Hi guys, im currently running in my newly rebuilt 4x4 engine. only done 150 miles was running sweet starts and drives fine, still starts fine now, BUT the other day I just jump in the car to pick someone up and driving through the village at roughly 20 mph, the cars engine tone changed like a deep bass line going off, the car juddered miss fired, i took it 200 yards down to my garage popped the bonnet and the whole water system pressurised the water pipes were solid nearly. Undone the header tank cap slowly and there was massive pressure build up. and the smell from the exhaust was immense. now the engine is a stage 3 and has been built to that spec and more. No expense spared and uprated everything, new water pump new oversized pistons, 4 layer wrc gasket new rad new turbo new uprated oil pump head overhaul you name it. it seems to me the head gasket has gone but how?????HELPPPPPPP

 

Were the head and block faces 100% perfectly flat? Multi layer steel gaskets are superb, but only if both faces are perfect, otherwise you are better off with a regular 'group a' gasket.

 

Hi there. Sounds like it may have had a massive airlock. Or the head gasket went and the exhaust gas pressurised the cooling system. Have u got access to a head test kit? The one with the blue fluid to test if there's any exhaust gasses in the coolant tank

 

Or can u smell exhaust gas from the expansion tank? I'd top the cooling system up again and run it on tick over to see how it behaves. May have just been a massive airlock if your lucky or bad luck the head gasket

 

hi, both faces were refaced and were flat as a flat thing. the coolant is still there haven't actually lost any don't think it had time to lose any. is it worth trying to torque the head again to check it?

 

im led to believe both the block and head need skimming prior to fitting multi layer gaskets on cossies however i have fitted many multi layer gaskets to other cars with only the head being skimmed and never had a problem

 

Take the spark plugs out as they can tell a story on there own if they've been contaminated with coolant. I'd run it up again after to check what it's like now it's had a chance to cool down and run it with the expansion cap off to let any air out

 

Removed the spark plugs they all seemed fine exactly the same colour on all plugs, like a biscuit colour. Also done a compression test on all chambers, all reading around 130psi on the gauge. ran the car for a few mins, when revving the car the water seemed to move about a lot in the tank and also the water looked like the head of a pint of larger:-(

 

so you got oil in the water too??

What head bolts did you use?

 

Water doesn't look oily but haven't properly checked I need to drain it to check properly, I've used the standard ford bolts that Matt lewis recommended. And really, driving at 20mph shouldn't lift the head.

 

is your rad cap working and letting pressure release at 15 psi ?

have you removed spark plugs yet ? if water ingress caused misfire you need to isolate which cylinder it is. could be leaking headgasket, cracked head or block.

ive seen cracked wet liners do it a few times on big diesels, with the misfire and loads of pressure its likely water in a pot but needs to be diagnosed and isolated 100% before stripping it ime.

 

Do you mean header tank cap? The cap is newish it came with my bailey tank. The plugs look good as I mentioned before. I need to use head gasket tester really to determine if it's knackered. And then figure out why its fooked.

 

Are you rad fans working. I know it might be a silly question.

 

Fans are working good. Working on a switch with new loom

 

Is the oil still looking good as I had simler problems about 4 weeks back and it was the block had cracked in number 3 bore

 

yes mate header tank cap just make sure it is venting at cap relief.

ive recently had a dozer presureising water system and blowing water out of the cap, it was a low liner on number 5.

if your system pressure got that high it should of vented some pressure and blew it out of the rad/header cap.


I have struggled myself with bleeding the water circuit on a yb so also make 100% sure you have a 100% bled system, my last rb26 was the worst ive ever had to bleed it was a complete twat

 

I will do a head gasket check tomorrow or Tuesday, I've heard people saying that the injectors can short and pump loads of fuel straight into the pot and blow a gasket that way, has anyone experienced that?

 

Is there a catalytic converter in the exhaust still?? Or back boxes?

Take the exhaust off at the turbo / downpipe an run it with no cats/back boxes to test it

I had this exact problem before on an escort gti !

The honeycomb stuff in the cat had broken up into chunks and 1 big piece had pretty much blocked the exhaust pipe completely, the gas had nowhere to go and pressurised the coolant system and all my water hoses and the rad blew up like balloons and rock hard to feel,

Took a lot of working out but ended up taking exhaust off, smashing all the bits of cat out the pipe put it back on and car was fine,

Marc

 

Hi pal. It hasn't got the cats on. I've just been checking the water there's no oil in there but there is a lot of what looks like orange juice. Very rusty water but not sure why? Unless there was a massive blockage in the block where the water sits???? Baffled.

 

When ticking over is the gas exiting from the exhaust fine? Feel it with your hand if you cover it (careful not to burn yourself of course)

 

Sounds like loadsa silt in the system. Drain it out, add a coolant flush (all motor stores sell them) and run it up hot with plain water and coolant flush in. Then drain it all out and re fill with coolant. May have to do it a couple of times. U can also back flush the cooling system putting a hose pipe up various coolant pipes. Cheers, Gary

 

It ticks over fine smells strong of fuel though.

 

Most Cossie do lol :-( I take it needs setting up after running engine in may be running rich at the mo

 

But if and when u do coolant flush make sure u run it up with coolant cap off to let air out or you'll get another air lock. Cheers

 

I'll try a flush in a minute when I go back to the garage. I still need to check the headgasket.

 

Just done a head gasket test, and all is well thank fook what is next to do? Complete system flush?

 

Good news! As said earlier I would fully flush, fill up and bleed the cooling system and check correct operation of header tank cap

 

How will I know that the cap is working correctly? The cap isn't very old but it was on the car when I cooked it 3 years ago:-(
How quick should it take for the water to get hot in a cossie engine?

 

the question is why was it misfiring ?

 

Are all the water pipes hot? Could be a sticky thermostat, or blocked radiator.

You say the fans are on a switch with a new loom, are they spinning the right way?

Just a few ideas

 

if all normal stuff checked rad getting hot thermostat opening check the water pump I've see a few cars that actually suck air into the system and pressurise the system.

 

have you been able to flush out the coolant system yet?

 

Flushing system this morning. I will say that when running the radiator stays cool nearly Ice cold. And all the pipes around the engine get hot as hell. The header tank gets hot really quick. I'm going to check all pipes later for debris etc. thermostat is brand new but will check that as well.

 

Sounds like the rad could be blocked, had the same prob on mine. Take the pipes off the rad and run a hose pipe from the top of rad and check the flow coming out the bottom. Do the coolant hoses feel pressurised when it's hot?

 

To me if you say the radiator stays cool nearly ice cold when the engine is running it has to be blocked. take off top and bottom hoses stick a hose in the top and make sure the water passes through it ok. If not that is your problem. If you cant unblock it yourself take it to a radiator specialist they will unblock it for you and check it is working as it should be. If you are running quite big power I would advise you get a new high flow /capacity aluminium radiator. Keeping Cosworth engines cool is always a problem and the more modified and powerful you make it the more you need to do to upgrade the cooling system.

 

The rad is a new alloy one, but I will say I took a gamble and bought a cheap one of eBay one for Ł129 no make. I was told there all right. Perhaps they are I have not had it long enough to know.

 

Think the car is now sorted. Done a complete flush removed all pipe work and stuffed a hose in each to flush out any possible debris, ran the car for 10 mins on the spot and all seemed fine, the rad got hot this time whereas before it was stone cold, one thing I did notice when sorting the pipe work out was the thermostat housing on the inside was corroded to hell, so might try and get a fresh housing from somewhere.

 

have you installed the correct stat

 

Got a similar problem on mine.

Rebuilt it 1300 miles ago and left sitting for 30 seconds / a minute the temperature gauge rises quite quickly and the fans kick in. Removed the plugs which look normal, done a block test which has no traces of exhaust gasses in the tank, to me it just doesn't seem right. Boosts fine with no problems.

Some say that's normal cossie behavior, other says their temp gauge never moves. Unsure what to believe.

 

I've never had a problem like this before on my Cossies in the past, that's why it baffled me so much. My thermostat is new but will buy a new one as I have just purchased a new thermostat housing from burton power