Almost stranded today

[6670charger]

On my way home from work today, my dash lights (all of them) started flashing on and off intermittently, and then stayed on. Temp gauge pegged, although the car didn't seem to run any differently. I assumed it was part of the dash lights going berserk and completed the remainder of my half mile drive.

 

Once I got stopped, I saw green coolant leaking onto the ground. Popped the hood and don't see where it's coming from. No steam or anything. I did notice that my alternator belt is quite loose, maybe broken. Not sure if that would have caused all of this or not.

 

Any thoughts?

 

88 E30 325i

[jc43089]

How much coolant and can you tell where from?  I forget but does the alt belt also run the water pump?  If water pump bearings failed it could cause leaking from the seal and wobbling enough for the belt to be loose causing charging problems.  Just the first thing that popped into my head.

[6670charger]

The thing that scares me is that the coolant is hitting the ground vicinity of the firewall. I don't see any leakage anywhere around the radiator or hoses. The water pump was changed last fall along with the timing belt and should be in good shape assuming it was a decent part. Not sure if the alt belt runs anything else or not. Just don't remember. I didn't change the accessory belts when I did the timing belt as they all seemed to be in decent shape. If the alt belt does run the water pump and broke due to age, it could explain the overheating. Still not sure where the coolant is coming from though. I hope to god it didn't blow the head gasket somehow.

 

Unfortunately, I'm living in a hotel in the Indianapolis area for a few more weeks to complete some new job training, and nowhere near home or most of my tools.

[Boris3]

Water pump and alternator are on the same belt. I did a quick search and found a similar thread that I can't seem to paste here but the possible scenarios are: 

 

1) water pump seized and broke belt: belt bit into coolant hose, and/or if the temp red pegged immediately maybe broken belt whipped into sensor wires?

 

2) or what turned out to be the case the guy's alternator bracket came loose, belt slipped, alternator and water pump stopped, electrics went haywire and car overheated

 

 

As for the leaking coolant near firewall, a few possibilities:

 

1) overheated and blew coolant out of the overflow tank hose which dumps behind your fender well (?)

2) heater hose blew/broke, leaking

3) blown head gasket; overheated and cracked head (check your oil/overflow tank for milkshake)

 

Anyway, contact me at Friman@sbcglobal.net  I know some Spec E30 guys down in Indy area that might be able to help or suggest a shop for you.

[B C]

Check with the regional forums on r3vlimited as well if you need more chance of someone coming to the rescue.

The loose/broken belt is likely the cause of extra heat and pressure building up in the cooling system an bursting a hose.

There are 5 coolant hoses back there which may have come loose or burst. All of them are visible/accessible from the drivers side. Assuming your coolant reservoir is on the drivers side instead of the passenger side like on early models.

#1 is a smaller diameter hose that connects to the engine block far back under the intake runner for cylinder 6. This hose connects to the coolant lines that loop around the breather port on the throttle body.

(not an m20 shown but it is the same location)

The aluminum heater core bypass valve can cause confusion especially with difficulty seeing everything clearly back there so here is a breakdown of what coolant hoses connect to it and where they go.

Ignore the non colored hoses in the following image, those are custom made hoses for bypassing the heater core bypass valve

(Eliminates the blue hose and aluminum heater bypass valve)

#2 (green) and #3 (yellow) are heater hoses going into the firewall these should be 5/8" heater hose

#4 (purple) is a sneaky lil bugger that connects to the backside of the cylinder head right next to the firewall. If it is the culprit, This one is best repaired with copious amounts of radiator hose tape since it has two different diameters on the ends and creating a quick fix from plain heater hose may not work well

#5 (blue) is a small diameter hose that takes a sudden blind corner into the heater bypass valve.

When you fix the belt and leak and its time to add coolant and bleed the system then the bleeder screw is 8mm.

If you need any technical support at all or just moral support i am a phone call away. Just PM me and i will send you my number

[Boris3]

I heard back from a SE30 friend in Indy. He's got a garage, tools, and advice waiting if you need it. Contact me and I'll send you his information. 

[6670charger]

Water pump and alternator are on the same belt. I did a quick search and found a similar thread that I can't seem to paste here but the possible scenarios are: 

 

1) water pump seized and broke belt: belt bit into coolant hose, and/or if the temp red pegged immediately maybe broken belt whipped into sensor wires?

 

2) or what turned out to be the case the guy's alternator bracket came loose, belt slipped, alternator and water pump stopped, electrics went haywire and car overheated

 

 

As for the leaking coolant near firewall, a few possibilities:

 

1) overheated and blew coolant out of the overflow tank hose which dumps behind your fender well (?)

2) heater hose blew/broke, leaking

3) blown head gasket; overheated and cracked head (check your oil/overflow tank for milkshake)

 

Anyway, contact me at Friman@sbcglobal.net  I know some Spec E30 guys down in Indy area that might be able to help or suggest a shop for you.

I'm going to pull the air box tomorrow so I can see better underneath and behind it. 

 

Option number two seems really similar to my circumstances. Not sure if the alt bracket broke or came loose, or if the belt simply broke due to age. My hope is that the alt belt simply broke. I didn't replace it when I did my timing belt a year ago due to limited funds. I have no idea how old the belt is, or any of the other rubber parts under the hood. I've been meaning to start replacing them little by little, but just haven't had the money lately. I should probably replace both the alt and power steering belts while I'm under there. 

 

I did look at the overflow tank to check the level, and it's still pretty full. I checked the car about an hour after I parked it, and there wasn't a lake of coolant under it, so I think all that leaked out was just from pressure due to heat and the engine running. Almost sounds like coolant blew out of the overflow tank hose. I suspect that if one of the heater hoses had blown off of a mount on the firewall that it would have dumped a whole lot more coolant than it did. Also, my coolant level warning light never came on the entire time. Only the dash lights came on.

 

Although I didn't take the cap off, the coolant didn't appear foamy or anything. Looked normal from what I saw just looking through the side of the tank from the outside. Will pull the dipstick first thing tomorrow and check that. I plan on changing out the belt, and checking the heater hoses near the firewall just to make sure none of them blew off. It's easy to think the worst right away, but I've been working on cars long enough to know that often it's something really simple. Replacing a busted belt is about as simple as it gets. I can only hope.

[6670charger]

OK. Pulled the airbox off this morning to open things up a little and found that the alt belt separated in by the grooves. The flat surface you can see from above was still intact. The pulley to the alternator itself spins freely, as does the fan, so my assumption at the moment is that my belt of undetermined age simply broke. Gonna change out the power steering belt while I'm at it as I have to take it off to put the new alt belt on anyway. Coolant looks good in the overflow, just a little low now. Need to pull the dipstick and check the oil for foam, but at this point I don't anticipate seeing anything odd, at least that's my hope anyway. Will also take a look at the heater hose connections at the firewall just to make sure nothing popped loose.

[6670charger]

Success!  Had to call in reinforcements in the way of a friend of Boris3's down here as I didn't have a 32mm wrench to take the fan off with. He came over with wrench in hand and even gave me a hand. Very nice guy! Changed both belts, added some coolant and got it running. Runs fine and holds temperature great. Only issue is that the Check Engine light stays on, so will probably have to get that reset somehow.  Otherwise, so far, so good.

[B C]

Glad to hear!