850CSi's E90 Thread (old Cooling Issues thread)

[850CSi]

Hey guys, here are the facts:

'06 E90. There are two different cooling system indicators in this car: a yellow one and a red one. I believe the yellow one is supposed to say your level is low/you're slightly overheated and the red one is basically 'stop immediately before you fuck up your engine'
Sometime August/September, I was driving along I-40 and the yellow light hit, followed by the red one. I basically parked on the shoulder and walked a mile to the previous exit and got some distilled water. Sure enough, the level was really low. I remember it taking like half a gallon of water. I was baffled that the level had gotten so low before the car detected something wrong, but whatever. No problems until...

Today, after getting my battery swapped (see other thread), I turned the car on in the parking lot and was on the phone. Five minutes later, the yellow light went on. I pulled out of the lot and hadn't driven 1/4 mile before the red one hit. I immediately pulled over and turned the car off. Then started it back up and headed back to the shop where I got the battery fixed. Mechanic at the shop said E90 water pumps fail all the time and sometimes intermittently fail. I learned my lesson from the summer and I keep BMW coolant with me in the trunk. Waited for the car to cool down and popped the hood - the level was at the 'min' - so not nearly as low as before but still low. Added enough to get it up to the max (probably less than a pint) and went on my way. No sign of trouble.

Background:
I used A/C more this summer than I've used in the first 5 years I owned the car combined

Do I have an intermittently failing water pump? A leak somewhere? Or just a really shitty thermostat?


Water pump job is over $1k. If that's the case, I think it's time to sell this car. I don't want to, but I've already dropped over $2k in the past 12 months or so on random things like this.

[VTEC_Inside]

I'd have the system pressure tested to start.

Dye in the coolant could help find any leaks as well.

[Rich]

+1... pressure tests.  If it comes out through a crack in the block, then new car time!

[Rupert]

If nothing else, pressure tests make it very obvious where the leak is coming from!

[850CSi]

+1... pressure tests.  If it comes out through a crack in the block, then new car time!

Heh if that's the case I think I'd rather not know...

[GoCougs]

Being down a pint or even half a gallon down on coolant isn't the make or break between operation or destruction. The real indicator is engine coolant temp and I'm guessing you didn't get any actual signs of overheating.

Usually when a pump goes it's the internal seals or otherwise the pump loses the ability to circulate coolant. I'm at a loss how this would lead to a low coolant signals unless of course when E90 water pumps go "bad" they crack and leak fluid.

I'm going to go with bad coolant level sensing. If you are losing coolant I'm going with bad head gasket.

[Rich]

I'm going to guess it's a radiator or thermostat gasket leak.

[Rupert]

I'm going to guess it's a problem that only $500 at the BMW dealer will diagnose, and another $4000 (for a simple coolant change) will fix.

[hotrodalex]

Usually when a pump goes it's the internal seals or otherwise the pump loses the ability to circulate coolant. I'm at a loss how this would lead to a low coolant signals unless of course when E90 water pumps go "bad" they crack and leak fluid.

I've heard a few stories about the pump seizing. Although that usually ends up with a broken serpentine belt and overheating (if you don't shut the car off quick enough), not just a dash light.

[AutobahnSHO]

-Turn the heater on- does it smell sweet?  (easy way to tell if the heater core is busted)
-Run the car, look under, see if you see any loose or swelling hoses or coolant dripping anywhere.
-Look at the exhaust, it will be smokier than usual if you're burning coolant.
-If you can, let the car sit for a while (few days) then Don't run it and drain the oil... Coolant would come out FIRST as it's heavier than the oil.  -If you have some kind of block or headgasket leak?

[/amateur hour]

So I had a 1990 "SLO" taurus, seemed to be leaking coolant, I drove it to the garage and right as I put it in park the waterpump assploded and antifreeze dumped all over the parking lot..

[2o6]

How many miles?


Might be time for a belt and pump job?


Otherwise, that sounds pretty terrible for a "new" BMW.

[shp4man]

It will take an infrared temp sensing gun to diagnose this properly. A bad water pump will leave the radiator cool and the engine hot, as will a bad thermostat. If the car overheats at low speed, check the radiator fan operation. A chemical block test, which detects CO in the coolant, would test the head gaskets. If the oil looks like coffee with creamer then it's going into the crankcase.
If the problem is intermittent, it's probably not the head gaskets. It may also just be a bad coolant temp sender. 

[850CSi]

How many miles?


Might be time for a belt and pump job?


Otherwise, that sounds pretty terrible for a "new" BMW.

65k. 6 years. Apparently these water pumps are notorious for sucking.

More info:


The signal, at least yesterday was for high temp. I don't believe there's a check coolant level light, though I could be wrong. I'll double check that when I get back to NC.

When it starts overheating you can feel it - the car basically starts shutting down on you.

FWIW over the last week or so I've noticed my idle feels a little lower and rougher than it used to be, and my HVAC seems to cut out intermittently.




I really don't know WTF to do. I was planning on driving down to Ft Lauderdale but I'm not sure I trust the car at this point. Getting stranded in bumfuck, SC would SUCK. My dad is telling me it's time to get rid of it. I don't really want to, and as soon as I entertain the thought it goes to "well even if I did WTF would I get to replace it?" A used car may cause the same problems and I don't really like new cars in general. Is shit like this more DIY on older cars? E90s are a bitch to do anything on.

And on top of that I'm worried now about the fucking battery blowing up (see $500!? thread)

[Rich]

Bring it to a local repair shop, and just as them for a pressure test.  Just tell them that if they find something that you won't get it fixed there, you just want to pay them to test it and give you the result... you'll get it fixed at the dealer if they find a leak.

That way they won't try and rip you off with finding and repairing a leak that wasn't there

Buy a used Miata.  Reliable as all get out.

[CALL_911]

Get a BRZ.

[850CSi]

Buy a used Miata.  Reliable as all get out.

So tempted to do this. Only thing is they're not great long-distance cars, are they...

What would $10k buy me?


See if I could chose anything it'd be an older E46 cabrio but that solves like zero of my problems. sigh ... German cars and their fucking habits.

[Laconian]

Great in what sense? They're super reliable, just a wee bit fatiguing...

Chimp drove his from Seattle to Blowhio and back.

[Rich]

So tempted to do this. Only thing is they're not great long-distance cars, are they...

What would $10k buy me?


See if I could chose anything it'd be an older E46 cabrio but that solves like zero of my problems. sigh ... German cars and their fucking habits.

I guess I'm a masochist, but I pulled off 11,000 miles in 45 days around the country last year.  I'm more comfortable in it than the Mustang

[850CSi]

Great in what sense? They're super reliable, just a wee bit fatiguing...

Chimp drove his from Seattle to Blowhio and back.

That, really. Especially transitioning from such a great long distance car. Also, I'm 6'3". I've driven a Miata before and I remember fitting OK (and I had a fucking blast, but I'm not sure how I'd feel about a 4 hr drive in there.

[850CSi]

FWIW over the last week or so I've noticed my idle feels a little lower and rougher than it used to be, and my HVAC seems to cut out intermittently.

Oh, and there seems to be a bit of a rattling noise coming from the engine, almost like it's a really quiet diesel. Whirring might be a better way to put it. Might just be my ears playing tricks on me but there's definitely something not totally usual.


I hate this I fucking love this car. Fucking BMW. If you're going to make your cars have shitty reliability, at least make them somewhat self-serviceable. Or don't put your shitty water pump in a place that guarantees replacing it costing over $1k.

[850CSi]

http://www.e90post.com/forums/showthread.php?t=620327

Seems like the water pumps suck.



Question: could this in any way be caused by someone programming the battery wrong?

[SVT_Power]

How does one "program" a battery?

[Rupert]

They program it by it's a BMW.

[Byteme]

So tempted to do this. Only thing is they're not great long-distance cars, are they...

What would $10k buy me?


See if I could chose anything it'd be an older E46 cabrio but that solves like zero of my problems. sigh ... German cars and their fucking habits.

What do you call long distance.  We've taken ours on 500 mile per day road trips and felt perfectly fine.  There's enough room in the boot for whatever two people need for a week.  Check Autotrader, but 10K ought to get you anything up to about 2005 with about 100,000 miles down here. Or older with less miles. 

[Byteme]

Oh, and there seems to be a bit of a rattling noise coming from the engine, almost like it's a really quiet diesel. Whirring might be a better way to put it. Might just be my ears playing tricks on me but there's definitely something not totally usual.


I hate this I fucking love this car. Fucking BMW. If you're going to make your cars have shitty reliability, at least make them somewhat self-serviceable. Or don't put your shitty water pump in a place that guarantees replacing it costing over $1k.

That could be the car's death rattle. 

Sounds like it could be a water pump going bad. 

[VTEC_Inside]

http://www.e90post.com/forums/showthread.php?t=620327

Seems like the water pumps suck.



Question: could this in any way be caused by someone programming the battery wrong?

dealt with this issue twice in the past two months. the first was due to a bad water pump....so i had the pump and thermostat replaced. then recently same overheating issue again....i'm thinking did i get a bad pump. it turned out to be a bad power distribution block on top of the battery...the bad connection caused the built-in fuse to blow which powers the water pump. they replaced the power distribution block and the water pump was operating just fine.

I suppose that's a possibility in your case as well.

[AutobahnSHO]

True story- my 1983 15yr old Civic had a "rattle" at idle- it sped up with engine speed.

Took it to a little backyard alley shop (who ALWAYS had tons of cars waiting)- they said it was the waterpump. I asked if the guy wanted to come out and listen to it, he came out, I started it up, he said "it's your waterpump".

$150 later no rattle, new waterpump.

------------------------------------------------------

Even if it's more money to get it fixed on your car- if you keep it and fix it, that's one component you shouldn't have to replace again.

So even if you have to spend $1k the next few months on repairs, that's only like 3-4 car payments.
3-4 car payments' worth of fixes vs. 36-50months of payments for a new car.

Too many people get caught up in the "oh noes! it's starting to break down!" and sell it.   Someone else buys it, fixes a few things and resells it at profit.

[93JC]

But there's a pretty big difference between $1000 worth of repairs on a Honda Civic and $1000 worth of repairs to a BMW.

Even today a Civic's water pump is only a few hundred bucks. If it's an older one with a timing belt, you pay a little more and have that taken care of at the same time. Farris is looking at ~$1200 just for the water pump. Never mind diagnostic costs if there's something else causing the water pump to fail, like faulty electrics.

[850CSi]

I don't think the pump itself is very expensive. It's just that it's in a really shitty spot and so apparently takes 9+ hrs of labor.

Check Autotrader, but 10K ought to get you anything up to about 2005 with about 100,000 miles down here. Or older with less miles. 

That's another thing. Would I really want to trade my car for an older Miata with more miles and only pocket ~3kish in the process?

[Rich]

I don't think the pump itself is very expensive. It's just that it's in a really shitty spot and so apparently takes 9+ hrs of labor.

That's another thing. Would I really want to trade my car for an older Miata with more miles and only pocket ~3kish in the process?

Yes.  It's nice having a car you can get serviced pretty much anywhere with no issues.  I've been down the road of having a fairly unique (in my case the MINI, in yours technologically advanced BMW) car that I didn't feel comfortable bringing to most shops.