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Old 10-27-2014, 10:12 AM   #1
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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, 110/120C with 30C outside temp, maybe obstructed coolant holes in the engine or poor water pump working?
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Old 10-27-2014, 11:13 AM   #2
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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.
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Old 10-27-2014, 12:15 PM   #3
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AFR?
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Old 10-27-2014, 12:28 PM   #4
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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.
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Old 10-27-2014, 12:37 PM   #5
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thermostat is in the spacer, and at 92/93C "starting" temp should be already open, don't?
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Old 10-27-2014, 12:38 PM   #6
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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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Old 10-27-2014, 12:42 PM   #7
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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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Old 10-27-2014, 01:00 PM   #8
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Quote:
Originally Posted by festersays View Post
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

Quote:
Originally Posted by hornetball View Post
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...
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Old 10-28-2014, 03:23 AM   #9
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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; 10-28-2014 at 04:48 AM.
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Old 10-28-2014, 12:07 PM   #10
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Giuseppe, I didn't give you an opinion. Your data is clear.

Had the same problem.

Replace your HG.
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Old 10-28-2014, 12:13 PM   #11
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Rick is likely right, at least it looks that way
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Old 11-07-2014, 01:47 PM   #12
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Well, swapped to cometic mls head gasket with new studs...

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Old 11-07-2014, 02:25 PM   #13
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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?
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Old 11-07-2014, 02:40 PM   #14
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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...
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Old 11-07-2014, 02:58 PM   #15
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Quote:
Originally Posted by Pepino View Post
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)?
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Old 11-07-2014, 03:03 PM   #16
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Quote:
Originally Posted by NiklasFalk View Post
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; 11-08-2014 at 05:09 AM.
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Old 11-08-2014, 05:08 AM   #17
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other opinions?
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Old 11-11-2014, 08:49 PM   #18
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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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Old 11-11-2014, 09:11 PM   #19
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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.
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Old 11-12-2014, 08:20 AM   #20
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Quote:
Originally Posted by brainzata View Post
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...

Quote:
Originally Posted by hornetball View Post
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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