Overheating 97' 850

johnjohn · Post by **johnjohn** » 18 Mar 2008, 07:57

Greetings Gentleman , I own a 97' 850 with over 200K miles on it. I have a major problem. The overflow plastic reservoir tank keeps overflowing and bubbling. If I drive 5 miles the plastic tank ( has a small crack in it , ordered a new one) is bone dry. Once I pour water into the tank, the water starts to boil and I hear a gargling sound . The temp gauge reads 3' o'clock and never goes higher. I seldom see white smoke, but I have a few times, once I add water, no more smoke. My Rad fan is working fine. Car starts up with no hesitation and does not die or misfire. I tried to change out the thermostat but stripped the infamous " hard bolt ", I even used a long Torx 40 , still stripped out. Guy's do you think it's a blown head gasket or could it be the thermostat. Thank you fellows !

Post by **MadeInJapan** » 18 Mar 2008, 10:33

Welcome to MVS.
I think by adding water, you've diluted the intended value of the coolant and therefore, you're boiling, plus any leaks will cause this to some extent. Stick with ethylene glycol formulated coolant only 50/50 solution (with bottled distilled water). The coolant (Prestone, etc.) bottle will say, safe for aluminum on it. Flush out the old and replace with new when you change the over-flow tank. It isn't hard to do. That said, you will continue to leak if you even have a pin-hole in the over-flow tank. No, I do not believe you have coolant in your engine at this point. You might have a small pin hole in one of the hoses, so check them too. If you keep boiling the "water" out of your radiator, eventually you will compromise your engine, so beware. www.fcpgroton.com is your friend. About your thermostat- it does not seem at this time that it is bad, but I would go ahead and order the new, hardened "hard" (as you call them) bolts for when you do have to replace it (btw, they're not expensive from the dealer either)...what the heck, go ahead and order a thermostat too- they're cheap and you'll have it on hand when yours goes, as they all eventually do. When you change these bolts, spray liberally with PB Blaster the night before and they will be easier to get out. If you've buggered up the bolt head, you can try a dremel to cut a slot so you can use a screwdriver. Good luck and keep us posted.

johnjohn · Post by **johnjohn** » 18 Mar 2008, 13:05

Thank you sir for that quick insightful reply ! I am still shaking in my boots though. I just moved to a new city with a new job, not a good time for a hi $$$ repair. I will do the radiator flush tomorrow, Heavy thunder storms in Houston , Texas today.. If you had to bet , do you think it could be a blown head gasket? Please say No..

Post by **MadeInJapan** » 18 Mar 2008, 13:24

I've already answered that question. If it's blown, you would be getting constant white smoke and it would smell like burning sugar.

Volgrrr · Post by **Volgrrr** » 19 Mar 2008, 02:24

johnjohn wrote:Greetings Gentleman , I own a 97' 850 with over 200K miles on it. I have a major problem. The overflow plastic reservoir tank keeps overflowing and bubbling. If I drive 5 miles the plastic tank ( has a small crack in it , ordered a new one) is bone dry. Once I pour water into the tank, the water starts to boil and I hear a gargling sound . The temp gauge reads 3' o'clock and never goes higher. I seldom see white smoke, but I have a few times, once I add water, no more smoke. My Rad fan is working fine. Car starts up with no hesitation and does not die or misfire. I tried to change out the thermostat but stripped the infamous " hard bolt ", I even used a long Torx 40 , still stripped out. Guy's do you think it's a blown head gasket or could it be the thermostat. Thank you fellows !

1. Fit your new coolant reservoir.
2. Fill up with approved coolant, purge and pressure test cooling system.
3. Report your findings back to forum.

johnjohn · Post by **johnjohn** » 19 Mar 2008, 07:34

Thank you guys, I will follow your instructions today. I really appreciate all the help! I will fix this issue and report my results back, then ask about the last problem my 850 baby suffers from. The frustrating battery drain. This car has been the best car I have ever had. I have never been left stranded. Paid only $2,400.00 for it 4 years ago. A/C is ice cold, sound system is great, handles great on the highway. Only one dent on the side (angry former girlfriend)
Yes, I love my 850!

Post by **MadeInJapan** » 19 Mar 2008, 08:46

Good luck with everything.
Look for small lights on when the car's doors/back hatch are closed for the battery drain. One place that most don't suspect but is the #1 reason, is the glove box door which gets so it doesn't turn off the little light inside. Easily fixed by taping or gluing a penny or two to the door's striker plate. If any of these suggestions don't help, start a new thread about this issue and others will help you trouble shoot it.

johnjohn · Post by **johnjohn** » 31 Mar 2008, 08:38

Guys, Thanks again for the help, I replaced the plastic radiator reservoir
tank with a new one then drained the radiator and added new coolant. Drove the car in stop and go traffic for an hour. No leaking and no bubbling of the coolant. When I drained the radiator from the bottom (plastic wing nut) the liquid was pure water no coolant in it! Again, that problem is fixed.
I also unplugged the little light bulb in the glove compartment because every once in a while my battery drains down and wont start. Well that worked for 3 days then this morning the battery was dead, I had to jump it and it started right up. I checked all indoor lights and it appears none stay on. I had a guy tell me sometimes the anti-theft device on the car stereo, or the car alarm will do drain the battery. The thing here is my car wasn't locked when it drained out this morning.

Thanks guys.

chuckcintron · Post by **chuckcintron** » 31 Mar 2008, 14:14

I had a similar problem. If you have a multimeter you can disconnect one of the battery leads, put the meter in 'ammeter' mode and check the current drain on the system with the car turned completely off. IIRC should be around 50mA. If you are seeing high current drain then "something" is being left on.

My problem ended up being a two year old Exide battery that had simply gone bad. Replaced under (prorated) warranty; problem went away.

-Chuck

johnjohn · Post by **johnjohn** » 31 Mar 2008, 15:56

Thanks for that tip, I will try it. The only other thing I can think of that might be draining the Battery ( its a new battery) is the radio antenna. The antenna does not extend or collapse, but when I turn off the car I can hear the antenna motor run for about 45 seconds then it stops. Maybe this could be the culprit?