Need 7M Guru's! Having 7M Heating Issues

[jdm2191]

Ok im assuming I might have a BHG but just want some opinions before I get it block tested...I've searched/googled but doesnt sound like everyone had the same exact problem mine is giving

So this how the story starts on the 2nd of this month I was driving back home from visting family which are 60 miles away. Once I got home & turned the car off I immediately heard water gushing into my overflow & right away I knew it overheated I turned my key to AUX & it shot up to about/little over 3/4 on my Temp Guage!

The next morning I checked my Oil & Coolant the Oil seemed fine,not milky But my coolant was low so I added coolant

Then tested her out, drove her around let her get up to operating temp & no overheating, but NOW my heater wasnt hot!

So the next couple days I would drive her around to go to work/run arrons & nothing (heater still not working).
Then finally she acted up again! Well I was at a Fast food drive through she went to about 3/4 on the TEMP guage (total drive was maybe 30mins). SO I immediately turned her off then started to drive again. Once I left & she stayed cool, which seemed odd to me?

A few days later I got some coolant from Toyota did a proper coolant flush (I believe) Jacked up the car on a slope, drained the coolant, flushed her out with a Water hose, added coolant/water(not distilled), with the heater on full blast & Burped her the best I could do with a Cut in Half 2 liter Soda Bottle & my heater came back to life while doing the flush...

So started driving her again & the heater would kick on & off, but still not overheating

I got fustrated & said whatever & the next day I had to meet up with a friend which ment I had to drive on the freeway & is about a 35 mile trip there & back , which I thought would be a good test since there is a big hill the car would have to climb. & surprisingly she did well I went there & back with no issues, with the exception of a troubled heater

For maybe about a week she was good (heater would kick on & off & seriously come on for about 2 minutes then kick off)

About a few days ago she started to play games with me again while running some arrons I would come to a light & she would slighty heated up (like 3-5 lines over half) & once I started to drive again back to normal temp (a line or 2 UNDER Half). So I took her on the freeway for a little test (ABOUT A 7 MILE STRETCH) out of curiousity to see if she'd HEAT up & nothing PERFECT TEMP?

So I finally this past Friday the 25th I had a buddy of mine Dad check it out He's been a Toyota Tech for about 20 Years, He just tested her with known signs that he is fimilar to with a BHG (no block test) Just added coolant to the overflow (which I previously didnt do) Topped of the Radiator, checked the oil, let it run for about 15mins just listening to it/holding a rev. He also checked my clutch fan (which he said was a little weak) & he felt from his knowledge it didnt have a BHG just coolant was low & then my heater started working so I was happy for that at least. He just said keep a eye on the coolant level on the Overflow & if it get lows thats NOT GOOD!

SO last night me & a buddy of mine went out to a meet which is about 60 MILES AWAY there & back. Which I thought would be a test of all test so we went there no problems, heater worked great, she stayed right under half all the way there. Came back same thing stayed under half/working heater. THEN once I got back into town we went to grab a bite to eat & had to sit in a drive thru then the needle started to go up again FML! To maybe about 3/4 soI sat & watched her & she didnt go higher then that & my heater wasnt hot AGAIN! & once we left she went back to normal temp...

So today in the morning I checked my overflow tank & it was low & the radiator looked a little low as well. I took her for a spin & the heater was cold at first then got warm once I drove her. Then once I stopped it got cold again (no overheating)

SO IM STUCK AT IS IT THE CLUTCH FAN WHICH MAKES IT OVERHEAT SLIGHTY WHICH IN RETURN THROWS MY COOLANT OUT MY RESORVOIR? OR IS IT JUST A BAD BHG SUCKING UP THAT COOLANT?

Also BTW a few days prior to this all happening my heater would slighy get cool for a minute or two then come back & also there is NO White smoke coming out my exhaust...

SO PLEASE LMK WHAT YOU THINK?

 

[jetjock]

I think you should stop referring to inanimate objects in the female vernacular...

 

[jdm2191]

Lol if it will fix the problem sure

 

[Insidious Surmiser]

lol.... do a compression test, then get back with us.... sounds like you're leaking exhaust gasses into your coolant... that will trap air in your heater core making it not really want to work.....

 

[supra1jz]

I would say I had the same problem a few years ago and I didn't want to say I had a BHG when my car only had 95k on the motor but in the long run I just pulled the head and saw it was if you have to keep add coolant and you don't see a leak anywhere. Mines did not have oil and water in it but I didn't have a BHG.


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[mecevans]

-Block test (from dead cold till op temp. Some only leak cold)
-Pressure test (~15psi)
-Compression test
-Vacuum test cooling system

My car block and pressure checked out good, but a had a leak under vacuum only. When the coolant cooled it would suck in air at the upper heater core hose. Got new hose and clamp an its been fixed ever since. Dont use the wire clamps.

 

[amped12345]

alot of my problems were due to stupid hoses. replace them all ...you will be happy in the long run .

 

[NashMan]

the easiest way to see if can has a bhg is 2 things


if bubbles don't go away bhg
if you coolent has oil shine to it, some what like if you has put tad bit of gas in water bhg

clutch fan's only cool sitting in traffic once you moven air flow takes over

so you these clues to find your issue

 

[jdm2191]

lol.... do a compression test, then get back with us.... sounds like you're leaking exhaust gasses into your coolant... that will trap air in your heater core making it not really want to work.....

I think you right but it still overheats when stopped after a long drive

I would say I had the same problem a few years ago and I didn't want to say I had a BHG when my car only had 95k on the motor but in the long run I just pulled the head and saw it was if you have to keep add coolant and you don't see a leak anywhere. Mines did not have oil and water in it but I didn't have a BHG.


Sent from my iPhone using Tapatalk

So your saying if I have to keep adding coolant & I don't see a leak I have a BHG?

-Block test (from dead cold till op temp. Some only leak cold)
-Pressure test (~15psi)
-Compression test
-Vacuum test cooling system

My car block and pressure checked out good, but a had a leak under vacuum only. When the coolant cooled it would suck in air at the upper heater core hose. Got new hose and clamp an its been fixed ever since. Dont use the wire clamps.

What new hoses did you buy? The Heater Hoses?

alot of my problems were due to stupid hoses. replace them all ...you will be happy in the long run .

You replaced all your coolant hoses? Did you take apart your Heater Core too? & would your car heat up like mine when stopped?

the easiest way to see if can has a bhg is 2 things


if bubbles don't go away bhg
if you coolent has oil shine to it, some what like if you has put tad bit of gas in water bhg

clutch fan's only cool sitting in traffic once you moven air flow takes over

so you these clues to find your issue

Ill keep an eye on it




BUT SOME SLIGHT NEWS

HAD ANOTHER BUDDY OF MINE CHECK OUT THE CAR HE IS A MERCEDES TECH, SO HE KNOWS HIS WAY AROUND A CAR

MY CLUTCH FAN, THERMOSTAT & WATER PUMP ALL ARE IN WORKING ORDER

THE COOLANT WAS LOW WHEN HE CHECKED IT OUT SATURDAY EVENING SO WE ADDED WATER & PLAYED AROUND WITH IT BUT STILL HAVING ISSUES FIGURING OUT THE PROBLEM BUT WHAT WE THINK IT COULD BE IS A CRACKED WATER JACKET OR A BAD CLOG IN MY COOLANT SYSTEM. ALSO ONE SIDE OF MY RADIATOR IS HOTTER THEN THE OTHER SIDE & MY LOWER RADIATOR HOSE IS COLDER THAN THE TOP ONE?

ALSO DID A MINI TRIP TODAY & DROVE 3 HOURS TODAY ON THE FREEWAY (HOUR TO ONE PLACE, 2 HOURS TO ANOTHER) NO PROBLEMS (WAS UNDER HALF ON MY TEMP GUAGE) TIL I GOT BACK IN TOWN ONCE STOPPED AT LIGHT & IT HEATED UP TO 3/4 THEN ONCE I DROVE IT WENT BACK DOWN.....IT PLAYED AROUND WITH ME FOR ABOUT 10 MINS

HEATER WAS WORKING FOR THE WHOLE DRIVE TO BTW

 

[mecevans]

Keep overheating it and your going to anneal your head bro.

 

[jdm2191]

Keep overheating it and your going to anneal your head bro.

Anneal? But I turn it off & let it sit as soon as it goes up, it doesnt go all the way up either. Then once I drive it immediately drops down

 

[NashMan]

Keep overheating it and your going to anneal your head bro.

lol that wonte happen only way that happens is when ya melt the head from detonation

 

[Insidious Surmiser]

yeah I had a overheating issue in a 7m once.... turns out it wasn't the first time.... in the end I did everything to make sure the cooling sys. was up to spec, but the bottom end was eating it's-self. you could tell when the engine was torn down because the crank was all sortsa crazy colors.

I don't think that's the issue... but if you keep blowing coolant out your cooling sys. it will cause it to overheat.... and constantly overheating your engine will run a pretty good chance of fucking it in the long run (I think that's what killed my 7m before, BHG, then constant overheating, or just overheating it once REAL good)

 

[jdm2191]

UPDATE:

Passed Block Test

Now im just going to take out the Radiator clean it out along with hoses & flush out the system & see what happens?

 

[mecevans]

Pressure and vacuum check....

 

[stew_7mgte]

Wait so the Mercedes tech couldnt figure out why the lower radiator hose is cooler then the top one? Did i read that right? Having your radiator heat up inconsistently or one half hotter than the other could cause overheating issues. I dont think it would cause any of your other symptoms but it is a problem you need to fix by either flushing or replacing it. Look for crap stuck on the other side of your radiator preventing airflow, like leaves or a trash bag.

 

[jetjock]

^ Crack me up. Are you serious?

 

[Rollus]

Got the very same problem some month ago. In the long run it reveals a BHG, plus gaz in water and water in oil (then wore bearings).
The cooling system was in pressure (too much), sometimes heater ol sometimes not, then more and more coolant consumed, got my radiator cap gasket broken and leaking, etc.. Until BHG.

-Block test (from dead cold till op temp. Some only leak cold)
-Pressure test (~15psi)
-Compression test
-Vacuum test cooling system

Would also check radiator cap for any wear, as that won't be revealed by pressure test..

 

[NashMan]

Wow this is still going really there not much to a cooling system


sadly no one here has told you to do basic stuff like test thermostat or rad cap

or just replace them cause there so bloody cheep

 

[Insidious Surmiser]

it still never ceases to amaze me at how something so simple can easily become so complicated