QuestionHi Evan got the car from Germany & believe me its awesome especially since I had it chipped now produces 236 bhp. Anyhow I had one more try at bleeding it I turned heating to max temp, turned the fan to low opened the two drain plugs & let it drain then refilled it very very slowly until no bubbles came out of the bleed screw. Also checked the rad & found it was clogged along with the a/c compressor removed the debris and hosed it down, boy was there a lot of muck. I closed the cap & let it idle until warm then took it for a drive & presto no more overheating. Before it used to reach temperatures between 115 to 124 degrees. Now it does not go above 96 degrees with full a/c & 100 mph without the a/c temp sits around 87 to 89 degrees. Turns out I probably dont need the cap relaced.Excellent well done you were bang on with your advice.
Mo
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Followup To
Question -
Hi all the checks were done by a BMW specialist, I dont lose any coolant at all & there is no oil in coolant & no water in oil. If it is the water pump then would it not overheat without using the a/c as I have no trouble getting both hot & cold air & why does this happen only at cruising speed. Another thing I noticed was that after bleeding it again it was a little better in the sense that I dont have to put heating on to cool it down. It now fluctuates between half & three quarter mark on the guage with the a/c on full, before I had to put heating on to take guage back down to half way mark. Could it be airlock? Someone else also suggested water pump but it does not overheat without a/c also someone suggested possible lack of coolant flow through radiator. Please help.
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Hi I have a BMW 330 diesel 2002 under normal driving conditions its fine but if I put the a/c to max and drive at cruising speed it tend to overheat. I have had the head gasket check, compression test and electrical diagnostic all was cleer. The thermostat and expansion bottle was recently replaced as expansion bottle cracked while driving.The viscous fan and auxillary fans were also replaced. Nobody seems to know what the problem is can you help?
Answer -
Mo, a 330 diesel is not an US market BMW. Where did you get it? Please check the Radiator cap for holding pressure. How did you check the Head gasket?. Is water pump working well? If the expansion bottle burst then there is too much pressure built up in the system. The thermostat is a good move anytime a car overheats. Check for coolant in the oil and oil in the coolant. Looks like a brown baby crap looking stuff in the cooling system. You will also see it under the radiator cap. If you find this stuff it is either a head gasket failure a cracked head or block. I don't know anything about a 330 diesel I am speaking on general BMW cooling systems.
-Evan
Answer -
Mo I am glad that you checked for air in the system and are taking your car to a specialist. You are, in my eyes still driving a purple unicorn in the U.S. market. No one has a great knowledge or experience with in the U.S. even if he is a so called "specialist." If the temp is fluctuating while maintaining a constant speed then air lock is a strong possiblity. Please make sure that the condenser and Radiator fins are not clogged with debris. This would give more of a consistant temp, but if crusing speed is your problem then ram air-flow volume through the radiator may be the key. There is a vacuum filling coolant bleeder system that our shop used to have and it worked well for 740I. You might try to find someone with one of these tools. It sucks the coolant system into a vacuum (no air) and then slowly releases suction and fills with a coolant bottle. When did this problem first start? Where did you get this car? Did you replace the radiator cap yet? Try some 'Water Wetter' product from local parts store, although technically you shouldn't need it. Hope I gave you some ideas.
-Evan
AnswerMo, thanks for the feedback and I'm glad to hear that you got the Temp issue under control. Please email me some specs. of your car and what you have done with it. I would like to see a picture of that M57 engine if you have a digital camera.
-Evan
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