head panic

[just sam]

Howdy folks this is my first post so i will be brief .

I am, fearing the worst... are there any tell tale signs of a cracked head?

sam

[Driver+Passengers]

It's not immediately obvious to tell the difference between a cracked head, a blown head gasket and a leak/airlock in the coolant system.

Have you recently overheated, blown coolant out of the header-tank or ran the vehicle with an empty header tank?

Does the coolant look oily/contaminated, is there mayonnaise on the inside of the oil filler cap or are you getting a lot of steam from the exhaust when you start up?

A poorly bled Bongo, a leaky hose/gasket/joint that leaks coolant and/or sucks in air when the system cools down or combustion gasses being allowed to enter the coolant can cause elevated temperatures, any air to thermally expand and possibly cause an airlock, overheating and coolant to get blown out of the header tank pressure relief cap. A cracked head may also do this.

So there are a few signs and symptoms that indicate problems, but it may not be possible to determine the cause as the head itself without stripping it down and having it tested separately.

What's your history?

[MountainGoat]

Hi Matt, Sam gave me this info when I first came across this problem a few days ago. Suggested that more expert explanations than I was able to give. All that I was able to give was the advice not to drive this Bongo or have it towed if it was a 4WD and the name of a fairly local Bongo garage.

Tony

I have recently acquired a 2.5 td bongo freindee off my folks, it had a hard life as being they were using it as a work vehicle, so its in need of some TLC.
I have done oil swap, check brakes ect, oh and had timing belt changed.
I am having issues with cooling though, she boiled over on me the other day sitting in traffic even though the temp was showing normal so i emergency topped up with water and nursed her home. i then waited to cool and took for a run looking for clues all seemed normal until temperature gauge climbed rather rapidly until the fan kicked in. Am i rite in thinking the fan should come on before the critical temp is reached?
Having looked on the internet for clues, i am now totally baffled by the whole obscure system.
I am thinking about taking her to main dealer having new rad, new hoses and getting them to bleed the system for me, is this wise ?

[Driver+Passengers]

Where is Sam?

Absolutely, definitely need to bleed - but root cause will require some investigation. I'd agree, don't drive. Can't tow an auto very far at all, believe it then doesn't matter if it's 2WD or 4WD. Flat-bed may be required.

Sam - I think your plan of action may be premature, but I haven't seen the Bongo. All the replaced parts and labour at the garage will be for naught if the cause is elsewhere or if it's not bled properly afterward.

[just sam]

hiya supreme, i didnt say did i, shes a 2.5 4wd auto.
Yes driving to town the other day i heard the dreaded gurgle of over heating, so i pulled over and check. on opening the bonnet the header tank cap was sitting on the wheel arch (now it has dawned on me a few days before, i went to Norfolk and back, before i left i checked fluids, there is good chance i forgot to put cap back on and just closed bonnet)
This morning curiosity got the better of me, i topped all fluids up, pulled bung out bleed pipe lowered it to floor level, there was a lot of gurgling n then a sudden splurge of coolant. when done i sealed everything back up and against common sense took her for spin round the block a few times. (i know im a plumb)
Now the temp gauge sat happily at 11 oclock with no fan action or anything.
I have no steam from exhaust on start up.
There is no condiments under oil cap, which is a shame really (no laughing) because i have noticed a distinct aroma of seafood from the header tank, cant have prawn cocktail with out mayo.
But i did notice on test drive steam coming from front under bonnet, im guessing at a leaky/split rad.

Sorry about the terrible grammar and punctuation.

[Titan1995]

Was thinking that we as members could pool resources and do a few head jobs for other members.

The amount of them that require replacement.

Just a thought. I would be happy to help out for local ones.

[widdowson2008]

I have recently acquired a 2.5 td bongo freindee off my folks, it had a hard life as being they were using it as a work vehicle, so its in need of some TLC.
I have done oil swap, check brakes ect, oh and had timing belt changed.
I am having issues with cooling though, she boiled over on me the other day sitting in traffic even though the temp was showing normal so i emergency topped up with water and nursed her home. i then waited to cool and took for a run looking for clues all seemed normal until temperature gauge climbed rather rapidly until the fan kicked in.
Am i rite in thinking the fan should come on before the critical temp is reached?
Having looked on the internet for clues, i am now totally baffled by the whole obscure system.
I am thinking about taking her to main dealer having new rad, new hoses and getting them to bleed the system for me, is this wise ?

In answer to your question, the fans will (should) kick in when the temperature gets to 96 - ie when thermostat is no longer in control.

Further to other replies, I would add that you will get a boil over if the expansion tank cap is either faulty or incorrectly fitted.
Personally, I would check this out first because if it is the cap, then:
a) it is easy to spot and
b) it is a relatively cheap solution.

[just sam]

header/expansion cap looks all good n solid to me..

[Driver+Passengers]

You should do a cold pressure test. If you have a spare cap, it can be modded by removing the lower seal and hoseclip a cut off bike inner tube valve into the and of the overflow hose on the header tank and inflate to 10 psi with a bike/car pump with a good resolution pressure gauge. Watch for pressure drop...

[longhaul8]

If need be you can tow the van but first you will need to disconnect the prop shafts from the gear box.

Always handy to know in desperate times. every time we tow a hgv the prop is always unbolted so the gear box is not being driven.