I Think I Killed It

[Ducked]

Originally Posted By: mk378
When the engine is running there is very high pressure in the cylinders which can force its way through even small leaks in the head gasket. Any serious test of the head gasket is done with the engine running while looking for gasses (especially CO2, which is a distinctive product of combustion) to appear in the cooling system.

Pressurizing through the radiator while cold is good for looking for leaks to the outside such as bad hoses or cracks in the radiator. Head gasket not so much.


Makes sense. MkI gassing detector was no good.It'll be at least a couple of days before I can try the MkII.

 

[Ducked]

Mk II gassing detector (MkI was a toy balloon)



No gassing detected, but also inconclusive, since its managed to lose some coolant (green stain) without moving the piston, so presumably it wasn't holding pressure.

I pushed the bung in tighter and the piston didn't move on a short local drive, but it needs a longer test. Maybe I can wire the bung in, like a champagne cork.

 

[Ducked]

Longer drive on expressway (but at or below 80 kph) same result. Bit of spitting but no piston movement. Sealing needs improved.

 

[Jetronic]

How much pressure does it take to move the plunger? Those syringes have rather a lot of friction. The total pressure in your cooling system will be that + the radiator cap pressure.

 

[Ducked]

Originally Posted By: Jetronic
How much pressure does it take to move the plunger? Those syringes have rather a lot of friction. The total pressure in your cooling system will be that + the radiator cap pressure.


Don't THINK the total pressure in the cooling system is relevant, since the syringe isn't exposed to it.

IF the overflow reservoir is sealed (which it normally isn't, and clearly isn't so far with this setup, though that's the intention) it'll be pressurised by thermal expansion (which will be reversible on cooling) and any gassing (which won't be reversible on cooling).

That's my theory anyway.

With the 60 ml enema syringe, the pressure due to friction (referred to as "rebound pressure" above) was about 1.5 psi. Havn't attempted to measure it with this syringe but I suppose I should.

Can't easily use the enema syringe in this role since it isn't built to take a hypodermic needle.

 

[PandaBear]

Most likely you have a cooling system leak that causes air pocket in the cooling system, that eventually warped the head enough to cause head gasket sealing issue.

I've gotten that twice in my 97 Integra. 1st time it was the CSF all metal radiator that leaks, at 185k miles, 2nd time it is the Stant radiator cap stuck. For the amount of rust you have on your radiator, the rest of your cooling system is probably not in good shape already and caused the leak -> under pressure -> losing coolant -> head warp / gasket issue.

If I were you I'd look for another used car instead of trying to fix it. Labor is cheap in Taiwan but it is probably still not worth the effort unless it is a valuable antique. You should have a lot of good choices there, like Daihatsu or Mitsubishi in 3cyl, 1L size, at around 10 years age?

 

[Ducked]

Originally Posted By: PandaBear

If I were you I'd look for another used car instead of trying to fix it. Labor is cheap in Taiwan but it is probably still not worth the effort unless it is a valuable antique. You should have a lot of good choices there, like Daihatsu or Mitsubishi in 3cyl, 1L size, at around 10 years age?


I'd prefer to avoid that, since I may be leaving the country fairly soon. Generally I try and fix things until that becomes impossible, and I've invested quite a bit of time (though very little money) in this already.

In the UK cars mostly got scrapped because of inconveniently timed inspection failures, which is much less likely here. Cheap used cars, especially manuals, are hard to find (along with everything else) and I dislike newer cars.

I had a look under the bonnet of Merc Sport Coupe recently but I couldn't see anything. Every F-ing bit of the much more extensive real estate under there was packed full of mysterious Teutonic toyware. I prefer to avoid that sort of thing. I've got no ABS, no FI, no cat, no electronics of any kind. That less is quite a lot more.

 

[Ducked]

Originally Posted By: Jetronic
How much pressure does it take to move the plunger? Those syringes have rather a lot of friction. The total pressure in your cooling system will be that + the radiator cap pressure.


Misunderstood you.

I was considering the potential pressure in the overflow tank only, but you are of course correct in stating that will be added to the rad cap pressure internally, and the system is therefore (slightly, I think) over-pressurised as a result.

I doubt this will be enough to cause a problem but its certainly something to bear in mind. I'll try and get a measure of this syringes back-pressure.

 

[Ducked]

Originally Posted By: Ducked
I've got no ABS, no FI, no cat, no electronics of any kind. That less is quite a lot more.


Actually, I suppose there's some electronics in the alternator, which may have developed a recent charging problem which I havn't looked into yet. (Battery light comes on now which it didn't before)

 

[The_Eric]

I'm not why you're so scared of a slightly more modern car? I realize you may be leaving country soon, but realize that on most cars from the 90's-00's you can get an awful lot done with the most basic of hand tools, a volt/ohm meter and a simple scan tool.

 

[Jetronic]

I agree. In general fuel injection cars last longer than carburetted, and start on a turn of the key. Fuel consumptio is generally better aswell. It's not like carburettors are fail safe either.

 

[Ducked]

Originally Posted By: Ducked
Originally Posted By: mk378
Not necessarily. It should say "DO NOT ADD WATER" somewhere on it. Even where I can read all the words, the difference isn't always super clear. You could also test it with a hydrometer.

If you fill up with 100% concentrate and then get on the freeway, you're going to have a bad time.



I'll try and check. Actually quite hard to find the SG of 100% ethylene glycol (assuming that's what it is).

According to

ww.alfaowner.com/Forum/alfa-gtv-andamp-916-spider/157080-specific-gravity-of-ethylene-glycol-coolant.html


“Looking at Texaco spec sheets, raw is about 1.12SG at 15.6 deg C. Is the SG scales relationship with temperature linear? Temperature compensated to 20deg C”


http://www.newtonnet.co.uk/coupe/service/webtech/iindex.asp@id=12106

Shows 50% EG at 20C as 1.082

I have a battery hydrometer I bought when I was recently in the UK. Havn’t used it yet, and don't have it handy but

http://www.freeasestudyguides.com/battery-specific-gravity-test.html

shows the reading range of a battery acid hydrometer as 1.1 to 1.3

So if its in the reading range, its concentrate, and if its below the reading range its probably diluted.




Coolant didn't bring the bought-in-the-uk battery acid hydrometer float off the bottom (minimum SG scale reading 1.1) so its probably dilute, though ambient temperature was probably about 30C.

 

[andyd]

Ducked , Just carry water, in case of a leak. For short runs, take the cap off. Taiwan doesn't freeze does it? If you can cure the troubles, fine, but for the short term, manage them. My first fuel injected car was a XJ6, big mistake. But the 528e 30 yr old EFI is far more reliable than a carburettor. Troubles have been mostly tarnished fuses and relays. You'll like relays, most the time, they react well to unplugging and replugging.