Ok ive been lucky so far tapping into coolant system when fitting turbo and had no issues with coolant airlocks....until now!, last night i was sorting a leak on one of the turbo coolant feed pipes and when i came to test driving it to work today after lunch i noticed cold heater and then temp gauge starting to go above half after about 1 mile!...stopped took coolant cap off while idling and massaged the big coolant pipe you can access from back then drove back home with res cap off and heater came hot again, parked it checked/tightend up all hose clamps to make sure no more leaks and went back to work.
Came to it again tonight to see if ok but heaters colds again and temp is rising!....tried the standard bleed procedure using under frunk bleed pipes and got some air bubbles but still not getting hot water to front of car!...after 3 hours faffing about ive given up for tonight and now feeding and drinking wine!... left it with rear jacked and res cap off...hoping for the best!
Im doubting its fixed in morning so any tips people have used to free up airlocks on these is welcome ?
To be honest im close to putting it all back to stock and selling the turbo kit as im starting to loose the will!!!....if i hadnt had a good drive on boost at weekend it would already be off the car, its so nice to drive with the turbo i just need to find the motivation to iron out the last few niggles!...problem is i want to get out on track asap so need things sorted!
TIA
I really went hell for leather squeezing/massaging the pipes, with the spare wheel well fully removed I had decent access to all four. I had swapped for silicone ones so they were a little less pliable but I was really ensuring a full flow of the coolant up towards the drain bits.
Forgive ignorance on my part but the piping that goes off to the turbo - how much higher/lower is it than the four factory hoses near the rad?
Assuming you're following all the procedures and have the heater set to full heat while you do it then my guess would be you've got a small leak somewhere letting air back in.
I tend to recall a chat with Steve some time ago, he had a stubborn air lock, the work around was to raise the rear of the car whilst doing what you would normally do.
Just wish he was around to elaborate.
I just kept squeezing all the pipes I could get my hands to whist the engine was running. I then turned the car off and opened the coolant cap. Rinse and repeat. You can also pull the coolant tank of the body and raise it as high as you can whilst the engine is running so the air has an escape.
Quote from: Bossworld on February 4, 2020, 21:25I really went hell for leather squeezing/massaging the pipes, with the spare wheel well fully removed I had decent access to all four. I had swapped for silicone ones so they were a little less pliable but I was really ensuring a full flow of the coolant up towards the drain bits.
Forgive ignorance on my part but the piping that goes off to the turbo - how much higher/lower is it than the four factory hoses near the rad?
Yes ive been giving the 2 big pipes under frunk a good massage but no joy as yet and they remain cold, also been underneath back of car squeezing other end of these big pipes at engine they get hot here but it doesn't travel to front at other end of pipes, more effort needed I think.
Turbo coolant taps into the system that feeds the heater circuit from what I can see, its more annoying that ive managed to have these pipes on and off several times without getting a airlock then this time just messing about with clamps etc I get the lock, I think when I left it last night there was still a small leak and that's when air got in, if I had just gone for test drive last night im sure it would of been ok!...oh well
Quote from: Call the midlife! on February 4, 2020, 21:38Assuming you're following all the procedures and have the heater set to full heat while you do it then my guess would be you've got a small leak somewhere letting air back in.
Yes followed the correct procedure and had car jacked up at the back, im pretty sure all leaks are sorted but as above it got a lump of air in last night I think as I didn't take it out after playing with clamps.
Quote from: JB21 on February 4, 2020, 21:50I just kept squeezing all the pipes I could get my hands to whist the engine was running. I then turned the car off and opened the coolant cap. Rinse and repeat. You can also pull the coolant tank of the body and raise it as high as you can whilst the engine is running so the air has an escape.
Thanks, so far Ive had cap off when squeezing pipes and engine running, might try it with cap on and maybe the extra pressure will help shift the air!
Why the rear jacked up?
Jack up front, remove radiator cap, make sure coolant to top of radiator then replace cap.
Open coolant bleed nipples under frunk at bulkhead, now top up coolant reservoir until no air bubbles come from bleed nipple.
Now you can start up engine, heater on hot and full blast, keep eye on coolant level etc
If the heater does not get hot enough, rev the engine 2-3K rpm a few times
:-X :-\
Quote from: moredun on February 4, 2020, 23:52Why the rear jacked up?
Jack up front, remove radiator cap, make sure coolant to top of radiator then replace cap.
Open coolant bleed nipples under frunk at bulkhead, now top up coolant reservoir until no air bubbles come from bleed nipple.
Now you can start up engine, heater on hot and full blast, keep eye on coolant level etc
If the heater does not get hot enough, rev the engine 2-3K rpm a few times
:-X :-\
You obviously haven't seen the radiator and coolant layout on a roadster :) there is no rad cap at front only at rear on coolant bottle, hence raising rear unlike when there is cap on rad at front where you raise front.
Mine is just being stubborn! :(
Little bit of progress this morning before having to go into work, left car overnight with rear up on stands and res with plenty of coolant in it, when i came to it this morning level had dropped so gave all pipes a good squeeze and then fired up car and let it warm up, now have heat out the heater which is good and hot water to one side of the rad, however its only side and outlet on other side isnt gettin hot even when upto temp so still some air in there.
I think part of the issue is the bleed screw on side of rad isnt the best, i have to open it a lot to get fluid to come up into the extension tube and by this time its leaking out past the bleed screw so difficult to get all air out as at that point its lot lower than rear res tank, tonight i will drop car down off axle stands and reverse it onto drive so front is a touch higher which should help get last bit of coolant out the radiator bleed screw....i hope!
Based on this i dont think the rad has ever been properly bleed before, there was evidence of some coolant in the extension tubes so someone has had a go in past and the fact car has always run quiet high coolant temps (90-93c pretty much all time) since i got it and before turbo install leads me to believe is not been using all the radiator capacity, probably a big pocket of air in the top of it and will be interesting to see if it runs any cooler once i get all air out.
See how we go tonight, fingers crossed!
Quote from: thetyrant on February 5, 2020, 09:25Little bit of progress this morning before having to go into work, left car overnight with rear up on stands and res with plenty of coolant in it, when i came to it this morning level had dropped so gave all pipes a good squeeze and then fired up car and let it warm up, now have heat out the heater which is good and hot water to one side of the rad, however its only side and outlet on other side isnt gettin hot even when upto temp so still some air in there.
I think part of the issue is the bleed screw on side of rad isnt the best, i have to open it a lot to get fluid to come up into the extension tube and by this time its leaking out past the bleed screw so difficult to get all air out as at that point its lot lower than rear res tank, tonight i will drop car down off axle stands and reverse it onto drive so front is a touch higher which should help get last bit of coolant out the radiator bleed screw....i hope!
Based on this i dont think the rad has ever been properly bleed before, there was evidence of some coolant in the extension tubes so someone has had a go in past and the fact car has always run quiet high coolant temps (90-93c pretty much all time) since i got it and before turbo install leads me to believe is not been using all the radiator capacity, probably a big pocket of air in the top of it and will be interesting to see if it runs any cooler once i get all air out.
See how we go tonight, fingers crossed!
Is it the stock radiator or the usual cool parts replacement? If the latter, the O-ring supplied is the wrong size, and usual preference is to re-use the Toyota bleed screw with a new O-ring (6 x 2.5)
No idea :( it was on the car when i bought it is there a way to tell ? if this o-ring is wrong would it give the issue im having with me having to fully open the bleed to get fluid into extension ?
It's normal to have to unscrew the bleed screw out a long way.
Is the turbo coolant system is tapped off the heater circuit in any way? If so, this could be part of the issue. The thermostat is on the return from the radiator. If it doesn't open, the coolant will not circulate through the rad. The return from the heater supplies heat to the back of the thermostat allowing it to open.
If anything impedes, or short-circuits this the thermostat will either not open, or be very slow to open. An air-lock in this part of the system will also cause the symptoms.
It's probably more than a coincidence that you did something to that part of the system and the symptoms appeared.
I would have to see the actual set-up to know for sure, but I've had experience of a partial blockage in the heater return pipe that caused exactly the problems you report.
We did an engine swap on JVanzyl's car. The new engine had been stored for some time and the guy had put a plastic cap inside the heater return pipe that is bolted to the side of the cylinder head, as part of an effort to seal the engine. I went through all kinds of madness until I happened to find it!
Once I got that out (and it wasn't a complete blockage, but enough to cause an air-lock) it bled up just fine.
I didn't need to bleed mine at all. Read online this is the only way to do it but no need in my experience. Just lots of squeezing of all the pipes, following the flow. let the coolant get up to around 90-100 degrees using torque pro, engine off and unscrew the coolant tank cap, rinse and repeat. Radiator fans kicked in on the 3rd cycle of doing this and coolant fully recirculating.
Quote from: Carolyn on February 5, 2020, 10:57It's normal to have to unscrew the bleed screw out a long way.
Is the turbo coolant system is tapped off the heater circuit in any way? If so, this could be part of the issue. The thermostat is on the return from the radiator. If it doesn't open, the coolant will not circulate through the rad. The return from the heater supplies heat to the back of the thermostat allowing it to open.
If anything impedes, or short-circuits this the thermostat will either not open, or be very slow to open. An air-lock in this part of the system will also cause the symptoms.
It's probably more than a coincidence that you did something to that part of the system and the symptoms appeared.
I would have to see the actual set-up to know for sure, but I've had experience of a partial blockage in the heater return pipe that caused exactly the problems you report.
We did an engine swap on JVanzyl's car. The new engine had been stored for some time and the guy had put a plastic cap inside the heater return pipe that is bolted to the side of the cylinder head, as part of an effort to seal the engine. I went through all kinds of madness until I happened to find it!
Once I got that out (and it wasn't a complete blockage, but enough to cause an air-lock) it bled up just fine.
Ah ok i think its just a bad seal on the bleed screw now, looking at pictures on here of coolparts bleed it looks same as mine, as in round with a slot in it and not a butterfly shape like toyota so no doubt part of the problem and making bleeding more difficult, lifting front will help get last bit of air i think and will see if i have a o-ring to suit.
Turbo coolant is spliced into the heater circuit yes, basically the sharp angle coolant pipe that goes to heater under PCV valve is removed and turned the other way to feed into turbo, then a new pipe from turbo back onto cars coolant system above gearbox completes the circtuit, no doubt this is where my problem started and as mentioned before ive been lucky not to have to bleed anything depsite unhooking this turbo coolant feed several times, ive always used clamps on pipes and tried to get coolant flowing out of pipes before reconnection and been ok up until now.
This morning all was working ok upto a point so think im nearly there, just rad wasnt getting fully heated and returning back to engine/stat etc which im thinking is last bit of air issue, also i think its been like this for awhile to be honest and only me getting air into heater circuit which has then got into main coolant feed pipe showed up the problem, when i ran car up this morning it warmed up as it used to and stopped around 93c sitting there same as it did prior to issues but the rad was still cold on exit side, looks like the heater circuit on its own is able to hold coolant in the 90's temp wise without really using main rad fully!
Yesterday when running it up and heater circuit was airlocked the coolant temp was hitting 100c before i shut it off.
Quote from: JB21 on February 5, 2020, 11:21I didn't need to bleed mine at all. Read online this is the only way to do it but no need in my experience. Just lots of squeezing of all the pipes, following the flow. let the coolant get up to around 90-100 degrees using torque pro, engine off and unscrew the coolant tank cap, rinse and repeat. Radiator fans kicked in on the 3rd cycle of doing this and coolant fully recirculating.
Sounds like you were lucky and it burped out any air on its own, ive seen that before on other cars, also its worked for me a few times since fitting turbo as well.
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You obviously haven't seen the radiator and coolant layout on a roadster :) there is no rad cap at front only at rear on coolant bottle, hence raising rear unlike when there is cap on rad at front where you raise front.
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You need to raise the front of the car, not the rear, both radiator and heater matrix are at the front ...
If your radiator has no cap, it has side bleed nipples ...
and the highest point for coolant bleeding is the bleed nipple under frunk beside the bulkhead
Note: all at the front of the car, not the rear.
I've found that raising the rear with the cap off the bottle and the bleed points open, allows the system to fill.
I've done this several times. It always works.
You must use the bleed tubing, though.
Quote from: moredun on February 5, 2020, 12:32You need to raise the front of the car, not the rear, both radiator and heater matrix are at the front ...
If your radiator has no cap, it has side bleed nipples ...
and the highest point for coolant bleeding is the bleed nipple under frunk beside the bulkhead
Note: all at the front of the car, not the rear.
Ordinarily no you dont that is what the extension tubes that go on the bleed points are for, they effectively raises the front water level threshold to aid bleeding, you need the fill point as the highest level in system so the pressure is greater pushing the coolant into the system, res bottle is already highest point but raising the rear further aids this as give more pressure as its a bigger drop to front.
Problem ive got at moment is i cant get the rad bleed screw to seal externally and also allow coolant into the tube to allow expansion and air to bubbles out, i managed a bit more at lunch time with some careful twiddling of rad bleed screw and massaging pipes under bonnet, this got a fair bit of air out so hopefully thats it but will try same again later before running car see how it goes.
I could really do with removing the bleed screw and sorting out the o-ring to allow proper bleed procedure but i will need to raise up front of car to prevent too much coolant escaping and way ive got car in garage at moment i cant get jack under front..DOH!... so will treat that as last resort.
With the cap on the expansion tank, you can remove the bleed screw and very little will come out. Done it.
Quote from: Carolyn on February 5, 2020, 14:18With the cap on the expansion tank, you can remove the bleed screw and very little will come out. Done it.
Ah yes never thought of that of course i might do that then at least i can bleed correctly, although i am cautious in that at moment it seals ok when fully closed so might be opening a can of worms if i take it right out!, will see what happens tonight and also what i have o-ring wise then go from there i think.
How to drain and replace coolant.
http://brollachan.net/images/Coolant.pdf
Quote from: moredun on February 5, 2020, 14:54How to drain and replace coolant.
http://brollachan.net/images/Coolant.pdf
Thanks ive had a read of that previous, it doesnt say raise the front though...in fact it says......
"NOTICE:
In order to do sure filling of the coolant, perform the operation where the vehicle can be kept evenly flat" :)
Raising the end of car coolant is being poured into (rear in this case but front typically on a front engine car yes) to give more pressure on system is common practise so im not sure why your arguing and we will just have to agree to disagree on this occasion, lifes to short :D
Hmm ok few more hours on it tonight and a revelation confirming something i mentioned earlier, after much buggering about with bleed screw on rad changing o-rings etc so i could bleed system properly i think ive got the air out system.
Start the car and let it warm up massaging all pipes to help keep coolant moving and all pipes nice and hot heater blowing hot as well , BUT the one from rad outlet going back to engine/thermostat is still cold, as is half the rad!....bled it some more but nothing much came out! sick to death of it i buttoned everything up and went for a thrash to see what happens.
Closely watching coolant temp on Laptop it soons upto its usual 90-93c while driving normally but goes no higher until you give it some death, it then goes up a couple of degrees but drops back down while cruising, go to shops and park up letting it idle to heat soak everything for 5minutes or so and again it goes up a couple of degrees but stable around 95c dropping back to 92-93 when driving again, all in all pretty much what its always done from memory so i dig through my data...
Ive always thought it runs a bit hot but its been stable and never overheated on hot days in traffic or trackdays etc so havent worried about it, now looking back more closely at my datalogs right from when car was NA before turbo went on and the coolant temps are the same, sat in low/mid 90's but stable at that.
Seems all along the car has been running without the radiator cooling things since i got it in 2018!, ive done about 8k miles several trackdays and sprints its never had an issue with temp going any higher than middle of gauge, which now looking at Link G4 data is where it sits until it gets over 100 then it goes up, as i noticed the other day when airlocks heater circuit as its the only thing cooling engine it seems.
SO what do i do now!!...im thinkings its probably the thermostat stuck closed not letting water back from rad.... or the water pump not pumping it but my money is on the stat as if water pump wasnt working i wouldnt get heat in car and it would overheat im sure ?
Any ideas welcome ? :D
I would be astounded if your rad has not been providing any cooling for all that time.
When my rad blew a leak, it was not much normal town driving at 30mph before the temp needle was off the top of the scale and car was into complete limp mode.
Then again I guess having coolant in the system even if not actively cooled and pumped is infinitely better than having none.
What temp is your fan(s) kicking in at?
Could be an issue with the pump? A radiator as far as I understand is a complete passive device. Fans and pump are the moving parts in the puzzle right? And the thermostat is there to make decisions based on temp.
In my limited wisdom I would suspect the pump if your fan is coming on at the right time and with the right gusto.
Quote from: househead on February 5, 2020, 21:42I would be astounded if your rad has not been providing any cooling for all that time.
When my rad blew a leak, it was not much normal town driving at 30mph before the temp needle was off the top of the scale and car was into complete limp mode.
Then again I guess having coolant in the pipes even if not actively cooled and pumped is infinitely better than having none.
What temp is your fan(s) kicking in at?
Could be an issue with the pump? A radiator as far as I understand is a complete passive device. Fans and pump are the moving parts in the puzzle right? And the thermostat is there to make decisions based on temp.
In my limited wisdom I would suspect the pump if your fan is coming on at the right time and with the right gusto.
Im as stunned as you, ive never checked the coolant pipework/rad temps until now but I can say for sure that right now the coolant isn't passing through the rad back to the engine and it never gets much about 95c and generally sits at 93c like its always done....unless its cooling so well the pipes are cold back to engine which I doubt, as mentioned looking back over all the data I have since I started preparing for the turbo install shows ECT has been sat in low/mid 90's all the time once warmed up, even before I fitted Turbo.
Ive got a log from stock Ecu via torque app as well I will check on that.
Fan is set to come on at 92c which was set by previous mapper of the Link ive not touched that part of map, basically the fan is always on once your warmed up which I did notice once I fitted Link just presumed they had it set like this to help cooling on track, don't think it was the same on stock ecu but I never paid lot of attention to be honest until I fitted the Link ecu, what temp does stock ecu fire up the fan ?
I think if it was the pump it would overheat quickly as coolant couldn't circulate at all, its certainly getting through the the heater matrix and input to the rad, its just not getting back to engine, when I squish the pipework I can move the coolant through the rad so its not blocked, its just not allowing flow back to engine which I can only think is the stat stuck closed stopping or restriction heavily the flow.
For reference here are a couple of datalogs which show ECT, ive checked the Link G4 coolant temps compared to ones the stock ecu shows via Torque app and they are within a degree or so, just in case here was a sensor calibration issue but all ok.
First a 25minute run out including warm up back in October last year, just after fitting Link G4 ecu onto otherwise stock car.
(http://carbotech-europe.com/images/MR2/Pre-turbolog-oct2019.jpg)
Second is a 20minute run out last weekend after a few jobs on turbo, before i airlocked the heater! as you can see same sort of temps.
(http://carbotech-europe.com/images/MR2/turbolog-020220.jpg)
There's no way it's maintaining temp at 95 under significant load without the coolant going through the rad.
It's more likely that your fingers are numb and you have a 95 deg thermostat.
According to a thread on Spyderchat which references the BGB, stock fan activation temp is 93C and it will stay on until it drops below 83C. Not sure if Spyder vs Roadster is relevant but can't see that it would be.
95C then seems a fairly stable and reasonable temp to me.
Quote from: jonbill on February 5, 2020, 22:24There's no way it's maintaining temp at 95 under significant load without the coolant going through the rad.
It's more likely that your fingers are numb and you have a 95 deg thermostat.
I wouldn't believe it either if I couldn't see it right before my eyes, I can promise you rad exit pipe on drivers side going back to engine has no heat in it and that side of rad is cold as well, its hot on other side of rad and all pipework upto to that point, coolant sloshing back and worth ok when squeezing pipes during bleeding so no blockage, at least not total ones as coolant is moving by hand pressure.
I guess only way to be sure would be to plug the pipes in and out of rad and run it again but don't think ive got any bungs that size, the amount of coolant in system and the long pipe run seem to be enough along with the heater matrix to keep it at 95, as soon as heater was locked out the temps soared, it must be a miracle!
Im thinking easiest job is going to be remove/check/fit new thermostat then re-bleed and go from there, I cant honestly think what else would cause it and still be stable under hard use and for so long but open to ideas ?
Quote from: househead on February 5, 2020, 22:38According to a thread on Spyderchat which references the BGB, stock fan activation temp is 93C and it will stay on until it drops below 83C. Not sure if Spyder vs Roadster is relevant but can't see that it would be.
95C then seems a fairly stable and reasonable temp to me.
Makes sense and maybe fan was on a lot before the Ecu change just being a stock car I never paid a lot of attention and temp gauge always sat in middle.
It is pretty stable as it is now, highest I can see on logs is a few points where it creeps upto 98 but soon drops back to 95 area, its weird alright and if I hadn't airlocked heater I would never question it.
Quote from: thetyrant on February 5, 2020, 23:15I can promise you rad exit pipe on drivers side going back to engine has no heat in it and that side of rad is cold as well, its hot on other side of rad and all pipework upto to that point, coolant sloshing back and worth ok when squeezing pipes during bleeding so no blockage, at least not total ones as coolant is moving by hand pressure.
That sounds like a working rad to me! Warm stuff going in, cold stuff coming out?
Could it just be your heater that's playing up?
Quote from: househead on February 5, 2020, 23:57That sounds like a working rad to me! Warm stuff going in, cold stuff coming out?
Could it just be your heater that's playing up?
Rads are not this good though and don't drop temp down to ambient like this, its not even slightly warm on hose heading back to engine, remember your trying to keep engine temp in the 80's generally.
In my experience both hoses at rad feel about the same once car is warmed up and stat is open so coolant is circulating correctly.
Also when fans come on it doesn't drop coolant temp.
Heater circuit which is seperate return to engine is working fine now, seemingly stopping engine overheating!