway. It became very soft once warmed up and split right at the clamp. I'm wondering how much the upper radiator hose (with the heater hose attached) will be?