The_7

i don't know how many of you read the other posts, but my car was overheating and i could get the guage to max out pretty quickly if i didnt stop driving. so tonight i finished doing a bunch of work on it. i have a new thermostat, new water pump, radiator cleaned out by shop, and a new water temp sender. tonight i realized my OMP wasnt working so i premixed about 12oz of MMO in with a full tank. so i went for a little test drive....i was dissapointed. the guage doesnt max out anymore but still gets too hot. it also takes a lot longer to heat up than before so i have made some progress. the guages goes up to about 3/4 and holds steady there. i tested the actual guage also, using ohm values rx7 carl gave me and it seemed to be up to spec. however, the numbers he gave me were for the guages for a different year so i dont know if they are different for mine. at the end of the test drive i did a little spirited driving to see what would happen and it still stayed steady at 3/4. so first i want to make sure the guage works again. does anyone know the ohm values for the water temp guage for an 83 gs? also, any other thoughts regarding the situation are welcome as well. thanks. one of these posts is going to say "FINAL chapter in overheating saga", i just hope it is soon .

mar3

iTrader: (8)

You were running it with the OMP dead? If that's the case, you are seeing the 3/4 mark because you've put the engine on it's deathbed. Any smoke on start-up?

The_7

nope, no smoke. well i put everything back together and then realized i forgot to put the OMP lines back on (i took them off for being in the way). so the engine was running for a while and i looked at the omp lines and they were dry. i had a little bit of MMO in the tank before and now i have the proper premix amount. so what actually is different inside the engine when its on its "deathbed"? what causes it to run hotter even tho the rad, pump, etc is working?

edit: now that i think about it, i have had it smoke a little bit on startup before after it was sitting for a while. however, there wasnt any smoke tonight and it has been sitting for weeks.

AdrenalifeRX7

The apex seals on each rotor CANNOT be lubricated by the oil from the oil pan as a reciprocating piston engine can. Lubrication is vital to the seals longevity. An OMP mixes a measured amount of engine oil from the pan into the intake manifold where it mixes with the incoming air/fuel. The oil will mix with the A/F and lube the seals as it gets burned off in the combustion process. This is why rotaries burn oil. Without some sort of premix, whether it by by means of OMP or gas tank mixtures, the apex seals will deteriorate at much faster rate, possibly scarring the rotor housing walls, causing compression leaks/loss, etc. If you aren't going to use an OMP then make sure you premix with a cheap 2 stroke oil or if you want Marvel Mystery Oil works the best IMO. Using the MMO can get expensive after a while from what I've learned personally. The ideal premix ratio of 2 stroke/MMO to gas is 16oz oil/1 full tank. To say your motor is on it's deathbed is probably best summed up to the fact that you might have ran the motor too long without the OMP and the seals have fried themselves. I believe it would cause overheating from the friction and some smoking. I hope you figure it out.

NATE

The_7

lol, i know what the OMP is. in my previous post i said i just premixed tonight with MMO and ran it for a while so the overheating cant be from friction from the seals because i was running on premix.

AdrenalifeRX7

Yeah but the friction might have already done it's damage to the seals, that's why Mar3 said "on it's deathbed". You can't "fix" worn seals without a rebuild.

The_7

i know but why would worn seals cause overheating? i see that the compression wouldnt be too good and the power would drop but why would it overheat?

bliffle

I have developed an overheat condition in city driving with my 83. Goes back down to 1/3 on the hiway. I suspect the fan clutch is shot, so I figure to switch to an electric fan. As I recollect, the thing to do is go to the boneyard and get a fan, shroud and sensor from an Escort or Taurus.

B

The_7

well i got up to around 40 on the main street and it didnt really go down at all.

MarkPerez

When re-installing a thermastat make sure BEFORE you install it that you fill the engine with coolant. NO AIR POCKETS !! and make sure you install the thermastat the right way. something is going on with that engine
and it sounds to me that it wants to die !! sorry.

mar3

iTrader: (8)

I'm sure I could find an answer with a little digging, but it's just been my personal experience seeing three different 12As die, all in their 100,000+ mile stage of their lives, that the temps always rose about a year before they simply wouldn't start one day.

mar3

iTrader: (8)

Two things...

• He nailed it on the money, make sure the thermostat goes in correctly...
• BEFORE you install the thermostat, drill a tiny hole in the metal part of the thermostat base plate that sits in the pump housing so water and air can pass from one side to the other. I said a small hole, OK??

When you have the whole thing bolted back together pour in your anti-freeze mix, leave the cap open and start her up. Let the engine warm up and keep an eye on the coolant level in the radiator. You should see it drop suddenly. Dip your finger in there to see if the water's hot. If it is, you can now top off the radiator and close the cap. Fill the overflow tank and you will have no air-in-the-coolant woes. You might also want to try Redline Water Wetter.

The_7

hmm, well im not too worried cause im saving for a 13B bridgeport . but i was planning on doing a lil custom work - chaning the housings to se housings, getting new rotors, and 13B eshaft. if my engine is done can i still use the side plates?

mark p, ya i filled the rad as far as it would go with the engine cool, eventually starts coming out of tstat housing, stopped there, installed the tstat, gasket, etc. turned it on with the rad cap off to bleed the system and add coolant as the tstat opens...so im pretty sure i got everything right. how the hell do u put a tstat in wrong, lol ? .

id really like to know....im one of those people who cant just know that something DOES happen, i have to know WHY it happens to

AdrenalifeRX7

How's your oil cooler? Having a bad oil cooler will rise the temps considerably. Just a thought.

The_7

even if im running premix?

AdrenalifeRX7

Yes, even if you're running premix. Oil is 1/3 of a rotary's cooling system. If your oil is overheating your coolant will most likely overheat. Like I said..just a thought.

The_7

hmm, thats a good possibility. the rotors are cooled from oil sprayed through jets in the eshaft right? i think it would be wise for me to do a check of the complete oil system. how should i test the cooler to see if its flowing properly? can i run water though it and measure how fast it comes out to see if its clogged?

Matty's first 1st Gen

just a thought but perhaps try making a cold air intake, I have definatly noticed results with mine, i have an 83 gs as well, and my gauge goes up to 1/6th max

The_7

1/6th? holy ****, isnt that a little too cold? the coldest i ever had mine was 1/3 when it was running good. i dont think a cold air intake will help to the degree that i need, but would still be nice to have. im going to fabricate a custom one sometime in the near future.

Matty's first 1st Gen

i;d rather it be too cold than too hot,

i'm running an aftermarket rad though

DriveFast7

iTrader: (1)

That tells me the car cannot cool itself when stopped. Classic bad fan clutch. Good time to upgrade to Black Magic electric fan. summitracing.com sells them.

Doing the thorough repairs on your cooling system like you did would not fix the bad fan clutch problem, although it certainly would restore the cooling effeciency of the system back to stock levels. If you drive the car hard then park and idle, to the temps still go up? They should go down.

Not having apex seal lubrication will wear the chrome off the rotor housings much faster. Typically doesn't gouge the rotor housings until (if) the apex seal fractures then you got big problems.

Best way to check oil cooler for functionality is to have it sonic cleaned and flow tested. Costs $45 for a 12a oil cooler at "Sonic Cleaning" in Carson, CA and they vacuum seal it in a plastic bag when done!

Might be a good idea to spray the oil cooler with lots of Castrol Super Clean, let it soak then spray off with hose. I see you have an 83, if it has the stock beehive oil to water oil cooler now is a good time to upgrade to the 79-82 air-to-oil oil cooler. The latter works much better.

The_7

i couldnt get it to cool down anymore even when going 40+ mph, could it still be the fan?

ill try that tommorow, if it still goes up its most likely the fan right?

i dunno if i can find a place to do that around here. what exactly is the process anyway?

MarkPerez

Yeah, no ****. with all the pieces he's replaced, it should
run cooler. I know the water , or coolant passages in the housings are small, and alot of them !. It IS possible
that either you've got a clog, or something is blocking (a)
or some of the passages, or you've got a warped housing and your burning off coolant. When all is good in the cooling system, with the radiator cap off, coolant should be moving pretty fast around in there, if it's not that means no circulation, ( not moving ) Very bad.
Flush the living **** out of the engine with a de-greaser
like purple power. Is the heater still in the car and hooked up ?? make sure no kinks in any hoses too.

The_7

yea in one of my earlier chapters (lol) i was asking if it was possible for the coolant passages could get clogged, somehow that topic died tho. ill have to get some good stuff to flush the engine and do that (i did it recently but not very thoroughly). yea the heater is still working fine. it is getting really annoying, i have drained and refilled the coolant sooo many times in the past couple weeks. i dunno if this is relevent at all but i have noticed a new sound. in the engine compartment i can hear this clicking sound. not that loud, but pretty fast repetitions.

AdrenalifeRX7

What's the condition of your water pump? Yeah and check all the hoses. A collapsed hose can cause the problems you mentioned too.