1989 coupe rear hatch question, over heating, and parts vendors

[Bolisk]

Hello everyone,

I'm helping a friend of mine buy a 1989 coupe remotely. One of the thigs that the previous owner said was the the "string" (as in a peice of rope) that releases the rear hatch from the gas cap location broke. So the rear hatch does not open.

I've restored my 1970 vette, so I know enough to be dangerous, but I don't know specific details about C4's.

First question:
So the string feels like a bubba fix. Having said that, how is the hatch release supposted to work? I assume that it's normally electronically controled from a switch inside the cabin. Is that the case? Also, is there a manual override cable somewhere?

Second question:
Are these cars known for over heating? This car has a secondry fan with a switch in the cabin to aid in cooling during track days (did I mention this is a track car). Just curious. Also the car has a 160 degree thermostat, which people sometimes use for overheating conditions. I know the normal thrmo is a 195.

Last question:
Which parts vendors do you all recomment?

Thanks!

 

[Baldie88]

I will try and answer your questions but I'm sure someone with more knowledge will chime in.

I've got an 88 and there was almost no change from an 88 to 89.

First, as for opening the rear hatch, I don't know about anything in the gas door area to open the hatch. I'd have to check my manual to be sure however. I believe the hatch has an electric switch. Mine opens either with a button in the console or a switch on either door.

Second, C4s are notorious for running hot. I have the auxiliary fan also and use to run a switch so it came on at 200 degrees. After talking with Gordon Killebrew, the father of C4s, I went back to the original setup. The front fan kicks on at 228 and the main fan kicks on at 240. Although I hate seeing these temps I've done a lot of parades and the fans always kick on and cool it right down to 195 which is what thermostat I'm running.

As for a parts vendor, I've used them all, Mid-America, Ecklers, GM Parts Direct, etc. All seem to be within a few dollars of each other.

All this being said, if this is a track car it is hard to tell what modifications have been made along the way. Mine is stock.

Good luck.

Ron
"Baldie88"

 

[boomdriver]

Hello everyone,

I'm helping a friend of mine buy a 1989 coupe remotely. One of the thigs that the previous owner said was the the "string" (as in a peice of rope) that releases the rear hatch from the gas cap location broke. So the rear hatch does not open.

I've restored my 1970 vette, so I know enough to be dangerous, but I don't know specific details about C4's.

First question:
So the string feels like a bubba fix. Having said that, how is the hatch release supposted to work? I assume that it's normally electronically controled from a switch inside the cabin. Is that the case? Also, is there a manual override cable somewhere?

Second question:
Are these cars known for over heating? This car has a secondry fan with a switch in the cabin to aid in cooling during track days (did I mention this is a track car). Just curious. Also the car has a 160 degree thermostat, which people sometimes use for overheating conditions. I know the normal thrmo is a 195.

Last question:
Which parts vendors do you all recomment?

Thanks!

If the hatch cable had been d/c...there IS a short emergency pull cable on the latch lever under the rear cargo trim. You;ll have to crawl in and remove the trim (few phillips screws, shorty driver) or fish around under the trim with needle nose to find the wire end...

The solenoid is tucked in the side of the cargo area where the harness runs to the rear...rt side.

Overheating...everybody went crazy when they saw their c4 wanting to run at 220+ degrees. That sent old schoolers to the emergency room and increased prozac sales back in the 80's.
It was designed to run that temp. Its scarey high and leaves little room for error, but it CAN be managed better than a bunch of bubba wiring and fan switches glued to the dash.
First make damn sure there is no trash blocking the radiator between the rad & a/c condensor (if its still there.) ALL radiator shrouds MUST be in place to guide the air. The nose is the only source of air for intake or cooling, so the shrouds and baffles are critical parts that need to be inplace. The air-dam is a gotta have things as well.

Next, in order to have efficient and good heat exchange you need more than the tiny plastic radiator that GM uses. For $250 you can get an all aluminum double row that holds more water,. exchanges heat much faster, and is much more durable than the glued plastic/alum stock radiator. If temps were 220+ before, this will lower them to 200 or less and keep them more stable.

The ECM (and motor) need to run this hot to work right, and oil needs to be this hot to be efficient and burn away excess moisture.
People use the 160 stats in the old school hope of better cooling, but if the fans are not on, the car has to be moving at 50 mph steadily to have the wind to get heat exchange...
So, since you want a stable operating temp of 190-200 anyway, install a 180-190 thermostat and just make heat exchange more efficient so it stays at 190 area.
Sounds like you need to de-bubba this car a little :ugh but I'm sure you can get it under control.

That hatch emergency cable sticks out toward the passenger side about 4-6" from the center of the latch, but its UNDER the long trim section around the back...
Make sure its just not a fuse or switch problem. There is a button in the console and on the back edge of both doors and they will not work if the car is in gear or moving. have fun !

 

[Bolisk]

We had the car inspected and the car got a good bill of health. The only problems appear to be faded paint, and some normal wear parts (rotors, pads, shocks, maybe springs) will need to be replaced.

The rear deck hatch thing was a concern before the inspection because the owner said there was s tring that you pulled by the gas cap to open the deck hatch. I thought that was odd. The owner sent us a picture after I posted the origional thread, and sure enough there is a string coming out from the hatch and laying on the rear deck. I suspect it was attaceh to the manual pull cable. Funny thing is the inspection said that the switches inside the car work just fine. So I have NO idea why this was done. Very interesting.

Anyway, the car will be shipped next week, and we will finaly get to see and put our hands on it. Well see what other "surprises" it has in store. Having said that. . .I'm not all that worried about it.

-JonR

 

[boomdriver]

We had the car inspected and the car got a good bill of health. The only problems appear to be faded paint, and some normal wear parts (rotors, pads, shocks, maybe springs) will need to be replaced.

The rear deck hatch thing was a concern before the inspection because the owner said there was s tring that you pulled by the gas cap to open the deck hatch. I thought that was odd. The owner sent us a picture after I posted the origional thread, and sure enough there is a string coming out from the hatch and laying on the rear deck. I suspect it was attaceh to the manual pull cable. Funny thing is the inspection said that the switches inside the car work just fine. So I have NO idea why this was done. Very interesting.

Anyway, the car will be shipped next week, and we will finaly get to see and put our hands on it. Well see what other "surprises" it has in store. Having said that. . .I'm not all that worried about it.

-JonR

You'd be amazed at how many people buy a C4 and do not learn to pop the rear hatch...for months...years, if ever.

You;re probably right....the string was tied to the emergency release cable thats pretty useless because its hidden under the hard plastic trim panel. Law requires all cars with a hatch or trunk to have an emergency release cable that can be operated from inside the vehicle. Kinda like the bathroom fan...law requires you have them. They don;t actually vent anywhere or do anything, but all city building codes state they have to be there.

 

[WhalePirot]

The rear deck hatch thing was a concern before the inspection because the owner said there was s tring that you pulled by the gas cap to open the deck hatch.

I never found that backup 'pull' in my '84, but I added one. This, after none of the three switches worked (for a time). BTW, the center console button doesn' work on mine, when the ignition is on, probably to prevent inadvertent 'popping' the hatch while driving.

The gas-charged lifters for that glass go bad but are fairly easy to R&R.

I like GM Parts direct but compare other pricing. My last order with them, aka Flow, took a whole week to get from their web site to the warehouse, BEFORE shipping. I have found many better deals and a heckova lot faster shipping on our favorite online auction place. that, seemingly new, partts place in TX is on the web and has some good quality at great prices.

I suggest learning to search on here and getting a FSM.