Same coolant leak after replacing water pump and thermostat

[fedisrico]

Also, do I actually have to replace the washer that comes with the engine block plug? If so can I just buy any 14x20mm washer from the hardware store because I'm not gonna pay 7.99 shipping and wait for two weeks to get a 49 cent washer from fcpeuro.

[Chedley]

Well, my advice is do not touch those engine bloc plugs. If they do not leak, leave them alone.
It is a royal PITA to reach them under the heat shield. And it is really not necessary to properly flush the cooling system.
To flush it, you can simply pour (distilled) water in the radiator, disconnect the hose at the bottom of the radiator, then run the engine until hot. Rinse and repeat.
Then, reinstall the hose, refill with 50/50 coolant/water mix, and bleed the system.

[MotorMouth93]

Also, do I actually have to replace the washer that comes with the engine block plug? If so can I just buy any 14x20mm washer from the hardware store because I'm not gonna pay 7.99 shipping and wait for two weeks to get a 49 cent washer from fcpeuro.

The block plugs have crush washers and they should be replaced. Call up the nearest BMW dealer and I bet they'd have them for $0.50, but if not then take the washer to the auto parts store and see if they have one that will work, they should have a variety of sizes available. Those washers are used on pretty much every BMW model made in the last 30 years though so I'd be surprised if the dealer doesn't stock them.

Well, my advice is do not touch those engine bloc plugs. If they do not leak, leave them alone.
It is a royal PITA to reach them under the heat shield. And it is really not necessary to properly flush the cooling system.
To flush it, you can simply pour (distilled) water in the radiator, disconnect the hose at the bottom of the radiator, then run the engine until hot. Rinse and repeat.
Then, reinstall the hose, refill with 50/50 coolant/water mix, and bleed the system.

There is nothing wrong with removing the block drain plugs, in fact I would argue that it's much better than running the engine up to operating temp with a non-functional cooling system.

[fedisrico]

I'll try to see if I can move the heat shield, but if I can't I might not be able to remove the drain plug from what I've seen. Should I try Chedley's method or are there other ways to drain as much coolant out as possible? I already have the bottom radiator hose disconnected from both radiator and atf, and the waterpump hose disconnected, but I'd like to get as much out as possible later today. It's going to be in the 40's and then it's below freezing for a whole other week so I'm trying to finish today and see how it runs with everything back together and not leaking

[Chedley]

Well then, because of the cold weather, I'd say try to get out as much old coolant as possible, then refill and bleed the cooling system. Do not touch those plugs. That would be good enough for driving it and testing for leaks.
I'd wait for better weather in spring or summer to do a thorough flush, with replacing those plugs if you are so inclined..!!

[fedisrico]

Well I keep trying to secure the hose on to the water pump but it’s always loose, even with the c clip on. It won’t come off completely but it’s not right at all and wiggles around. Is there an O ring in here that I broke when taking it off? If so I’ll just order a new hose but I want to make sure it is the hose that’s the problem

[Chedley]

Which hose are you talking about #1 or #2 on this diagram ? http://www.realoem.com/bmw/enUS/showparts?id=DN63-USA---E39-BMW-540i&diagId=11_2267
If so, these are quick-connect hoses: you have to close lock the connecting clip BEFORE inserting them.

[fedisrico]

Where #9 connects to the water pump, the clip locks in but I can still move the hose around and that’s where it was dripping from

[mattmar1]

yes there is an o ring in there

[MotorMouth93]

The hoses can wiggle a bit when attached, that's fine. If the hose is leaking it needs to be replaced, if you can find the O-ring that might be enough but most people just replace the entire hose.

[fedisrico]

The hoses can wiggle a bit when attached, that's fine. If the hose is leaking it needs to be replaced, if you can find the O-ring that might be enough but most people just replace the entire hose.

Could it be the Salerni waterpump I got? Maybe the nipple is too small, either way I'll order the hose and have my car in the garage for ANOTHER week, at least now I can order the coolant drain plugs while I'm at it.

[BimmrMeUpSnotty]

Man! It’s like feeding time at the zoo.... Fedisrico, have you ever thought about getting dirty and inspecting your car, your parts, seeing WTF is good, WTF is bad??? Every cooling hose has an o-ring in the groove of the couplers. You could actually pick at it with a pick, try not to rip it, Clean the channel out, lean the o-ring with either warm soapy water, or silicone. LOOK AT WHAT YOU HAVE, rather than just getting on here trying to get everyone to figure it all out for you. I swore I wasn’t gonna do this, but Jeezuz, you’re like a little child that can’t figure out how to dribble a basketball . Here’s some desert, before popping the hoses on, make sure the o-rings are in the groove. Get a tub of Vaseline apply some of it onto the o-ring. It will be like well lubricated sex popping that bastard on. It’s not rocket science man, maybe you should know your limitations.... <<<< Dirty Harry. Wow man, it’s like a soap opera, get wrenching and fix it.

[fedisrico]

Man! It’s like feeding time at the zoo.... Fedisrico, have you ever thought about getting dirty and inspecting your car, your parts, seeing WTF is good, WTF is bad??? Every cooling hose has an o-ring in the groove of the couplers. You could actually pick at it with a pick, try not to rip it, Clean the channel out, lean the o-ring with either warm soapy water, or silicone. LOOK AT WHAT YOU HAVE, rather than just getting on here trying to get everyone to figure it all out for you. I swore I wasn’t gonna do this, but Jeezuz, you’re like a little child that can’t figure out how to dribble a basketball . Here’s some desert, before popping the hoses on, make sure the o-rings are in the groove. Get a tub of Vaseline apply some of it onto the o-ring. It will be like well lubricated sex popping that bastard on. It’s not rocket science man, maybe you should know your limitations.... <<<< Dirty Harry. Wow man, it’s like a soap opera, get wrenching and fix it.

Yes god forbid I ask questions about repairs on a question board bud

[BimmrMeUpSnotty]

Fix it!

[JimLev]

LOL, Snotty's getting wound up again.

60+ posts over 8 days for a leak?? Shouldn't take that long.

[BimmrMeUpSnotty]

Exactly!!!

[jicaino]

I'm with Snotty. I'd slap you in the face if you were a buddy of mine and show up asking that silly ass questions, disregard my advise, come up with funky ass theories and divert your attention to problems that were there before you noticed them, just to end up where we started only to find out you didn't install properly the expansion tank to water pump hose. A QUICK CONNECT HOSE, FOR CRYING OUT LOUD!

[mattmar1]

yeah but the 100 plus post thread on the other forum for "does a new battery for an E39 need to be programmed" still has him.....

[JimLev]

yeah but the 100 plus post thread on the other forum for "does a new battery for an E39 need to be programmed" still has him.....

That "other" forum is full of rookies. They need to have Snotty over there to kick some butt.

[BimmrMeUpSnotty]

Lol, Man, I’m just tired of these feed me Seymour threads...

[mdistel]

My 03 530i with 109k miles has had an extremely slow leak that even with a pressure tester I still couldn't identify (didn't remove belt/fan/shroud) but I suspected the thermostat area due to spray lines on air box and side of expansion tank. This last week however it became a full leak and went from topped off to low coolant after one 30min drive. I monitored the temp using the dash hack and it never rose above 94 C which is normal.

Based on my inspection it appears to be the upper coolant hose leaking. I'm going to borrow the pressure tester again and diagnose before replacing the hose. Possibly its just the o-ring or some dirt but I did carefully clean before installing.

71k Dealer replaced radiator and thermostat
72k I purchased car from first owner
92k expansion tank split at top of Grandfather mountain in NC, patched with gorilla glue & gorilla duct tape, made the 8hr drive home. Never overheated per temp gauge.
92.5k replaced expansion tank, water pump and new coolant
every 4-5k after that coolant light would come on, before the expansion tank I would top off but my records don't list a light coming on. I suspect this leak has been there for some time.

Mark

[BimmrMeUpSnotty]

So..... Like our pal Fedisrico, you were aware of the ongoing leak, but still you continue to drive the car, trying to pinpoint which hose it may be. Obviously, the cooling system has been nickel and dimed, only replacing what has gone bad. Ever think about just ordering everything? All the hoses, the thermostat, the radiator is probably popping a boner at thinking about a blow out, change the water pump, I’d do the expansion bottle too, unless you trust what the po told you. Do it all, and be ahead of the curve. It’s a well known issue, why do it one at a time???

[jicaino]

That's a common leak point if the o-ring is tired. Renew just the O-ring and make sure it's seated properly. Also lube it up before assembling it, a drop of pure glycol, some glycerin, or spit (yes, the world's oldest and most resorted to lube) Those big hoses uses 38x4 metric o-rings.

- - - Updated - - -

So..... Like our pal Fedisrico, you were aware of the ongoing leak, but still you continue to drive the car, trying to pinpoint which hose it may be. Obviously, the cooling system has been nickel and dimed, only replacing what has gone bad. Ever think about just ordering everything? All the hoses, the thermostat, the radiator is probably popping a boner at thinking about a blow out, change the water pump, I’d do the expansion bottle too, unless you trust what the po told you. Do it all, and be ahead of the curve. It’s a well known issue, why do it one at a time???

this times a zillion

[jicaino]

If the section in the O-ring is ovalized it will leak under the extreme pressure a cooling system develops past 99°C

[mdistel]

Just wanted to report back that after replacing the one o-ring at the thermostat and lubing both with Danco waterproof silicone the leak is gone. Glad the Audi part is readily available, I purchased it from ECS Tuning and was back on the road in a week.

Mark