BMW M5 Forum and M6 Forums banner

1 - 18 of 18 Posts

·
Registered
Joined
·
1,548 Posts
Discussion Starter #1
Hey guys.. haven't been on here much lately. Been super busy with work and school.
Just graduated college after many years and now it's time to give my beast some attention and decide what I want to do with her.
Yesterday I got a check coolant level message so I checked and it wasn't super low so I topped it off with bmw coolant and the check coolant level warning just came back on. Checked and its a little low.
There is a hissing noise from the radiator area passenger side and when I squeeze the radiator hose on the passenger side it makes a whoosh noise. There is a small puddle of what looks like coolant under the passenger exhaust manifold area. Can't see any leaks though.
Also not sure if this is related but I have been getting a random rough running engine that sometimes triggers a check engine light.
Have to find my laptop with evolve software to run the codes and see what pops up. The rough running either goes away if I rev up to 4-5k rpms or if I shut off the engine and turn it back on. Related?
112k miles on my engine.. original water pump..
Any help is appreciated :)
Will run codes tonight hopefully
 

·
Registered
Joined
·
413 Posts
Coolant loss
Check engine light
Rough running engine
Coolant by exhaust manifold, close to where heads meet block

Any white smoke from the tailpipes?
 

·
Registered
Joined
·
1,548 Posts
Discussion Starter #3
No. Check engine light is gone right now too
 

·
Registered
Joined
·
1,548 Posts
Discussion Starter #4
And no overheating.. its weird
 

·
Registered
Joined
·
6,918 Posts
sounds like a broken plastic weld on the radiator. they crack open only under pressure, so it isn't always visible unless you know to look for.
 

·
Registered
Joined
·
1,548 Posts
Discussion Starter #6
sounds like a broken plastic weld on the radiator. they crack open only under pressure, so it isn't always visible unless you know to look for.
I'll look for that. I just changed my radiator and expansion tank not too long :/
Don't think it's a head gasket either.. The rough running happened like 3 weeks before I got the check coolant message so it might not be related..
 

·
Registered
Joined
·
1,548 Posts
Discussion Starter #7
Ok so I found some white residue under the reservoir.. Maybe a small drip is causing my coolant loss. That's what I'm hoping for at least.. will try to monitor it..
Got my codes I'm going to have to make a new thread though :/
 

·
Registered
Joined
·
3,793 Posts
There are so many little things that needs to be checked.
Thermostat
Sensor on lower radiator hose

Keep an eye on the coolant. If it decreases and you have no major leaks, it must go somewhere. Check the oil color as well. Make sure it doesn't look like chocolate milk.
 
  • Like
Reactions: m5rosemont83

·
Registered
Joined
·
2,548 Posts
I was thinking lower radiator hose sensor as well. I've had it happen to me where I was slowly losing coolant but couldn't pinpoint where it was coming from at first. I started getting nervous about a head gasket as well, but then later found some small dips onto the undertray. Turned out to be the oring leaking on that sensor.

Good luck, seems like you have a multitude of issues!
 
  • Like
Reactions: m5rosemont83

·
Registered
Joined
·
1,548 Posts
Discussion Starter #10
There are so many little things that needs to be checked.
Thermostat
Sensor on lower radiator hose

Keep an eye on the coolant. If it decreases and you have no major leaks, it must go somewhere. Check the oil color as well. Make sure it doesn't look like chocolate milk.
I was thinking lower radiator hose sensor as well. I've had it happen to me where I was slowly losing coolant but couldn't pinpoint where it was coming from at first. I started getting nervous about a head gasket as well, but then later found some small dips onto the undertray. Turned out to be the oring leaking on that sensor.

Good luck, seems like you have a multitude of issues!
I'll look at that sensor a little later tonight.
Hope it's something like that and not my water pump dying!

I do have a wet undertray as I can see water right under where the passenger side headers are.
It's too hot out to be working on my car :/
 

·
Registered
Joined
·
3,793 Posts
I'll look at that sensor a little later tonight.
Hope it's something like that and not my water pump dying!

I do have a wet undertray as I can see water right under where the passenger side headers are.
It's too hot out to be working on my car :/
Might be heat exchanger as well, which is under the plenum, under the throttle actuator
 

·
Registered
Joined
·
1,548 Posts
Discussion Starter #12
Might be heat exchanger as well, which is under the plenum, under the throttle actuator
That might be it.
I found water dripping from what looked like the waterpump area..
On the front of the engine I see a trail of coolant that leaks onto the oil pan and drips to the undertray..
Does that sound right? I was thinking my waterpump was leaking from behind or something
 

·
Registered
Joined
·
3,793 Posts
That might be it.
I found water dripping from what looked like the waterpump area..
On the front of the engine I see a trail of coolant that leaks onto the oil pan and drips to the undertray..
Does that sound right? I was thinking my waterpump was leaking from behind or something
Sounds about right, there will also be residue on the trans bell housing. If its the heat exchanger, you will see drips after about 10-15 minutes idle.

if you gonna remove the plenum, run the car without it for 10-15 and if its the heat exchanger you will see it fluid coming from it.
 

·
Registered
Joined
·
1,548 Posts
Discussion Starter #14
Sounds about right, there will also be residue on the trans bell housing.
I'll try to look at that too..
The car never goes all the way empty.. It gets to about 2/5 and stays at that level until I put coolant in..
I'll go look for a diy.. it would be the o-rings or hose I'm assuming not the actual heat exchanger itself yeah?
 

·
Registered
Joined
·
3,793 Posts
I'll try to look at that too..
The car never goes all the way empty.. It gets to about 2/5 and stays at that level until I put coolant in..
I'll go look for a diy.. it would be the o-rings or hose I'm assuming not the actual heat exchanger itself yeah?
Its usually the O-ring's
 
  • Like
Reactions: m5rosemont83

·
Registered
Joined
·
2,548 Posts
It's possible the pipe/oring going into the back of the waterpump is leaking, or the pipes from the thermostat. It really depends on where the coolant ends up traveling. I have seen the coolant to thermostat pipes leak and travel back to the transmission as well. You might want to either buy a bunch of orings for everything in that area, or at least pull the plenum and see if you can notice anything.
 
  • Like
Reactions: m5rosemont83

·
Registered
Joined
·
1,548 Posts
Discussion Starter #17
Sweet I'll look into that.
Looks like the waterpump has to come out too though..
Might as well change that too while I'm there right? Car has 112,000 miles..
Keeping her nice has been really expensive.. I might have to bail soon.. LOL
 

·
Registered
Joined
·
4,488 Posts
It won't be the oil cooler itself if coolant is leaking down the front of the engine. Leakage from the cooler all would drain out of the two holes at the back of the engine into the bell housing and come out of the holes at the bottom of the bell housing.

It could be the pump mechanical seal leaking. There is a drain hole in the underside of the pump to allow this leakage out so it doesn't get into the sealed bearing.
 
1 - 18 of 18 Posts
Top