Grille Blocks in the Summer

[QuickLTD]

66k? Dammit man LOL that car is almost new. I am at 166k. Were you able to get away with the 3/4th block? At idle or in traffic how are your temps at 3/4th blocked

[99LeCouch]

The 3/4 block is on and working well. That 1/4 made the world of difference in cooling I've been babbling on about.

My temps are ~177-182 on the highway, and ~184 at idle in traffic. I do a lot of coasting up to lights, so that low load and downtime don't let the engine heat up too badly.

The engine has 66k miles on it. The rest of the car is your typical 10-year-old GM car. 4 big rust holes patched so far, and the struts were replaced at 64k miles. My driver's seat foam is gone, the dash rattles over every bump, and I didn't re-install the interior trim quite right cleaning up from the rust hole that poured an inch of water into the backseat, so the trim squeaks incessantly. And the OEM speakers were toast this past December. Fortunately the replacements sound amazing to drown out the squeaks of the interior.

[99LeCouch]

Update: I reinstalled the lower half of the grille block earlier tonight. The temperatures are low enough where it's likely not an issue running the full block. Mid-70's during the days and low 50's at night.

I'm also experimenting with blocking off the transmission cooler more to promote faster transmission warmup.

[itsmedc]

Maintenance Reminder:
For all you owners of GM 3.8 engines made before 2008 you can either replace the lower intake manifold (LIM) gaskets, upper intake manifold (UIM) gaskets and upper intake manifold (plastic) around 100K or you can wait until it does the expensive oil into the coolant routine.

[99LeCouch]

I'm doing mine in a few weeks. And running the lower-temperature thermostat I'm hoping will help keep the degradation slow. My car is over-cooled, so blocking off part of the grille is not an issue.

And it's coolant into the oil. ;-). No worries, it's bad either way!

[QuickLTD]

Did you ever sign up on that Bonneville forum I told you about?.. So much info for our cars..TONS about the LIM change. I would shy away from anything that makes the trans hotter.. heat is the enemy wit hautomatics. I would hate to see you shorten its life.

[gascort]

Do your 3.8s not have a lower air dam to direct air up into the lower opening? (it doesn't sound like it)
My wife has an Intrigue (98) and it has NO grille whatsoever - only a lower opening that's VERY small. If the air dam is removed or ripped off her car is prone to overheating on the highway.

[QuickLTD]

My car does. There is an open space between the front fascia and the Lower radiator support. My chin spoiler mounts on the lower radiator support and there is a front tray behind it. Supposed to be anyway. Both are missing on my car and in the Florida heat it does get warm when driving below legal highway speeds (65 & 70). I can't speak for the Buick but I believe that car is sealed from the bottom of the front fascia back.

[99LeCouch]

Yeah, I'm a member on PontiacBonnevilleClub and BonnevillePro. That's where I am getting all my information on the LIM change.

About my transmission, there's a giant external cooler hooked up. It took ~50 miles this morning for the transmission to reach 150*. I want to see the transmission at about 160-170 for optimal mileage. My best mileage segment came on a 100 degree day with the transmission at 170. From what I've read, 170 is the upper limit for safe transmission temperatures. I'm putting in Dexron-VI to help with heat protection. The new stuff is extremely shear-stable and lower viscosity than Dexron-III. In short, I'm not worried about heat.

gascort, the only ventilation on my car is from the 4 grille openings. My car is cooled fine up to about 80*F with the entire upper grille blocked off. And my car cools much better on the highway than in the city. Strange your wife's car doesn't.

[QuickLTD]

Awesome. I am glad to see you are monitoring trans temps and It appears you did the proper research! I recently had to do my UIM and found this (see pic) Keep an eye out the runners were warped to hell. I have a much better powerband now. Dont forget to check the EGR passages in the UIM they get really brittle. Sorry not trying to threadjack just trying to give some friendy advice.

Dan and some others over on the other forum blocked the coolant passages from the LIM to the UIM. Maybe that would give you a touch of heat in the plenum kind of like a free WAI?


New runners on top.. See the difference? The photos dont show how bad they really were. Some were totally deformed and not sealing to the LIM.