JHew84

iTrader: (9)

hey guys, i'm pretty much a rotar newb so bear with me and try to explain things in as 'simple' terms as possible, i've been working on cars for awhile, but when it comes to rotary's i get lost in the jargon sometimes... anyway, onto the problem, heres the whole story, from the start until now...

I just bought a 93 R1, the guy drove it from TN all the way up to MI (like 600 miles or something, great guy) and the car had zero issues the whole way up, he got here early friday morning (3-31-06) and we went for a test drive, the car rode and drive just fine, no issues, stayed a constant 83-84 degree's, boosted fine, everything was great... we took care of all the paperwork and went over some other stuff in regards to the car and FD's in general, then we went back out to the car to remove the power FC and put the stock computer back in (he wanted to use the power FC for the drive up but was keeping it), well once we hooked the stock computer up the car wouldn't start, so we put the power FC back in and it still wouldn't start, he thought the car was flooded so we tried unflooding it for a few minutes to no avail ... well it did end up being flooded, monday (4-3-06) i did the unflooding procedure a few more times and replaced the plugs and it fired right up, and i enjoyed the show ... the AWS kicked in and the idle jumped up to 2500 as i expected it would, BUT there was some smoke coming from inside the engine bay as well, upon further inspection it smelled like burning coolant, so i kept trying to find where the smoke was coming from and it looked like it was coming from the rear turbo, i got back in the car and checked out all the vitals on the power FC, the temperature at that point was starting to rise from around 40 degrees pretty quickly, faster than i had thought it should so when it hit around 60 degrees i blipped the throttle (so it wouldn't flood again) and shut it down... me and my roomate jacked up the car and started checking stuff out and the coolant was dripping off the engine cradle, towards the firewall on the passenger side, after climbing under the car and looking a little closer the only place i could really see any coolant sitting on was the turbo housing, which would explain the smoke, but looking from both the top and bottom we couldn't find a leak... so i shut it up and pushed it back into its place in the driveway and went to bed, when i got out of class today i decided that i'd give it another go and see if i could find the leak, so i started it up and once again the rpm's shot up to 2500, not nearly as much smoke came out of the exhaust, hardly any at all actually, and no smoke was coming from the engine bay, so i got on the ground and looked underneath, there was no puddles, no drips, nothing, was still idling high so i got back in to watch the temp, it seemed to be going fine and steadily increasing until it was around 35-40 degrees, then the temperature started rising a little faster and then a little faster but this time i decided i'd let it get up to operating temp before shutting it down, well it hit 89 degree's and didn't seem like it was going to level off so i shut it down, checked under the car again and there was no puddles, and no drips on the engine cradle either...

and thats where i'm at now, to ME it sounds like there is some air in the system, maybe from when it leaked out the other nite it sucked some air in at the same time? but again i am definitly a rotary newb and something might have happened that i dont understand yet... also the leak may not be fixed or gone, but just covered up...

anyway, ANY help is greatly appreciated, me and the seller are frantically trying to get it fixed in a timely fassion, he has been more than gratious during this process and has assured me that the car will be in good running condition before the sale is 'complete', even if it means flying back from TN to MI, naturally i would prefer to avoid this if at all possible...

thanks again for any help, and sorry for the book above haha...

- James

P.S. i've been searching these forums non-stop since friday afternoon, first with the unflooding (found lots of good info with those searchs), then with the overheating, and i can't seem to find anything useful...

Gadd

Your right, if you have a leak in the system it is likely your coolant is low, (search burping the cooling system) The leak is likely at one of the turbo coolant hoses. lots of autopart stores will rent a "cooling system pressure tester" that will help you pinpoint the leak.

Harold93

James, frst off welcome to the world of the FD. what you are describing sounds just like what i am going through it started about three weeks ago slowly and just got worse. let me start buy asking you a few questions, is you add coolant light coming on? have you checked your coolant level since it started over heating? if you do not have the alarm and your level is good it sounds like you have air in the coolant system. being a 93 it could be in a varity of places and could range from a cracked hose to a leaking seal. the first thing to do would be to go to the manual and follow the procedure for removing air from the coolant system. if you are still having problems after you are sure you have all the air out, have the system preasure checked. i think it is 26 psi you need to look it up but whatever it is charge the system and see if it holds the preasure. now also check the resivior the tank on the left side of the car about a foot and a half infront of the turbos. there is an over flow port on the top of the tank it alows air to escape while coolant enters to avoid preasurizing the tank and also alows over flow if too much coolant is coming into the tank. this might be the source of your leak it can run along the bar and dripp right onto the turbo. if you find that this is definatly your point of origin for the leak it could still be air in the system or a bad cooling seal. see when you have air in the system it will heat up and occupy more volume than the coolant, this will force coolant out and at the same time keep the system under so much preasure it will not allow more coolant to be sucked in through th hose in the over flow tank. the other problem it could be is what i am working on right now you have a bad coolant seal\ oring, there are only two little seals that seperate your jacket water passageways( coolant paths) from your chambers, if they go your coolant could be going into the chamber and is being burned and pushed out the exhaust. this will give you the no pools under the car. also while this is happening exhaust gas from the chamber is slipping into the coolant passages causing the rapid excceleration of the engine heating up. it also generates a lot of preasure that will force coolant int the resivior tank. when we were checking mine we put it on a lift , drained all the coolant and flushed the system to ensure there were not blocks \ leaks, then we followed the manual on filling the system. once we knew everythign was full and air free, we started it up after about 20 min the add coolant light came on, we shut her down and checked thre was no coolant under the car and everythign seemed to be full we let it cool pulled the fill neck and everythign looked ok, after we did this about 4-5 times we started it up and there was a ton of smoke, it smelled sweet the engine was also getting harder to start as we went almost like it was flooded what it ended up being was coolant in the chamber stoping the combustion untill there was so much fuel it over came it. i am in the middle of a rebuild right now and i will let you know what to look for as i find it. i hope you just have air in the system good luck
Harold

JHew84

iTrader: (9)

no, i had my eyes planted on it the whole time and only breifly looked away to check the temp reading on the power FC...

i checked it over the weekend when i did a full once over of the car while still figuring out a good way to go about doing the unflooding procedure and it was full then, checked it again after starting it on monday night, full (or at least there was coolant in between each of the little slits, looked full to the best of my knowledge), checked it this morning before starting it and it was full again, checked it after running it and it was still full, when i lost coolant monday night it was probably 8 drops total with a few drips still left on the cradle, not much at all, and i would figure that if the coolant level was low BEFORE we had the flooding problem brent (the seller) would have had overheating problems on the trip from TN to MI, so i'm ASSUMING the only coolant lost was the small amount that dripped out on monday after i got it started...

from all my searching i think its 13psi, but i'll double check the service manual before doing anything for sure... also from the searching and reading the newbie FAQ i came across that cool burping tool, my roomate works at a parts store that sells that brand of tools so he's going to check on it for me tomorow and see if he can order it through them for cheaper, if not i'll order it off the internet (seems to be the easiest way to purge the system of air)...

now your scaring me haha... although your symptoms do sound kind of like whats happened to me thus far, my exhaust is clean as far as smoke goes, and definitly doesn't have a sweet smell, while unflooding the car it obviously smoked like a civ, but when i started it up earlier today there was a much smaller amount of smoke for a minute MAYBE, then it went away aside from some usual condensation (just normal cold motor type ****), so it doesn't seem like i'm getting any coolant inside the actual combustion chamber, i'll check out the overflow tank tomorow before i go to class and see if i can't see anything, thus-far the only tank i've really seen is the fill tank that is like undert he passenger headlight, but i'll look further into the system... also if it was a coolant seal in the motor would it really be something that one day would be fine, the next be leaking? i know these motors are tempermental, but THAT tempermental? if its not air in the lines i was thinking it might be a turbo line, but can't know that for sure without pressure testing the system...



i was planning on burping the system before i did any pressure testing, hopefully i can get that burping tool tomorow and get it all tested, then after i do that a pressure test will definitly be a requirement, unfortunatly the local auto-zone stopped letting you take pressure testers home since so many people mis-used them , i will check a couple other auto-parts stores to see if they have one to rent, if not my roomate might know someone that has one, hopefully...


thanks for the help thus-far, any more ideas to bounce around are certainly apprecaited though, thanks again harold for the welcome and the help, it is VERY much appreciated

- James

JHew84

iTrader: (9)

oh and monday night we could hear a gurgling/bubbling noise from one of the caps, thats why i'm thinking it is air in the system... forgot to mention that

Harold93

that would have been a usefull bit of information i think you will probally need a new cap if you hear the bubbleing again i hope it was just air. good luck with it

RotaryResurrection

iTrader: (8)

For one, you dont need a special tool to burp a stock coolant system (all hoses and components present, versus a simplified setup with some stuff removed). Just find the uppermost hose in the system, ona stock engine this happens to be on the back of the throttle body. Just slip it off gently by twisting it with pliers. Now fill the system normally until it won't hold any more. The open hose allows the trapped air to escape, being replaced by coolant. You should also have the heater core open (heat on full) when trying to bleed the system, as air can get trapped in there.

WHen you think it's full, (with the hose you removed put back in place) put the cap on and squeeze the upper radiator hose as vigorously as possible for a few seconds. Remove the cap and refill. REpeat until it stops taking coolant...you're now good enough to start, run, and drive. Heat it all the way up to normal temp by driving a short distance, then let it cool completely down, refill, repeat. This might take 2-3 days to get all the way done.

Also, by putting pressure on the radiator hose, you can find a major leak at the same time. IF you squeeze the hose and something leaks out from the back of the motor, it's not too hard to find.

Oh, and re: you watching the temps on the PFC display, it's normal for temps to climb about 1 degree C per 4-5 seconds until it levels off around 90-95. On a stock motor, the fans dont kick on until around 95 as I recall, so you were worried about nothing the whole time.

JHew84

iTrader: (9)

the temps were rising maybe 5 degree's C every second or 2 at one point, it definitly was not a gradual warm up process like i thought it should be, but then again rotary's are known to run hot so i thought it MIGHT be normal, i am very confident it would have continued climbing at a rapid rate had i not shut it down since it hit 90 from 40 in a very short period of time... i've been told normal operating temp is in the 80's somewhere... and i know how to burp a coolant system, but there really is no good place to do it at the house i'm living at right now because spilling coolant anywhere really isn't an option for a few reasons, and that burping tool seemed like a rather clean process, i might end up doing it the old fassioned way though.... and i know i shoulda remembered all that earlier, i've had a lot of stuff going on the past few days with the FD and other things as well, lots of things have been slipping my mind ...

in the next couple days i'll burp the system, i'll give an update then, i dont think theres really anything else left for suggestion until i figure something else out, but if so feel free, any help is always appreciated ...

thanks again for all the help, its much appreciated ,

James

PS, kevin, the guy i bought the car from lives pretty close to you, we were talking about that red 7 you bought in ohio and he clued me in to who you were, i felt like a tool after that for giving you **** haha, guess that'll teach me to read peoples signatures from now on lol...

CantGoStraight

That sound usually means boiling cooant moving int the recovery tank. If you can get hold of a system pressurizer you have a better chance of finding the leak, You don't want to use the coolant recovery tank as you means for making sure the coolant level is correct, you have to remove the caps to do this (and only check with engine cold). Since you've lost coolant it has deffinately got air in the system. So first thing is to top off the system, get the air out and pressure test it if you can. The recovery tank should be a third to half ful when cold, this will allow for coolant to push out when hot yet not overflow your recovery tank.

Brent Dalton

iTrader: (31)

Normal operating temperature for this car is 84-85C, very rarely it gets to. I'm assuming it has gotten air in the system somehow. One of the old hoses may of finally given out once we got it up there. Like Kevin said, pull the coolant hose on the back of the throttle body and follow the rest of the procedure. It may need a new AST cap. Let me know how it works out.

Gadd

Find the leak, just burping the system is only treating a symptom of a larger problem. A coolant leaking around the turbos is nothing to mess with. Antifreeze will start on fire if gets concentrated and hot enough.

ptrhahn

iTrader: (9)

You let the guy leave with your money when he delivered a car that doesn't run right?

scotty305

iTrader: (2)

Jhew84, my car warms up from 40C (104F) >> 80C (176 F) pretty quickly. The coolant temp increases from 60-80 more quickly than it increases from 40-60. As mentioned by others, 85C is a safe temperature. You will probably see constant 80C temps when cruising at 60+ mph, due to the amount of airflow throught the radiator. If your idle temps don't level off around 95-100C when the radiator fans kick on, then it might be time to worry. As long as the pressure cap on your AST is working correctly, your system's boiling point should be above 105-110 C, depending on your coolant/water ratio. Most RX-7 owners will start worrying when their temps go above 105C (220F).

Have you checked the coolant level today?



Kevin (RotaryResurrection), have you tried that Lisle coolant funnel tool? After burping my system by disconnecting the TB line and squeezing the radiator hose, that tool STILL removed a lot of air; about half a litre's worth of air. This was after a coolant flush & refill, so you might not get the same results on a car that hasn't had a recent coolant flush.



-s-

JHew84

iTrader: (9)

he's an old school forum member, a military man, and just an all around stand up guy, i have signed documentation that the car would not remain in its condition and that he would do everything in his power to ensure that, i'm not worried one bit, he's already posted in this thread and i have pretty much either talked with him through PM's or on the phone every day since he left, again i'm not worried at all, if he was going to skip out he would not have been nearly as helpful as he has been, nor would he have kept such close contact ...

Gadd, i realize that, i definitly plan on pressure testing the system, first comes getting all tha air out though, and hopefully getting it to the point where it will run/drive without overheating, then i'll start trying to track down where the leak from the other night came from...

Scotty305, no i haven't had a chance to check it today, i've been using the dipstick but below someone is saying to check it otherwise, so i'll do that, the local shop will have the burping tool in tomorow which works out fine because i dont have enough time tonite to really give the car the attention it would need... and i dunno, it was rising pretty fast, it hit 90 degree's and showed no signs of slowing down, not to mention the stock gauge was starting to get up near the H line itself (which probably doesn't mean anything, but it was doing it none the less)... i figured it was better safe then sorry, and overheating the motor is not the first thing i want to do with this car haha...

scotty305

iTrader: (2)

JHew84, check the coolant level at the filler neck, but ONLY when the car is cold. Don't remove the cap if it's warm to the touch. There's a diagram here, if you don't know where to find the filler neck: https://www.rx7club.com/3rd-generation-specific-1993-2002-16/cooling-system-flush-info-441967/


You said that the stock gauge was rising towards the H mark. Do you know if the previous owner has modified that gauge? He might have performed the "temp gauge linearization." If he's linearized the gauge, you might be OK. If the gauge has never been modified, it's safe to say that your motor was getting too hot.

Good luck,
-s-

JHew84

iTrader: (9)

um, that i'm not sure of, when i talked with him on the phone the other night he said something about the gauge being linearized, but anything further than that i'm not sure, i'll ask him next time we talk or if he reads this beforehand i'm sure he'll chime in...

i've been checking it on the overflow tank, thanks for the link it will make it easier when i get out to check stuff over, i just got home and i'm beat so i'm gonna go to bed so i can wake up early for classes, but before i head out ill be sure to check the level (the car has been sitting for a day or so now so its definitly cold and not under pressure), when i get out of class i'm gonna swing by the parts store and pick up the burping tool, any recomendations on coolant? or just get some good green stuff? not sure if rotarys like a certain brand more than others for whatever reason haha, they seem tempermental enough that they'd differentiate between them like that ...

thanks,

James

Brent Dalton

iTrader: (31)

Yeah, thats what I was explaining to you the other day. The stock gauge is not linearized to my knowledge. A normal stock gauge basically has 3 settings, cold, operating temp, and hot. Once the needle starts climbing, most of the time it's already to late. But in your case, you had the Power FC hooked up and it's reading was 50 something. I would trust it over the stock gauge. Nonetheless, you did the right thing by cutting it off. Always better safe than sorry. This is a solid car. I'm guessing one of the hoses finally gave out. I drove the car 600+ miles to him and it sat at 84C the whole time. I arrived, we test drove the car. I showed him how cool it ran and what kind of power an FD has , and we parked it. As he has already stated, thats when the car flooded(which it has never done but I'm sure it had something to do with the drive up there). I actually amended the bill of sale(as he stated) to assure he was not getting a bad deal. Good luck tomorrow and let me know what you find. Thanks to everyone that has given advice.

pomanferrari

iTrader: (1)

I think you're SOL. Once the stock gauge goes toward H, you are dead because the stock gauge is tied to sensing the metal temperature of the rotor housing, not the coolant. Your coolant temp is measured near the filler neck so it does not reflect localized catastrophic heat transfer that the stock gauge would be measuring.


I should know. I had two engines go this way in about 40K each.

RotaryResurrection

iTrader: (8)

UH...no. No it isn't.

The gauge is run SOLELY by the temp sensor in the rear iron. Not only does it thread into the iron, but the probe protrudes into the coolant passage by about 1/4". The probe actively measures coolant temp.

The sensor by the water neck is also a temp sensor, but is used solely for the ECU's benefit, to determine rich/lean characteristics (like a choke on a carb motor).

The 2 have nothing to do with each other.

Even if you make the argument that there was air in the system, the dash sensor sits lower in the engine than the ecu sensor, so any air would be at the top, not the dash sensor. Either way you look at it, the dash gauge sensor measures coolant temp only.

CantGoStraight

Burping the system isn't a treatment of a symptom. You want as little air in the motor for many reasons, troubleshooting the leak when pressurising the system, avoid localized boiling and prevent the water pump from cavitating or possibly even not moving any water at all. When there's air in the systemit expands more than coolantand push's more coolant into the recovery tank than if it was just coolant. So it's necessary to burp it not just a treatment. I don't think anyone mentioned burping the system to mask the problem.

JHew84

iTrader: (9)

what he said ... your concern is duly noted and much appreciated, but i have every confidence in brent as a person and a seller, no worries from this end ...

i checked the filler neck today and sure nuff, couldn't see any coolant, i just got done picking up the burping tool and some coolant so when i get home from work in a little bit i'll do that and see how it turns out... as far as already toasting the motor, wouldn't i have heard something out of the ordinary if that were the case? the motor ran smooth as silk the whole time aside from the high idle, and the needle itself never went above the H line, i cut out before it reached there and it moved slightly upwards after it was shut down, then dropped, both times, not to mention the add coolant light never came on, i am pretty sure i didn't overheat it... and i was a little fuzzy on what you were explaining the other day brent but i got it now, my phone was breaking up (typical tmobile up in MI) so i probably missed part of the explanation anyway...

thanks for the new replys everyone , i dont have internet (power went out and comcast sucks at life) at my house right now so if i dont give an update tonite that would be the reason, but i'll give you a call at some point tonite brent to let you know how everything went ...

- James

JHew84

iTrader: (9)

ok guys, i burped the system and it took on about 1/4 a bottle of coolant (give or take a Liter), more than i expected it to take on, but still not terribly bad, so i started it up with the burp funnel still attached as per the directions, the idle was still at around 2.5K, but i watched the temp rise and it DEFINITLY was a lot smoother, MUCH different from the past 2 times, i see what you guys were saying about heating up faster after 40 degree's C (which i expected) but what happened the other nite was certainly not as gradual as it was today, it leveled off around 80 degree's C so i figured i would shut it down, remove the burp tool, and put the cap back on... so with the cap back on i started it up again and the idle shot rigt back up to 2.5K again, this bugged me somewhat since it was already warm the AWS should not be kicking in, so i blipped the throttle a couple times and instead of dropping slightly and then returning to the accelerated idle like it usually did it just dropped down slightly, then a little more, then a little more, so blipped it again and it went down to just over 2000 rpms, and slowly continued down til it hit about 1500rpms, then it started to surge a little bit ???? so i blipped the throttle again and it evened out for a second then surged again, so i blipped the throttle yet again and it evened out at just slighly above 1Krpms (which is normal, brent has it set a little high), i let it sit for a couple seconds, got out to check stuff over, was still idling smooth, figured i'd take it around the block just to make sure it would drive fine so i shut the hood and got back in, temp had risen to 84-85 degree's C and the stock gauge was sitting right where it should, so i start to back out but as i put the clutch in to go from R to 1st it starts surging again, so i blipped the throttle and it didn't go away, so i put it in 1st and started to take off, it took off smoothly, drove through 1st smoothly, 2nd smoothly, 3rd smoothly, 4th smoothly (not going fast whatsoever, maybe 35mph tops), come to a turn and put the clutch in and it still surged, so i went back through the gears and it still ran smoothly while in gear, got to the back stretch of my neighborhood with a longer straight road with barely any houses on it, gave it a little more gas (barely made boost) just to see if it would cut-out or anything and it seemed to accelerate fine with no problems, so i pull back into my driveway and stop and its not surging anymore ???? so i blipped the throttle and shut it down (i'll be damned if i EVER flood this car again haha)... oh and throughout this ENTIRE process i have been diligently checking under the car (mainly where it leaked before, but also in other spots) to see if any coolant was leaking out at all, and its not, there is a corroded looking peice of plastic on the overfill tank neck, but it is an outer covering and not the actual neck itself, i'll get a picture of it for referance, next step is to pressure test it and see what happens...


THE BIGGEST THANK YOU TO EVERYONE WHO HELPED OUT, you do not realize how much your warm welcome and help on this subject means to me, judging from brent and the help i've received thus-far i can already tell FD ownership is going to be one of the best experiences ever (aside from fixing it haha)... feel free to shoot anymore ideas about the surging thing my way, or just about anything in general, i'm going to be searching these forums like a mad-man for a few years i can already tell, there really is a lot of good information on here and a lot of good knowledgable people ...

- James

JHew84

iTrader: (9)

well i just cut/pasted the post above that i typed up earlier in word pad, but i have talked to brent since then (i typed that at around 2:30, its now 6:20) and he tells me the surging is a normal thing that the PFC does when indroduced to different climates/elevations whatever, and that it'll go away soon, so i'm not so worried about that anymore, i'm gonna take the car out to a meet my local racing club (legalized racing ) has and keep a close eye on everything, it isn't very far away from my house so i figure its a safe bet for a good test run... hopefully in the next few days i can get my hands on a pressure tester to see if there really is a leak, but at this time i'm thinking there was just to much air in the system and it pushed a little out of a seal that is normally sound, then again that doens't seem like totally fool proof theory to me either so i'm going to pressure test it regardless, what can it hurt right?

thank you all again very much, if you have anything else you'd like to throw my way knowledge wise i am ALWAYS looking to learn things...

- James

JHew84

iTrader: (9)

just got back from the meet, the car started up and drove fine on the way out there, but after sitting in the parking lot when i started it up to leave there was a little smoke for a couple minutes (it cleared up) and around 4 more drops of coolant under the car, while i was trying to see where the leak was the underhood smoke cleared up and there were no more drips, the AWS came back on tho (that is going to be really annoying) but was at a lower rpm, only around 2K, i drove it home with no problems stayed at an even 85 degree's C the whole way, no odd smells, nothing, let it sit and idle in the driveway for a little bit and it didn't drip any more coolant or smoke at all... so there is definitly a leak that needs to be addressed, what would the best way to find it be? pull off some of the turbo/intake piping and pressurize the system? because i gotta tell you i am having a hellova time seeing anything in the area that the smoke/drip is coming from...

later,

James

Gadd

You'll never remove all the air from the cooling system as long as you have a leak, I don't care what tool you use. As soon as the engine cools and the cooling system gos to a vacuum, in will pull air in from the leak. So what's the point? Find the leak, a pressure tester make it obvious, fix it and burp the system as Mr. Landers suggested. It will take a couple of cycles of warming the car to temp and cooling to truly remove all the air from the system.