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Weird (?) coolant temp fluctuation

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Old Oct 27, 2014 | 09:12 AM
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Default Weird (?) coolant temp fluctuation

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?







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?
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Old Oct 27, 2014 | 10:13 AM
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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.
Old Oct 27, 2014 | 11:15 AM
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AFR?
Old Oct 27, 2014 | 11:28 AM
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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.
Old Oct 27, 2014 | 11:37 AM
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thermostat is in the spacer, and at 92/93°C "starting" temp should be already open, don't?
Old Oct 27, 2014 | 11:38 AM
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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.
Old Oct 27, 2014 | 11:42 AM
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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.
Old Oct 27, 2014 | 12:00 PM
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Originally Posted by festersays
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.
level is ok

Originally Posted by hornetball
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...
Old Oct 28, 2014 | 02:23 AM
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Any other opinion?

coolant seems to be clean and there's a little smoke from exhaust but not on boost...

Last edited by Pepino; Oct 28, 2014 at 03:48 AM.
Old Oct 28, 2014 | 11:07 AM
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Giuseppe, I didn't give you an opinion. Your data is clear.

Had the same problem.

Replace your HG.
Old Oct 28, 2014 | 11:13 AM
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Rick is likely right, at least it looks that way
Old Nov 7, 2014 | 12:47 PM
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Well, swapped to cometic mls head gasket with new studs...

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Old Nov 7, 2014 | 01:25 PM
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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?
Old Nov 7, 2014 | 01:40 PM
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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...
Old Nov 7, 2014 | 01:58 PM
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Originally Posted by Pepino
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...
Does the VDO meter also drop that fast when you release the throttle (10(?) degrees C in one second)?
Old Nov 7, 2014 | 02:03 PM
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Originally Posted by NiklasFalk
Does the VDO meter also drop that fast when you release the throttle (10(?) degrees C in one second)?
a little laggish but yes

Last edited by Pepino; Nov 8, 2014 at 04:09 AM.
Old Nov 8, 2014 | 04:08 AM
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other opinions?
Old Nov 11, 2014 | 07:49 PM
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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?
Old Nov 11, 2014 | 08:11 PM
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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.
Old Nov 12, 2014 | 07:20 AM
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Originally Posted by brainzata
You do have a thermostat yeah? what temp rating? Is it in backwards and do you have bleeding holes in it?
oem 1.6 thermostat (two valve 85/87°), no bleeding holes...

Originally Posted by hornetball
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.
no problem, will try ground check...



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