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ChrstphrR · 09-26-2008, 06:56 AM

Hrm, I replaced most of the stock plastic undertray with a coroplast one before taking a trip. On the return trip, it was removed by a roadkill raccoon or porcupine (didn't stop to ask what it which one it was).

With just the undertray replacement (like OEM), I found that my water temperature was elevated at highway cruise speed into the high 70s, Celsius -- 74-78, in September, with air temperatures in the 10-20C range, while at 100kph

When I added a lower grille block for the radiator... I found my temperature rose much higher - Scanguage said I peaked at 96C at 110kph (legal limit for divided highways in Alberta), and 85C steady for 100kph.

I'll see about my fenderwells no matter what this year -- one is new as of August, the other is original, and the car was built in late 1999. The older ones are quite rough from all the debris flung up into the fenderwell over 8 years. Maybe the new one is the answer, and I'll get the driver's side replaced before winter. I'll probably try "greasing" the plastic inner fenders with a spraycan of kitchen vegetable oil (a.k.a. Pam®, but I'll go generic) if I find the newer one has clogging problems still.

Looking in atop and underneath my engine bay ... things are so crowded up. I'm not sure how sealing the compartment will do regarding coolant temperatures. Does anyone know what temperature the cooling system for a TDI can take, until it's liable to overheat? Unless my sensors are out, 80C and 90C from the Scanguage is still safe; 70C and up seems to give better mileage, too.

I'm not sure what the cooling system can take during warm weather. In winter, I'd be much more game to seal things up well, especially since I know I'm headed for some LOVELY -30C and -40C weather this winter.

I'm thinking next year, after the snow's gone, I'll be investigating a way to seal up the radiator better, so that there's proper ducting both into and out of the rad. Perhaps exiting the air out to the fenderwells, perhaps out along the exhaust to cool the turbo. Part of the reason to leave it, is to think about the best approach, and to plan trips so I can get enough time and distance to test out any ideas I try

09-26-2008, 06:56 AM	#20 (permalink)
ChrstphrR EcoModding Apprentice Join Date: Jul 2008 Location: Sault Ste Marie, ON, Canada Posts: 128 Schwartzejetta - '00 Volkswagen Jetta TDI GL 90 day: 52.87 mpg (US) Thanks: 19 Thanked 16 Times in 16 Posts	Hrm, I replaced most of the stock plastic undertray with a coroplast one before taking a trip. On the return trip, it was removed by a roadkill raccoon or porcupine (didn't stop to ask what it which one it was). With just the undertray replacement (like OEM), I found that my water temperature was elevated at highway cruise speed into the high 70s, Celsius -- 74-78, in September, with air temperatures in the 10-20C range, while at 100kph When I added a lower grille block for the radiator... I found my temperature rose much higher - Scanguage said I peaked at 96C at 110kph (legal limit for divided highways in Alberta), and 85C steady for 100kph. I'll see about my fenderwells no matter what this year -- one is new as of August, the other is original, and the car was built in late 1999. The older ones are quite rough from all the debris flung up into the fenderwell over 8 years. Maybe the new one is the answer, and I'll get the driver's side replaced before winter. I'll probably try "greasing" the plastic inner fenders with a spraycan of kitchen vegetable oil (a.k.a. Pam®, but I'll go generic) if I find the newer one has clogging problems still. Looking in atop and underneath my engine bay ... things are so crowded up. I'm not sure how sealing the compartment will do regarding coolant temperatures. Does anyone know what temperature the cooling system for a TDI can take, until it's liable to overheat? Unless my sensors are out, 80C and 90C from the Scanguage is still safe; 70C and up seems to give better mileage, too. I'm not sure what the cooling system can take during warm weather. In winter, I'd be much more game to seal things up well, especially since I know I'm headed for some LOVELY -30C and -40C weather this winter. I'm thinking next year, after the snow's gone, I'll be investigating a way to seal up the radiator better, so that there's proper ducting both into and out of the rad. Perhaps exiting the air out to the fenderwells, perhaps out along the exhaust to cool the turbo. Part of the reason to leave it, is to think about the best approach, and to plan trips so I can get enough time and distance to test out any ideas I try __________________ Current mod: Skidplate/Undertray for my MkIV Jetta. Next mod: CAD drawing for skidplate so other Jetta/Golf drivers can make one too!