Weird (?) coolant temp fluctuation
4 Attachment(s)
Data: 1.6 engine, td04 14psi, 42mm alu rad ducted, reroute, std Tstat. eMS2.
look how temp go up and back drop in a small time, is that normal? https://www.miataturbo.net/attachmen...ine=1414415574 https://www.miataturbo.net/attachmen...ine=1414415574 i am looking to improve cooling as i use to track it, but i am having overheating in 2/3 fast lap, 110/120°C with 30°C outside temp, maybe obstructed coolant holes in the engine or poor water pump working? |
This was talked about slightly in my build thread, but mine sure as hell didn't hit no 240F. I climbed maybe 15*.
Fix your AFRs. |
AFR?
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I'd look at your reroute, to me it looks like the thermostat takes way too long to open, has no problem shedding the heat. Is it a remote mounted thermostat setup?
Your AFR is all over the place, as well. |
thermostat is in the spacer, and at 92/93°C "starting" temp should be already open, don't?
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Not normal. Tracks RPM and MAP. That's a head gasket leaking cylinder pressure into a water passage. If you have a 1.6 with the OEM composite HG, it will not stand up to track use with a turbo. MLS gasket and ARP studs highly recommended.
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Taking it back to basics, have you checked the coolant level? It would be all bad, but that could by why it's getting those funky readings. Just thinking out loud here.
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Originally Posted by festersays
(Post 1178839)
Taking it back to basics, have you checked the coolant level? It would be all bad, but that could by why it's getting those funky readings. Just thinking out loud here.
Originally Posted by hornetball
(Post 1178837)
Not normal. Tracks RPM and MAP. That's a head gasket leaking cylinder pressure into a water passage. If you have a 1.6 with the OEM composite HG, it will not stand up to track use with a turbo. MLS gasket and ARP studs highly recommended.
it overheated from the beginning when tracked it, and yes gasket is the oem... |
Any other opinion?
coolant seems to be clean and there's a little smoke from exhaust but not on boost... |
Giuseppe, I didn't give you an opinion. Your data is clear.
Had the same problem. Replace your HG. |
Rick is likely right, at least it looks that way
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1 Attachment(s)
Well, swapped to cometic mls head gasket with new studs...
https://www.miataturbo.net/attachmen...ine=1415382445 |
Follows the duty cycle very well, electric gremlins in the injector harness? But I'm NB-focused, I have no idea where you have the temp sensor or where it's can get noise from.
Or there is a real problem from cylinder pressure, but why should then the temp drop so quickly? |
ecu sensor is on reroute spacer, back side under coils, i also have a VDO sensor on inlet heater core hose and it read same fluctuations...
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Originally Posted by Pepino
(Post 1181476)
ecu sensor is on reroute spacer, back side under coils, i also have a VDO sensor on inlet heater core hose and it read same fluctuations...
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Originally Posted by NiklasFalk
(Post 1181484)
Does the VDO meter also drop that fast when you release the throttle (10(?) degrees C in one second)?
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other opinions?
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You do have a thermostat yeah? what temp rating? Is it in backwards and do you have bleeding holes in it?
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Well, I already screwed you once, so here goes . . .
Like Niklas said, it REALLY tracks the duty cycle trace (I wish your original graphs had shown duty cycle). I would be cleaning and refastening all engine grounds before doing anything else. I don't think what you're seeing here are real temperature fluctuations. Sorry about the bad advice earlier. If it makes you feel any better, I'm pretty sure you would have eventually encountered head gasket issues with track driving. I sure did. |
Originally Posted by brainzata
(Post 1182293)
You do have a thermostat yeah? what temp rating? Is it in backwards and do you have bleeding holes in it?
Originally Posted by hornetball
(Post 1182295)
Well, I already screwed you once, so here goes . . .
Like Niklas said, it REALLY tracks the duty cycle trace (I wish your original graphs had shown duty cycle). I would be cleaning and refastening all engine grounds before doing anything else. I don't think what you're seeing here are real temperature fluctuations. Sorry about the bad advice earlier. If it makes you feel any better, I'm pretty sure you would have eventually encountered head gasket issues with track driving. I sure did. |
Apologies for the 6 year thread revive (better than starting a new thread on the same topic) - were you able to get to the bottom of this?
I'll start with I know boost control needs tuning. Status 5 is setup to monitor CLT ADC counts. Does the CLT rise/fall rate shown in the first image below seem pretty normal of a turbo setup? Maximum rise rate is 6°C/sec and fall rate is 4°C/sec. Max delta of 3°C while NA seems ok, how does 8°C for a turbo setup fare? Interestingly it is most evident from the last WOT pull that CLT begins to fall while WOT is maintained for another 1 second. FMIC is 1.5" away from the radiator with no ducting, only an LRB undertray is used. Coverage is most of the radiator laterally and up to the bottom of the hood latch vertically. NA setup only differs by having a thermostat installed (Thermostat was removed during the turbo log to remove a variable when troubleshooting overheating - hovered around 110ish °C at some point). Cooling system includes new water pump, kia reroute and supermiata rad. Turbo water lines were also temporarily removed for the same reason above. ARP studs and OEM gasket since it was mentioned above. Turbo: https://cimg4.ibsrv.net/gimg/www.mia...19d5ec4ba7.jpg NA: *Status5 would have been monitoring TPS here https://cimg1.ibsrv.net/gimg/www.mia...907c5d3811.jpg Appreciate your input, thanks. |
Tried to see the effects of holding near max engine speed at light load tonight. Probably should have done the opposite for comparison as well.
Would this be symptomatic of a head gasket problem? High load high rpm = CLT spike Low load high rpm = CLT stable https://cimg2.ibsrv.net/gimg/www.mia...87e65ef98b.jpg |
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