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Well, after all my debating, and diagnosing, I finally determined that my head gasket is in fact done. It's a very minor leak. How minor? Pressure tester lost less than 7lb over 2 hours. The car ONLY steams out the pipe until it warms up, and then it clears up. It never over heats, nothing. I pulled the plugs, and cranked the engine over. Green stuff pumped out of cylinder number 1. Bummer. Could be worse though. A friend's 94 Chevy Corsica blew it's head gasket last week. Gasket set for the POS is $360 Canadian!

Al

[Edit by Al Canuck on [TIME]1109404145[/TIME]]


[Edit by Al Canuck on [TIME]1109567920[/TIME]]

join the club brother, mines getting a new one put in now, also a custom porting job

No fancy porting going on here. This mill has 320000 km on it. It will get checked for cracks, planed only if it needs it, and then bolted back on. Hopefully have it running by mid week.

Al

OK Al, we were right about the head gasket. How about the gas smell? Did you check if the cold start injector is leaking?

Gas smell is simple. Water in cylinder 1 was stopping the plug from firing. Raw gas being expelled out the pipe.

I'm ripping the head off today. Will report back.

Al

Not sure if you have smog requirements, but I have heard that antifreeze damages catalytic converters.

Good luck with everything. Headgaskets aren't particularily hard just time consuming.

Craig


[Edit by Craig in Davis on [TIME]1109549508[/TIME]]

Hey Craig,

I don't think I was burning enough coolant to worry about the cat. This was a small leak, as you can see here. Head is obviously off now, and I will pick up the gasket set tomorrow. I checked the head with a straigh edge, and it's fine. It will be going straight back on, after a decarbon, and a little surface cleaning.

Of the dozens of head gaskets I've performed, this is truly one of the smallest ones I've ever seen. No wonder it was a bugger to diagnose. It got gradually worse until it became easy enough to figure out. I put a few thousand km on this engine with it leaking coolant into number 1. Never over heated.


Here's a close up of the corrosion around the metal ring.


Here you can see number 6 was starting to corrode as well. Wasn't long before it started leaking.


Can you figure out which one was leaking? Mmmmm, steam cleaned!


Al

WOW! That last pic just says it all right there.

Maybe you should put a small nick in the other 5 openings on the old head gasket, put it back on for a few thousand KM, and then replace it. Maybe you'd have SIX clean pistons after that!

That would be nice if I could steam clean them all that way, but I'll pass, thanx! Solvent and a brass brush will do the dirty work for me tomorrow.

Al

[QUOTE="Shifty"]WOW! That last pic just says it all right there.

Maybe you should put a small nick in the other 5 openings on the old head gasket, put it back on for a few thousand KM, and then replace it. Maybe you'd have SIX clean pistons after that! [/QUOTE]

Didn't they use water injected engines back when pump gas was like 75 octane or something?

[QUOTE="Shifty"]WOW! That last pic just says it all right there.

Maybe you should put a small nick in the other 5 openings on the old head gasket, put it back on for a few thousand KM, and then replace it. Maybe you'd have SIX clean pistons after that! [/QUOTE]

[QUOTE="pdx 528e"]Didn't they use water injected engines back when pump gas was like 75 octane or something?[/QUOTE]

Don't know about that, but I do know that a pop can full of water, sucked through a vacuum port on an intake manifold will basically do the same thing. Just don't let the car stall out!

Al

Al,

I'm curious, what did the spark plug for number 1 look like? Did it give any hint to the leaking head gasket?

As said before the last picture of the block tells it all. Well done.

Craig

All the plugs were nice and clean, except for number 1. It was brown from getting wet with water, and then not firing the excess fuel. Usually with a head gasket leak, the plugs will be steam cleaned as well, but that's how small this sucker was.

Al

Finished up the head gasket re&re today. I also took the opportunity to scrub and clean everything in site, service the timing chain tensioner, and replace all the fuel lines under the hood. She runs like a champ again.

I forgot to take a pic, but I was amazed by what I saw when I pulled the head off. Even with 320k km, the bores had PERFECT cross hatch marks, and ZERO ridge at the tops of the cylinder walls! Never seen that small amount of wear on an engine with this kind of mileage before. M30 rules my world!

With this list of new cooling system parts, she should stay running cool for a long time to come.

- Thermostat
- Rad cap
- Several hoses
- Coolant level sensor
- Water pump
- Head gasket
- Fan clutch
- Rebuilt water valve

Even the rad appears to be fairly new, although it must have been done by the PO.

Al