Coolant steam from expansion tank

[kevinbowe2000 10]

Tried your airlock solution Jim. Ran it for a short bit squeezing the hoses. Temp hit about 70 and coolant flowed out of expansion everywhere.

[GusPW 0]

yea, you've got to be quick with getting the cap back on when it starts to rise :-).

 

I believe there should always be some coolant returning through the little pipe on the top. It's just difficult to see if your expansion tank is all grubby. Checked mine by opening the cap when cold, starting the engine and peering in whilst revving by hand on the throttle body.

[kevinbowe2000 10]

Nearly 100% sure no coolant returning to the expansion tank. When I squeeze the hoses I can see coolant flow into expansion. Coolant temp was near 90 and still no flow back the expansion. Think it could be one of the pumps?

Anyone in Glasgow that might be willing to take a look for a good couple of beers?

[easypops 8]

How is the heater inside the car? If it gets toasty warm it's likely that the pump is moving water about ok. Although I'm sure someone with far better knowledge will come along with better info :)

[Dox 23]

At 70 degrees the thermostat will open sending coolant to the radiator, does the rad get hot? Do the top and bottom rad hoses get hot?

 

It sounds like the rad may be blocked or have restricted flow

[kevinbowe2000 10]

The car inside gets like a sauna.

Both the pipes to the rad are roasting. Just got the tstat replaced so struck that possibility off the list.

If it is the HG, I thought that there would be signs of mayo or oil in coolant? But none of that.

[kevinbowe2000 10]

Rad getting hot but to me seems strange. Getting very hot where it enters rad but taking a while to move that heat along the whole rad.

[kevinbowe2000 10]

Seeing what temp it gets to before bottom right (exit) of rad is hot

[kevinbowe2000 10]

Got to 85 before face of rad at exit was even slightly warm

[kevinbowe2000 10]

While the top right (enter) is boiling. Would have thought a more even distribution of heat across it.

[kevinbowe2000 10]

Let temp get up to just over 100 again. Fans never came on. Oil temp was 106.

Fans came on when I turned it off. Rad is freezing really quick but the hoses and expansion are roasting for a good while. Could this all be electrical? Bad sensors?

[Dox 23]

Drain the coolant into a clean bowl for re use and flush the rad top to bottom and bottom to top with a hose pipe. Id do the same to the engine once its cooled down

[Jim 2]

Let temp get up to just over 100 again. Fans never came on. Oil temp was 106.

Fans came on when I turned it off. Rad is freezing really quick but the hoses and expansion are roasting for a good while. Could this all be electrical? Bad sensors?

 

There is a test you can do to determine whether the fans actually work on the various speeds.. someone has thoughtfully done this on YouTube:

 

 

My gut feeling is there's air somehow around by the radiator fan switch meaning it's not getting a reading, and causing the coolant to overheat - or the fan switch is not working correctly. Test the fans using the above method to confirm they're coming on correctly.

 

I recently swapped from a known working radiator fan switch, to a new Febi one and I've found that the fan switch I did have in was a lower temperature one that kicked in a lot sooner. The 'standard' Febi one seems to let the temperatures get a lot higher than they did before, before the fan comes to life.

[kevinbowe2000 10]

Ta jim. Started putting a load of electrical tests together. I'm prob just in denial but don't think it is a HG issue. Got one quote so far to replace it of 690+vat. Gonna get a few more though.

[kevinbowe2000 10]

Did that check of the fans with the paper clip. Stage 1 and 2 work fine. Then reved it up to test. Fans never came on. When you turn off your engine, fans come on but I am guessing this in independent of temperature?

Guessing fans never come on cause it is not registering any temperature at the rad.

[GusPW 0]

Exactly that, mine was doing exactly the same when the thermostat was jammed shut. As Jim said could be airlock or the water pump if there's no flow back into the tank when revving or the new thermostat was duff.

I had a new vs one fitted a few years ago and it never worked properly until I replaced it for one I tested before fitting. I think it was only partially opening.

[GusPW 0]

Fans probably come on when you turn the engine off because the after run is triggered by the stage 3 sensor in the thermostat housing, or something like that. Same thing happened on mine when the rad wasn't getting any flow.

[kevinbowe2000 10]

Hoping the thermostat isn't duff but could be a possibility. Though both of the hoses connected to rad get roasting hot. Would have thought that one would stay closed/cold.

Been reading around but getting a bit confused. Would the fan control module have anything to do with the problems I'm having. As after run is turning on, I wouldn't have thought so. I'm going to change the electric fan switch, flush the rad and maybe the engine too. Make sure nothing is blocked. Then fit a new water pump, bleed system with G13 and see if I can get it going. Might just through a new fan control module at it to as you can get from China delivered for a tenner.

If not, I guess it'll have to be the payout of the HG :(

[easypops 8]

I have a spare fan control module from a mk3 golf vr6 i broke/still have, not 100% sure if its the same part number, but it looks the same......your welcome to borrow it to see if it changes anything. Welcome to any other stuff i have lying about as well, should have the rad fan switch too, again not sure its the same but would guess so?

[owens 0]

Kevin

 

I have recently had a similar problem with my VR6. I had a local garage flush the system out only to find out I was losing coolant. Letting the car tick over parked up I had coolant spill out of the expansion tank once up to temperature. The local garage did a chemical test on the expansion tank and advised the head gasket had gone but via the manifold so no oil/water mix. I was not convinced so phoned Vince at Stealth for advice who advised me to check the cap on the expansion tank and see if the rubber ring was sitting in the groove correctly first. He said that he would check this first rather than me drive a hundred miles or so to see him and he would just do that! He was convinced it wasn't the head gasket. I was lucky and I could not believe the rubber ring in the cap was not sitting in the groove right and so was not pressurising the system correctly and boiling over. I simply popped it back and bingo problem solved!! I have not used a drop of water since and this is some 2 months ago with it being a daily driver.

 

Not sure if this is your problem but defo worth a check as I was in a similar position to you and facing an expensive bill. If not give Vince a call at Stealth - true gent who is only willing to help

[kevinbowe2000 10]

Thanks for the tip Owens. The first question I asked both the aa guy and the garage was about the expansion tank cap. Both said it wasn't the issue. Never checked myself though so will do that tomorrow morning before work.

Thanks for the offer easypops. Might take you up on it. Parts aren't too expensive but waiting for them is annoying. Really want to get her back on the road asap. Bigger worry is actually tackling the work.

I bought a project car to learn. Just didn't think it would be this much this early on in ownership.

[Jim 2]

I just dont think it's that fan control module, if bridging the pins makes the fan activate. It makes me think that coolant isn't circulating in the radiator properly, or the fan switch isn't working.

 

I'd be thinking about getting the thermostat out and testing it in a pan of water to make sure it's opening at the correct temperatures.

[kevinbowe2000 10]

Should I see some coolant flow into the expansion tank when the aux pump is working?

[kevinbowe2000 10]

Decided today at lunch to start from scratch with the problem and test everything.

Naturally first point of call the fuse board.

Took off the panel and low and behold, only 4 fuses in the fuse board.

Couldn't believe it.

Not 1 or 2 but 3 different mechanics have looked at this car including one that put it through the MOT.

No fuse in the rad fan so naturally it wouldn't come on. Ordered a bunch of new fuses so fit them tomorrow.

Played around with the ones that I did have and sure enough, fan stage 1 and 2 came on when i had a fuse in it. Think that the original issue was that no fuse so no cooling. Caused coolant to steam and then air lock. Going to get it professionally bleed when i get the new fuses in it as I don't think my job was that great. Still think there is an air lock in the rad.

Learnt my lesson anyway. Don't presume that professionals will check the most basic of things that could cause the issue.

 

On a side note, put a fuse in for the spoiler and it went up fine. But very slow coming down and then blow the fuse. Guessing some blockage in it? Take it apart and grease it or is there something I might be missing. Put in 15 amp fuse as thats what it says in the manual. Should it be a larger fuse or is that correct. Second guessing everything now.

Looking better and better that it isnt the HG though.

 

Thank you everyone for all the input into this issue. Has helped a lot.

Edited January 28, 2014 by kevinbowe2000

[GlosterOx 0]

Might be worth lubing the spoiler mech, see: http://www.corradoclubgb.co.uk/ccgb16/index.php?option=com_content&view=article&id=108:lubrication-of-the-spoiler-mechanism&catid=49:technical&Itemid=169

 

Ian.