High intake temperatures

[MonsterTDI09]

On my 2010 Jetta the intake temps our high. Here is a example outside temp 75* intake is 102*. The engine temp is 190*. I cleaned out radiator and inter cooler with water, and bent the fins back on the A/c condenser. A couple time the engine stalled at a stop light. The no codes

 

[FJ40Jim]

The air filter has a wax pellet thermostat that moves a door to pull air from out front or off the exhaust manifold. It tries to maintain a constant temp, usually well above normal daytime highs, so the emissions programming only has to deal with one constant air intake temp.

It's easy enough to modify out the door to get constant cold ram air if desired.

 

[JELLOWSUBMARINE]

It's easy enough to modify out the door to get constant cold ram air if desired.

Have you done this? What good or bad have you noticed?

 

[FJ40Jim]

Yes, it was done on day 2 of ownership. There was a campaign waged against airflow restriction.

The baffle/restrictor was cut out of the intake pipe on the turbo.
Hot air intake was cut out of the airbox.
Snow screen baffle was removed from bottom of airbox.
Front intake was modded by taping shut 1/2 of the bypass to increase ram pressure.


IDK if any one mod made a difference, but the engine seems to pull hard at all RPMs, never feels like it runs out of breath. One thing I definitely notice (and like) is there is more intake noise. This was all free stuff, didn't cost a dime, so if it makes .1 more HP, it was a good deal.

 

[MonsterTDI09]

The air filter has a wax pellet thermostat that moves a door to pull air from out front or off the exhaust manifold. It tries to maintain a constant temp, usually well above normal daytime highs, so the emissions programming only has to deal with one constant air intake temp.

It's easy enough to modify out the door to get constant cold ram air if desired.

The wax pellet thermostat pulls air exhaust. When I look at it it was close.

I never had this problem before. Do you know the temperature split for the Intercooler.

 

[oilhammer]

The G42 IAT is part of the G31 MAP, so post-turbo... so yeah, it WILL be higher than whatever the ambient temp is that day. That is normal. The charge air cooler will have dropped it back down some (it was actually HOTTER after it left the turbocharger).

And on the CJAA, much of the time during normal engine operation, the air charge is being pulled/pushed in via one of the TWO EGR systems anyway... so not all the incoming air even goes through the airbox.

No idea why your car stalls at stoplights, but the IAT value is not the cause. All IAT does is back off fueling, timing, and boost. It won't ever cause the engine to flat out turn off.

 

[MonsterTDI09]

The G42 IAT is part of the G31 MAP, so post-turbo... so yeah, it WILL be higher than whatever the ambient temp is that day. That is normal. The charge air cooler will have dropped it back down some (it was actually HOTTER after it left the turbocharger).
And on the CJAA, much of the time during normal engine operation, the air charge is being pulled/pushed in via one of the TWO EGR systems anyway... so not all the incoming air even goes through the airbox.
No idea why your car stalls at stoplights, but the IAT value is not the cause. All IAT does is back off fueling, timing, and boost. It won't ever cause the engine to flat out turn off.

It stalled about 3 times. I recall the intake temp was around 125 on a 95*day and high humidity. With the AC on the temp just takes off.

When the car in regen and the Ac on the intake temp drops down to about 10*above ambient. I know the fans on super high speed.I will post some pictures so you look at the numbers.

 

[oilhammer]

Yes, when the A/C is running, the IAT will potentially go up. Because the condenser for the A/C is in front of the charge air cooler. Again, normal. Typically this heat load isn't *that* bad for that long since once the heat is removed from the cabin the compressor's duty cycle backs off and the high side pressure is not as high. When regens happen, the fans run on high no matter the coolant temp or refrigerant pressure. This is to help keep air moving under the hood.

Not sure why, maybe they did not think it necessary OR felt the A/C would be running anyway, but the IAT has no impact that I know of on fan operation, despite the fact that the fans do pull air over the charge air cooler just like the condenser and radiator.

You'd have to get some datapoints for "normal" IAT on CJAA engines to get some idea of what is going on here. But again, I don't feel like that is the reason your engine is stalling.

The circulation of coolant, refrigerant, and the charge air passing through should be fairly dynamic but predictable.

 

[MonsterTDI09]

 

[MonsterTDI09]

Do you want a Vcds log? Just let me know what you want.

 

[oilhammer]

Do you want a Vcds log.

No. Because I do not think you have a problem with high IATs. You have a dataset of ONE car. And the ECU is perfectly happy with it (which tells me it is probably within normal parameters).

Not sure why you randomly picked this one PID to blame on your stalling. In fact, from your picture, your coolant temp is rather low. It should be closer to 90 C (or about 200 F). But that isn't a cause for stalling either.

 

[MonsterTDI09]

No. Because I do not think you have a problem with high IATs. You have a dataset of ONE car. And the ECU is perfectly happy with it (which tells me it is probably within normal parameters).
Not sure why you randomly picked this one PID to blame on your stalling. In fact, from your picture, your coolant temp is rather low. It should be closer to 90 C (or about 200 F). But that isn't a cause for stalling either.

That was just example of the kind of numbers I’m seeing. It only stalled 3 times and those were on 95* plus days and sitting at a stop light. I watched ITAs just up I press the go and it stalled.

I just didn’t remember ever seeing these kind IATs temp before .The only time I recalled seeing high ITAs blasting up a big mountain

Every since I straightened the fins on the condenser and clean all crap out of it, the cooling temp doesn’t get to 190* like it did before.

 

[JELLOWSUBMARINE]

Since you have the polar, what are your injector readings under different conditions. I don't have much experience here but I'm thinking this could be a root for everything you mentioned.

Can you post various polar readings side by side pictures? 1 thru 4 injector?