We have a 2000 740il. A few weeks ago we cracked the radiator (long story). Soon after, the car started overheating. On my way to work one morning it overheated and I heard a loud pop. The coolant reservoir had blown apart. Since then we have replaced the reservoir, radiator, radiator shroud, t hose, bleeder screws, upper hose, thermostat, and water pump. Yet it's still overheating. It's not showing any of the usual signs of a blown head gasket. Also, we changed the upper hose tonight and when we lifted the hood, we found the old upper hose was flat instead of round, almost like it had been suctioned flat. Based on my research, we will try to bypass the heater tomorrow and see if that works. Any other ideas in case it doesn't? I'm really quite frustrated at this point. Any help at all would be appreciated
Last edited by Grrrimacloud; 08-11-2018 at 01:22 AM.
sounds like air in the system. What is your experience bleeding the infamous e38? they are difficult and there is a very specific procedure.
1997 740iL; 5/96 build. Purchased 12/04. Off the road build project 2013 - 2021. back on road 3/2021. Became daily driver (only vehicle) 6/12/2021. Still not completed. Stay tuned as the adventure continues.
I knew I was forgetting to mention something, lol. We had the mechanic bleed it before he put the water pump on in hopes maybe that was the culprit. No such luck
Last edited by Grrrimacloud; 08-11-2018 at 04:49 AM.
A collapsed hose is a sign of low coolant. You have air in the system.
1999 740IL, 1999 Corvette C5 roadster, 2000 Jaguar XJ8
+1 on bleeding. I've owned few different BMW models that utilize expansion tank right next to/level with the radiator, and all of them were a hassle to properly bleed the system.
Current: 2007 Z4 M Coupe (blue/black)
Previous: 2001 740iL Sport (black/black), 2000 528i Sport (black/tan), 1995 318is (black/black), 1991 318is (white/black)
+2 on bleeding. I was at the track and blew my upper hose. After I repaired it I used Timm's method and had no problems driving home.
01' 750il Chromeline
95 M3 LS swapped
07 M5 Manual
06' M5, Spartan wheels and a 507hp V10
00' 740il Dinan, CAI, Romulus exhaust, Stage 5 engine and transmission tune, 750 brakes, camber plates, strut tower brace. Sold
00' 323i wagon for daughter
03' 525i wagon for the wife, sold
98' 740i for the daughter, wrecked
92' 525i with over 200k, wrecked
02' R1200 CLC, hit by a bus and broken in half. That one made the news!
It's like herpes there is no cure but if treated properly you can live with it for the rest of your life
Check underneath the oil filler cap when hot, hows that look? Black?
Here's the procedure:
https://www.meeknet.co.uk/E38/E38_Bl...ing_System.htm
Also, if you haven't - replace the expansion tank cap - it has a pressure relief valve fitted in it - nothing should pop or explode if that is working correctly
Timm..2007 E64 650i Individual Sport..1999 E31 840ci Individual Sport..ex owner of 2000 E38 740..1999 E38 740i V8 M62..1998 E38 735i V8..1993 E32 730i V8..1988 E28 518i
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