1987 BMW 325 car starts to over heat

Tiny
MIKE JAG
  • MEMBER
  • 1987 BMW 325
  • 6 CYL
  • 2WD
  • MANUAL
  • 25,000 MILES
Car heating gauge goes close to hot when I turn on the AC. It does not do it when the AC is off. The radiator fan in front of the rad. Is on and so is the one in back of it. What could be the problem. I had it flushed out with new antifreeze to see if that would help. It did a little, but still gets hot. Thanks, Mike
Sunday, June 14th, 2009 AT 10:51 PM

2 Replies

Tiny
MIKE JAG
  • MEMBER
  • 2 POSTS
Was this
answer
helpful?
Yes
No
Sunday, June 14th, 2009 AT 10:52 PM
Tiny
DR LOOT
  • MECHANIC
  • 2,311 POSTS
Assuming the car runs for extended periods without overheating as long the air conditioning is off, it is unlikely that you have a coolant circulation problem. That leaves poor heat to air transfer as the problem. The most likely cause of that would be a weak fan clutch. Use a popsicle stick to put drag on the mechanical fan from the back side (Yes, I mean letting the moving blades hit it). If you can easily stop it, then the fan clutch is kaputt and you need to replace it. If you can't stop it easily, then look for clogging in the radiator fins. I once spent a half an hour with a pressure washer blowing cottontree fuzz out of a woman's radiator. It fixed her problem. Other than that, it could be internal clogging from corrosion inside the radiator.

BTW, if you have to remove the fan clutch, you need to use an inch and a quarter open end wrench turning it in a reverse direction. Don't make the mistake of trying to unloosen the 10mm cap screws on the water pump pulley.

Good Luck,
Dr. Loot's Assistant
Was this
answer
helpful?
Yes
No
Saturday, August 1st, 2009 AT 9:33 AM

Please login or register to post a reply.

Sponsored links