Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Albus Dumbledore]

Hi!
I have recently done a motorchange on my Omega B 8 valve engine (I had a crack in the motor block, so all the engine oil came in to the expansion tank).

My problem now is that the engine overheats!
When I first started the new engine it worked fine, but I broke the temperatur sensor (the one that shows the temperatur of the coolant on the dash). I decided not to drive the car untill I had replaced the sensor, and just to be sure I fitted a new thermostat as well.

Since I did these things, the engine has overheated. When I was replacing the thermostat, one of the skrews broke, so I had to replace the thing the thermostat is fitted on (don't know what its called). It's a metal thing, that is fitted on the front of the cylinder head, and (standing in front of the car) the thermostat is fitted on the left on the thing, and on the right side there are two hoses connected. On the "thing" the temperatur sensor is fitted as well, on the left by the thermostat.

Now, I have tested the thermostat, and it works fine, checked the waterpump and that works fine too, tried to run the engine with the filler cap off and on, with the bleeding hose from the radiator to the eks. tank off, tried to blow in various hoses to get the water circulating (and check that nothings blocked), tried to elevate first the front, then the rear, and the sides to get the water flowing...!

If I have the filler cap off and start the engine, the coolant level rises slightly, so in my head that means that the water pump is working. I tried to take the thermostat of while the engine is running, and hardly and coolant came through, but if I take the filler cap off when the thermostat is off, the water poors out:( I don't have any coolant loss eather, (from what I can see).

To me the problem seems to be that the coolant doesn't want to circulate! The coolant never reaches the radiator in order to be cooled off!

I'm sorry if this is a veeeeery long post, but I'm desperate and feel I have tried everything (obviously not, since I have the problem still), and I have been working on the car since November (with various other things) to get it in prime condition!

Please help!!

[Marks DTM Calib]

You say you checked the water pump, how did you check it, removed and inspected?

It does sound like coolant is not circulating, what is the history of the engine?

With pipes removed and stat out, can you flush water through the block with a hose pipe?

[Albus Dumbledore]

Yes I removed and inspected the pump, and I compared it to the old pump (from the engine I changed). The "propeller" that circulates the water was whole (made of metal, not plastic like som are), and the timeingbelt sprocket turned like it should.

I haven't tried to flush the block with the pipes out, I just took it for granted that it wasn't clogged. I tried to take the stat out, and then took of the filler cap to the eks. tank, and then the water came pouring out, but only if I removed the filler cap.

And when I start the engine, and put the ventilation system on full heat, it only comes cold air, even when the engine is over a 100 Celsius.

Should I try to flush anyway?  What do you mean with the history of the engine?

It comes from a Vectra:) but its the same engine (8valve)

[Matchless]

If you had oil in the water expansion tank from the old engine then it is likely that the radiator is blocked with an oil / water emulsion, and the heater also.

You try flushing radiator and heater with a hose pipe, once you get some flow you can try filling the system with a detergent or degreaser and run the engine.
Keep degreasing and flushing until the system is clean then refill with antifreeze.

[Albus Dumbledore]

Ok, I'll try that!
When you say heater, do you mean the heater matrix?

How do you flush the heater? Gardenhose trough the bottom radiator hose?

[Matchless]

Garden hose through radiator bottom hose with top hose disconnected.

Remove heater hoses and flush heater matrix.

[Albus Dumbledore]

Ok! thanks! I'll try and give an update!

[Albus Dumbledore]

Well, her is an update!
I have flushed the radiator, the engine, the eks. tank and all hoses i could find. When I flushed through the bottom hose (the one connected to the radiator, it came out where the thermostat should be.
I tried to run the engine with the thermostat of, and felt that som hot water came to the thermostat hose, but it wouldn't circulate.
I tried to fill ut the whole system from the radiator top hose (with a garden hose, and it didn't help!

Ok, I just modified this post. I thought that I had petrol in the cooling system, but a friend of mine told me that oil will also show these rainbow colours in contact with water, and since I had oil in the cooling system I'm guessing thats what it was.

But still I have the circulation problem. Any suggestions?

[Albus Dumbledore]

Or do I have to give in and have a garage check it out? (even though I don't want to)...

[Mike Collins]

Did much oil get into the coolant, could your radiator be partially blocked with an oily emulsion?

Flushing with a degreaser solution may help.

This is needed after oil cooler failure when the coolant becomes contaminated with oil.

[Albus Dumbledore]

Yes, quite a lot of oil vent in to the coolingsystem. The engine (the old engine that is) was drained of engine oil twice (since I started with changing the cylinder head gasket, then the cylinder head, before it changed the whole engine), and all the oil went in to the eks. tank.

But I flush the radiator today with a garden hose, and clean water came out (after a while), and I flushed the engine. Should I still use the degreaser?

Could it be my heater matrix? or cylinder head gasket?

[Mike Collins]

I would flush using a degreaser, maybe several drain/refill cycles and see if the temperature comes down.
What is the outside air temperature where you are?
If it's low there must be a serious flow reduction to have the engine overheat.

[Albus Dumbledore]

The air temperatur here's about 7-8 celsius, that's about 44-46 fahrenheit (use fahrenheit in the UK right?).

So, if one passage is completely blocked, would the degreaser open it?
Do I flush the system with the degreaser, or pour it in the system, then run the engine and drain after?

[Albus Dumbledore]

Ok, I've booked time with a garage. I can't figure out what the problem is. I'll give an update on what the problem is/was, after I've been there, in case anybody else has a similar problem in the future:)

[Albus Dumbledore]

My beloved car is in the shop now (finally), after 2 weeks waiting.
Will update with the problem:)