View Full Version : Buying 85 C4, Need Advice

04-18-04, 08:36 AM
I am buying a 1985 C4 from a friend that has been in storage for 8 or 9 years and need some advice before driving it 1500 miles cross-country to my home in Tehachapi, CA. The car has been garaged continuously, started at least monthly, has 112,000 miles on it, has Gatorback tires with good tread. He loves the car, is the original owner, ran nothing but synthetics it it, but somehow lost interest in it and stopped driving it. His beloved wants it out of the garage before he buys a C6. He has two copies of the shop manual, knows the car inside and out and all work was done by the dealer. About 4 or 5 years ago he took it to the dealer and had all fluids replaced and all rubber hoses, belts, etc replaced. Has been parked on its tires in his garage since. Car starts and sounds great, short drive around the neighborhood has me drooling (my first car with solid handling) and that combined with that great hood that completely opens up the engine compartment has me convinced this is my dream car.

The car is completely OEM and has the engine oil cooler, heavy duty cooling, and what I think is duplicatively listed as the "Z51 Performance Handling Package" and "High Performance Suspension" and "Preloaded Gas Shock Absorbers". The paint needs washing/waxing but is original Lt Bronze upper/lower without a scratch except the clearcoat on the soft plastic front and rear trim is peeling on the top. The A/C and Bose stereo work except the power antenna needs repair (easy fix as I have learned from this group). It is an Automatic but oddly has a 3.07 rear end (RPO G44) which the 1985 specs page on this site lists as a manual transmission rear end.

I am reasonably competent, do all my own car work (mostly on engine but have rebuilt a couple of 4-bangers and a manual transmission), am unafraid to trace through a schematic, and have read the GM shop manual well enough to be very familiar with the ECM (looks like a great, straightforward system to work on), have even found the software to read the serial data. So my questions are:

1. Other than loading a tool box and the shop manual in the back and changing the oil, what should I do to prepare for a cross-country trip of 1500 miles down I-40? Shold I run injector cleaner during the trip, if so, what brand. What about seals? Any experience here.

2. My friend is insisting that I buy new tires since the car has been undriven for so long. The current Gatorbacks are in good shape but have been low (not flat) on occassion and not. Do you think this is necessary? If so I would like to buy the tires from Costco (best tire service center I have ever experienced) and their choices are Michelin Pilot Sport, Michelin Pilot XGT V4, and the Goodrich Comp T/A. My friend wants me to by the Pilot Sports but I drive 50 mi each way to work from a mountain pass California railroad town where we get some winter weather (and it gets cold) to the Mojave high desert where we get summer rains/winds that can be very heavy and it looks like for that kind driving the Michelin XGT V4's might be a better choice. Looking for advice.

3. Is there anything that can be done to clean up the peeling clearcoat on the soft plastic bumper covers front and rear? The paint is great otherwise and I want to keep it original if possible since it looks so good.

Sorry for the long post and thanks for all advice. This looks like a very knowledgeble group of serious corvette enthusiasts.


04-18-04, 10:29 AM
You've basically covered everything that I would think of, except make certain you have your AAA, Sears Auto Club, and Visa and Master Cards with you. AAs long as you don't push too hard, you should be able to use the present tires, unless they have a flat spot. If they have been sitting that long, the cords may have developed an knot or two which will never come out.

Tirewise, I bought Kumho's and they work great. You ought to consider them for the area which you describe. Fairly inexpensive but they do get good traction in slush and snow. If money is no object, check out the picture of moonunits 86, in the C4-Mod. They look so aggressive, that "he could pull a five bottom plow through mud to 14 inches and break plow pan."

Lots of Luck!!

04-18-04, 11:47 AM
FYI, the Z51 option came with,

3.07 rearend
Tighter steering ratio
HD sway bar
HD Bilstien shocks
HD Fan and cooler

and maybe bigger wheels, for sure on 86' not sure about 85'

So the 3.07 rear is part of the Z51 option, manual or auto, the auto without Z51 has 2.59 rear.


04-18-04, 08:07 PM
I would take a spare alternator, and here's why: 90% of all the problems I've ever had with my various C4s can be traced back to the alternator. It is the one part on the car that will fail repeatedly and without warning, and usually at the most inopportune time (on a freeway in the middle of nowhere, for example). From bearing failures to brush failures to regulator or stator failures, the cs-130 alternator is, for lack of a better phrase, "a piece of sh*t". I strongly recommend you take an extra one at the very least, or find a local alternator rebuilder and buy a heavy-duty cs-130 from him. Unless your friend has already had this problem and addressed it adequately, I can pretty much guarantee that the alternator will poop out, perhaps not on your 1,500-mile trip but somewhere else down the line, within the next couple of years.

It sounds like a really nice car, and I wish you much joy in owning it.

04-18-04, 10:58 PM
After 8-9 years of sitting I would trailer it home. There are way too many things that can fail on cars stored for long periods. Rubber products like belts and hoses. oil seals on axels, trannys, fluid breakdowns, water pumps seal, Rusted brake lines, varnished fuel supply that will really muff up a carb and toast FI units. Not to mention the dreaded rodent infestation that can render your entire vac supply useless making engine run poorly at the least. Get it home, go through everything, and don't go too far away from home with it for a while.

04-18-04, 11:16 PM
Hey,..tell me how golden hills is now,..last time I was there was 1988,..i lived in mojave for 5 years and boron for 7 years,..Knowing this I would change the tires sometime soon, due to the heat and the roads,..the wind and sand(blasting),..I would have the paint protected somehow,..anyway good luck


04-18-04, 11:42 PM
you just need AAA dont trailer it save yourself the money. It will make it. If it doesnt thats why youve got AAA.

Good Luck,

04-19-04, 10:43 AM
I would warn against driving the car far on the old tires. I witnessed a blowout and spin at freeway speeds caused by old"new looking" tires. At the least have them inspected by a reputable tire shop. Good luck.