2007 BMW 4.8is Runs great but has coolant leak….$1500 ?

[LennyBoy1]

So I saw this X5 advertised nearby on Facebook: 2007 BMW 4.8is Runs great but has a coolant leak $7500. I messaged owner & stopped by to look at it and I test drove it (very short trip). It had 180,000km (112,000 miles), the body and interior seemed to be in very good shape & it started and ran good. I ended up buying it for $1500. Ok so the coolant leak….

From my mechanical inspection & research on this forum and other sites, it probably has the coolant pipe and valley pan leak. There is not a lot of evidence of coolant leaking from the weep hole on water pump but there was a lot of coolant dripping off rear of engine and down bell housing. As well after I removed the intake there was lots of coolant collected around valley pan. I decided to replace the valley pan and the coolant pipe and the small Y pipe under the intake (about 3/8”) that connects the cylinder heads to the upper radiator hose.

I bought the URO Valley Pan for about $100, and the N62 Collapsible Coolant pipe kit with o-ring kit for about $100 from Amazon and a Febi Y pipe, as well as the heater pipe o-ring and BMW intake gaskets. I’ll try to add pictures…

First question: Should I have bought a better quality coolant pipe kit like AGA, URO, ECS, MTC or some other brand? I have not installed the pipe yet but I’m hoping to start this weekend. I have read some owners have used a lower cost pipe but also ordered the URO O-Ring kit.

Second question: Is there any advise you could provide on this coolant repair if you completed it ?

Third question: Is there any other common coolant leaks that I should also investigate and replace?

Thanks in advance for your input and help.

[aureliusmax]

Haven't done it. But AGA is legit, (I have their tool kit) and looks well made. Personally I wouldn't trust URO with anything but really simple, easy to access parts replacements. They are more of a scam brand that makes parts with hollowed up material quality.

Your other coolant leaks are just going to be wear and tear, aged plastics caused by the original hot thermostat, which reminds you to get a cold thermostat ! I've made my own by replacing the wax inside with a lower temp melting point from one of those temperature wax sticks.

You will replace your parts, and then pressure the coolant system to 25psi and run the engine cold. keep it for 10 minutes or back off the bleeder valve when it increases past 25. and shut the engine. look for small leaks on radiator sides, or coolant hose orings.
the lower rad temp sensor oring also tends to leak. you can buy complete coolant oring sets off ebay which are a good start so you can replace only the bad pieces without having to buy entire expensive hoses.

[LennyBoy1]

Thanks for the advice, it’s greatly appreciated. So I was planning to cut the original aluminum BMW coolant transfer pipe under the Valley Pan today….but then I noticed the pipe connection on the upper side of the Valley Pan to water pump (short rubber coated pipe - about 1.5” diameter by 3” long) looks like it was leaking quite badly….(connects valley pan to the water pump). Also the small 3/8” Y pipe under the intake shows minor signs of leaking, it connects cylinders to the upper radiator hose.

My question: if I just replace the valley pan, the short rubber coated pipe from water pump to valley pan and the Y pipe….could that be my coolant leaks. My reasoning is there is not much evidence of coolant leaking from the weep hole on the front cover. If I don’t cut out and replace the coolant pipe since I bought the aftermarket telescopic coolant pipe from Amazon with new o-rings…probably not worth installing (cheap product…might leak anyway) ??.

[aureliusmax]

Originally Posted by LennyBoy1

My question: if I just replace the valley pan, the short rubber coated pipe from water pump to valley pan and the Y pipe….could that be my coolant leaks. My reasoning is there is not much evidence of coolant leaking from the weep hole on the front cover. If I don’t cut out and replace the coolant pipe since I bought the aftermarket telescopic coolant pipe from Amazon with new o-rings…probably not worth installing (cheap product…might leak anyway) ??.

no. this is not how this process works. you have to repair what is obviously defective, pressurize the cooling system and check it again.
the only other work you could do at same time is buy an oring kit and replace all the orings like i said in my past post. or you can replace all cooling system parts at once if you have unlimited money !

[LennyBoy1]

Hi, thanks for the advise and I agree…I should test it so I ordered a 28 piece coolant pressure testing kit from Amazon (it has 4 BMW adapters so hopefully one fits). It won’t arrive till next Saturday so I guess I’ll install the valley pan, the short rubber coated pipe from water pump to valley pan and the Y pipe then the system should be sealed up again and ready for pressure testing.

[Nanniepoo]

I just did this, this past July. Found coolant dripping from belly pan. Saw one drip from weep hole. Having owned the vehicle for a while and knowing it's history, that was enough for me to immediately pull the trigger on valley pan and transfer pipe.

Maybe you're in a different stage of life, but as a father of two (1.5 yrs and 3 yrs) my time is far more precious to me than anything else. Considering the amount of labor involved, I would not cheap out on parts. I bought the AGA pipe.

[Nanniepoo]

Depending on the DIY you follow, you could wind up removing the water pump. If you don't know the history, I would replace the water pump while you're at it.

[LennyBoy1]

Thanks for the advice. You are right regarding the AGA pipe. I bought the Amazon version of Telescopic Coolant Transfer pipe which was about $100 which I can still return to Amazon. The AGA pipe in Canada is about $800-$900 plus shipping & tax a (so about $950 to $1000 Cdn) which seems excessive but obviously it is the best option. I actually ordered a new N62 water pump just in case I needed to change that part....plus I was thinking it would be possible to see the front o-ring seal on the coolant pipe from the water pump side....would that be correct ?