Inefficient radiator

[pfmc24]

Hi, new member requiring advice..................
I recently had a head gasket replaced, caused by blocked radiator. I sourced a second hand radiator which was guaranteed for 90 days, but the car still overheats in traffic.
My local garage say the radiator is corroded internally (they got it tested), and does not dissipate enough heat.
I'm also not sure if it was the correct type replacement, the radiator looks thinner than the original.
Is this the cause of the new overheating problem?
Car is a 520 1989 automatic, and has had a new stat, water pump, fan clutch and head gasket (and head skim).
Any advice would be most welcome, as I would like to get a refund on the replacement radiator!

[Pwr2spare]

Your cooling system may not have been properly bled. Here is the proper method taken from www.bmwe34.net. Good Luck!

M20 Bleeding experience by moots:

Just to share a simple method to bleed the cooling system.I really cannot comprehend why we need to bleed,bleed and re-bleed the cooling system after every maintenence.I did this after replacing the thermostat and flushing the coolant:
(Mine's an m20 engine with the reservoir by the side of the rad)
1.Fill up the rad with the plastic bleeder screw(on reservoir) and metal bleeder screw(on t-stat housing),open.
2.When full,put a finger over the reservoir bleed hole and blow,yes,blow into the reservoir filler neck.(we are basically pressurising the system)
3.When water flows out of the t-stat housing bleed hole,tighten the screw.
4.Top up reservoir if required.
5.Now blow again until coolant exits the reservoir bleed hole and tighten when bubble free.
6.Top up coolant to the cold/kalt mark,tighten cap.You're done. No more bleeding required as all air is purged from the system. I have done this 4 times on three cars and it worked like a charm.

[uscharalph]

Hi, new member requiring advice..................
I recently had a head gasket replaced, caused by blocked radiator. I sourced a second hand radiator which was guaranteed for 90 days, but the car still overheats in traffic.
My local garage say the radiator is corroded internally (they got it tested), and does not dissipate enough heat.
I'm also not sure if it was the correct type replacement, the radiator looks thinner than the original.
Is this the cause of the new overheating problem?
Car is a 520 1989 automatic, and has had a new stat, water pump, fan clutch and head gasket (and head skim).
Any advice would be most welcome, as I would like to get a refund on the replacement radiator!

I replaced my radiator with a brand new Nissens on eBay for under $180.00.

[genphreak]

Don't mess around driving the car- if it overheats you could end up needing to do the gasket again... just buy a new radiator and check your thermo fans too. There's a lot to lose if a half job was done - did they replace any hoses- and the coolant, is it BMW blue? Did they change the head bolts?

I replace my hoses every 2 years- all of them.

It all needs to be working perfectly or it'll never be right- new radiators are not hard to find on the German eBay... you just need one to ship to you.

[shogun]

Tell me which engine you have, M20 or M50, if original aircon is installed, and you confirmed already the car has automatic transmission.
Then I can tell you within a few minutes what it will cost in Germany, new and the size. Or you can select here online by yourselves, if you can understand German a bit, but maybe you can manage even without.
http://www.bm24.de/d/kuehler/kuehlersuche1.htm

[pfmc24]

Its an M20 engine