Heater Core Bypass

[CustomOHioSupra]

I changed my post. Adding multiple hoses, clamps, and failure points to a perfectly good cooling systems really shows how ignorant I am. The way I maintain my car is truly sad to have to resort to this kind of ghetto rig. I do not deserve to own a Supra or any other high performance car.

In fact, I'm an immature, self-centered adolescent that can't take any kind of criticism or interact with anyone who doesn't agree with me. Basically I'm a sociopath. As a result of posting rude comments to the members and abusing my privileges here by posting a totally inappropriate thread, I was permanently banned. I am such a retard, it took less than 10 posts.

 

[jetjock]

Not to rain on your parade but....

1) The heater hose is far from the hottest coolant coming out of the engine.

2) There is flow even with the valve closed. It's designed not to present a total obstruction to flow when closed.

3) It says in the owners manual to fill on a hill? Not in my manual it doesn't. Nor does it say that in the service manual.

Btw if I were you I'd throw all those screw drive clamps in the trash...

 

[Justin]

IIRC the valve controlling the flow of coolant through the heater core only blocks off coolant when your air conditioning is switched on.

 

[jetjock]

Well, it only closes when the CC is set to 65. You'd think a CC color change specialist would know that

And as I said, it never totally blocks flow, even when it's closed.

 

[CyFi6]

And as I said, it never totally blocks flow, even when it's closed.

As you can see in this picture.

 

[jdub]

The diagram does not show the heater control valve...that is what JJ is referring to. It's a fact, it never completely blocks flow through the heater core...and, doesn't close till the climate control is set to the lowest setting (65 deg).

 

[jetjock]

I always get a headache from looking at that

I meant the valve itself. There is a stamped protrusion on it's mounting bracket that spaces the actuator away from the bracket such that when the actuator is off it's stroke is limited to where the valve is not fully closed, thereby letting a trickle of coolant through.

 

[CyFi6]

The diagram does not show the heater control valve...that is what JJ is referring to. It's a fact, it never completely blocks flow through the heater core...and, doesn't close till the climate control is set to the lowest setting (65 deg).

Isnt it true though that the heater core valve is on the "To heater" line? So if you imagine that line being mostly blocked, you still have flow through the back of the head via the throttle body and the opening on the fitting directly opposite the "to heater" side, as it is a T going either back to the radiator or off to the heater. Does that make any sense at all? And if so is it correct?

 

[CustomOHioSupra]

(yes Cyfi6, there is t- connection that allows water to flow, even when the heater core hose is "partially flowing" or "barely flowing)
(for the sake of the arguament, lets pretend i have 500hp and the T-connection is no longe larger enuff for my trip to the baja and the african desert.)






(as for the other comments)

1. i like how you said the hottest fluid does not come from the back...it does....i also see you did not mention where the hottest fluid comes out....so i assume your going to say the 192 degree thermostat,,,, well, have you ever blown a heater hose....end of story, or if you have not blown the heater hose then you have not driven a supra mk3 long enuff

2. read up about the restriction that takes place....you say it not "total restriction" but the restriction is there!!!!!....you can bypass the vacuum to get ride of the VSV warm up time ( i have done it temporarily)\

3. hate to rain on your parade, but read your owners manual again, i will help you find the page, i have a 1989.

it will read: to fill coolant:

fill on a hill with A.C. on and heater full blast
allow to warm









it also goes on to the manual to say if your over heating while stopped, rev engine up to 1500 RPM....


but it is unforunate that if you talk about overheating or water noises after refilling the only reponse in the mk3 forum is BHG.

anyways, i am not the only one to bypass the heater hose, it has been done before. it does keep tempature down on a 7m



7m orginial cooling equipment does have a cooling problem:


1:the fact the toyota owners manual says to fill it on a hill and let it warm up to get rid of the air. (it also explained that the heater core + ac must be ON)

2:heater core hoses blow way earlier than HG.....(that could be debatable i know, but NOT FOR ORGINAL mk3 OWNERS)

3: the egr is near the heater core hose

4: the rear of the engine is hotter

5: the tendency for rods to knock at #4 and #5

6: mk3 owners reporting loss of heat

7: owners manual talks about 1500 rmp if it overheats while your stopped

8: the heater core hose does not flow unless heat is turned on

9: overheating = causes deteriation of the HG leading to early leaks around the loose head bolts




i am the orginal owner from 1989, i had orginal head bolts + orginal head gasket last until 199k. I have replaced the engine since then



the MK3 stinks at cooling.....show me one mk3 in the junk yard with coolant still in it.....your response is BHG, but i always say the master mechanic knew to torque the head bolts to 75lbs but didnt realize how to get air out of the heater core (chasing air bubbles.....again your response to that is that the BHG is 100% the only reason for bubbles appearing)



i have had 3 blown head gaskets, if you have coolant being pushed out the overflow, YOU HAVE A BHG, i wont argue

if you drain and refill your coolant....start the engine and hear sounds or hear sounds when heat is activated, that is not a BHG


i have been around the mk3 for over 19 years, i know where hot coolant flows out and i cant beleive you think it is not hot when you say

"""""""""1) The heater hose is far from the hottest coolant coming out of the engine."""""""""""""


i disagree with 100%, it is by far the hottest....(for good reason)


it is unforunate that many of these cars are in junkyard while owner claims a BHG was the cause (loose heads bolts)


can anyone point me to a MK3 that blew a head gasket becuase it overheated?


mk3 owners have many excuses for blowning a head gasket but overheating is not one of them....maybe you should reconsider.....unless you like seeing your engine rebuilder every 60k....


i got 199k off the orginal engine and i hate how people tell me that i need a metal gasket or clevite bearings.....those people only get 60k out of there rebuild


""""""""""""""""""""Btw if I were you I'd throw all those screw drive clamps in the trash...""""""""""""""

i have been on the supra forums since the y2k scare, i havent heard anything new in years, just a lot of talk with mk3 owners who have little miles driving it + a lot of time working on it (BHG).


thats the crap that is goin in the trash....the ordinary stuff mk3 owners do that keeps them off the road and on the forum....


i cant afford to rebuild the 7m every 60k like somepeople on here, so i will be doing things differently.....(you know who you are)



p.s. i have a toe-package on here + with heavy jet ski
p.s.s. the best thing you could ever do to a mk3 is drill a small hole on top of the jiggle vavle on the thermostat
p.s.s.s. try not to mention the word BHG when talking about why it might be nessessary to drill a hole in the thermostat, try to talk about 7m undercooling.......a.k.a. overheating



200,450 miles and counting......drove her off the show room floor.....many like her, but they are in the junk yard with no coolant or/and are parts cars

 

[jetjock]

That's an impressive post there Sparky. I'd offer a technical rebuttal but I know it'd fall on deaf ears. See, I can smell your type a mile away. All I can say (said in fact) is my owners manual doesn't say that (nor does my TSRM) but then again I have an early model year. And fwiw in 21 years of owning this car I have never filled it on a hill, never had air nosies, never had a BHG, and have never had to burp it. However, feel free to do as you like with your car. Lastly, you'll forgive me if I'm not inclined to take advice from someone who does the quality of work shown in the photos.

 

[Nick M]

You have blown 3 head gaskets and you are trying to give advice?

 

[CustomOHioSupra]

Nick M (blew one gasket at 199k, the other two did not work at startup) i got this car running AGAIN from not listening to people blab about how much they know, or who should be giving advice, or what they would do.....the mk3 forum is repair forum without the mechanic....just a lot of people with pleny to say because they spend much of there tme working on the mk3 and not driving it....that the people who i don't take advice from + i dont take advice to people who think it is normal to rebuild every 60k.....if you would like to keep your 7m from THERMAL BREAKDOWN (head gakset included), you might want to recosider why these cars show up at the junk yard with no coolant....why most mk3 do not run.....BHG is your first thought, i jsut wont to consider the heat the 7m puts off as being a "contributing" factor to the loosening of the headbolts, the warped head, the deteroriating head gasket...the BHG.....you dont have to take my advice, i am just putting it out there.... i know that the rebuild average on the mk3 forum is less than 60k.....(thats without including the startup-BHG after the rebuild)....



as for the guy with 21 years ownign a supra:
post some pictures up Mr. Mechanic.....never replaced the head gasket in 21 years,,,,how many miles you got....


if you average 12,000 miles x 21 years thats pretty good for the old 7m head gasket....show some pictures of this OEM masterpiece....btw...i know someone who "claims" to have 272,000k "orginal" on a 1987 mk3


i got 199k OEM with last bolt torque at 120k (that was my problem)


i bet my pictures are not half as funny as watching you race your 1987 masterpeice at the track....so put up some pictures of your orginal owner with OEM engine thunderbeast.....


i think posting pictures will go one of two ways for you-

1) your 1987 is a stinker and it would get last place at the track....

or

2) it is not OEM....including the Headgasket


but as for now i beleive you have a 1987 orginal HG....how much did you pay in 1987? how many miles as of today + whats your head bolt torque history?



(hmmmmm..........a mk3 that has not been rebuilt ....now i know 2)



the

 

[ILikeCarsYesIDo]

There is no need for the enter key to be pressed that many times.

 

[CyFi6]

post some pictures up Mr. Mechanic.....never replaced the head gasket in 21 years,,,,how many miles you got....


if you average 12,000 miles x 21 years thats pretty good for the old 7m head gasket....show some pictures of this OEM masterpiece....btw...i know someone who "claims" to have 272,000k "orginal" on a 1987 mk3


i got 199k OEM with last bolt torque at 120k (that was my problem)


i bet my pictures are not half as funny as watching you race your 1987 masterpeice at the track....so put up some pictures of your orginal owner with OEM engine thunderbeast.....


i think posting pictures will go one of two ways for you-

1) your 1987 is a stinker and it would get last place at the track....

or

2) it is not OEM....including the Headgasket


but as for now i beleive you have a 1987 orginal HG....how much did you pay in 1987? how many miles as of today + whats your head bolt torque history?



(hmmmmm..........a mk3 owner who never rebuilt....now i know 2)

Are you trying to make a point in this thread or start a useless argument?

 

[shaeff]

Here is what I see from the pictures you posted:

1) You added TEN extra potential points of failure to the cooling system.

(the three way split on the passenger's side, exiting the bottom then going to ANOTHER union, that makes 5 on the passenger's side. Then on the driver's side, you have that three way split again, AND the hose fitting/cap, which makes 5.

Hell, if you want to count the actual cap as a potential point of failure, then you've added ELEVEN more points that the cooling system can fail.

And that's about it.

CustomOHioSupra- Calm down, man. We are stating facts. Lay off the hostility, otherwise your stay here won't nearly as enjoyable as it should be. Thus far, everyone has given you solid advice, which I suggest you take.

 

[CustomOHioSupra]

"""""""""""""""We are stating facts"""""""""""""""""""Thus far, everyone has given you solid advice"""""""""""


lol, the weakest leak is the owner or maybe the forum

enjoy your 60k rebuilds everyone....



i tried to tell you about the hole in the thermostat + the heater core not flowing, but all you could do is defend the toyota OEM cooling system and ignore that most mk3 are in the junk yard and are worth 250 dollars when they dont run.



ILikeCarsYesIDo, it is nessessary to hit enter that many times, i hit it once everytime a 7m boils over ;(



Shaeff-you are correct about adding areas which could fail......i was already worried about the heater hose failing.....so i wanted to lowered the tempature coming out of of the heater hose....i could get rid of the heat if i was worried about it failing...but this is my daily driver....(i have over 500 miles with no leaks....jet can't beleive it i know)



however, despite jet saying my pictures makes him inclined not take advice from me, i know the heater hose in the 7m is something that owners have decided to keep a spare of inside the vehicle.....for good reason....




ever replace the heater hose Jet? i replaced mine at like 115k,125k,185k....


anyone one on this forum have 110k miles driving and never replace the heater core hose? i am sure everyone on the forum has messed with that heater hose before...


the question is: does a 1989 camry or a 1989 mr2 heater hose have to replaced at 120k or so?

if not, we can agree it is not the rubber hose that is the problem, but the engine

 

[Poodles]

while I'm not defending him really, many companies in japan sell the bypass kits because it seems to be a known issue with cooling the back of the engine...

abflug makes one in fact...

 

[CustomOHioSupra]

Poodles;1013837]while I'm not defending him really, many companies in japan sell the bypass kits because it seems to be a known issue with cooling the back of the engine...

your not defending me really....well you really are.....bypass kits to cool the KNOWN hot spots in the back of the engine



i have a bypass kit to cool the back of the engine....but people who claim to be giving the facts and advice say i am crazy....


if you have a 192 degree thermostat, your number cylinder might be 192 degrees....but number 6 is not even close......


my car on the other hand might have an advantage to cooling down the rear....


side note - most poeple, in my opinion, blow heater hoses + BHG in the SUMMERTIME!!!!!!!


why does the heater core + most BHG happen in the summer?


hint: heat in the summertime causes the BHG/heater hose failure


7m cooling is sufficient in alaska summertime,


but these cars get HOTTTTTTTTTTTTTTTTT.......7m gets hottttt, regardless of aspiration.....you dont have to BHG to overheat....


overheat in a 7m= not good for head gasket

I see to many young guys (no money + no spare car) try to make the mk3 there daily driver, but ends up being a barely drivable or rarely driven....

i want to help theses guys out by giving them as many miles as they can get....that is why i beleive this information is vital...so laugh all you want, play sides, play favorites,


but i did'nt keep quiet + i didnt go back to o.e.m., i dont plan on it, the car has ran great for the 500 miles i have driven with this custom hose....stays nice and cool also....


nice and cool 7m.....that was the point.....


192 degree in cylinder one is 225 degrees in cylinder 6......(oem system)


40 degree day the cars runs at 192 degrees
80 degree days the car runs at 278 degrees (it just feels like it i really dont know)


7m=over heated, under cooled, + egr causes even more problems


thats why you never see a mk3 on the road anymore...the loose bolts from the factorys should have been fixed by 60k or 120k tuneup so dont blame the BHG on the OEM bolts/gasket, blame the heat....or both

 

[ILikeCarsYesIDo]

Your inability to use a basic and simple internet forum makes me side with JJ on your abilities to work on any sort of automobile.

What the hell is with " """""""""""""""We are stating facts"""""""""""""""""""Thus far, everyone has given you solid advice""""""""""" "

Do you seriously have to use a hundred quotation marks for ONE QUOTE?

 

[suprarx7nut]

This was a hard page to read because of both the words within and the physical structure of the posts.

CustomOHioSupra: Please stop it. Use some sort of logical spacing to your posts. I spent more time scrolling through your "enter hits" than reading through actual info. There is a "quote" feature in this fine forum. USE IT.