78 Pontiac Grand Prix Project worth?

naminator

Not-quite-so-new-guy
Jul 21, 2020
41
18
Alright, so I am in Canada. I have been unsuccessfully looking for a fun project mobile to tinker with and hopefully drive. Looking for something that "sounds fast" but it doesn't actually need to be fast. If she can light the tires up, all the better. In my recent searching, I have looking at an early 80s regal with a swap motor, an early 80's regal "with a v8", an 80's Grand Prix with more rust than metal but a 350sbc and an 85 Monte with a v6 with a body held together with spit and prayers.

Yesterday, I went and looking at a 78 Grand Prix SJ model. The car is red/silver and has not ran for over a year. To nobodies surprise in Canada, it has rust. Rust aroudnt he rear driver wheel well, some (hopefully) surface rust in the floor pans which made the padding under the carpet damp (or the shot weather seals are letting water in) and you can see some sunlight through a spot in the corner of the trunk. It has dings, chips and scratches that show some rust but it looks pretty solid. The frame seems good, the tank looks good and the chrome is decent. As a plus, all the glass is free of major chips/cracks, but the sunroof is taped up.

Here is where things go pear shaped. The tires are flat on the passenger side but hold air (new winters in 2019 with only 1 season), there is what appears to be trans fluid leaking quite quickly under the car, the interior has seen more cigarettes than kilometers, the odometer says 47k, but that was rolled at least once and someone put in and then removed an aftermarket stereo with dozens of random wires running all over. The headliner is sagging, trim is damaged or poorly installed, the vinyl top is pretty decent but cracking etc. I opened the trunk and it had a spare, but it also had a jug of ATF, Coolant, washer fluid, battery and a snapped belt. The current owner said it was safetied 2019, then he picked it up, "swapped" the brakes, installed a new battery and had his mechanic friend check it out who said the frame is solid.

Again, it appears the bones are solid enough, some patching, some bondo, some paint and it will probably freshen up decent. I was told the owner before the previous owner swapped the motor in it with a 307 Olds of some sort and that he removed all the heat circulating stuff? I don't know. I brought minimal tools a breaker bar, forgot my ramps and a can of ether. My plan was to see if it spun freely then try and get a spark of life from it with the Ether/gas I brought then make a decision. Turns out the last guy to look at it, about a month ago, snapped the hood latch release cable. Climbing under a Grand Prix with 2 flats on the same side to try and free the hood/unbolt the latch/remove the grill wasn't in the cards last night.

As with most abandoned projects, the current owner has a story attached to the car, wants to move, cant afford to fix it and doesn't want to move it. He wants $2000, but it has both a for sale sign saying that and the advertisement has been up for a while. Lots of g-bodies pop up, many of them running, most of them more rusty. I was told the owner drove it, reliably and happily the winter of 2019/2020, then spring 2020 on a smoke run, she got about 1km from home and start to sputter and run extremely poor until it just cut out. He could crank it and he got it started, but basically needed to keep the hammer down to get it to limp back home and it barely got there. he tried starting it a few times but nothing. The gas in the tank didn't smell fully varnished, but unless I could get into the engine bay and pull a fuel line I wasn't going to be able to start diagnosing the issue. Obviously the hood latch is easily fixed, but it would take time, effort and money to do so.


What would you do? Show up and try to pop open the hood and check out the engine, knowing it stopped working mid drive and still limped home, then pay closer to asking? Or do I super low ball the guy and tell him it is basically an as is sale, then pop open the hood and accept whatever may happen...
 
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JAMCAR223

Royal Smart Person
Jun 6, 2014
1,727
113
Houston, TX.
Keep looking
 
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g0thiac

Master Mechanic
Sep 6, 2020
400
43
Alright, so I am in Canada. I have been unsuccessfully looking for a fun project mobile to tinker with and hopefully drive. Looking for something that "sounds fast" but it doesn't actually need to be fast. If she can light the tires up, all the better. In my recent searching, I have looking at an early 80s regal with a swap motor, an early 80's regal "with a v8", an 80's Grand Prix with more rust than metal but a 350sbc and an 85 Monte with a v6 with a body held together with spit and prayers.

Yesterday, I went and looking at a 78 Grand Prix SJ model. The car is red/silver and has not ran for over a year. To nobodies surprise in Canada, it has rust. Rust aroudnt he rear driver wheel well, some (hopefully) surface rust in the floor pans which made the padding under the carpet damp (or the shot weather seals are letting water in) and you can see some sunlight through a spot in the corner of the trunk. It has dings, chips and scratches that show some rust but it looks pretty solid. The frame seems good, the tank looks good and the chrome is decent. As a plus, all the glass is free of major chips/cracks, but the sunroof is taped up.

Here is where things go pear shaped. The tires are flat on the passenger side but hold air (new winters in 2019 with only 1 season), there is what appears to be trans fluid leaking quite quickly under the car, the interior has seen more cigarettes than kilometers, the odometer says 47k, but that was rolled at least once and someone put in and then removed an aftermarket stereo with dozens of random wires running all over. The headliner is sagging, trim is damaged or poorly installed, the vinyl top is pretty decent but cracking etc. I opened the trunk and it had a spare, but it also had a jug of ATF, Coolant, washer fluid, battery and a snapped belt. The current owner said it was safetied 2019, then he picked it up, "swapped" the brakes, installed a new battery and had his mechanic friend check it out who said the frame is solid.

Again, it appears the bones are solid enough, some patching, some bondo, some paint and it will probably freshen up decent. I was told the owner before the previous owner swapped the motor in it with a 307 Olds of some sort and that he removed all the heat circulating stuff? I don't know. I brought minimal tools a breaker bar, forgot my ramps and a can of ether. My plan was to see if it spun freely then try and get a spark of life from it with the Ether/gas I brought then make a decision. Turns out the last guy to look at it, about a month ago, snapped the hood latch release cable. Climbing under a Grand Prix with 2 flats on the same side to try and free the hood/unbolt the latch/remove the grill wasn't in the cards last night.

As with most abandoned projects, the current owner has a story attached to the car, wants to move, cant afford to fix it and doesn't want to move it. He wants $2000, but it has both a for sale sign saying that and the advertisement has been up for a while. Lots of g-bodies pop up, many of them running, most of them more rusty. I was told the owner drove it, reliably and happily the winter of 2019/2020, then spring 2020 on a smoke run, she got about 1km from home and start to sputter and run extremely poor until it just cut out. He could crank it and he got it started, but basically needed to keep the hammer down to get it to limp back home and it barely got there. he tried starting it a few times but nothing. The gas in the tank didn't smell fully varnished, but unless I could get into the engine bay and pull a fuel line I wasn't going to be able to start diagnosing the issue. Obviously the hood latch is easily fixed, but it would take time, effort and money to do so.


What would you do? Show up and try to pop open the hood and check out the engine, knowing it stopped working mid drive and still limped home, then pay closer to asking? Or do I super low ball the guy and tell him it is basically an as is sale, then pop open the hood and accept whatever may happen...
You’re in Canada like myself, so rust should be expected.

First check the frame rails, if they are gone, DON’T BUY IT. Floor pans, rockers etc aren’t as bad.

Before buying any project, I suggest you find a good body man or learn to weld yourself.

Second, if it doesn’t have a good motor or transmission DON’T BUY IT. Unless you have a hoist or block & tackle that is.
 

naminator

Not-quite-so-new-guy
Thread starter
Jul 21, 2020
41
18
You’re in Canada like myself, so rust should be expected.

First check the frame rails, if they are gone, DON’T BUY IT. Floor pans, rockers etc aren’t as bad.

Before buying any project, I suggest you find a good body man or learn to weld yourself.

Second, if it doesn’t have a good motor or transmission DON’T BUY IT. Unless you have a hoist or block & tackle that is.
Frame looks solid, rockers are solid, sills on the doors? Solid. The only shot spots are a hole by the rear driver wheel well in the corner and another bubbled spot behind it. The floor pans seem solid, but the driver side padding under the carpet felt damp and was rusty underneath, but that might be shot weather stripping.

As for the engine/trans, I could see the trans leak but figured it would be typical for a 43 year old car that sat for a year, but the engine was the wild card. Why someone would pull the 301 and put in a 307 is beyond me, if it was even done (couldn't open the hood at that time obviously). The question then turns to the issue, my first thought is a real rough idle/surging is a fuel issue, which I could test with what I brought, or it could be a shot distributer or something, hard to say. As for a hoist, I do not have one on had, but would acquire one if things worked out. I have limited space to do an engine swap, but I have seen people do more with less, I am pretty handy and I learn quick. As for welding? I took some courses a long time ago and I did ok, but it has been a long time. I know I would need to weld some patches so I am mentally prepared to do so and the cost of a welder is considered.

Honestly I was considering offering $800 as is. If he took that, I would pull the grill, unbolt the hood latch and get inside the engine bay with the goal of limping the thing home. Failing that I would tow it. I would rather get the "307" up and running, clean up the interior/body and enjoy it. Or if it is running decent and I clean up the inside, maybe I can flip it for a few bucks and put that towards something else. If she is totally shot, I would probably part out bits, buy a runner that needs changes and could use the parts or ship her to the scrap yard for a few bucks (as long as I get it there like $500 or something).
 
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g0thiac

Master Mechanic
Sep 6, 2020
400
43
Frame looks solid, rockers are solid, sills on the doors? Solid. The only shot spots are a hole by the rear driver wheel well in the corner and another bubbled spot behind it. The floor pans seem solid, but the driver side padding under the carpet felt damp and was rusty underneath, but that might be shot weather stripping.

As for the engine/trans, I could see the trans leak but figured it would be typical for a 43 year old car that sat for a year, but the engine was the wild card. Why someone would pull the 301 and put in a 307 is beyond me, if it was even done (couldn't open the hood at that time obviously). The question then turns to the issue, my first thought is a real rough idle/surging is a fuel issue, which I could test with what I brought, or it could be a shot distributer or something, hard to say. As for a hoist, I do not have one on had, but would acquire one if things worked out. I have limited space to do an engine swap, but I have seen people do more with less, I am pretty handy and I learn quick. As for welding? I took some courses a long time ago and I did ok, but it has been a long time. I know I would need to weld some patches so I am mentally prepared to do so and the cost of a welder is considered.

Honestly I was considering offering $800 as is. If he took that, I would pull the grill, unbolt the hood latch and get inside the engine bay with the goal of limping the thing home. Failing that I would tow it. I would rather get the "307" up and running, clean up the interior/body and enjoy it. Or if it is running decent and I clean up the inside, maybe I can flip it for a few bucks and put that towards something else. If she is totally shot, I would probably part out bits, buy a runner that needs changes and could use the parts or ship her to the scrap yard for a few bucks (as long as I get it there like $500 or something).
Assume that the floors are done in the car.

Now that said of course, try and diagnose what you can while there. It could be something small like a vacuum leak, or big like a head gasket. Assume the worst, but hope for the best.

If anything I’d be more concerned about the cost of bodywork. G Body floor pans are expensive and in shortage here in Canada.
 

naminator

Not-quite-so-new-guy
Thread starter
Jul 21, 2020
41
18
Assume that the floors are done in the car.

Now that said of course, try and diagnose what you can while there. It could be something small like a vacuum leak, or big like a head gasket. Assume the worst, but hope for the best.

If anything I’d be more concerned about the cost of bodywork. G Body floor pans are expensive and in shortage here in Canada.

He said it was running great and then suddenly it was not running, stalled and he limped it home but it was idling rough and shaking. I really wanted to pull the dipstick and check the oil, assuming it wasn't flooded with gas/coolant, I was going to try and spin the engine by hand, if that worked I was going to pull a spark plug or two and check them out and then pull off a fuel line and try and crank it and see if it pulled fuel.

If it did pull fuel, I was going to hook up a can with some fresh gas and try to start her up and figure out from there. It could be a completely shot engine, it could be a distributor, it could be the carb getting gummed up or a fuel issue or something. Honestly, sounds more like a fuel/carb issue than anything else at this stage.

As for the floor pans, the majority of the moisture/rust I found was close to the door. Everything looked and felt remarkably solid and the car wasn't moldy smelling. The previous owner had a stereo system in it so it looks like jumbled mess on that front. Right now he basically wants 2k obo. He joked it will be much harder to sell with the hood latch broken. I pointed out the mystery fluid underneath and the rust in the trunk, both he was surprised by. I feel like this is a "buy it or it goes to the scrap yard after I haul it around some more". At $550 from the junkyard, plus 1-2 tow's (from his current place to a new place and/or junk yard, he might get $500 or less. He won't part it out and won't fix it, so it is 100% going to the scrap yard or somebody buys it for 2k or less and judging by how you can't check out the engine at all until the hood is bypassed, it further devalues the car.
 
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Ribbedroof

"That wagon guy"
Supporting Member
Jan 4, 2009
4,156
113
Wellston, OK
Sorry, but everything about your story SCREAMS run away

Rusty, hacked, non-running....that's a no

ALWAYS buy the best car you can afford, even if you have to save a little while. Better to buy a $4000 car for $3500 than a $2000car for $800 IMO
 
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79 GP 4 speed

Master Mechanic
Nov 12, 2017
370
63
I may be wrong but I thought all Pontiacs for Canada with a v8 had Chevy engines. I would also be concerned about what is hiding under the vinyl roof
 
Oct 14, 2008
7,453
113
Melville,Saskatchewan
No, I have seen a few of the Grand Prix's with the Pontiac 301's up here. It seems the Firebird, Grand Prix and big cars were the exception to the rule. GM did weird things up here. They did the same thing to Oldsmobile's up here in the 80's. You guys basically trip over the 307 down there, none in the Cutlass except the 88 model year, H/O and 442. The non swirl port version is much more common up here due to the vehicle's they came in.
 

pontiac guy

G-Body Guru
Oct 28, 2016
551
93
Royse City, TX
As the owner of the 78 I'd like to warn you that some parts are harder to come by. Basically body stuff. I prefer the early body to the Euro body but most people are the opposite. If you need body panels expect to work hard salvaging what you have.
 
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