Small Coolant leak from side of Engine Block

-2004 325i E46 87K miles

Previous Issue:
-At 56K miles had major coolant leak, engine overheated, took into indy shop and they determined that the source of the coolant leak was the cylinder head gasket at left front corner just below the plastic heater supply pipe connection to the cylinder head. They also said due to the overheating, the head was warped, needed to be machined, and time certs installed.

-Pressure test and machined head

-Drilled cylinder head bold holes and installed time-certs

-----------------------------------------------------------
Current Issue:
-Car had a slow coolant leak, now drips coolant much quicker than before. Always drips faster after use.

-Coolant light comes on when coolant level is low.

-Temperature needle doesn’t get up into the red.

-No leaks from any other cooling components, all replaced at 56K miles (upper and lower radiator hoses, water pump, expansion tank + cap, thermostat w/ housings)
-Car drips coolant from left corner of engine, indicated in the red:
http://i70.photobucket.com/albums/i1...lloch/Leak.jpg

http://i70.photobucket.com/albums/i1...loch/leak2.jpg

-I’m wondering if the bolts are not holding torque properly?
- In the RealOEM diagram, number 8 is a steel gasket, is there ALSO a rubber gasket that goes on top? It seems as though there is rubber missing from the area on the engine with the red dot in the photo.

Any thoughts on how I should proceed?

Thanks,

Sean

Take it back to whoever did the work and force them to do it right.

Originally Posted by E46Mango

Take it back to whoever did the work and force them to do it right.

+1

That seems to be nasty issue and afaik there is only metal gasket there.

did you check the gasket on the drain plug?

OP,

I'm a little confused, but you've included a link to the oil pan gasket, but you're talking about suspecting a cylinder head leak...as in

http://www.realoem.com/bmw/showparts...69&hg=11&fg=15

Anyway, anything is possible. It's a long time after the head replacement so presuming you haven't had another overheating incident, that still is a possibility, but I'd certainly eliminate everything else...and it looks like you're trying to.

First, just coz all new parts, doesn't mean they don't leak, and if you didn't replace, say that hard plastic line(s) coming from engine, that might be something to consider. There are many parts of the cooling system that aren't easy to see and which might drip down and show where you're seeing them.

A mechanic could add a uv dye to it and you could then id source more accurately, you know.

I'm not really sure what I'm seeing in the photo...can you orient me better?

Have you tried inspection mirror and led flashlight to see better...maybe remove airbox to get better view of things?

HTH

Doug

did you check the gasket on the drain plug?

+1

If the leak is off the front left oil pan, as you've indicated, the least expensive place to look is on the engine block where the drain plug is. It's normal procedure to use an aluminum crush washer after opening up the block to drain it. Perhaps when the work was done they didn't?

Originally Posted by Sansho

+1

If the leak is off the front left oil pan, as you've indicated, the least expensive place to look is on the engine block where the drain plug is. It's normal procedure to use an aluminum crush washer after opening up the block to drain it. Perhaps when the work was done they didn't?

OP...that's a perfect theory! Think you win this round, Sansho!

There will be others!

Originally Posted by dmax

OP...that's a perfect theory! Think you win this round, Sansho!

There will be others!

how did he win when he quoted me huh...just use a crush washer same size

Originally Posted by bishop1977

how did he win when he quoted me huh...just use a crush washer same size

Oops...sorry. You definitely win, Bishop. Sansho...you should be ashamed capitalizing on Bishop's knowledge! 2 pts. deduction!

I doubt that most shops bother replacing crush washer, though I'd hope most would know to at least use the old one and not totally forget it.

Thanks guys, I will check tonight and report my findings.

You had a coolant leak 21000 miles ago. I really don't think that the garage that did your head gasket etc is gonna buy you trying to claim it is their fault. Follow what dmax said & add ultra-violet dye to the cooling system & really find out what is exactly leaking. The other suggestions might be spot on, but you're shooting in the dark. Do the uv test & be sure. Chas

Wow +3 ... -2 .... whiplash!

When I got home tonight, I went to the car and all the coolant was purged from sitting the last couple of days. I was able to get underneath the car and check for the crush washer (which was intact) and no wetness around that area. I was able to dry the corner of the engine block then fill the expansion tank with water. (my idea to pinpoint the leak). This is what I saw: http://i70.photobucket.com/albums/i1...och/engine.jpg
Water was barely flowing in the direction of the red arrow, then dripping down at the corner. Its almost like the origin was somewhere behind the flywheel? This sparked another idea: What if the gasket to the water pump was blown and leaking down by the flywheel, then following the engine casing down to the corner, and finally dripping down to the ground. Is there anyway I can tell if the water pump O-ring gasket is blown without pulling it off?

Your thoughts are appreciated...

-Sean

It could be either the water pump or thermostat leaking. If you haven't replaced both of them yet, it may not be a bad idea to do so at your current mileage. They will fail at some point and it's peace of mind to not risk overheating on the road when they do fail. I tried to only replace what was leaking on my e39, but ended up replacing the hoses, water pump, thermostat, coolant tank, and radiator. If I'd just accepted that I'd have to shell out the $ all at once, a month of my life would have had less stress of chasing down coolant leaks.

I agree with andyman. It could be the water pump or the tstat. Also there are coolant hoses in that area. I know you had the wp, tstat, hoses, replaced 21k ago so maybe one of those parts have failed. I think you're gonna find the leak is coming from up higher on the engine than your red highlighted area. Either pressure test the cooling system or add the UV dye to it. That way you will end all guessing games. Chas

I am also experiencing exactly the same problem. There are coolant dripping from the side of engine block. I went to a independent mechanic and have him check it out. He took a mirror and found out that my water pump is leaking. I just changed my water pump like three weeks ago and it failed on me. You might want to invest in a mirror and check it out.

Hugo