1973 504GL Heating issues

[dckirba]

Hello everyone,

My name is David and I live in Ethiopia. Please excuse my newbie questions and lack of automobile knowledge. Buying a new(ish) car is pretty expensive here, so my wife and I have bought a 1973 504GL for our first car. I am sorting out issues one by one since I can't afford to get everything done in one go. The biggest issue I have right now is with the engine overheating and then stalling. The radiator is in bad shape, but a replacement radiator is hard to come by. So my first question is:

1. Can I use a newer radiator from another car as a replacement? If yes, which one would you recommend?

Also, when I sorted out the electricals last week, the oil light came on and stayed on. The electrician says this might be an issue with the switch, but recommended that I have a mechanic check the oil pump as well. My next question:

2. Could the oil pump be another cause for overheating, or should I sort out the radiator first (which I know for a fact is bad) and then check the oil pump?

The overheating has increased this past week (my first week of really driving the car around). I was able to drive it for a couple of hours at a stretch in city traffic the first day. Since then it has started heating up much quicker and even a 20 minute drive needs to be taken slowly. Whenever the heat starts climbing up I just pull over and let it cool for a while. If I don't the engine starts stalling and asking for more gas.

Thanks in advance for your time,

David

[Peter.N.]

Hi David

Welcome to the forum, very nice car the 504, is yours petrol or diesel? The first thing I would check for the overheating is the thermostat, if you can't get e replacement just take it out, at least that will prove if it is that. It could well be the radiator at that mileage, anything that will fit should work.

The oil pump won't cause it to overheat but it will cause the engine to seize up if you have no oil pressure, I suspect that it is an electrical fault or the sensor. You will be able to hear if you have no pressure because the engine will be rattling quite loudly.

Peter

[spider]

I'd concur. The thermostat if in the slightest doubt temporarily remove it as on a carbed engine its not going to effect fuel consumption too much I think (injection engines will drink fuel if they stay colder) and I think your location means its not going to stay cold so should not get mayo from short journeys. I think I'd remove it for a few days to see if there was any improvement.

I'm starting to wonder if the water pump has missing impellers or other such a concern.

The larger radiator the better really, there are things such as flow rates to worry about but I'd go for whatever fits and the bigger the better, find one that has the inlet / outlet stubs and mountings etc in the same location (or as near as possible) to the one you have now.

Agree. Lack of oil pressure or lack of oil will cause damage and eventual seizure, it will run hotter with lower oil but as said you'd hear noises if it got that bad.

Viscous (bolted to crankshaft pulley sort of) radiator fan or electric ? a bad coupling could cause it to overheat if its viscous and at low speed driving but that seems rare.

[Oldpug]

I presume that this 504 is an African spec` model?? (and its had a tough life in hot dusty conditions.) if so the cooling system will be slightly different to Europe spec`.I`m sure it will have a fixed fan as opposed to the Peugeot electro magnetic hub type.If it does? have the elecro hub you can adjust the air gap until it locks the fan solid.Being an old model I`m sure the overheating is due to a blocked radiator core so the only answer in African conditions will be a reconditioned radiator.The water pump could be an issue? there is a core plug that can only be checked by removing the w/pump from the head and looking in the aperture.I`ve known them to work loose and then touch the water pump impeller blades causing them to fail.If this happens the engine would overheat in no time though.I`m not sure if African 504`s have thermostats?
I bet the oil light problem will be the switch on the oil filter housing or the wire from there on? oil pumps very rarely give problems but if the oil is contaminated due to poor servicing the oil relief valve in the pump can stick.
So I suggest a good clean radiator with a clean cooling system.If the oil switch or wiring does not cure the fault remove the sump and clean out,remove the oil pump clean and free the relief valve.
Those old Peugeot`s are as tough as old boots and go for ever.

[dckirba]

Thank you all so much for your time and replies. This particular 504 (petrol) doesn't have a thermostat and the fan runs all the time (and is coupled to the engine, not electric). I'm having the radiator looked at tomorrow to see if it can be reconditioned. If not, I'll follow your advice and look for a large radiator with inlet and outlet in similar locations.

Regarding the oil, the engine does run quite smooth with no excessive rattling. If I have time after the radiator guys look at the radiator, I'll drive down to a Peugeot mechanic and see if he can check the oil pressure switch. The wire is fine, the electrician verified it last week. The oil is new, but it did run with old oil for a couple of days (was parked for months before I bought the car). Thanks for the head's up on the potential water pump issue, I'll ask the mechanic to check that as well.

Once again, thank you all so much for your time.

Have a great Sunday,
David

[harditk]

Hi David, hopefully your heating issue sorted.

Dear experts,
I am new member here and I am having heating issue also for my newly rebuild engine.

Me and my mechanic has already nailed down the root cause - a corroded breech plug behind water pump.
I already purchased new plug from serie04 in which according to drawing should be the correct one.

However when seeing the actual head, seems that there's another layer of "ring" that is corroded.
And the plug is screwed on top of it.

The corrosion is actually creates water passage between front and back of the plug. That hole is not clearly seen from this photo.

What could be that part?

[harditk]

Drawing to clarify location of plug mentioned in my previous post:

[xantia_v6]

That is not pretty... Someone has had a couple of attempts at repairing it badly. Is the new plug the same diameter as the outer ring visible in the photo?

To make a proper repair, you probably need to remove the head and get the hole machined back to a clean round surface.

[harditk]

The new plug has smaller diameter than the "ring"...
At this monent head is already removed from the main block.

[Oldpug]

That’s the dreaded core plug I mentioned in my previous post.
By the look of that photo it’s been well and truly “got at”, possibly ruined the head? All I can suggest is for you to find an “old school” metal expert, who with the help of some ally welding, could make the new core plug fit properly.
Failing that it’s a replacement cylinder head I’m afraid.

[Oldpug]

Serie04 have a NEW cylinder head in stock at 495 Euros!!! Dean Hunter at www.peugeotparts.co.uk will have a second hand cylinder head, BUT! by the time its shipped to Singapore it will still be very expensive.

[harditk]

Thank you all for replies! I will try local machine shop first to see what they can do, otherwise I will source a new or secondhand head.