Head gasket confusion

[andyfb78]

Hi All,

Have started the replacement headgasket work...strip down achieved yesterday.

I'm a bit confused as to a couple of finding...

A bit of history first..... split hose meant over heated engine, but My girlf assures me she shut it down pretty quickly so has been fine for a while since, garage said no head gasket problems, but hydraulic lock and lumpy starts with associated clouds of white smoke and black watery splatter on the garage door, along with slow coolant loss mean I don't believe that. The oil is still black, so I conclude water is leaking directly into the cylinders after a run.....

right... so...

I strip down and i find water and a bit of rust and a bit of emusified oil in cylinders 2 and three, but gasket looks absolutely fine.... hmmm that leads me to worry about the head itself, though there are no obvious signs of cracks, so that will be tested next week.

the block shows blocked water ports, which break down with a bit of prodding with my fingers. however these line up with blanks in the gasket... this makes no sense to me, why build these matching ports in the head and the block only to shut them off in the gasket.... that sounds like a gasket manufacturing fault to me, however a thread on here and all the pics of the gaskets seem to show these are all blocked off.... so I can only conclude mazda/ford mucked it up and were not going to re-tool the castings so they just blocked off with the gasket... maybe its a casting complexity thing.... anyway.... it looked very odd that these three ports had blocked up with gunge....

I also find that more than one of the exhaust studs has been drilled and re tapped.. so maybe a new head is not such a bad idea.
anyhoo

so questions:

- should the gasket ports be blocked off, or is this a faulty gasket?
- where should i get a head from? (club sold out with 2 month lead time), bridge recommended, but any recommendations would be appreciated.
- anyone know what the tappet gaps should be set to cold?
- any other guesses as to where the water is coming from, the bores looks absolutely fine.
- has anyone else replaced the injectors while doing this?
link to pics here as I can't figure out how to post directly in the post....
http://www.flickr.com/photos/51530727@N04/

thanks all.

Andy

[haydn callow]

It is rare for a gasket alone replacement to cure the symptoms you describe...Almost always a new head is required.
If the exaust studs have been done properly then I would not let that affect my thinking.
Do check the top surface of the engine block.....having had a long conversation with a engine remanufacturer this week .... they average 3 Bongo rebuilds a week which involve "skimming" the block after peeps/garages have fitted new heads which failed after a very short time.

[missfixit70]

It's very rarely a gasket problem as Haydn said, it's usually cracks in the head (mine was), it may well even pass a pressure test if its not done up to working temperature, but very few get away with reusing the old head. Allan fitted mine for me, may be worth giving him a shout to see if he can supply?
As already said, check the block for true, Simon Jones had this issue & had to redo his, flatted it back using a piece of granite/marble I think & grinding paste, blocking all the bores as best he could & then he used gasket compound too I think.

[andyfb78]

Thanks. I guess I have the following concerns:

I want to ensure I get a fully assembled head, (or at least a bag of all the bits) that I know are the correct ones, not rubbish copies, but I don't know how to ensure that. Bridge offer new and reconditioned, and I worry that the new ones may be copies and poor castings.

I want to ensure the gasket is correct, I'm really thrown by the blocked hole thing, is it bound to be a gasket weakness as water pressure will build up behind the gasket and eventually force through.

I will get the block checked by a local motor engineering shop, though the 'skimming' that you refer to, do you mean a proper skimming on a grinder, and hence engine out, or do you mean just an abrasive to remove lumps and bumps?

I'm a bit concerned that the bores may be cracked, though there is absolutely no evidence for that, and the car actually runs smoke free, it just starts poorly, so I have probably just caught a gasket/head on the way out. Strange to say it, but I wish I had found an obviously blown gasket, at least I would feel like i had found the fault. At least finding water/rust in the bores confirms water is where it shouldn't be.

Ah well it is a good opportunity to clean out all the black gunge in the turbo, intake and other areas and maybe get a new clean head... power should be WAY up with all that extra air flow

Does anyone know what the cold tappet gaps should be, or can I trust the 'new head' to be set up correctly (i'd very surprised if I could, but I have never bought a 'fully assembled' head before, used to grinding valves into the old head)? number 3 cylinder seems particularly loose on the current head, but I haven't measured it yet.

Well another learning experience with the bongo, she is certainly beginning to cost more than she should...

[haydn callow]

http://www.igmaynard.co.uk/bongo/forum/ ... ppets+cold

Most questions can be answered by a simple "search"

[missfixit70]

Couple of threads on "assembled head" experiences

http://www.igmaynard.co.uk/bongo/forum/ ... mbled+head

http://www.igmaynard.co.uk/bongo/forum/ ... mbled+head

http://www.igmaynard.co.uk/bongo/forum/ ... hilit=head

[andyfb78]

Thanks folks much appreciated.

I spent several hours on the forum search, just didn't actualyl do the right (and obvious) search.

Did folk have to replace the tensioner pivot pin, or did that come on the new head?

Thanks

Andy

[widdowson2008]

Thanks folks much appreciated.

I spent several hours on the forum search, just didn't actualyl do the right (and obvious) search.

Did folk have to replace the tensioner pivot pin, or did that come on the new head?
Thanks

Andy

On spenners, the head came with the pivot pin built in. (assuming you are talking about the cam belt tensioner)

[DanO]

sounds exactly like mine, gradually got worse, lumpy start, repeated head/coolant checks.........mine has ended with a new engine - everyone I spoke to recommended a whole engine rather than just the head. Sorry, I really hope yours is cheaper option.

[missfixit70]

Where did you get yours from DanO? recon or used with guarantee? fitted? what sort of cost? Always good to know what the options are.

[DanO]

API - picking it up sometime this week.......it aint cheap!! £2K+ Finally have the Bongo back and a reliable van .....It's an investment, although I seem to have a habit of buying vehicles and having major costs, my VW T25 Westy needed a new engine, turbo.....etc etc when I bought it, hopefully this is it for the time being with the Bongo - i guess anyone that buys from me knows all the expensive bits have been sorted properly