I've read other posts on this subject, and I fear the worst, BUT...what do you guys think?

About 8 months ago, my '95 Z began mysteriously losing coolant. I counldn't smell it, I couldn't find a leak, pressure test was good. It got to where it was losing about 2 quarts a week. My mechanic (a friend who is a master mechanic at Chevy dealer) suspected water pump and replaced it (bearings were shot anyway!). All seemed fine for 3 months, then coolant started disappearing again. Pressure tested again, this time my engine locked up after test! Pressure forcing coolant into cylinder, right? It did start after several tries, belched out a ton of steam, then went back to normal (RUNNING FINE, coolant still disappearing about 1 qt./week).

SOOO... it pretty much sounds like water jacket to cylinder leak, right? No oil in coolant, car RUNS FINE! Will it damage anything to keep driving it? Why did it seem ok for 3 months, was it just because the system had been purged of all air?

Also, another friend (also from CHevy dealer) gave me these GM coolant pellet things, and said GM recommeds newer aluminum-head engines (esp. Caddys) get these things once a year to counteract porosity of aluminum, and they also fix small leaks in system. You just drop 5 of 'em in a cold radiator. They a re a GM product. Ever heard of these, any opinions? I just put them in 2 days ago, I'll post any positive results.

Thanks!

 

I would highly recommend getting the car looked at before driving it any further. There is a chance when you locked the motor that you possible could have damaged valves and also could have cracked a head from hydrolocking.

 

if you want the truth looks at the spark plugs they tell you everything.

 

It MIGHT work for a while,then you will have to fix the problem...Head gaskets.

 

Another vote for head gaskets. Thats simply the most likely way coolant would leak into a cylinder.

 

Sounds an awful lot like the typical dropped head gasket...

does your oil appear milky?

 

Definitely get that looked at... Coolant and bearings =

 

Definetly no oil in coolant. It gets changed every 3k and looks fine, and the dipstick and filler cap look ok too. No "chocolate milkshake".

I don't think the engine was damaged when it locked. I was really afraid of that at first, but that was a month ago and it still runs great.

Thanks for you replies. I was pretty sure of the verdict, I just needed some second opinions! I will check the plugs next just to be sure. Incidentally, ran a code-checker on it a couple of days ago and came up with nothing.

So, has anyone heard of or used those GM coolant pellets? Pretty weird...they contain nutmeg shells and turmeric. Yum!

BTW-- I've driven this car every day for 6 years, bought it with 40k on it, it has 121k now. This is the only problem (and oh what a problem!). I LOVE this car, it runs so strong, and I'm just really bummed.

Any head gasket recommendations? OEM or is there something better?

 

It still may be a head gasket- it's possible that the gasket cracked in a different spot and is not allowing coolant into the motor... I don't really know. My tech knowledge is somewhat limited...

If it is the head gasket, Fel Pro 1074s will treat ya good..
http://store.summitracing.com/partde...art=FPP%2D1074

 

Sounds like a head gasket to me. You can do a simple test of taking the cap off while it is running and check for bubbles in the radiator through the filler neck. Don't try this when the engine is hot. You can also buy a block tester from Napa auto parts part # BK. 700-1006. It will change from blue to a yellowish greaan color if there is any exhaust gases coming out of the radiator. which means the head gasket is toast. Good luck!

 

Sounds excactly how my head gasket went. You are catching it before it becomes a full blown head gasket. My advice is do not drive it and fix it right away before it does become something way worse.

I think these pellets if they work will be a false sense of security, I would fix it asap.