Originally posted by AngelaTheLegend My overheating problem has been fixed. Problem: Thermostat
The thermostat (which is located near the bottom radiator hose, NOT on top) had a rubber gasket that was cracked in more than 10 places. Moreover, a section of the gasket was missing. This caused it to take an unusual amount of time to heat on cold mornings because a considerable amount of coolant was able to move through the broken gasket and keep the engine cool. However, when the engine began to heat up, the thermostat would still be closed creating an overheating situation. At this point the thermostat would pop open, cooling the engine and dropping the temp guage. Once cool, the thermostat could close, still allowing a considerable amount of coolant through until the engine would overheat from the restriction and the thermostat would pop open. In addition, the spring was also becoming stuck, delaying the open.
This isn't MY opinion, this is a cooling-specialist opinion who's been doing this for 40 years. I have to agree with him, because it makes sense, i saw the junk/[email protected] thermostat and so far, so good.
My advice once again, don't go crazy, check the obvious things first, radiator cap, thermostat, external hose leaks, air in system, low coolant.
To everyone on this cheerful 16 page thread: Thanks for all the advice.
I am going to question what the cooling specialist said was happening.
How fast exactly was the temp guage rising and falling?? if it rose to H slowly, then droped slowly... I will agree with him, but if it spiked in a couple of seconds, I'm going to disagree with him.
Also, if your engine went through an actual overheating and then cooling situation..... you may have caused HG dammage, I would still keep a close eye on everything.
How long ago was the problem fixed? Most people think they fixed everything then 2 weeks later come up with similar problems... Just keep a close eye on everything, and I am glad to hear you found the problem!
Originally posted by HondaEnthusiast Hello everyone. I have recently bought a 1991 legend with a BHG. I knew about it and that is why I got the car cheaper. After building the engine back up, I still have the overheating problem. I love hondas (My family has 4), they are great cars; but I think whoever was designing the 3.2L V6 for the legend either was an idiot or they did it on purpose.
Here is my theory and theory only (If anyone knows otherwise, please shut me up): All of the engines that I have ever worked on (Especially HONDAs), the thermostat is always on the side of the coolant flow that is going TO the radiator and that is why even if you have some air in the system there is always hot coolant pushing against the thermostat and opens it up. On this engine the coolant is being pulled away from the thermostat and if there is even the smallest amount of air there, it will most likely stay in the thermostat housing and hot air will not open it up, only hot coolant will. Also the return line from the heater goes directly to the THERMOSTAT - well what happens to the coolant that just went through the heater core - it is obviously cooler and thus can close thermostat (if it is cool enough) and cause overheating. So it looks like in very cold weather with the outside vent open, it will cool the coolant enought for it to close the thermostat and overheat (and that is what I see on my car and many of you have the same symptoms). I am going to research it more and maybe somehow try to redesign and put the thermostat on the upper hose instead of where it is now. But maybe I am just full of it and dont know what I am talking about. PLEASE comment on this...
That is a very intresting theory... and it seems very likely. I would strongly suggest you look into this idea.
However, I have noticed that almost everybody first experiences no heat (no coolant in heater core) because that is the highest point on the cooling system, so the likely hood of enough air getting traped in the thermostat to keep the thermostat closed is sorta slim... because most of the air travels to the heater core first.
and now that I think about it... its stupid the thermostat is connected to the lower radiator hose.... its got the cooled coolant flowing over it, so exactly how does the thermostat open?
Also, please correct me if I am wrong, but I belive the thermostat works because the spring gets hot, making the spring easier to compress, allowing coolant to flow into/out of the engine.... and if that is how a thermostat works, it would make absoutly no sence to place the thermostat on the coolant return to the engine.
It would be nice to find a diagram of the cooling system in a G2 legend.
EDIT I just found this info on how stuff works.com
The secret of the thermostat lies in the small cylinder located on the engine-side of the device. This cylinder is filled with a wax that begins to melt at perhaps 180 degrees F (different thermostats open at different temperatures, but 180 F/82 C is a common temperature). A rod connected to the valve presses into this wax. When the wax melts, it expands significantly and pushes the rod out of the cylinder, opening the valve.
So With that information, I would guess that even a significant amount of air around the thermostat would not cause it to not open.... the only real problem may occour if the car is cold, and the air is around the thermostat, and the thermostat never heats up to its opperating temperature...
Ive noticed mine at 120k started to overheat ..I add coolant about once every 3 weeks, and its fine..it has a slow leak somewhere..I noticed some coolant around the top of the radiator splashed onto the hoses etc...i was told by a mechanic to replace the radiator..ive also noticed when i run the heat or air conditioning, a slight odor of coolant every so often..and the heater and air conditioning dont kick in until the cars moving...any thoughts??
So question: If I come across a high-mileage Legend, and I let it idle for 10-20 minutes, and the gauge does not move much, and actually stops moving, the cooling system is good, right? Assuming "proper" maintenance is done, how long should the engine last? (I know this is a loaded question, please flame away if necessary).
Rythmic, systemic and world control Magnetic, genetic, dement your sou...
Gunrman: You are definitely due for a new radiator. Call some radiator shops and they have a metal top one now. Don't get the plastic top OEM one because it will crack and fail in about three years again. You probably also need new hoses, and maybe a thermostat too from the sound of it.
Duck, Yeah, I'd take it and drive it highway for about 10 miles, then about 10 miles city, and then let it idle for about 15 to 20 minutes at least. Are you getting heat inside cab?
If a car with a head gasket problem is bled for a while, it can take a little while to show up. Also check out the overflow reservoir, and if there is dark slimey oil in the bottom and on the overflow hose, watch out, BHG is happening already, just maybe a slow seep, but it's coming. (Don't let them give you the that's just old coolant number either, dip a white napkin in there and you'll see the oil separate.)
Also check the dipstick for foam on it which means coolant is getting into the oil which happens on most cars with a blown head gasket, but is more rare on the Legend since engine is designed differently. Check the trannie stick too and make sure it's good and red, and no foam as well.
If all that checks out, let it sit overnite somewhere and see if you get the real dark oil spot (differential pinion seal leak) which is about a 350.00 to 500.00 fix.
Look at the brakes and rotors good too. If that checks out, yeah, it would probably be a good to go.
Gunrman: Looks like your going the same route I went . Noticed the coolant leaking from the top tank and there was a leak towards the bottom of the radiator. Replaced radiator and upper and lower radiator hoses. Still overheats, and now due to all the pressure that built up inside the cooling system the lower radiator hose blew, most likely from a BHG. I will replace the hose and put a new thermostat in and prepare myself for getting a BHG repaired.
No oily spots on dipstick, no white clouds of smoke, no oil in the reserve.. Its drivable if I keep bleeding the valve and release the pressure once in awhile.
Luckily a Honda dealership will the Head Gasket for 700-850 .. I got a lucky break.
A mechanic recently told me that if all Acura owners jointly began to make a big stink about the gasket problem that these Acuras have they would be forced to do a recall on it, and/or do something to solve the problem...That would be nice instead of spending money hand over fist on trying to figure out what the overheating issue is only to find out it is the gaskets....
I am thinking a used or rebuilt motor instead of replacing head gaskets which..seems to be going to cost about the same amounts...does anyone have advice about that?
Should i just do the gasket repair..(my motor was great until this prob) Or does it make sense to just put in a diff motor???
But before I go this route, reading everything that you guys have written my car doesnt have those symptoms..no leaks...no drips from top...so I dont know if i just need a motor , gaskets, or thermostat or what..they tell women anything!
If so, so i wont get ripped off again..what should the pricing run around about for either of these two things??
Especially as we're all in the same general area - age wise - on our cars (mileage varies greatly - but that just proves it isn't necessarily about mileage). Of course, Acura's first statement will be "if properly maintained...(read, by an Acura dealer)...a Legend will never incur a BHG". But if Mike D uses just a little higher torque setting on the bolts when replacing a head gasket - that would seem to drive toward a factory spec that was just a little out of line... and we all end up paying for it.
This is not just a coincidence - this, my friends - is a trend. How do we get Acura to react to this???. recall our cars and fix em?????
Legend owner since '98, lovin it more & more
94 Pearl White LS Sedan
Eibachs & Konis w/ Ingalls, GS Rims, RangerJoe CAI, MLS copy bar
Alpine 7892 HU, S694 CD / MP3 Changer (factory location), 10" Type R Sub, Kenwood Amps
Focal 690 CA & MB Quart PCE216
New 2-tone leather, Tint - 35% all around, DEI keyless / remote start
Roof wind deflector, Clear corners & bumpers
Well.... $2000 later..... wife is driving her Legend again..... and she is happy!
What did I get for my money.... Headgaskets replaced, Heads decked and valve job done, replaced the heater hoses, new Knock sensors, new head bolts.
While my buddy had the motor apart.... I stopped by to see what this engine looked like torn down..... (I'm an old pushrod V8 type of guy)......All I can say is one thing....... What a stupid way to design an engine cooling jacket.... Its no wonder they fail after high miles...... I'm no engineer, but it just looked really wierd to me.... way too much open area around each cylinder..... I dont know.... maybe I'm wrong, but it just looked like a poor design......
Well, I still think the car is a beautiful piece....
I tend to agree with you. I still think the Acura Legend is a beautiful car and BHG or not, still is worth every penny
Katt: Just think if you get a used engine you are most likely going to have to replace the Head Gaskets again down the road. My opinion would be to replace the head gaskets and not worry about doing an engine swap . These engines are used and generally have the same problems as the previous engine.
If you are to go the route of repair than figure
New Head Gaskets 250 bucks shipped
May want to look at new upper and lower rad hoses 20 bucks
Labor would be the only big part of the costs
You can cut alot of the costs by ordering the parts yourself and having a mechanic put them in and charge labor
This is one site to order the gaskets from
The Thermostat can be purchased locally from a Napa or Autozone or whichever, sometimes these are alittle diffrent than the OE thermostats and its not worth the hassle getting all the correct seals just to have it fit.. Might as well order the thermostat from the dealer and than order the gaskets from a online site like that one.
Get a quote on the labor involved(shaving the heads included) of doing the BHG with gaskets provided
..but now I'm skeptical about my BHG diagnosis. A couple weeks ago I thought I had a BHG because of the rising & falling temp gauge. I do have a cracked upper tank on my radiator, but since topping the fluid levels, I've had no problems. ? I'm going to replace my radiator this week and then we'll see what's going on...
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