Intercooler/blocking off grill with Pipe Insulation questions?

rrolsbe

Well-known member
Joined
Dec 27, 2010
Location
Albuquerque
TDI
2011 TDI Sportswagen
From what I have read, the intercooler on the the 2009+ JSW Diesel is sandwiched between the radiator and AC condenser and is basically the same height and width. On other VW Diesels the intercooler is not mounted between these two heat exchangers and has its own separate grille vents to cool the intercooler. So my questions are:

Is what I stated above correct?

Are the three heat exchangers mounted radiator front of car then intercooler middle and finally AC condenser rear? If so, maybe the car would get to normal operating temps quicker if the radiator where behind the other two? but might have the reverse problem and not cool enough at high ambient air temps?

Blocking off the grille vents that cool the radiator/AC condenser on the VW Diesel's, that do NOT have the intercooler sandwiched between the other two heat exchangers, should not effect the intercooler cooling: likewise, blocking off the grill vents on our 2011 JSW Diesel would affect the intercooler cooling? Good/Bad? less efficient turbo wise?

From what I have read, the cooler the air at the outlet on the intercooler the better (may not be if you are forcing VERY cold air into the intercooler heat exchanger)?. Some people even mount spray units that spray into the intercooler heat exchanger to cool the air further. That said, if the intercooler heat exchanger were in very front would it cool turbo air better especially when blocking off the cooling vents with pipe insulation in cold weather?

I am sure the engineers have taken all of what I have stated above into account during the engineering of the car; however, since I have blocked off all but one of the lower grille vents but NOT the vent in the hood for the winter, I need to understand both the pluses and minus of doing so.

Note: Here is a data point on engine warm up time with all but one of the lower vents blocked.. This past Sunday I drove back from our mountain property. Car had set out all night and the air temp was around freezing. The first three miles has some ups and downs but the car temp gauge was still pegged at its lowest reading. The next few miles was level to slightly uphill. After these few miles the temp was about half way to normal operating temp. The next seven miles is mostly downhill and the temp actually dropped somewhat. The last seven miles had some uphill sections and the car finally reached and maintained normal operating temperature. Since the temp reading is being controlled by one of the ECU's and not directly reading the coolant temp, who knows what the actual coolant temp actually was. All I can say for sure is my average fuel milege for the 20 mile return trip, according to the computer, was about 16MPG less than it is during warmer weather (70MPG versus 86MPG) Since the car is normally garaged in town the outbound average consumption is always around 36MPG (mostly uphill).

Thanks for taking the time to read my post!
Comments welcome!!
Regards, Ron
 
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MayorDJQ

Top Post Dawg
Joined
Dec 4, 2001
Location
Williamstown, Mass
TDI
'10 Golf 2dr 6m, sold.
From what I have read, the intercooler on the the 2009+ JSW Diesel is sandwiched between the radiator and AC condenser and is basically the same height and width. On other VW Diesels the intercooler is not mounted between these two heat exchangers and has its own separate grille vents to cool the intercooler. So my questions are:

Is what I stated above correct?
Yes.

Are the three heat exchangers mounted radiator front of car then intercooler middle and finally AC condenser rear?
No. The other way around. From the front: A/C, Intercooler, radiator.

blocking off the grill vents on our 2011 JSW Diesel would affect the intercooler cooling? Good/Bad? less efficient turbo wise?
Yes, maybe if you block the grill 100%.

Otherwise, I think you're overthinking the situation. The uphill drive is killing your mileage, the downhill is helping it but with less engine heat. Diesels don't generate a lot of "waste heat" like gas engines. Add to that the fact that while coasting in gear no fuel is injected, even less heat is generated, possibly allowing the cooling system to lose heat.

Are you noticing low power? If not, leaving one grille slat open is probably safe. If you were to block the upper and lower grilles completely you may wind up melting stuff under the hood during an active regen.
 

rrolsbe

Well-known member
Joined
Dec 27, 2010
Location
Albuquerque
TDI
2011 TDI Sportswagen
Thanks for the clarification

Thanks foe the post MayorDJR!!!

No. The other way around. From the front: A/C, Intercooler, radiator.
That makes more sense the air flow should be reduce to the radiator by having the other two heat exchangers in front of it.

Thanks Again!!!!
Regards, Ron
 

> Luke <

Veteran Member
Joined
Jun 16, 2011
Location
West Los Angeles
TDI
Golf 2011 TDi DSG
Fm > Ron
....Since the temp reading is being controlled by one of the ECU's
and not directly reading the coolant temp, who knows what the actual coolant temp actually was......​
Your comment is interesting to me, would you elaborate ? For we all continue to learn ...


Fm > Mayor
..If you were to block the upper and lower grilles completely
you may wind up melting stuff under the hood during an active regen.
Super comment/feedback, thank you for the heads up.
 

rrolsbe

Well-known member
Joined
Dec 27, 2010
Location
Albuquerque
TDI
2011 TDI Sportswagen
Your comment is interesting to me, would you elaborate ? For we all continue to learn ...
Luke

I have read in several threads on this forum that the ECU knows the exact coolant temp but it tells the gauge what to display. If I remember correctly for example, when the temp gauge displays 190 degrees the actual temp might be as much as +/- 10 to 20 degrees off. Sorry could not find the exact thread I was reading. Anyone feel free to correct me.

Regards, Ron
 

MayorDJQ

Top Post Dawg
Joined
Dec 4, 2001
Location
Williamstown, Mass
TDI
'10 Golf 2dr 6m, sold.
That's pretty much correct, but it's not really "off", it's just indicating that the temp is in the normal range. The gauge is really just a fancy idiot light, has been in VWs for 15 years at least.

Most people don't comprehend what an actual temp gauge would tell them. In normal driving, coolant temps will fluctuate. I can see a lot calls to VW roadside by drivers who see the needle rising above 190*.
 

> Luke <

Veteran Member
Joined
Jun 16, 2011
Location
West Los Angeles
TDI
Golf 2011 TDi DSG
Whow, thank you Ron & Mayor DJQ.
I'm familiar with the gauges from working on 60's VW while in the Air Force in Europe; therefore appreciate the head up on the current tech side of the gauge readings. Now I understand more fully why my temperature gauge always read "perfectly" centered -- even after sitting in freeway traffic..
 

MayorDJQ

Top Post Dawg
Joined
Dec 4, 2001
Location
Williamstown, Mass
TDI
'10 Golf 2dr 6m, sold.
It's kind of odd that VW does that, but there are probably studies out there that show how informed/uninformed people are about their vehicles.

If you have a VagCom/VCDS cable, you could plug your computer in and do some real time tracking, but having a laptop in the car can be a distraction.

Another (safer) option is a ScanGaugeII. It plugs into the OBDII port and you can program it to read all sorts of data.
 
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