In Reply to: Re: E34 535i: Coolant leak from rear of head...gas posted by Brock Fraser on March 31, 2000 at 22:04:47:
My 89 535 had a nearly identical set if symptoms: topping off with coolant every 3-4 weeks, leakage from rear of head. Using a mirror, it was pretty certain that it was the ol' head gasket leaking--slowly.
Car was like this for nearly 2 years. My driving was fairly light 15 mi trips twice daily. I was told the gasket could go any time (like yours might have worsened).
Finally, rather than running the constant risk of a complete blow and melt-down, I opted for gasket replacement. The coolant hadn't gotten in the oil, but the leak was steadily getting worse.
It ran some $900 (ouch!). Cost a lot, but it's nice not having to worry about the head melting down. Unfortunately, mech discovered some heavily worn parts (chain tensioner, sprocket)at 120k mileage, that jacked up the price a bit.
Bottom line: seems to be the gasket and don't think there's a cheap fix.. Given the symtoms you mention, you should put the $ of testing the oil towards a new gasket. Good luck.
89 535 w/stuff
: : Hi Brock,
: : Sorry to hear of your problem. Your diagnosis regarding the had gasket may be correct but can you recall any particular incident that may have caused either the initial slow leak or the sudden spew now?
: No, no noticable incidents other than today... The gauge hit the red zone when I was a half mile away from home. I turned the heater on full blast, and idled the rest of the way home. I've owned the car for one year, and the gauge has always pointed straight up at the halfway mark. Like I mentioned though, I'm constantly adding coolant little by little (the "low coolant" warning was coming on about once every 3-4 weeks)
: : Grasping at straws here, in the hope that you can avoid a head pull - is the coolant reservoir by any chance the culprit? The plastic can age and become brittle at either the overflow or output hose bib. Trace them carefully (a pain as it is tight in there) but it may be worth it. The overflow does run out to the right side so there's a slim possibility there.
: I don't think it could be the reservoir. I'm staring at the firewall, above the rocker cover and below the reservoir, and see nothing. When I look from below, it's all running down from the head gasket joint area, down the block and down the tranny bellhousing.
: : You stated that you "watched where the leak
: : came from once it got back up to temp"; does that mean nothing leaks when the engine is cool? A head gasket would leak at all times.
: It is drips now even when cool, but as it gets hot the leak spews since the pressure builds.
: : Keep those fingers crossed!
: : Good luck,
: : Adnan