Running with a cracked cylinder head?

Technical questions and answers about the Mazda Bongo

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owens

Running with a cracked cylinder head?

Post by owens » Thu May 28, 2009 3:20 pm

Hello all, I'm looking for some advice and was hoping some of you might be able to help.

I've just had a service in Bristol and found out that I've got a cracked cylinder head. The level in the header tank was really low (must admit it'd been a couple of months/few hundred miles since I checked it last) and evidence of rusty water marks all down the side of my engine.

I really cant afford to get it fixed at the moment (ads quote was 1700) but I'd be gutted to be without it for camping and festivals over the summer.

My plan for the time being is to keep running it as it is and top up the coolant as needed before every trip.

I won't be using it much, maybe 2 weekends a month, and most places would be less than an hours drive away. But then another weekend we'll be going about 150 miles away.

Has anyone got any experience running a bongo with a cracked head and do you think my plan its likely to work for the trips I've got planned? What could happen? Could it go entirely and be undriveable leaving me stranded on the side of the road?

Cheers for any help in advance

owen
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westonwarrior
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Re: Running with a cracked cylinder head?

Post by westonwarrior » Thu May 28, 2009 4:21 pm

It can allways get worse but

If it drives ok now and doesnt loose too much coolant and doesnt over heat you can risk it I did and drove to london and back in a day once but got it sorted in the end

especialy if you have a recovery service to bring you home in the event of a melt down.

in which case a replacement engin is, it seams not alot different to a new head rebuild.

If its over heating obviously its unusable.

Its best to get sorted but your call

How much coolant does it use?
owens

Re: Running with a cracked cylinder head?

Post by owens » Thu May 28, 2009 4:39 pm

westonwarrior wrote:
How much coolant does it use?
I'm not sure at the moment. I guess it'd be a good idea to do some test runs to see how much it's loosing before embarking on anything too major.

But ye it runs really well and seemed completely fine. I'd recently modified the temperature gauge and while i thought it was running fairly high it was comparable to reports on here of what other peoples do so i didnt think there was anything wrong with it.
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westonwarrior
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Re: Running with a cracked cylinder head?

Post by westonwarrior » Thu May 28, 2009 4:48 pm

White smoke /steam at start up?

Why do you think the heads cracked was it tested?
owens

Re: Running with a cracked cylinder head?

Post by owens » Thu May 28, 2009 5:10 pm

Nah no real smoke or steam to speak of. I've maybe noticed a tiny cloud when putting my foot down, but nothing when it starts

The garage (ADS bongo specialist) kept it overnight after topping up the coolant. When they looked at it again today the level had dropped and then on inspection they saw that there was rusty water marks all down the engine showing that coolant has been leaking from the cylinder head. So ye I'm fairly convinced they're right

I had them instal a coolant loss alarm for me yesterday before they discovered the head, talk about closing the stable door after the horse has bolted :(
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Re: Running with a cracked cylinder head?

Post by francophile1947 » Thu May 28, 2009 6:16 pm

Not normally recommended but, as it doesn't appear to be leaking into the cylinders, it might be worth just bunging some Bars Leaks or Radweld into the coolant to get you through the summer - make sure it's not just coming from a leaky hose first though.
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dandywarhol
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Re: Running with a cracked cylinder head?

Post by dandywarhol » Thu May 28, 2009 6:57 pm

It certainly won't get any better and you're liable to damage the block - new engine then matey :?
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owens

Re: Running with a cracked cylinder head?

Post by owens » Fri Jul 03, 2009 9:11 pm

So it's been about a month now since my bongo was diagnosed, and by now I really don't think its got a cracked cylinder head at all. I've taken it from Bristol to Birmingham and back and to Bath and back and a number of runs around town. There's still no symptoms, it's not overheating and it hasn't lost one drop of coolant.

Here is a picture of the engine:

Image

and here is a close up of the rusty water marks that made the mechanic think it might have a cracked head

Image

Now what I'm thinking is the hose that attaches to the engine there is incredibly clean compared to the bit it connects to. Is it possible that this hose was replaced by the previous owner without properly bleeding the system and that's whats caused all the water marks?

When running my bongo and checking for leaks i did however find a lil drip of a bright yellow almost flurecent liquid dripping off this thing here:

Image

but it certainly doesnt look like coolant. It's only dripping a tiny bit and as far as I'm aware only when the engine is running. Here's a close up of what I caught in a bowl over about 5 mins. Any ideas what it is or if it's something to be worried about?

Image

Cheers for your help :)
owens

Re: Running with a cracked cylinder head?

Post by owens » Fri Jul 03, 2009 9:14 pm

oh and also as the mechanic thought I was loosing coolant he put quite a bit in to get me to where I was going. As I havent lost any since though the coolant level is quite a bit above the max level. Should I take some coolant out?

cheers
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Re: Running with a cracked cylinder head?

Post by mister munkey » Fri Jul 03, 2009 9:23 pm

A bit above is fine Owens.


Pleased to hear all is well & thanks for the feedback. You've got a coolant alarm on now, much easier to keep tabs on things. Assuming it has all settled down, it may be a good idea to invest around 30 quid on a Mason alarm to keep a closer eye on temp.

More often than not on here, problems seem to pop up, its always nice to see a positive result.

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nfn

Re: Running with a cracked cylinder head?

Post by nfn » Sat Jul 04, 2009 8:33 am

The liquid could be diesel leaking from the injector pump if it's coming from the driver's side of the engine.

Even though you are not losing coolant, you should check to make sure that none of the hoses are swollen, very soft, or otherwise look suspect.
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