E34 M50 Radiator Leak & Running Rich$$

[0llie 0]

Hey guys,

Had this slow radiator leak in my car for a while, gets quite annoying having to top up all the time!

It appears the radiator fluid is coming out of these two connections on the end tank

Is this a common problem? I planned on emptying the radiator, unscrewing the pipes from the end tanks and resealing them with some thread tape, any other suggestions?

Where do they actually go, they run down the side of the engine towards the transmission, wasn't sure if they're the heater hoses?

Also she's running a bit rich from my the smell of the exhaust, any suggestions on this? She has the 'hunting' idle going on...

Thanks in advance.

[bravo 35]

There the auto trans fluid hoses. The trans fluid is cooled by the radiator and is pumped through.

You should not be getting any coolant out of these as this would mean coolant in your fluid! Perhaps the top radiator hose is leaking and dripping down onto the trans hoses giving the appearance they are leaking?

Running rich and hunting idle is most likely the cold start valve sticking, or a vacuum leak. The cold start valve applies extra fuel for when the motor is cold. If it is sticking open this would give the rich smell, and may cause the hunting idle as the computer will be calculating the AFR wrong.

Edited March 3, 2009 by bravo

[BM WORLD 1283]

commonish problem . also trans coolant can sometimes go into the trans fluid (very bad for trans).

i havev a good used radiator for v8 .

also yes check/replace the pcv valve at the back of the inlet manifold .

but be carefull not to round out the torx bolts that hold it on . otherwise you will have to left the manifold up and grind the bolt heads off .

pcv valves cost about $120-150new

v8 doesn't have cold start valve or injector . all done by the ecu and temp sensor.

[QuickSilver 0]

On my old radiator I had a small leak at one stage, and this was coming from those too. What was happening is, the fitment that attaches into the radiator was loose, the pipes then screw into THAT fitment, as far as I'm aware the fluid runs through a metal pipe inside the rad cooling the fluid down. I dont know if that makes sense, but I tightend the bit that screws into the radiator (not the actual fitment of the pipe itself) and that fixed the problem.

Edited March 3, 2009 by QuickSilver

[QuickSilver 0]

Just to add to this, because my previous post just does not make sense even to me.

Now, I meant the fitment inside the blue bubble, tighten that with a big or adjustable wrench and the problem should disappear.

The fitment inside the pink is what contains the trans fluid and water wont be leaking from it.

Edited March 3, 2009 by QuickSilver

[0llie 0]

Hey guys, thanks for the replies I pulled it apart today and managed to fix it.

I unbolted the fat bolt on the pipe and it popped off, didn't get a chance to read your posts before i did it and when it popped off some trans fluid came out... i was like what the... lol

Anyway, there's a canister thing that sits in the end tank of the radiator, with both of those nuts on the each of the hoses undone the canister inside and sorta floats around in there, the coolant is kept separate from the trans fluid. That flat nut closest to the radiator pulls the canister to the inside wall of the end tank and helps it to seal the radiator fluid when it's tightened. That fat nut seals the transfluid.

Even tho there was coolant there the fat nut kept the trans fluid sealed separately so the trans fluid wasn't mixing with the coolant... The leak was coming from behind those flat nut washers, a bit hard to explain but yeah QuickSilver you were right with your description

What I did to fix it was put some washers between the radiator and the flat nut, it seems to hold under pressure, just tightening it didn't seem to do the job unfortunately!

Thanx for the input on the hunting idle, i'll let you know how I go!!