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Discussion Starter · #1 ·
Hi folks!

Ok, got a rather odd one here!

I've just recently taken ownership of a Vectra c with the z22yh Ecotec engine. It was going about 5 miles before overheating, so I did a few checks. What I'm noticing is that the top radiator hose gets really hot and pressurises, whilst the bottom hose remains cool. I thought this was a thermostat issue at first, so I removed it. The problem still remains. I also noticed that the heater won't blow warm air inside the car, suggesting a circulation problem. Today after much [email protected]&£ing about I changed the water pump, but the problem still persists. I've ran a garden hose through every pipe and there appears to be good circulation!

No water in the oil and vice versa.

Anyone have any ideas as to what's going on here?

Thanks.
 

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Discussion Starter · #5 ·
It sounds like you have an air lock in the system to me, Or a faulty thermostat
Hi Turbo,

New thermostat fitted (tested). Followed the recommended procedures for filling the system. I got the car with this same issue! Have since ran a hose through the system, disconnecting various hoses to ensure flow at the various points. I then replaced the water pump today, and on this car it's a painful task. You need patience and some improvisational strategies ready!

I've seen a few posts relating to this elsewhere, but no one seems to have come back to post the fix.

I'm a bit stumbled on this one to be honest.
 

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In your post you said
"I've ran a garden hose through every pipe and there appears to be good circulation!"
Did you flush the heater matrix. I would suggest flushing the heater matrix both ways for 15 minutes incase there is a blockage in there somewhere. Possibly try back flushing the radiator aswell.
 

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Discussion Starter · #7 ·
I never did it for that length of time, but yes, I removed the two matrix hoses, put the hose in one side and then the other. There was as much flow coming from the open end as was coming out of the hose pushing the water in, yet no hot air in the car.

I'm definitely on the line of a blockage somewhere.
 

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Discussion Starter · #8 ·

Here's a video of the car before I changed the pump. The thermostat was removed here on the belief it may have been stuck closed.
 

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Discussion Starter · #10 ·
Hi Voxvect,

I slowly filled the system until the header tank was full, pulled off the hose on the right side of the matrix as viewed from the engine bay until fluid came rushing out, started the car and did the 30 sec, 2500rpm process (twice as instructed). I waited on the car heating up. No heat inside the car at any point.

I haven't really done much to it except change the water pump. There appeard to be be water evidence around the weep hole, which is why I changed it.

The thermal gun was around £30 from what I remember. Yeah, it's handy for a lot of things, cats included!
 

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Hi folks!
What I'm noticing is that the top radiator hose gets really hot and pressurises, whilst the bottom hose remains cool.

Thanks.
I thought that's what it was supposed to do. I.e. hot water goes into top of radiator, cooled down water comes out of bottom of radiator.

I assume car/engine is still overheating, as indicated by the temperature gauge on the dash.
Is it possible to check the overheating another way? i.e. your temp. gun, what temperature does that indicate for the water entering the top of radiator/engine/header tank?

Temp. gauge/sender maybe faulty?
 

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Discussion Starter · #12 ·
I thought that's what it was supposed to do. I.e. hot water goes into top of radiator, cooled down water comes out of bottom of radiator.
Not when the car has been sitting stationary and running for 15 mins with the thermostat removed! It's cool air passing through the radiator that cools the engine when the car is moving. It's the fans that cool it when it's not. There's some residual heat transfer from the engine at various points, but there's clearly no flow!

A 30 degree reading on the top hose and a 4 degree reading on the bottom tells me there's some sort of restriction. This is confirmed with no flow through the matrix, which is why it won't blow hot air.

I haven't spent a great deal of time on this, but I'll post the fix as soon as I get to it. Just wondered if there was anyone else who had similar issues.
 

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We are assuming the water pump is working ok 100%.
Is it a new genuine Vauxhall pump, or other?

If you have eliminated a physical blockage, then it points to a gaseous blockage - to an air lock.

Or possibly some electronic problem.
 

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Discussion Starter · #14 ·
Yep the pump is fine. The impeller spins with the gear flange as it should. Not original, but good enough replacement.

Can't say with complete certainty that there's no blockage. I've ran a hose through all inlets and watched it flowing out of various outlets, radiator, matrix, thermostat housing etc..

Electronic problem?
 
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