78 GP with 83 Olds 307 AC/Cooling

[naminator]

Currently chasing a few gremlins while tackling other small things. The current 2 cooling issues are:

1. The temp gauge is pinned at the lowest reading and the engine is getting pretty hot. The upper rad hose has fluid in it and if you give it a squeeze, you can see/hear it moving into the expansion tank. However, half the upper rad hose is getting really warm, the other half cold. The bottom rad hose is also not warm, neither is any other coolant. On one hand, it seems like the coolant isn't flowing, which could be a water pump? Or maybe the thermostat is shot or something. I haven't run it for any length of time for fear of damaging something. I plan on pulling the current thermostat this weekend and doing a quick blow torch test, instead of just throwing parts in. Anything else I should be looking at during that time?

2. AC is gone. So previous owner(s) installed the AC system from a 79 Grand Prix, but the Compressor is just sort of missing. The connectors are a bit messed up. Honestly I am looking around and it sounds like I should be replacing a large amount of the AC system, on top of getting a new/rebuild compressor, then after I get that done I still need an AC flush. I am slowly adding everything up and man, it is getting pricey fast, $300 for R43 compressor, $25 belts, $200 for the hoses/misc parts, couple hundred for the flush/charge. Now, I could probably score a junk yard R4 for about $50 and work on re-building it myself with all new seals, doing all of this in an inexpensive way, but with zero guarantee it would work. I figure it will be at least $400 for all the parts from various sources plus plenty of time, versus close to $1000 or more for a more profession job. Or, I could buy a $30 block off plate and rip all the AC junk out. It does get pretty toasty here, but I have power windows. Is it really even a worth while thing to pursue? I think the half installed AC system looks like hell right now, so I need to either rebuild or remove.

 

[olds307 and 403]

The big issue is the quality of the R4 compressors. They sucked in the original equipment form, made noise, leaked oil then seized. The aftermarket ones are possibly even worse. I want to eventually add A/C in my 70S, a factory non A/C car. It will include nothing GM, my serpentine set up that came with a R4 will get the Sanden adapter brackets. Get a complete aftermarket system with a reliable Sanden compressor.

 

[naminator]

The big issue is the quality of the R4 compressors. They sucked in the original equipment form, made noise, leaked oil then seized. The aftermarket ones are possibly even worse. I want to eventually add A/C in my 70S, a factory non A/C car. It will include nothing GM, my serpentine set up that came with a R4 will get the Sanden adapter brackets. Get a complete aftermarket system with a reliable Sanden compressor.

You are amazing. I love how I ask goofy questions and you have the answer it seems. I think I am going to go AC Delete with block off plate, then I can decide later what to do while cleaning up all this AC crap under the hood.

 

[565bbchevy]

I have a new 4 seasons compressor on my 86' Regal and it has been working great for 3 years but my entire system is also all new including the new 134 condenser.

https://www.amazon.com/gp/product/B000C2OFGG/?tag=gbody-20

 

[olds307 and 403]

I have a new 4 seasons compressor on my 86' Regal and it has been working great for 3 years but my entire system is also all new including the new 134 condenser.

https://www.amazon.com/gp/product/B000C2OFGG/?tag=gbody-20

View attachment 183139

A brand new one seems the best chance of these living. They just weren't good, long term compressors even as new equipment. Pulling the clutch to even replace it or the front seal is a major PIA as well.

 

[naminator]

ALRIGHT

So I pulled the thermostat. It had a 195 in it, I swapped it for one of those fancy "fails open" 180 thermostats. I also changed the water neck gasket. I did confirm, with the ol' blow torch test, that the thermostat opened. I tightened the bolts down (not enough) and during a test it shot some coolant out of said bolts. Tightened them more, no more issues. I decided I would flush the block/rad and start with fresh coolant, since the previous owner could have put who knows what into it and the previous expansion tank was cracked and filthy.

Well I started flushing with distilled water, draining the rad via petcock with that being the lowest point, closing it, filling with distilled water, running the car with the heater on and squeezing the hoses to get out bubbles. It looks like all the bubbles are gone, but the upper rad hose is unreasonably warm, the fluid in the rad slowly warms and it seems to circulate, at least when it was low I could see some fluid coming through the fins in the rad (and a hose push LOTS through those fins) but the engine is getting really hot. Like unreasonably so. I drove maybe 8 blocks to a car wash and was trying to blast off some grime/grease and water hit the sides of the block and flash vaporized into steam. The manifold is getting warm, the hoses are hot, everything is just heating up really really quick. Maybe it is the A/F mix, maybe it is an exhaust restriction or spark or timing, but it is like the thermostat won't open, but I know it should be. I thought the water pump was going, but it was able to really push coolant out of the bolts holding the water neck down, with some serious force, so it seems to be working.

Am I missing something? I am thinking about pulling the lower and upper rad hoses, replacing them, replacing the little bypass hose thing, potentially pulling the rad to clean the fins out, and hopefully one of those fixes my issues.

 

[ELCAM]

Might want to run a combustion leak detector on it.

 

[Mac442]

My advice, get the AC running. Don’t go the block off plate route. You will enjoy your car more when you’re not sweating your butt off.

My GM Performance compressor is holding up just fine. Make sure you put the correct amount of oil in the system if you go that route.

It comes with adapter washers to fit the stock manifold hoses to the back of the compressor. Just flush everything out good. Replace the o rings, drier and orifice valve. Pull vacuum and fill. Other than the compressor it wasn’t very expensive at all.

 

[Texas82GP]

Here in Houston, in my opinion, if the car doesn't have A/C, it's junk. Here, you wouldn't want to drive it between early May and mid October. On my car, I'm going all new. New evaporator core, new accumulator, new hose assembly, new Delco compressor and new condenser. All that is being reused is the liquid line from the evaporator to the condenser. It will be thoroughly flushed.

The key to keeping an R4 Compressor alive is to buy a new one (I prefer a Delco or Delphi) and keep the RPM's below 4,000. We have an R4 on my brother's LS swapped 78 Z28. We have a "window switch" that controls a relay, which controls the compressor. When the RPM is below 500 or above 3900, the window switch cuts the compressor out.

The key to having success with reviving an A/C system is to have a clean, leak free system. I would recommend strongly against a used compressor.

An alternative to going back with an R4 is to buy a kit (compressor and brackets) to put a Sanden compressor on your car. They are tough. You'll have to make custom hoses but its doable. We did custom hoses on my brother's car. We bought the hose material and fittings, mocked the hoses up and marked them and the fittings up for clocking, then pulled them and took them to a shop to have them crimped....