2001 E39 530i - Coolant leak under intake manifold

[Arma 134]

Hi team, long time no post.

Wanted to ask if anyone has done this particular 'job' on an e39 before? There is a major coolant leak under my intake manifold (M54B30) and I'm pretty sure it's one of the coolant / heater inlet pipes. 15 minutes of driving makes a noticeable difference in coolant levels in the expansion tank to know that its a big leak. From what I've researched, the only way to replace these is to have to disconnect and move the intake manifold altogether. Just deciding whether to tackle this job myself or expect to dish up $$$ for 20 hours of labour at a shop. If anyone has done this before - any indication of how big a job it is?

Cheers

[Young Thrash Driver 1020]

Hey Arma

I have done it a couple of times, the job does take a while but is easily doable over a weekend for a novice. There is nothing hard about it if you are already familiar with bleeding the cooling system and fixing the oil filter reservoir housing leak. You will wreck the CCV system while you are in there- it will all be old and brittle by now unless recently done- so factor that replacement while you are in there. You will need to do both heater pipes too.

[Gabe79 410]

8 hours ago, Young Thrash Driver said:

Hey Arma

I have done it a couple of times, the job does take a while but is easily doable over a weekend for a novice. There is nothing hard about it if you are already familiar with bleeding the cooling system and fixing the oil filter reservoir housing leak. You will wreck the CCV system while you are in there- it will all be old and brittle by now unless recently done- so factor that replacement while you are in there. You will need to do both heater pipes too.

Agreed.  Time consuming, but not hard. I was an even greater novice when I did it too... Lots of videos online on how to do it, 50s kid has a good video on this, as does Nathan's DIY Garage, and Shop Life also has a good one. Spend a few hours watching videos, take lots of pictures as you go, get a few boxes to group parts together in and you should be good.

 

EDIT: In addition to the hoses and the CCV, if you're taking out the intake manifold and it's been awhile... consider getting new gaskets for the manifold, and get the full CCV kit that includes the throttle body gasket too. If your oil filter housing leaks, this is a good time to replace that gasket too...

Edited December 28, 2018 by Gabe79

[Young Thrash Driver 1020]

Yeah there's a few "While I'm there" jobs. I took the opportunity to do full CCV system replace, both intake elbows, valve cover gasket, both heater pipes, all the o-rings on the oil filter housing screw-on cover, dipstick o-rings, and of course intake manifold gasket which was rock hard both times. Both receipts ran me about 300USD from FCPEuro, but not all the parts were Genuine BMW.

No "special" tools required from memory, but you will need a torx socket set and I found a set of gasket picks useful for getting the broken ends of the heater pipes out of the head, and I found a mix of 1/4'' drive (access is tight on some of those nuts) with a wobble joint and bigger stuff was needed to remove the nuts on the intake mani. Be prepared to be horrified at the state of the plastic pipes...

[NZ00Z3 187]

Add fuel injector top and bottom O Rings to the list of spares to have on hand.

[Gabe79 410]

2 hours ago, NZ00Z3 said:

Add fuel injector top and bottom O Rings to the list of spares to have on hand.

Note that if you get the CCV kit from FCP EUro, these come with too.

[hotwire 352]

Yep agree to all above. I did everything including thermostat housing in one hit on mine. Fit & forget. Radiator is the only part not replaced as yet.

[Young Thrash Driver 1020]

I seem to remember OP has done a cooling system refresh... @Arma? I never removed the injectors the 2nd time I did this job, there was no need so I left them alone. The other thing worth noting is the bolt that holds the remote +ve terminal is easy to snap and not available to replace if you do break it, WD40 it to death and be gentle when undoing the nut.

[Arma 134]

Thanks all.

6 hours ago, Young Thrash Driver said:

I seem to remember OP has done a cooling system refresh... @Arma? I never removed the injectors the 2nd time I did this job, there was no need so I left them alone. The other thing worth noting is the bolt that holds the remote +ve terminal is easy to snap and not available to replace if you do break it, WD40 it to death and be gentle when undoing the nut.

Yep - well mostly. I've done the radiator, thermostat and waterpump (multiple times!) and all the coolant hoses that are in the vicinity of the radiator. I've not changed these inlet hoses that are under the intake manifold, so I'd imagine they would have just deteriorated due to age - car is at ~150k kms now. Hopefully it hasn't messed up the engine - i noticed it pretty quick since the coolant level warning came on, so i pulled over in the next couple kms. Sounds like I may as well get a number of parts to replace as part of the overall job, to prevent doing the whole thing all over again. I'll make a list. Will just have to find the time to do it - if not then I'll just have to take it to a shop :). Just avoiding running the car at all for now (motorcycle gets me around).