Just Bought an 89 Vert...few questions

[gilbybarr]

Hello to all....just brought home a 1989 Avanti Convertible yesterday. It has just 17,000 miles on it and is in great shape. I do have a couple of questions for those of you with similar cars/years. On the way home, cruising at 75 at an outside temp of about 85 degrees, the motor temp ran what looked to be 205 degrees (a bit of assumption here...the guage goes from 160 to 220 with a couple of slash marks in between). Just to be safe (I had 1000 miles to drive) I kept the AC off for a good bit of the time and it stayed right aroung 195 or so. Can you give me some insight as to "normal operating temp" on these cars......of course it has the 305 motor Monte Carlo Chassis. The owners manual doesnt give you this info.....it does reference 220 degrees as the threshhold level for overheating.

Also....any tips on tire/wheel combos? It has the standard "C4 Corvette look" wheels on it in great shape....I just dont care for the look. I saw some wheels that looked like Magnum 500's on an 89 on the internet recently, but I thought they were all Mopar and Ford bolt patterns? Suggestions or ideas? I do like the Magnum 500's.....that is what is on my '80 Avanti Coupe and they always look great.

One last question......the windshield on the 89 has "AVANTI" in big white letters....not in the correct logo, just the name. I have seen this on others from this era.....including the Wheel of Fortune red convertible. Was this something the factory did? I am thinking of taking it off but didnt want to do that until I determined if this was something factory original.......Thanks! Ed in Knoxville.

Edited August 20, 2008 by gilbybarr

[IndyJimW]

Hello to all....just brought home a 1989 Avanti Convertible yesterday. It has just 17,000 miles on it and is in great shape. I do have a couple of questions for those of you with similar cars/years. On the way home, cruising at 75 at an outside temp of about 85 degrees, the motor temp ran what looked to be 205 degrees (a bit of assumption here...the guage goes from 160 to 220 with a couple of slash marks in between). Just to be safe (I had 1000 miles to drive) I kept the AC off for a good bit of the time and it stayed right aroung 195 or so. Can you give me some insight as to "normal operating temp" on these cars......of course it has the 305 motor Monte Carlo Chassis. The owners manual doesnt give you this info.....it does reference 220 degrees as the threshhold level for overheating.

That apperar normal, my '87 uses the same setup, 195 thermostat and would register about the same on the gauge. You can install a 185 thermostat and it will lower the engine temperature 10 degrees, but it is not recommended as the engine ECM is designed to run 195 and may not come out of open loop.

Also....any tips on tire/wheel combos? It has the standard "C4 Corvette look" wheels on it in great shape....I just dont care for the look. I saw some wheels that looked like Magnum 500's on an 89 on the internet recently, but I thought they were all Mopar and Ford bolt patterns? Suggestions or ideas? I do like the Magnum 500's.....that is what is on my '80 Avanti Coupe and they always look great.

I am running 16x7 rims, 4" backspace, Chevy 5 x 4.75 bolt pattern and P225/60R16 tires. Thats about as big a tire/rim combo that you would want, the only rub I have is if you crank the steering wheel all the way to the left hand stop the inside rear of the left front tire will rub the parking brake cable. That size tire will only change the revolutions about 2 tire turns in a mile so no change is needed for the speedometer. More performance tires are available in that size and it REALLY changed the handling.

I do have a set of 15" Magnum 500's that I took off my '87 that are for sale.

Jim Wood

[Ernie]

Congratulations on your purchase!

1. Temperature: Did you have a front license plate on your Avanti when you had the temperature problem? The grill opening on the 1989 is small do to the fog lights. A front license plate blocks over 50% of the opening. Then at highway speeds, the plates deflects even more air away from the grill opening.

In the summer, I remove my front plate. With the plate removed I no longer experience the high temperatures you described. If I leave the plate on, I have the same situation that you described.

If you did not have a front plate, I would suggest the radiator be flushed and the thermostat replaced with a 195. Our cars are 19 years old; so, when was that radiator flushed last?

2. Rims/Tires: Don't replace your 'C4' rims. My Avanti came with the wires, and the Midwest potholes destroyed them quickly. I have had two different rims since then I am still not satisfied. We have another member in the Chicagoland Avanti Ass'n with a 1989 Convertible with the same rim problems.

The 1987 and 1988 Avanti's are built on the Monte Carlo chassis. Our 1989's are built on the 'square' Caprice chassis. The rear axle length on the Caprice is too wide for the tapered rear end of the Avanti. The offset on the C4-rims is the maximum allowable. Any other rims will 'stick-out' too far and your Avanti will look like "rice!" Be careful!

Notice the rear wheels sticking-out with my current rims: http://www.cardomain.com/ride/2809906

3. White AVANTI: That was a factory option, and it is rare.

Edited August 21, 2008 by Ernie