528i M52 cooling system bleeding, overhaul, overheating

[VacMan]

Here's a terrific pictorial walkthrough on another board to supplement what e39dream has gone out of his way to provide on this thread already. Thanks again e39dream!

Tim

[naplese39]

Ok, so now I am starting to overhaul my cooling system. I am taking it in stages since it is so expensive.

First I will replace the hoses and thermostat including an aluminum thermo housing and the radiator plus expansion tank.

Second I will replace the water pump, fan and fan clutch a month or so later.

My questions:

Pelican sold me SEVEN hoses to do a complete replacement. I was shocked to see that my upper radiator hose had a '96 stamp on it so it was obviously never changed. I suspect likewise for the others. How do I find where every one of these hoses goes??? Can all be accessed with relative ease?

How do I completely drain my cooling system?

I have links for the radiator, thermostat as well as system bleeding from above thread but I don't want to jump in until I have all the info in hand.

Thanks.

[e39dream]

theres diagrams of the hoses on realoem, not the best diagrams but might help. otherwise just match the hoses one by one to the ones already on the car- shouldnt be too big of a deal.

To drain your coolant open the drain on the drivers side bottom of radiator- theres a valve.

[UnderPAR]

Ok so im new to this board (daily Bimmerfest member) But lately I have had trouble with my car overheating. Ive learned alot about my engine so much that I watch the Temp needle religiously. But It all started when me and my father were leaving the BMW dealership here in Houston and we pulled out of the driveway there and got about a mile down the road and I looked over from the passenger seat and the needle was at 3/4 . I was really worried, so we stopped and let it cool off. Then we make our way to Walmart and and we get on the freeway and cruise at about 60mph for 13-15 miles. We get to the parking lot and as we are looking for a parking spot it starts to climb to 3/4 again so we pull off to the side and put it in park and rev for 25-30 sec. it went down to the middle again. We were in Walmart for a good 15min or so, and we start to make our way home. The needle was steddy for the whole trip home so I thought ok just some random thing. I went on with my business of going to work a 8min drive there and back after about 5 hours there in the parking lot cooling off. I did this for about 1 week and then it started doing it again in the 8min drive(I didnt know this was possible) But it only does when Im either pulling down my street or in my driveway. Mind you it hasnt got to red yet just 3/4. So thats three times now. Now this Saturday we go to get gas and thats probably a 10 min trip one way. It did it AGAIN as we get into the driveway. But this time as we are sitting in the driveway idleing it actually hit RED(the red part of the little gauge lit up red). I quickly shut her down. I was frightened!! I didnt drive it for 3-4 days while Im talking my parents about how we are going to ge it to the local indy. One night my dad comes into my room and says "come here and hold this flashlight" We proceed to go outside and open the hood and look in the radiator cap, to my surprise the tank was EMPTY . We were kinda eyecrazy thinking that the car should have told us that it was low on coolant. I mean it was bare dry!! The next day my dad brings home some coolant the Prestone pre mixed, and we put it in to the Cold Kault line. Now Today has been its second day of me driving it to work(8 min there and 8 min back after sitting for awhile in between). No problems yet, she warms up good to the middle and stays there. My question is do you think im ok now?? Do I need to bleed it?? Im 16 years old and I want to learn as much as I can about these cars and I think im in love! (with the car that is)
Help me please?!

[e39dream]

hey underPAR- welcome to bimmerforums. You'll notice theres alot of 528i people here

if the expansion tank was bone dry you can bet your keyster theres air in the system. grab another gallon or two of the same coolant and top off/bleed the system.

"when in doubt, bleed it out." lol

[UnderPAR]

hey underPAR- welcome to bimmerforums. You'll notice theres alot of 528i people here

if the expansion tank was bone dry you can bet your keyster theres air in the system. grab another gallon or two of the same coolant and top off/bleed the system.

"when in doubt, bleed it out." lol

Alright man thanks.
Is there a proper way to bleed it? Sorry if this was already posted.

[e39dream]

theres a link to the bleed procedure on page 1 of this thread.

[UnderPAR]

theres a link to the bleed procedure on page 1 of this thread.

thanks again, and im sorry.

[e39dream]

hey no problem- if it wasnt there I'd have typed it out for you- I'm just lazy

[naplese39]

As I posted above, I purchased an aluminum thermostat housing. I have seen some posts that seem to imply the OEM resin is better. Can I have some feedback regarding experiences with the alu vs. resin products before I put mine on the car?

Thanks!

[TomiJ]

Hey e39dream, that last post reminded me of how my issue turned out. Low coolant. I did bleed the system 2 or 3 times per instruction and topped off. Haven't had a problem since. Best 8 bucks I ever spent!

[Alpha5]

It's about time for me to do this. What kind/brand of coolant do you recommend using?

[e39dream]

I'm just using some prestone premixed stuff I got from my local auto parts store. I had originally thought I'd go get some BMW coolant and switch to that but I've been busy and the prestone is keeping her cool.

[lotus1]

Okay, I just got a 540i for the wife. 82K on the clock. The first thing I'd like to do is have the cooling system checked and address anything as needed.

I called a local indy shop in town and wanted to get an estimate for servvice. They only work on Europeon cars...and they specialize in BMW's.

This is the prices they gave me:

Radiator - Labor $169.20; Parts $215
Exp Tank - Labor $131.60; Parts $71.75
Water Pump - Labor $357.20; Parts $140
Thermostat - Labor $169.20; Parts $64.50
misc (coolant, extra parts..etc..) $40+

Sub Total: Labor - $827.20; Parts $491.25; Misc - $40 +
TOTAL (approx.) - $1360 + tax


I got the coolant system package price from Bill at Bimmer Clinic on here.
As a comparison this is what it would cost for parts from Bill at Bimmer Clinic: $435

Labor: Free (me )


So I'm looking at right around $1400-1500 parts and labor through these folks... YIKES.

There is something to be said about rolling your sleeves up and doing it yourself.

[e39dream]

I have been kicking around the idea of opening a bimmer only auto shop. hiring a certified bmw tech for major repairs and doing oil changes/ brake and cooling system jobs myself. Theres a shortage of good indy mechanics around here- I could make a fortune. I'd need someone with a big wallet to help me get started though.

[lotus1]

On a side note....do you have after market calipers on your ride or are they just painted? They look red.

[e39dream]

4 stock calipers painted red.

[Wiseguy ON]

I'm just using some prestone premixed stuff I got from my local auto parts store. I had originally thought I'd go get some BMW coolant and switch to that but I've been busy and the prestone is keeping her cool.

Switch it out with either Pentosin or BMW Blue stuff. Or I can give you pointers on changing your head gasket!

SRSLY.. do it.

[e39dream]

lol- it's on the to do list.

[Wiseguy ON]

Put it near the top... trust me.

[b528imcmanus]

I cracked my radiator, or it cracked... whatever, it's cracked. On the drivers side right beneath the fitting where that hose goes. So I'm ordering a new radiator, got a decent price and all seems good.

Here's the question. Would it make sense that the radiator cracked, therefore causing the engine to overheat, or do you think the engine overheated and caused the crack?

Ben
02/2000 528iA

[turbospool]

i know i probably did this the worng way but...

when i was filling up my resevior with coolant i left the cap open and just started the car and watched all the bubbles just come out then i put the cap on. I know the system pressurizes during driving but i figured since the car was cold the thermostat wouldnt open and everything would workout.

[Wiseguy ON]

I cracked my radiator, or it cracked... whatever, it's cracked. On the drivers side right beneath the fitting where that hose goes. So I'm ordering a new radiator, got a decent price and all seems good.

Here's the question. Would it make sense that the radiator cracked, therefore causing the engine to overheat, or do you think the engine overheated and caused the crack?

Ben
02/2000 528iA

Ben,

It overheated because it blew out all of its' coolant. If I were you I would also buy an expansion tank, thermostat, thermostat housing (Aluminum) and a water pump while you're at it.

Use OE Coolant.. BMW or Pentosin.

[e39dream]

what is pentosin?

[b528imcmanus]

I'm about to change the radiator out on my car and I need to get some fluid. I'm going to the dealership to get it, I just need to figure out how much to get. And at what mix