[DarrenH]

Just been up savages house trying to get the XE conversion running, and that we did. After a triumphant stare at the engine ticking over we went for a drive round the block. One thing we noticed is coolant temp got low, and then much lower, also there was a misfire at low revs, kind like running on 3 cylinders so we returned to base for a poke around. I guessed the stat was fubar as it was rising in traffic, then getting very cool when moving, quick trip down to motor factor, pick up new stat, return back to the house.

We had the stat housing off and sure enough the old one was snapped, cool, positive diagnosis. Another trip round the block at steady pace revealed the coolant temp was stable but the misfire had now turned into a major tractor action, buhbuhbuhbuhbuhbuhbuh pulling away. Back to base once again.

Next was a sniff around all the electrics to try and find the cause of the misfire, king lead was dodgy so we borrowed mine, but that didn’t fix it. Next we took the spark plug cover off, levered out spark lead 1 and FOOOOMPH face full of hot water, look down the plug hole to find more water boiling away round the plug base, levered off 2, 3, and 4, all were the same. All the coolant boiled dry after a few seconds, then we plugged it all back in and ran it up once again, it ran smooth as a babies bum. After a few minutes the misfire returned, turned the engine off again, spark plugs were all surrounded with water again. It definitely coolant because it smells (and tastes!) sweet, this is major bad news.

This engine has been sat out of service for multiple months I think rob mentioned 5. It was a runner before then. The only possible explanation I could think of was either cracked/porous head, but there’s no loss of power or cross contamination of fluids, cracked block, but it cant be cause it would be cylinder specific, and head gasket gone which is the most likely but still confusing as it would have to breach all 4 gasket partitions.

The head is coming off Tuesday, all comments welcome.

 

[Rob_S]

and its dry above the plug holes?
hows it getting into all 4 chambers? must be fecked in the head or major gasket failure.
i also assume you changed the oil for fresh stuff? and you put petrol in the tank, not water yeah?

 

[DarrenH]

-forget this reply-

 

[Rob_S]

oh, so the cam cover is swimming too? ermm maybe rather than water getting pushed up maybe its just falling down? the pipe going into the side of the head? i hate that little bugger, its gone on me a few times now...didnt put much water under the plug cover tho, but maybe?
if not then there might be a block somewhere? pressure forcing coolant up top?
but (looking at piccies of my head & the galleries) i cant see where from

 

[Ste_nova]

wack in a nova lead with no seal on it... then u can see the spark plug

 

[DarrenH]

-forget this reply-

 

[Chris_H42]

From the original description you never said there was water in the bores. Then you go on to say that theres water in the bores going up by the plugs?

What you are saying is the plug well (not the threaded bit) are filling up with coolant around the plug and HT lead?

Sounds like a few dodgy core plugs to me. They are a pain in the arse to change in a plug well. Some strategic manipulation of plires and screws etc will be needed.

Of course I may be wrong tand theres no core plugs in the wells but usually on DOHC engines there are.

The problem will have shown up quicker after the stat was changed due to the increased pressure of the cooling system around the head.

Chris

 

[Vectra Dave]

If I read it right, you are getting water in the holes the plug sits in, but not in the bores?
Then gasket failure seems unlikely to me, as would things like pourus or cracked heads. These could lead to water in the bores ok, but if the engine runs fine normally, then its unlikely that water is being forced up from the borse past the plugs and into the wells. This would mean the plugs werent sealing properly and huge compression loss like that would give very poor running.
I would run with Robs Idea of an external source like the hose to the head.
Before you take the head off you need to definately identify where its coming from so get some crappy ht leads that dont seal the hole, and run the car at fast idle till the coolant is hot and keep an eye on the holes and see where the water is coming from.

 

[Ste_nova]

crappy non sealing leads = 8v ones

 

[DarrenH]

I only said there is water in the bores because if its not getting in from above the plug, hows it getting there ? by osmosis ?

there are no core plugs or anything.

for those people less aquainted with what a XE head looks like from the tradesmans entrance, here is a pic

the cam cover has tube sections that meet with the plug seat.

 

[MartG]

With the head design being what it is, I think its unlikely to be the head gasket - this would require the water to be forced up past the spark plugs to get into the plug well - and would probably be obvious by the steam coming out of the exhaust.

The only thing I can think of is a major crack in the head, allowing coolant into the space where the plug wells go. It may only be going into one initially, but filling it up and overflowing the partitioning wbes between them ( see Oddball's photo .

 

[Chris_H42]

The water won't be workign its way up thats for sure. It will go down the exhauts not by the plugs. If the water can get by then the porcelin would have shot out. And believe me when a plug lets go like that yuo know it, the hole in the bonnet tends to give it away to! lol

Also if it was in the bores on all 4 the engine wouldn't run.

Its not really clear from the pic but are those water or oil galleries (never mind thats a drain back hole!) at each end of the head? Theres a core plug on the far side (i.e. dizzy end).

Which cyl goes first?

Chris

 

[Savage]

Cheers for posting this Odders.

If we whip the camcover off on Tuesday night, I am hopeing that the problem will be staring us in the face.

I would imagine that the 4 "troughs" that house the plugs are filling up with water due to a crack in teh casting between one of them and a water way in the head.

None the less I fear that the answer will be a new head.

 

[JohnnyB]

Originally posted by Savage I would imagine that the 4 "troughs" that house the plugs are filling up with water due to a crack in teh casting between one of them and a water way in the head.

My money is on a cracked head casting too for what its worth.

 

[DarrenH]

did it have coolant in it before you added yours rob ?

 

[Savage]

There was water in it when we lifted into my boot at Toms. There was also water already down the spark plug holes before the engine had already gone in the car - for some reason it just didn't twig that it was strange. It does now.

We'll find out tomorrow though. You still coming round McFly?

 

[DarrenH]

yeh

 

[Ed]

What would cause such a crack in the head?

 

[MartG]

Usually a crack is caused by unequal heating, often caused by low coolant level. Could possibly be due to the head being torqued down incorrectly though.

 

[Big Nick]

i'd come and help but, i can't get there