Help: Cost of Overhauling E46 Cooling System

[drophead]

Well known topic among high-mileage e46 owners!

105,000 mile 325ti with a bowed radiator and a weeping expansion tank. Think it's time to get the cooling system overhauled!

My question is what are the main parts that need replacement after 100,000 miles?

Also, how much is this gonna cost me?!

Apart from the cooling system, the tired sport suspension, bushes and window seals, it runs like a dream.

[8Tech]

Radiator, pump and belts should sort the cooling system.

Powerflex bushes on the front lower arms and front of the rear trailing arms should sort the bushes.

Loads of options for the suspension but I would not go cheap coilover kit. Either get a very good coilover kit or just new shocks and maybe Eibach springs, suspension sorted.

[drophead]

8Tech said:

Radiator, pump and belts should sort the cooling system.

Powerflex bushes on the front lower arms and front of the rear trailing arms should sort the bushes.

Loads of options for the suspension but I would not go cheap coilover kit. Either get a very good coilover kit or just new shocks and maybe Eibach springs, suspension sorted.

Ta for the information, 8Tech.

[andyiley]

Just to add my experience to the above DO NOT FIT CHEAP COILOVERS!

Spax sets are about £650 & well worth it with adjustable damping also.

[helix402]

+Thermostat.

[andyiley]

Also make sure you get a metal pump, not plastic.

[essayer]

May as well do the top hose while you're there...

[helix402]

essayer said:

May as well do the top hose while you're there...

Indeed, they often get a hairline crack on removal.

[SuperHangOn]

Just did this job on my E39, must be very similar price wise.

Stat £75 (mine was built into the housing with a sensor so not possible to change independently)
Rad £140
A/c & aux belts about £40
Water pump £75
Viscous fan £65
Expansion tank £30
Top & bottom hoses £30
Anti-freeze, the BMW stuff was a mental price so I used ECP pre-mixed stuff, about £25.

I paid my mechanic £150 to fit so just over £600 all in. I bought from the sellers motormec and c3bmw on ebay who were very good, main parts were BEHR and smaller bits Meyle.

Edited by SuperHangOn on Wednesday 17th December 16:01

[De Sisti]

Are the cooling system problems on E46s generally the ones with 6-cylinder engines?

[d_a_n1979]

De Sisti said:

Are the cooling system problems on E46s generally the ones with 6-cylinder engines?

Yes; the M54 is known to have a cholcolate based cooloing system - it's simply to remedy though

Fit a new water pump (Meyle), stat (Walher) and new hoses and that's it sorted really. Not expensive to do and may as well do the belts and a coolant flush & refill at the same time (Comma G48)

Did this with all my E39 530i with the M54; zero issues after that.

You can replace the rad too (Behr or Nissens) and replace the viscous fan clutch too 9stick with Behr or Sachs)

[Oliber]

There is a cooling system refresh pack from c3bmw for the M52/54s - £320; when I looked at Autodoc and others at the time, the pricing was pretty similar.

The pack includes:

• Radiator - Behr Hella
• Water pump - Meyle
• Thermostat - Wahler
• Expansion grenade - Behr Hella
• Expansion tank cap - Behr Hella
• Top + bottom rad hoses - Febi Bilstein
• Temp sensor - Febi Bilstein
• 5L of Quantum coolant (concentrate, bring your own deionised water)

I had the above fitted a year ago and had no issues so far on my M52B25TU.

Edit: to add concentrate on coolant and timing of last price check.

Edited by Oliber on Wednesday 1st May 11:45

[d_a_n1979]

Oliber said:

There is a cooling system refresh pack from c3bmw for the M52/54s - £320; when I looked at Autodoc and others, the pricing was pretty similar.

The pack includes:

• Radiator - Behr Hella
• Water pump - Meyle
• Thermostat - Wahler
• Expansion grenade - Behr Hella
• Expansion tank cap - Behr Hella
• Top + bottom rad hoses - Febi Bilstein
• Temp sensor - Febi Bilstein
• 5L of Quantum coolant

I had the above fitted a year ago and had no issues so far on my M52B25TU.

That's a great deal and C3BMW are a great reseller!

[The Conflated Outlier]

Also consider replacing the plastic coolant transfer pipe under the intake manifold. It goes from the front of the engine to the back for a heater hose. It's a real bd of a job that really requires manifold removal. Five hours of swearing should see it done. They are at the age now where they are just breaking.

[Oliber]

Good shout, and if you are taking the manifold off, consider refreshing the CCV system as a "while you're there".

There is no rest for the wicked.

[d_a_n1979]

Oliber said:

Good shout, and if you are taking the manifold off, consider refreshing the CCV system as a "while you're there".

There is no rest for the wicked.

This - CCV with mani off is much easier; ensure you've got the Elring manifold gaskets to replace the old ones.

I'd also look to replace the vac lines and the bung on the back of the manifold to stave off any vac leaks

[De Sisti]

d_a_n1979 said:

Yes; the M54 is known to have a cholcolate based cooloing system - it's simply to remedy though

Fit a new water pump (Meyle), stat (Walher) and new hoses and that's it sorted really. Not expensive to do and may as well do the belts and a coolant flush & refill at the same time (Comma G48)

Did this with all my E39 530i with the M54; zero issues after that.

You can replace the rad too (Behr or Nissens) and replace the viscous fan clutch too 9stick with Behr or Sachs)

That confirms what my local independant garage and Cotswold BMW have said.

After reading many contributors to the E46 Fanatics forum, I was beginning to thing all E46s had
that issue. However, as confirmed by my local independant, my 320d Touring is still going strong,
as long as I continue to keep up with regular servicing and keep an eye out for things that
eventually go wrong.

I am very happy with the Touring (52 plate on 131k with a full service history). Family owned from
new, so it's had lots of tlc.

[d_a_n1979]

De Sisti said:

d_a_n1979 said:

Yes; the M54 is known to have a cholcolate based cooloing system - it's simply to remedy though

Fit a new water pump (Meyle), stat (Walher) and new hoses and that's it sorted really. Not expensive to do and may as well do the belts and a coolant flush & refill at the same time (Comma G48)

Did this with all my E39 530i with the M54; zero issues after that.

You can replace the rad too (Behr or Nissens) and replace the viscous fan clutch too 9stick with Behr or Sachs)

That confirms what my local independant garage and Cotswold BMW have said.

After reading many contributors to the E46 Fanatics forum, I was beginning to thing all E46s had
that issue. However, as confirmed by my local independant, my 320d Touring is still going strong,
as long as I continue to keep up with regular servicing and keep an eye out for things that
eventually go wrong.

I am very happy with the Touring (52 plate on 131k with a full service history). Family owned from
new, so it's had lots of tlc.

The diesels aren't as prone IIRC but it's still work keeping the cooling system in check

The petrol straight 6s were more prone to issues through age/wear & tear etc

[The Conflated Outlier]

Diesels run cooler than petrols so the cooling system is not under as much strain. I don't recall ever having to replace a blown header tank on a 320d, a burst hose or the rad that's expanding downwards. Petrol E46's - loads.