Astron 1850, Sigma GL Wagon 1980

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Overheating1
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Joined: Tue Apr 14, 2015 5:34 pm

Astron 1850, Sigma GL Wagon 1980

Post by Overheating1 »

Hi, have a tidy wagon that im intending on using as a daily driver. Its a 1980 GL Chrysler Sigma.

I Have had some problems with overheating and I have some questions to ask anyone who is familiar with these care and particularly this engine. After not being able to solve an overheating problem, and the mystery of where the water was going Ive had the engine looked at by a mechanic friend of mine. There has been a substantial amount of work done and Im still looking for answers and Ideas.



Firstly, does anyone know if cooling issues were a problem with this motor (Astron 1850, 4G51) ? Does anyone know some of the common problems with this motor? Does anyone have a working original temperature gauge for sale?

When we pulled the engine apart it looked like a blown headgasket was the cause of the overheating. There was a very clean looking 4th cylinder and the head gasket was damaged.

We have been putting it back together and going through everything we can think of and still face the problem...

Ok here is what has been done so far,

1. Head has been stripped, checked for cracks, porosity and machined back, new valve guides... the list goes on; suffice to say the head should be in top shape. Head was professionally fitted with new gaskets. All valve clearances were set correctly.
2. Radiator has been flushed, does not need to be re-cored, is in top shape. The fan is freely pulling air through the radiator, no bugs of large amount of crap, it is as clean as a whistle.
3. New thermostat and thermostat housing fitted. - have checked that the thermostat works in a boiling pot; it does.
4. New water pump fitted.
5. Heater unit removed and is being repaired - blocked tap (Radiator inside was flushed and is in good condition). Heater is currently bypassed.
6. Have taken the thermostat out and used a hose to make sure water is flowing through the engine.
7. After market temperature gauge and sensor installed. - possibly reading a little hotter than what the thermometer we were cross referencing the temperature with was reading, but it is winding round to max after a few minutes of the car running.

The car sounds as if it is running smooth, its not blowing smoke or lots of vapour.

8. When the car turns off can hear bubbling noises coming from the rocker cover, there is a milky looking substance which is water/moisture and oil. I'm wondering if this is just moisture from putting everything back together joining with oil or whether it is the sign that things are fucked. There is no oil in the radiator, and the oil in the sump is still new ( no milky shit).

Im going to try get the original gauge replaced/ restored and have that in the dash working asap, hopefully I will get a clear reading... thats about where were at.

Fuck.


Help!



Regards Matty H
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75wagon
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Re: Astron 1850, Sigma GL Wagon 1980

Post by 75wagon »

I apologise for not seeing and approving this post earlier.

Dave...
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ddt
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Re: Astron 1850, Sigma GL Wagon 1980

Post by ddt »

Hi Matty
Overheating1 wrote:Firstly, does anyone know if cooling issues were a problem with this motor (Astron 1850, 4G51) ? Does anyone know some of the common problems with this motor?
No, there's no particular cooling problems with any of the Astron engines.

Common problems can be a noisy timing chain from worn guides and engine burning oil from burnt piston rings caused by running too rich for too long (badly tuned carb or auto-choke sticking).
Overheating1 wrote:8. When the car turns off can hear bubbling noises coming from the rocker cover, there is a milky looking substance which is water/moisture and oil. I'm wondering if this is just moisture from putting everything back together joining with oil or whether it is the sign that things are fucked. There is no oil in the radiator, and the oil in the sump is still new ( no milky shit).
So where are you seeing this milky oil/water coming from?
Are you losing water?
Double checked your plumbing connected Ok with no folded hoses etc?
Are you sure you are actually running hot? Would you be game to let it run a bit longer and see if the radiator cap opens?

Not sure whether if you had a blocked water gallery in your engine that it could cause overheating to occur like you are experiencing? Someone else might be able to confirm if that's possible?
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