Another sore head

[Jonthefish]

O dear o dear.
Just bought a Gen 2 turbo diesel. Private sale. Ran good for 200 or so miles with no change in coolants. Then:

1. On an 80 mile trip the truck was overheating on hills then hot all the time with coolant expelled via expansion tank.
2. Radiator cap and thermostat replaced today (bit of a bugger getting at that thermostat!).
3. Flushed rad and block both ways with thermostat out (lots of tiny sparkly coppery looking bits in what was flushing out)
4. Filled cooling system (just raw water for now).
5. Ran engine for only 5 seconds then popped radiator cap. Pressure in the cooling system and lots of frothy bubbles.

I can't see where pressure and bubbles would come from other than combustion gases but please tell me I'm wrong.

Am thinking the head has gone as do a couple of guys on this forum.

Any need for further diagnosis or should i just get on with removing the head?
Gloom

[Dobbslc]

Hi again Jon,
I'm afraid it does sound like the head has gone. I got a combination gas tester from eBay for about £40 that showed my head was leaking gases into the combustion chambers ( all four were cracked) you can always sell the tester on again after using it but it will confirm if the heads gone.
You can have the head off in a few hours but make lots of drawings or take photos. The engine is quite easy to work on with plenty of room around most of it.
The egr valve was a pig to get off but I blanked that off on the rebuild.

Roughtrax do most of the parts with fast delivery but you will need to get seperatly the water pipe gaskets for the rad top hose and heater pipe connections and the injector leak off washers as they don't come in the kit.
Good luck.

[RebelV8]

I did mine last year ( only a lowly 2.4 mind), it had been treat with an abundance of k-seal before I bought it. My first engine out and rebuild (the damage on mine had spread to the piston pots as well). I thoroughly enjoyed it and found relatively easy with a mountain of help from people on this forum.

I say, go for it, fix it, you'll learn loads about the Surf while doing it

[Jonthefish]

Thanks guys. Bogus (on original post) just suggested that the evil seller probably filled it with some copper based sealant. Seller had a feckin' great big house by the seaside and a fancy car full of golf clubs. Did he really need to stiff me over a 20 year old truck? Knob ends like that gie me the boak (can translate if needed).

Thanks for encouragement re the rebuild. I fancy giving it a go. Time is the problem - self employed and all that. If I go for it I'll know where to seek help.
cheers and thanks

[Dobbslc]

Take deep breaths, go out for a rip on the SS!

[Jonthefish]

OK. Combustion gas tester ordered just to make certain. Will report back with results and (I suspect) pleas for help!

[Jonthefish]

Now I'm really puzzled. I ran the combustion gas test twice and both times negative (test fluid stays blue). I had to do the test by filling a sealed bag with gas and froth from the radiator or tester would have sucked froth instead of gas. Tested gas in bag, sealing it round tester. Can't see this would affect result.

I also blew into the bag then re-tested as above. Tester rapidly went green from CO2 in my breath, suggesting it works.

As soon as i start the engine the radiator starts frothing - see pic. By the way, the test was run on a cold engine but with thermostat out so fluid circulating. Picture taken under same conditions.

The cooling system/radiator is pressurising almost immediately on start-up.

If not combustion gas then what/why?

[Dobbslc]

I tested mine by leaving the cap on and sticking the sniffer into the expansion tank, (I was getting bubbles from the return pipe co2?)

[BUSHWHACKER]

It's definitely the head I'm afraid.
In your original post you say you flushed the system and sparkly flakes were seen plus the coolant started frothing almost immediately.

The rad seal could have been in there before the previous owner bought it.

[Jonthefish]

I tested mine by leaving the cap on and sticking the sniffer into the expansion tank, (I was getting bubbles from the return pipe co2?)

Thanks Dobbsic. I've just tried that and got same result. Plenty bubbles going into the expansion tank but test still negative.
Also tried again while revving engine hard. Still negative.

The volume of gas produced is high. Not just a few bubbles - a real heaving froth. Thing is, I can't smell anything akin to diesel combustion fumes off the gas, the radiator or in the coolant tank. Just a slight whiff of warm coolant.

Probably a daft notion (I'm no mechanic), but if the coolant was not circulating properly could it boil at 'hot spots' creating bubbling? Mind you, even if it did, i can't see how it would bubble instantly on start-up, which it does.

So far I've flushed radiator and engine block, then renewed radiator cap and thermostat. Next steps?

[Jonthefish]

It's definitely the head I'm afraid.
In your original post you say you flushed the system and sparkly flakes were seen plus the coolant started frothing almost immediately.

The rad seal could have been in there before the previous owner bought it.

Yeh - bubbles immediately on starting. It does seem likely that it is the head. But if so then why no detectable CO2 in the coolant? Is there any way that cracks in the head could push air into the coolant without also pushing in combustion gases?

[MadScott]

If it's pressurizing right away when cold then stop yer grinnin' and drop your linen, time to open it up. The copper goo you found in there when you drained it is singing the chorus to that tune.

Not that hard really once you get into it, and once it's done it'll be done.

Funny, (prob'ly not to you, right now) but they never blow over here, absolutely unheard of... suspect the strict adherence to the maintenance schedule has something to do with it, combined with low mileage, most under 100k on the clock.

Hate to say it but the exports are usually the ones considered not fit for domestic sale, usually due to some evidence of scrimping on tlc over the years and high mileage; harder use overseas does not bring about the Best in those circumstances... Very fussy in Japan and the auction block is a hard judge.

Once you've got it properly sorted you'll be good to go, for quite a while.

[shokenore]

Was gonna say are you sure that it is not just air bubbles from bleeding the system but after seeing the pictures whoa that is quite frothy
The false negative from the test is quite confusing though, especially after you confirmed with your co2 from your breath.

[Dobbslc]

Been scratching my head over that as well.
My truck was almost the opposite in that it had co2 in the coolant but no frothing or overheating.

Also what Madscott says about the import surfs being the unwanted ones from Japan, it's a bit like that with the grey import 400 cc bikes, not necessarily all bad but a bit scruffy or higher mileage.
I'll still put my money on the head though.

[RebelV8]

Get the head off and confirm it, if it's not the head (but it will be), then you have peace of mind at the cost of a head gasket. At the moment though, you can't drive it like that, don't waste the good weather and light nights, get it done.