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Well that helps explain why normal temps are lower :)
I haven't checked into this thread in a while, but have you already verified your temp gauge readings are accurate? Do you have an oil pressure gauge to corroborate the temp readings? If you're getting big spikes in oil temps, but your oil pressure is staying steady, then that might imply it's just your temperature sensor being affected and not the oil.
 

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Discussion Starter #82
I haven't checked into this thread in a while, but have you already verified your temp gauge readings are accurate? Do you have an oil pressure gauge to corroborate the temp readings? If you're getting big spikes in oil temps, but your oil pressure is staying steady, then that might imply it's just your temperature sensor being affected and not the oil.
No pressure gauge, but the oil temp gauge was checked using a high-end IR thermometer. Readings from the thermometer at the sensor spot were within 5-8 degrees of what the gauge was reading.
 

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Discussion Starter #84 (Edited)
Well... another update.

Wrapped the headers -- no change in temps. Actually, temps are higher now than ever, but it's been getting warmer out so that makes sense. Today driving across town... zero boost, casual driving, all under 4k rpm in 78 degree weather got me 230 degree oil temps.

So seems that I can rule out the headers heating things up. I'm thinking that no matter what, if the radiant heat from them was heating up the oil then the wrap would have SOME effect.

But now this leads, again, to a very odd situation where the oil is getting hot but there doesn't seem to be any cause that I or anyone else can think of.

I'm going to check the gauge sender again... it was checked via IR thermometer but I'm thinking to test with boiling water as well.

Other than that... the only things that changed around the same time were adding an AOS, changing to Grimmspeed intake from SPT, and getting a retune.

Any thoughts or ideas are super welcomed :/
 

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Discussion Starter #86
Like I said before, it’s either the sensor or the tune. I think like you said, you have no choice to troubleshoot your sensor first.
I hope you are right.

How do you think the tune could affect the temp though? AFR's look pretty normal...
 

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timing?
 

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I hope you are right.



How do you think the tune could affect the temp though? AFR's look pretty normal...

The AFR itself is a ratio independant of heat. It follows the tune, so if all incoming data after the meters stay the same or don’t vary more than 25% from the tune, then the AFR will always be perfect.

It really depends on many things. The basic generalization is that a more agressive tune makes the engine perform harder which creates more heat. The tuner can control EGTs, cooling, timing, etc in different drive cycles. If the tune isn’t as efficient performance wise for the engine, as it could or used to be, then the extra energy has to go somewhere and most often that’s seen with a temperature change.
 

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I don't see this as tune related. A hard part was installed that should really make things cooler, aside from radiant heat. Also, the tune will only correct to *50% in closed loop, but you also don't want it to be there.

Have you tried a new sender and new wires?
 

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Discussion Starter #91
I don't see this as tune related. A hard part was installed that should really make things cooler, aside from radiant heat. Also, the tune will only correct to *50% in closed loop, but you also don't want it to be there.

Have you tried a new sender and new wires?
I haven't tried a new sender and wires. So far, I've verified the sensor using a high-end IR thermometer that I borrowed from a performance shop. But I'm thinking next step is to check again with a pot of boiling water. At this elevation, water boils at right about 200 degrees even, so that should be a good measurement for the sensor.

lowbee said:
Is your oil cooler working properly?
I'd wondered that as well. I do not have an external cooler, just the stock oil/coolant heat exchanger. From the research I've done... it doesn't seem like those really go bad. It did have a very slow oil weep at the seal, but I replaced that and it had no noticeable effect on the temps.

Noximus said:
The AFR itself is a ratio independant of heat. It follows the tune, so if all incoming data after the meters stay the same or don’t vary more than 25% from the tune, then the AFR will always be perfect.

It really depends on many things. The basic generalization is that a more agressive tune makes the engine perform harder which creates more heat. The tuner can control EGTs, cooling, timing, etc in different drive cycles. If the tune isn’t as efficient performance wise for the engine, as it could or used to be, then the extra energy has to go somewhere and most often that’s seen with a temperature change.
It's a theory for sure. The tuner's I've talked to have thought it was a bit of a long shot that the tune was causing the change... but as it's the only other thing that changed aside from the headers that could conceivably cause an issue...
 

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Hmm,

your temp readings are verified.

I don't know much about our oil coolers - but you took it off. Oils pressure is good. Kink or other restriction in a water line? There are water lines, correct? It's the only thing that completely fits your symptoms.
 

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except they already agreed - no?

They'll be very, no extremely close when the car is off and still - and the OP wasn't under it measuring when on the track - was he?. Did he poke a hole in the floor for "live monitoring"?
 

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Discussion Starter #96
So I'll pull the sensor and stick it in some boiling water. Hopefully that'll show it reading high.

Water lines... I'm not sure what lines there really are. But the water temps are all happy, haven't gotten hot or anything. So they should be cooling the oil, not heating it, correct?

(Possibly) dumb questions if anyone has any answers...

1. Any possible way anything with the AOS could be causing anything? Maybe if it was routed wrong or anything? It's an IAG Comp series.

2. Could there be anything internal in the motor that could be causing it? Something not letting the oil flow as well as it should?

Hoping the boiling water test shows a blown sensor but just trying to brainstorm. Really really hoping to run SCCA Time Trial event next weekend with this car.
 

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Since I don't really know the system I need to look some things up - later.

But, there are two hoses connected to the top of the cooler, and from reading here, my understanding is that the cooler is water cooled - which makes sense - cause it isn't going to cool anything in there with no air movement, no fins and no water. So, it must be water cooled. Again, I know there are two hoses. Oil goes in and out inside the filter gasket - and coolant enters and exits via the hoses. No?

Restricted coolant flow makes completes sense. That coolant path in in the bypass (I bet). It will not change your coolant temp at all as long as you coolant system is working. It is possible that it might change your heat inside. Whatever. It makes perfect sense.

I'm wrong often enough. Where is this wrong?
 

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Discussion Starter #98
Since I don't really know the system I need to look some things up - later.

But, there are two hoses connected to the top of the cooler, and from reading here, my understanding is that the cooler is water cooled - which makes sense - cause it isn't going to cool anything in there with no air movement, no fins and no water. So, it must be water cooled. Again, I know there are two hoses. Oil goes in and out inside the filter gasket - and coolant enters and exits via the hoses. No?

Restricted coolant flow makes completes sense. That coolant path in in the bypass (I bet). It will not change your coolant temp at all as long as you coolant system is working. It is possible that it might change your heat inside. Whatever. It makes perfect sense.

I'm wrong often enough. Where is this wrong?
Hmm... I do see what you mean.

My thought was always that the coolant temps are good... so the coolant would be cooling the oil. So the issue would not be caused by the cooling system having an issue. But if there was less coolant than normal flowing through that stock cooler, then I could see how it could be cooling less efficiently.

But... wouldn't that system be in-line with other parts of the coolant system? And if there was a blockage there wouldn't it be noticeable in the coolant temps as well?
 

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But... wouldn't that system be in-line with other parts of the coolant system? And if there was a blockage there wouldn't it be noticeable in the coolant temps as well?

It’d be a lot more obvious if it was a blockage. The only issues I would see is if the coolant already boiled in the past and is no longer efficient requiring a flush, or the thermostat isn’t opening when it should, or since the tune can control when the fans open or close, they may be turning on later than before.
 

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It’d be a lot more obvious if it was a blockage.
How? Difference? Yes. Obvious? Obviously not! Brapp would have figured this out long ago.

Cooling System Diagram in first post.
Updated Coolant Line Diagram (changed for many mods) - NASIOC

Oil Cooler is in a bypass in in the passenger side loop. But it's not the only path or the primary path. The only thing the thermostat controls is radiator flow. It has nothing to do with this.


The only issue I would see is if the coolant already boiled in the past and is no longer efficient
Coolant changes little if at all from getting hot or even boiling.

We have symptoms - and a logical diagnosis. Shouldn't have taken us this long! :(
Removal and replacement of oil cooler results in hot oil. Oil cooler not working should have been the primary suspect right off the bat.

ADDED: It was the title that threw us . . . like a riddle. The clues are there, but something else get the attention.
 
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