TheSamba.com :: View topic - Belt Broke, Engine Overheated, Coolant Spilled. Source?

Wed May 21, 2014 5:04 pm

My girlfriend and I were 20 minutes outside San Diego when we noticed the alternator light come on. Shortly after, the temp light. I pulled over to find coolant steaming and spilling on the ground. Coolant seemed to be coming from the tail end of the engine bay, but soon stopped.

AAA towed us the remaining 20 minutes to her sister's house.
I've replaced the belt, filled up the coolant, bled the system, and cannot recreate any sort of leak. The engine runs perfectly and the temperature stays where it should be.

Our final destination is Chicago, and we're hoping to head out in a few days. We'd originally headed to San Diego to work on a few other things with the help of her brother-in-law and his tools. (Tank reseal, clutch cylinder, etc.)

But now, we want to make sure the cooling system/engine are okay for the rest of the trip. I'll keep trying to diagnose the problem these next couple days, but I was wondering if anybody has any ideas... is there somewhere pressure could escape from without damaging hoses?

It feels unlikely (as much as I'd like to believe it) that everything is hunky dory without anything needing to be replaced.

I'll keep everyone up to date if I find anything new, any help would be greatly appreciated!

Wed May 21, 2014 5:13 pm

A pressure test on the system will pin point of failure immediately.

Wed May 21, 2014 5:21 pm

Alternator belt breaks and the water pump doesn't work. Car overheats and coolant is ejected through the pressure cap.

Wed May 21, 2014 5:28 pm

Thanks TK, I'll see if I can do a pressure test tonight.

eebeee, wouldn't it then go from the pressure cap to the overfill tank?

Wed May 21, 2014 5:46 pm

mrkuzoo wrote: Thanks TK, I'll see if I can do a pressure test tonight.

eebeee, wouldn't it then go from the pressure cap to the overfill tank?

Yup- which then "overfills", the cap on the overfill tank is not pressurized or sealed very well. Every vanagon I've seen overheat from belt snap has spilled coolant this way.. seems normal?

but TK is right with a pressure test as better approach..

Wed May 21, 2014 5:47 pm

The overflow tank is not sealed, it has a little vent at the top, along the seam if I recall correctly.

You've got bikes on board, so likely that you have a foot pump with a gauge No? Do some McGyver rigging and connect the foot pump to the outlet on the pressure cap. Now pump up the system around 15 PSI on the gauge. This will help you bleed the air out of your now refilled cooling system, and then leave it connected at pressure and listen/Inspect for drips.

Happy Road Tripping.

Wed May 21, 2014 6:21 pm

I forgot, missed the belt breaking, which would make the engine overheat for sure.

And it would cause the coolant to back blow into the reservoir, and onto the ground.

The system pressure check wouldn't hurt, and would give you a hand bleeding the system fast.

The plus here would be that if you had any additional leaks anywhere, you'd find them fast.

Good Luck.

Wed May 21, 2014 6:23 pm

Yup, sure enough, the overfill tank looks to be the source. The plastic around the lid is cracked, and coolant was spilling along that rear seam.

That seems to be that, on to all the other shenanigans we need to take care of.

Thanks for the help!!

Wed May 21, 2014 9:26 pm

There ya go--a real good source of leakation--time for a tank--no doubt.

Good find.

Wed May 21, 2014 10:02 pm

Good find indeed, since it looks like that tank is about to fall apart, but...
- that tank isn't pressurized
- the cracks pictured are above the MAX line - or so it seems, which would mean that coolant couldn't escape from there in normal conditions.

The main point of all this has been stated already, but I want to state it again:
- lit alternator light may well mean broken alternator belt
- the so-called alternator belt should be called alternator AND water pump belt
- so alt light on = engine not being cooled at all = something's going to be boiling real soon = something is boiling already = coolant will find a way out real soon, possibly through head gaskets.

Bottom line: you've been lucky. If the alt light goes on again (except on startup, prior to revving up the engine): STOP NOW.

(apologies if you knew all of this already)

Wed May 21, 2014 10:22 pm

Hot coolant blown back into the fill tank will take the path of the least resistance--regardless of the level--it'll seek it's own path.

The cracks look like a real good place to lose the green stuff if the expansion tank is blowing it back in there --en-mass.

Thu May 22, 2014 4:14 am

Timing is everything.

I had this happen just last week, but I somehow was on my game and managed to shut it down in about 20 seconds.
I lost about 1/2 of the expansion tank capacity, but have suffered no other ill effects. Temp light never came on.

http://www.thesamba.com/vw/forum/viewtopic.php?t=594984

New belt this week, keeping an eye on things and no problems at all - 20 min. commute every day.
No drips, normal gauge temp, normal all around for me. <whew!> Maybe you'll be as lucky.

Q) How long from when you saw the alt. light until you shut off the engine?

Thu May 22, 2014 5:23 am

If you still had coolant pouring out everywhere you most like did no harm to the engine. Replace the overflow tank and check the condition of the expansion tank as they fail with age as well. If you decide you need a new expansion tank then also spring for a new coolant level sender and o-ring as they age at about the same rate as the tank.

Thu May 22, 2014 8:10 am

If his expansion tank was perfect, and the rest of the system was, and broke the belt, the same thing would happen. The water pump stopped pumping and the engine overheated.

If the system pressure tests OK and you replace the belt, and properly bleed the system, I'd say you are set to proceed on the trip. Even with a cracked expansion tank. Most vanagons have a cracked expansion tank, they are 25-30yrs old, it's not unusual at all. I'd say one not being cracked is much more rare!

The expansion tank is vented and not sealed even when new, so a crack above coolant level is not going to affect anything really. But it is something that you should change when you get around to it, since it means cracks below the coolant level are in the near future.

Thu May 22, 2014 10:12 am

[email protected] wrote: If his expansion tank was perfect, and the rest of the system was, and broke the belt, the same thing would happen. The water pump stopped pumping and the engine overheated.

If the system pressure tests OK and you replace the belt, and properly bleed the system, I'd say you are set to proceed on the trip. Even with a cracked expansion tank. Most vanagons have a cracked expansion tank, they are 25-30yrs old, it's not unusual at all. I'd say one not being cracked is much more rare!

The expansion tank is vented and not sealed even when new, so a crack above coolant level is not going to affect anything really. But it is something that you should change when you get around to it, since it means cracks below the coolant level are in the near future.

Not to criticise but to try and cut down on confusion, in the terminology VW uses the expansion tank is the pressurized tank and the refill tank is the unpressurised one.