Hi guys. Thanks in advance for any responses. It's the standard HG story with a twist, because the problem has remained after replacing the obviously damaged HG.

 

Short version:

Water in exhaust, gas in coolant. New HG (old one clearly failed between cylinder liners and coolant passages) + head skim, problem remains. I'm confident in the HG job I did. The only thing I can think of at this stage is a cracked liner/block or similar. Throughout this all, I'm yet to see mayo on the filler cap. I think the car's scrap. And I'm not keen to take the head off again if it is a liner fault- it's a long job! Thoughts?

 

Long version:

 

My fabia 1.4 8V MPI had issues loosing coolant for the last year I owned it. Several months ago it started blowing coolant out of the expansion tank, about once a month. I replaced the cap, then the expansion tank and cap, assuming something wasn't sealed properly. Then it happened several times in as many days complete with gas bubbling through the coolant, so I asked around and got 'coolant pump' as my answer. So I replaced the coolant pump. Then after replacing the coolant pump, the main coolant hose going to the pump fell off whilst I was in around town driving- I didn't tighten the clip tightly enough. I drove for about a minute with the red coolant light on thinking it was just a slightly low level as per usual and no massive rush to check, not a complete loss of coolant. (I've never had the temp gauge go above half)

 

After putting that all back together it was fine if I was gentle, and lost coolant if I booted it, so I babied it 140 miles back home at 60mph on a motorway with no coolant loss. Hooray, I thought, mostly fixed it. Then I started loosing coolant badly again with gas in the expansion tank- had to put 3.5 litres of water in on a 10 mile journey, stopping whenever the heaters went cold. Also noticing large amounts of water in the exhaust. So I did the head gasket- the old one had obviously failed between the cylinder liner and the coolant passages. Head skimmed, new gasket, all clean and back together, drove it round the block (0.1 miles on the odo) and gas in the coolant again, water coming out the exhaust again. Confident in the job I did on the HG, now assuming something very bad has gone wrong. Thoughts?

 

There's something very particular about these engines, can't remember what as I've never worked on it, Taylor93 is the one to message as he's familiar with these. Ahh it's Temac HG I thinj

Cracked head is FAR more likely than block failure, a liner or seal failure would show in the oil.

 

Edit: You don't mention if you had the head pressure tested before it was skimmed.

Edited 31 January, 201511 yr by sepulchrave

Water coming out the exhaust could just be residual from when it was leaking into a cylinder. Is the coolant level actually going down?

Gas in the coolant is discouraging though, possibly a crack in the head caused when it was run dry?

There's something very particular about these engines, can't remember what as I've never worked on it, Taylor93 is the one to message as he's familiar with these. Ahh it's Temac HG I thinj

 

Yeah the TEMAC gasket is the modified one.

Stick a rad sealer in it....

Thanks for the responses! I used a TEMAC gasket, didn't get the head pressure tested but it looked pretty shiny after skimming- would a crack not be relatively obvious? Water level doesn't noticeably drop in the traditional sense, the system just massively overpressurises and dumps coolant/air mixture out the cap at which point heaters go cold and I have to pull over and pour 0.5-1 litre of coolant/ water in. Given the volume of steam out the tailpipe (high but not ridiculous) there would definitely be coolant loss if the overpressurising/dump cycle wasn't happening.

 

Cylinders were all dry (though did have rust marks on valves and top of pistons) when I had the head off so not thinking residual moisture.

 

Anyone had any permanent results with a rad sealer? Any recommendations?

 

One thing is that I didn't properly align the camshaft bolts when re-fitting so they wouldn't go in and I had to take the head bolts out after stage 2 tightening, put the camshaft bolts in, then retighten. I didn't think anything of it at the time but could that tighten-loosen-tighten stage have buggered the HG? I was v. careful not to disturb the seal whilst doing it and left bolts 1 and 2 a little bit tight until the camshaft was properly in at which point I slackened them, then back up to 20Nm in prep for stage 1.

Nope cracks can be so small, did you bleed the cooling system?

would a crack not be relatively obvious?

 

Anyone had any permanent results with a rad sealer? Any recommendations?

 

One thing is that I didn't properly align the camshaft bolts when re-fitting so they wouldn't go in and I had to take the head bolts out after stage 2 tightening, put the camshaft bolts in, then retighten. I didn't think anything of it at the time but could that tighten-loosen-tighten stage have buggered the HG? I was v. careful not to disturb the seal whilst doing it and left bolts 1 and 2 a little bit tight until the camshaft was properly in at which point I slackened them, then back up to 20Nm in prep for stage 1.

 

No, cracks are usually invisible unless some kind of crack detection dye penetrant is used.

 

Is your rad leaking? No? Then don't even think about it!

 

The bolts will be fine, however the gasket will need replacing since you crushed it when you tightened the bolts the first time. This may well be the problem.

 

Start the job over but get the head pressure tested, then use a new gasket.

When my hg went i think it was down to a leaking rad, where the fan switch goes, as it was leaking there and on removal i found a washer missing. PO had tried rad seal or something but it did bugger all, went from running fine with coolant levels ok, to no coolant and head gasket gone in 50 miles. I ended up putting in a new low miles engine for less than the cost of a repair

 

 

Cylinders were all dry (though did have rust marks on valves and top of pistons) when I had the head off so not thinking residual moisture.

 

 I was thinking of residual coolant in the exhaust system, not the cylinders!

i bought a golf tdi at an auction couple of years ago on  whim, was cheap as chips because it had this sort of problem, so took to a mates garage for them to do the head gasket ect.

he called me back to say who ever put it in the auction had already done the head gasket and even renewed the head ect, he said there seems to be a problem with the block :-(

 

surfice to say i got my money back on the resale to someone who was willing to go down the route of engine swap.

Update- all of the above were correct. Took a lot longer to burn off the water in the exhaust system than I expected, and when the thermostat opened it dumped a ton of air into the system- I pushed through that and it was ok. Took it for a drive and thrashed the nuts off it and only had a slight 'gas in coolant' problem when I got back.

 

In the meantime I've sourced myself some new wheels (honda!) so this one's going up for sale- not sure if I'll find the motivation to do the HG again or if I'll put it up for sale with HG problems straight away. Don't worry, I'll be honest

 

Thanks for the assistance, all.

Edited 3 February, 201511 yr by Jarl