Overheat Coolant No heat Question Tried All Simple fix?

[highgz]

I apologize for the long post but it seems that people that put more info in gets a better response. so i tried to post it all.

ok first off i have done a crap load of research. i would say im fairly knowledgable in my 1g dsm so i know more than an average person. but i cant find the exact problem

Intro
ok i hav a 91 gst and about 2 weeks ago i was driving home stopped at a light and i heard a pop(or it may have been my imaginaztion) so i see the temp start to rise and so i pull over and sure enough Water pump is gone. So i cripple it to the repair shop and my oil temp went to about 250 and i stop and let it cool down then drove the final mile and it got back to 250. So after a day in the Shop i get it back with new waterpump and thermostat. so i think all is well and drive home. no apperant problems. i then go to work the next day and temps slowly go up until i get to work(about 20 miles or so mostly on highway) and both coolant and oil are around 215 and boiling coolant . so i take it back to the shop and they pressure test the system and the FOCKERS had 2 leaks in it and the t-stat housing and radiator hose. so i drive home and again it all seemed fine. Now i ask them what parts they put in and the shop said water pump and mitsu t-stat....so next day i drive to work but before i go anywhere i have to refill coolant and it does the same thing overheats and boils .... so now im pissed off at the shop cuz i took the t-stat out to see if they put in in wrong and they used a $1 stat with 160F. so i went to autozone and bought a failsafe 192F one to see if that was my problem. still overheated and then ordered my OEM one. and i just put it in but cracked the housing with the bolts so on fri ill get a new one and test the OEM stat and new sensor at bottum of radiator that i got.

almost to my problem. I start the car burp the system. Tstat opens water flows, Rad gets hot, no bubbles, water pipes only get hard after a nice drive and sytem pressurizes, the car heats up w/in a good amount of time. fans appear to work(pass side) A/c fan bypassed to run all the time. check relay by swapping in a new one-both work the same, i have 2 temp gauges as well(stock and AC autotecknics) both plug in the Tsat housing. Now my true problem.....i can have the car sit there and idle for a hr and the temps dont go higher than 180.......but as soon as i drive around neighborhood it pics up but once it goes past 190 ...starts to overflow the overflow bottle.

ALSO if i just get in the car and drive it will be fine until i come to a stop then it will pic up. while the car idles the pass fan comes on and off as it should but it seems when i start to overheat it doesnt want to work...like once the temp goes over its turn on TEMP it should run at all times? right? cuz it should be tryin to cool the system. but it doesnt ill go under the hood at temps 220 and so and FAN not on!!!!GRRR so im pointin that as my problem but any solution i throw at it doesnt work Im have almost exhausted all solutions for this except major repair.
1)new stat
2)new rad cap
3)flushed system and burp
4)new pump and its flowing
5)checked and recheck for leaks and none
6) compression(while cold)ill post it warm once i get it running again) 160 155 165 170
7)new sensor at bottom of radiator(havnt run it yet since install--ran out of time
8)fairly new engine (timing jumped)yr or so old

also i havent had heat for a long time Even before this so i dont think that is my problem cuz before this the gauge would hold firm under any driving condition.

well if you got this far thanks for taking time and reading i just want this fixed and normally i dont post cuz ill find the answer and here anyways but ive tried all that i could and need more opinions.
thnaks

 

[highgz]

well i installed an OEM thermo.....change the rad sensor for the fan and flush the system one last time......and did a warm compression test.....170 160 165 170 so all seems ok in that department......so got it rdy started it up..........came up to 192f and held so i decided to do a drive around the neighbor hood and give it sum real gas.....came back to the house and all seemed to work fans came on for a long time and held the temps perfect.....so i hope this will actually be the end to this...i will find out tomorow when i actually take it for a real drive ill c if the coolant actually stays in and doesnt boil out..
thanks again

 

[Pj97GST]

Do a complete leak down test.. If you overheated the motor enough the 1st time, it's very possible that you may have some warpage in your head.. especially if it takes a little while to start to overheat..

Just something to be aware of if it keeps overheating like that .. good luck

 

[highgz]

yeah that was the next thing i was goin to do if tomorow doesnt go well. im going to have to start locating a shop to do it...or buy my own leak down tester....i can get them for like 60 on ebay...........i hope its not warp i already sent it to the machine shop when it got rebuilt 1yr or so ago and i dont feel like going through that again.....thanks for the feedback

 

[highgz]

still not solved

im stumped
no oil in coolant or vice versa
all things checked and rechecked

if the HG is blown would it overheat all time no matter what? cuz coolant will be constanly lost? or would i only do it at high boost? also if head is warped would that only be a factor at high coolant temps? cuz when i jus cruise or drive slow all is fine.....even when i boost hard i have no white smoke!!!!

plz help.....my last resort is to get a fluidyne....and im still trying to find a place for a leak down test

 

[BUCK]

also i havent had heat for a long time Even before this so i dont think that is my problem cuz before this the gauge would hold firm under any driving condition.

I say that still could be it - Install a Heater Bypass Hose & see what happens.

http://www.dsmtuners.com/forums/showthread.php?t=124419&highlight=bypass

 

[92TurboGS]

I currently have about the same issues, new radiator, fans come on, can sit and idle just fine, normal driving seems to be fine, but once i boost the car for a period of time, boils over, temps rise fast and lots of pressure in the coolant system. Im thinking possible head gasket, and its leaking boost into water jackets?

 

[Pj97GST]

That's what gets to be a pain in the ass and makes it even harder to diagnose.. You can ####yfoot it around all day and it may not overheat... If you get into it and it boils over, then you can pretty much count on having to yank the head, and having it re-surfaced..

Boost and blowby are slipping past the HG and surfaces and making it's way into the water jackets..

In that case, it's time for a new HG and invest in some decent studs... DO NOT re-use the old ones unless they are ARP's or the like.
Keep in mind that with a cast-iron block and an aluminum head, all's it takes is one good overheating to warp a head enough to cause leakage.

 

[BISHILVR]

pull your radiator and run water through it with hose, you may have a clog, especially if you tried using some type of stop leak in it..........

 

[highgz]

thanks for the input.......heres a little update.

BISHILVR
"pull your radiator and run water through it with hose, you may have a clog, especially if you tried using some type of stop leak in it.".........

^^^never used any stop leak and i pulled the rad and flushed it out the car 2 and it flowed fin....other than some bent fins it looks ok from the outside

even though i jus put in a new rad cap(13lbs) i was told that maybe because there is a new water pump in there that its is working better than my 12yr old one(which is the one that went boom) so tonight i put a 16lb cap.

the problem im having keeps jumping around.....at first i overheated once i drove(then found some leaks and put in new T-stat--OEM..seem to fix but then ...yesterday i drove it around and gave it sum good boost and held fine........then gave it 15lb boost and overheated.but not quick it took its time.(that was with the 13lb cap......

like you said
Pj97GST i "can ####yfoot it around all day and it doesnt overheat"... i can also give mod boost and fine.....

so tonight with the new cap i decided to take it for a good 40mile trip on highway and back (80 miles total) cuz i drove around town and never really lost much coolant. So i drive on the highway maintainin 70mph and temp held perfect...192F got off the highway and HELD i drove to my 1st destination and i was pulling into the driveway it started to hit 215F(but this was like 5min of stop and go traffic till this point) so i check for leaks and none the coolant is barely bubling....now heres the funny part.....my alt has been acting up on me since i got the car back and is good while i drive but volts drop to 12.5 when i stop but not all the time just when it seems to get hot (which is unaccapteable) so i gave it a good rev and turned AC on and TEMP DROPPED to 205 and altenator hit 14.8volts but when i just let it idle the temp rises again.......also damn belts are now squealing on me off and on ........Ok that was the trip up and now coming back.........PERFECT other than the alt dipping in volts it held great even when i pulled in to home......no Ac needed to be run no boiling just perfect like there was no problem...

so could loose belt tension on the Water pump and ALT cause the overheat at a stop cuz its not turnin the pump or alt fast enough and there on the sam belt drive?????????? im goin to check the tension it looked real loose.......i could push it a good bit.....more than a 1/2 inch i think...


sorry for another long post but this is pissin me off........im glad i can at least seem to drive it slow with sum boost and no problems......but i wanna solve this thing..
THANKS!!!!

 

[BISHILVR]

make sure your harmonic dampener is'nt falling apart............and yeah the belts have to be pretty tight on the 4g63 or they'll slip......................

 

[Bestwestranger]

I too have had some major cooling problems. I can drive real nice and won't have a prob, but if I boost at all it will puke water out of the overflow. I have replaced damn near everything in hopes that it isn't the head, but it looks like that is what needs replaced. Before someone says something about me replacing random stuff instead of going right to what I think the problem is, keep in mind that most of the equipment on this car is original, so its probably time to swap that stuff out anyway! For some reason whenever I turn the a/c on it only compounds the problem even though both fans are running. Sometimes with the a/c on I may not make the trek home (8 miles city) without having to pull over at some point to let it cool down, and to refill the water. The only thing that really seemed to help was replacing the original plastic tanked radiator with an all-metal unit. They temp needle stays put most of the time unless I am really getting low on water.

A little note on the leak down test; my Snap-On dealer used to work for Ford when they came out with the turbo'd SVO Mustangs. He said the cars used to have the same problem, and that most would not show anything abnormal with the usual tests, but as soon as they would take them out for a hard test drive, they would loose coolant and overheat. There was no water in the oil or vise-versa, no evidence of anything on the plugs, and no water out the tail pipe. They fashioned a pressure guage setup for the cooling system that allowed them to read it when they were driving. Turns out that under boost, the water pressure would really spike, blowing the fluid into the catch can and ultimatly loosing it on the street. What they felt was happening was that there may have been a very small leak that would not show up under a no load-condition, but as soon as you boosted and put some stress on it, it would open up and allow combustion gasses into the cooling system, which would not only heat up the already hot water, but displace it as well.

Now, they do have a tool that allows you to test and see if there is in fact combustion gasses in your water, but using it with our cars is a pain, if not somewhat impossible. You are supposed to lower the coolant level a couple inches so that you don't suck up any water into the tester, but on the Mitsu's, as soon as the t-stat opens you got a whole lot of water flyin through there, contaminating the test liquid in the tube. I thought that would be some good info before anyone else runs out like I did and bought something they can't use!

Hope this help and sorry for the long damn post!