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Discussion Starter #1
Hi guys hope someone can help me, just fitted a new radiator to my 156 as the old one sprung a leak, took it for a short run and the temp gauge shot right up after a couple of miles stopped and let it cool down and checked the coolant which was ok drove back home and it did same this time I turned the heater on but it was blowing cold air, think it may be the thermostat as engine is running smooth and no water in oil any advice would be great Thanks
 

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hi mate.

Classic symptoms of an air lock.

It will need bleeding. There is normally a screw or bolt on a coolant pipe to do this, but failing that try taking the cap of the expansion tank and squeezing all of the coolant hoses you can get to with the engine running.

Best of luck.

Luke
 

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Is there a bleed valve on the rad ... top left corner as you look at the engine?
 

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Is there a bleed valve on the rad ... top left corner as you look at the engine?
Yep
Plastic bleed screw on the rad.
Edit: there is if it has the correct rad...!!
 

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Discussion Starter #6
Hi again just done what Luke said and bleed the system still overheating pulled out the thermostat and check that working ok so what do you guys think could it be the water pump any answers would be great thanks again
 

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You should be able to see coolant flowing via the small pipe into the header tank if the pump is working.
But your symptoms do look like a pump issue (or lack of circulation for another reason).
Unfortunately a pump change is a big job as it means full cambelt job + pump.
 

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Discussion Starter #8
thanks for the answer David had a friend of a friend (who,s a mechanic) have a look and he suggested I change the stat as it may not be working right,so i will do that and see what happens or it will be the shortest time i have owned a car that i really like
 

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If it was the thermostat stuck shut the heater would have blown hot.
 

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it is almost CERTAIN you have an air lock. i have had this prob on most cars after changing the rad or coolant.

The best way to check this is if engine hoses are getting hot. try feeling the top/bottom rad hoses and bottom engine hoses when engine is running.

If you have an air lock the symptoms are:

very quickly overheating when turned on.
Very hard upper pipes due to pressure
cold lower pipes due to lack of decent circulation.

You need to find a bleed valve in the system and use that. I dont know what to suggest if the rad hasnt got one. You could try taking off lower rad hose then run engine until you get a good flow out of the hose into a bucket. you would need to be running a steady flow into the expansion tank though to stop the engine running dry.

The chances of your pump failing at the exact time you changed the rad is minute, compared to the chances of an airlock, which is VERY common when changing a rad.

Keep trying and squeezing hoses + bleeding from any possible locations, and check for the symptoms i describe earlier.

Best of luck.

Luke
 

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You could try taking off lower rad hose then run engine until you get a good flow out of the hose into a bucket.
As soon as you remove the bottom hose it will drain the system.
So that isn't a good idea!!

The system bleeds via the bleed screw on the rad and via the small return pipe to the header tank (you will have the cap off while bleeding).
 

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Discussion Starter #13
hi I know this is a stupid question but is there any way to tell if the waterpump is knarkered apart from the car overheating
 

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on v6 there is a bleed screw on pipe at back of rear cylinders it is held on with tabs off the rear cam cover under plenum chamber
 

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hi I know this is a stupid question but is there any way to tell if the waterpump is knarkered apart from the car overheating
Well in my last car after a week of owning it it started leaking water like a pensioner....

Changed the waterpump - all ok.
 

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on the v6 ,if its still got plastic impeller ,it cracks and slips so if any hard acceleration ,it slips and engine temp rises and if you rev it hard when cap is off there not a lot of water moving round which is consistent with higher revs
 

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Discussion Starter #18
well guys here the latest episode I think I bleed the system right took it for short run tem shot up to 110 stop, when I looked at the header tank no water gently released cap and the water flooded back into tank also heater still blowing cold air there is no oil in the water so head gasket ok any advice please or may just get rid of it for spares
 

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well guys here the latest episode I think I bleed the system right took it for short run tem shot up to 110 stop, when I looked at the header tank no water gently released cap and the water flooded back into tank also heater still blowing cold air there is no oil in the water so head gasket ok any advice please or may just get rid of it for spares
water pump not moving water around by sounds of it
 

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Hi mate.

Dont lose faith, i nearly did but things normally come right if you keep at it!! :)

Now yours symptoms still point to an airlock as the most likely possibility. It is human nature to assume the worst, i do it all the time with mine!!

If coolant isn't circulating properly it COULD be the pump but it also could be an airlock of some kind.

Did you perform the check i mentioned about checked all hoses to see if they are hot when the temp is high?? If water is in all parts of the system then all hoses will be hot. A classic sign of an air lock is the bottom hose remains cold as water is not circulating around the system, and is effectively boiling inside the engine!

My final advice is before you get rid of what is probably a perfectly good car with a brand new radiator, take it to an alfa specialist and pay the going rate for 1hrs labour to get it looked over and a second opinion. If its an airlock or something simple they will simply fix it for you in that time scale.

Best of luck.

Luke
 
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