Really Stupid Coolant Issue.:cry:

[unkillablepaseo]

:1zhelp:Alright , lets get this started.

I am having a really stupid problem with my coolant .... it keeps dissapearing. Now before everyone goes and yells "BHG, BHG" the car runs way too well to be considered.

Its just a plain jane 7mgte completely stock. My coolant keeps dissapearing through the reserve/expansion tank. I do have a mishimoto aluminum radiator, with dual electric fans. The car has never done anything like this before in the almost 2 years ive had it. It has NEVER been hot. I keep way too close of tabs on my coolant , oil , and guages.

Ive changed the radiator cap so far, I dont know why when I drive on the freeway it fills up my reservoir every time. I dont know if it could be a thermostat or what? Any and all help appreciated.

 

[IJ.]

Get a BHG Test kit from Napa BEFORE you start saying "it's NOT a BHG"

 

[jake8790]

Sorry to tell you, but if the reservoir is filling up it's probably a BHG. A couple years ago I popped the hood after driving, reservoir was overflowing. Temp was normal, running normal. BHG.

 

[GrimJack]

Check the hoses to the overflow. If you have a hole (even a small one) in the one inside the overflow tank, it will spit coolant into the tank as usual, and suck up only air. Cycle this a few times and you're low on coolant. They aren't high pressure lines, so you don't have to test them hard.

 

[Rollus]

If radiator cap doesn't seal correctly, circuit doesn't keep pressure...

 

[grimreaper]

my BHG took 2 years to fully develop and fail a block test. The reservoir level would take 2-3 heat cycles after a hard run to return to 'normal' levels. If I drove it like a normal car, no hard boost, the reservoir level always returned to normal after cool down.

Eventually it began slowly draining the reservoir. No smoke, sputters or other issues. If I wasnt so OCD about it, i could have ran it quite a bit longer before seeing major indications. The stock gauge never showed any signs of above normal coolant temps. My after market gauge showed a tendency for temps to rise with the ac on in stop and go traffic. Would hit 205-210 and slowly kept rising until I started moving. Never hits more then 195-200 with new motor, ac, summer heat, traffic etc..

Another odd thing I notice, my reservoir smelled very slightly of exhaust gas. Very noticeable compared to the coolant smell. Yes i was the guy smelling my reservoir in the parking lot :aigo:. That was my first real sign of an issue and is what started the religious reservoir level monitoring. Ive become much less involved in watching things these days.. I used to be a bit crazy with the car.

The lesson I learned is the subtle signs are an indication. Dont ignore them. Most wont think twice until its blowing steam or drinking a gallon of coolant a day.. and a different car for a daily driver makes life much easier

 

[jetjock]

It's not just a river in Egypt...

...Another odd thing I notice, my reservoir smelled very slightly of exhaust gas. Very noticeable compared to the coolant smell. )

Not that uncommon actually. Although I prefer the BTB test I've confirmed more than a few BHGs using an emissions analyzer on a bagged radiator neck. The long time to develop isn't that uncommon either, especially on these engines.

 

[unkillablepaseo]

Hmmm alright ive wrenched a few 7ms so ill check it out. But its not using coolant, it spits it out through the reservoir. the reservoir is filling up not draining it... Usually on the freeway.

 

[S.A. supra]

Sounds like bhg to me. Sorry if you dont want to hear it.

 

[S.A. supra]

Check for gases in the coolant first. If that checks out good, then try a new cap, and if that doesnt work then bhg.

 

[unkillablepaseo]

Well that sucks I already changed the cap..... the issue persists. Could it be a thermostat?

 

[hvyman]

Start by getting a block tester like others have said.

 

[jetjock]

It's not just a river in Egypt...

 

[Suprapowaz!(2)]

Welcome to the club. First time?

 

[mkiiichip]

. Now before everyone goes and yells "BHG, BHG" the car runs way too well to be considered.

Gotta love the reasoning.

Supra, turning boys into mechanics since...

 

[Grandavi]

I have had 2 MK3's do this. Filled the reservoir up. Both times.. BHG.. sorry... but that's how we roll ... lol.

Hiding from it wont help. Test.

Oh yeah.. both times I had your attitude... "couldn't be a BHG"...
both times after a length of time, the HG let go with really cool results like my daughter borrowing the car and saying "wow... does it ever smoke a lot!" (was perfectly fine before she drove it.. lol). The other time it actually blew up the top rad hose.

 

[IJ.]

Walks like a Duck Quacks like a Duck......

 

[unkillablepaseo]

well thats convenient that my car still kicks ass on a bhg well machine shop and metal HG it is.

 

[Backlash2032]

Make sure to fully disassemble the engine and deck the block with timing cover if you do go MHG. If not.. just use a Toyota or Felpro gasket with ARP *studs*. A MHG will not seal without a decked block.

Sent from my terrible HTC Rezound using Tapatalk. Don't buy HTC...

 

[Grandavi]

yeah.. and ARP studs help. Personally I wouldn't pre-buy the headgasket until you know the correct thickness. The ARP's are just a given. And you should plan to helicoil the exhaust manifold studs.

Of course.. it actually may NOT be a BHG... it just sounds like one.


btw.. I think your car is my car's twin. Mine's a 88, looked just like yours when I started.