Calling all backyard mechanics

[hatman]

I think I may have made a much mistake than I originally thought. I'll try not to turn this into a huge saga... but the fact is that it truly is a saga, with so many interrelating circumstances that I'm not sure what's germane and what's just me venting.

I normally drive a 2001 Pontiac Aztek (pause for derisive laughter). At least until last Wednesday... now I'm driving my wife's 2004 Aztak (insert cricket chirping here). Last Wednesday I had a catastrophic head gasket failure while driving to work... dumped me on the side of the highway about 30 miles from home. The sad part is that it wasn;t a surprise to me in the least... only the timing was in quesion. You see, I had been seeing signs of a small leak since last fall. Not foamy oil, which would have had me extremely worried right away. No, it went the other way: cylinder to cooling loop. I was pushing exhaust gases and fue-air mixtue into the cooling loop while the engine was running, with a small amount of cooling fluid leaking back into the cylinder when the engine was turned off.

Don;t get me wrong, I knw that this was serious, but the simple fact was that we were planning on buying a new car in the spring, so I started by refilling the cooling loop as needed. As the glycol started congealing from the hydro-carbon infiltration, I stepped up to flushing the system every couple of months when the weather got warmer, and reducing the ratio of glycol, eventually running straight water when the risk of freezing had passed. I kept a gallon of water in the back, and toppe dup the system as needed. No problems.

And then last Wednesday happened.

Because of the nature of the leak, the overheating problem was always worst when idling or coasting... as soon as the engine RPM's got high, the engine would always cool down, but not last Wed, when upping the engine RPM's just made it overheat quicker. So I pulled over, and started to evaluate. The overflow tank was FULL and dripping on the ground. Slighlty concerned, I pulled out a book and started to pass the time while the engine colled down enough to safely open the cap and top it up. When I finally got there, I prepared to purge the air from teh system, y starting the engine with teh rad cap removed. But as soon as teh car turned over, the water was vigorously expelled. The problem was that the pressurized exhaust gases from teh cylinder were being driven through the blown haed gasket so fast that the water was being pushed right out of the system. Even with teh cap in place, about 2 minutes of idling built up enough pressure to drive enough liquid into the overflow to fill it, even with a COLD engine.

By this time, I had limped to the Home Depot parking lot off the highway, which also conveniently had an auto parts place. I bought some Head Gasket Stop-Leak, and dutifully put it in, knowing full well that the likelihood was that it wouldn;t work... but I figured ther might be a possibility of avoiding a costly tow to my home 30 miles away. Needless to say, it didn;t work. So I bought a 5-gallon container of water at Home Depot, and drove home via the back roads (get it up to 50, shift to nuetral, turn off engine and coast.... repeat until I needed to pull over and pour the overflow container back into the radiator and top up from the 5-gallon jug).

At the time I observed a high concentration of stop-lak in teh overflow container. I didn;t think much of it until this weekend. After careful consideration of our budget, and teh recent upswing in used car prices, my wife and I determined that I need to get another six months out of my car. This weekend, I started the laborious task of replacing the head gaskets. I started by draining the liquid from teh radiator and block. Lo and behold, it dawned on m late last night that when I performed that drain on Sunday, there was absolutely NO EVIDENCE of the stop-leak in the liquid I removed. I can only assume that most of it is still in the system... probably in teh radiator. My question is this: does this stuff chemically require the glycol to keep it liquid, while it only sets up in teh absence of glycol? Is it possible that adding it to a system full of pure water caused it to solidify in my radiator? Am I wasting my time with the head gasket, since my radiator might be all plugged up? And will I be able to get the stuff out with a chemical detergent flush?

And lastly: Is anyone interested in buying a slightly used Aztek? Single owner, no accidents, 200,000 miles. Some assembly required.

 

[Atroxell]

Finally! A subject on MrExcel I have some knowledge (and unfortunately, experience) with!!

The fact of the matter is that any stop leak compound is not worth the package it comes in for head gasket problems. Works great for little leaks in radiators, but the dynamics within a motor just does not promote the proper setting of the compounds.

When you think about it it makes sense because would you willingly put something in your motor that would block a cooling channel of unknown (and unacceptable) dimension? Of course not. But that is exactly what a head gasket leak is--an unknown.

I have experienced that sinking feeling of a blown head gasket in my 86 Nissan pickup (go ahead and laugh--it's paid for) after my daughter failed to tell me that "it was running kinda funny the last time I drove it". Coolant being pumped right down on #4, then spewed out the exhaust.

Your only hope at this point is to go ahead and replace the head gasket/ Andwhile you are at it, you might as well have the radiator scrubbed out (maybe re-cored?) to get all of the crud that may be in there out.

I completely sympathize with you. This is a project no one wants to do. But when the money ain't there, you do what you have to do--not what you want to do.

And I am also officially passing on the sales offer. Thanks.

 

[hatman]

Finally got the Lower Intake Manifold off last night. I found about 1/2 the container of stop-leak... completely blocking one of the two the LIM cooling passages. I'll need to chisel it out with a hammer and screwdriver, but at least that leaves a much smaller quantity of the stuff unaccounted for elsewhere in teh system. I knew I should have listened to the little voice in my head that told me "NO, YOU IDIOT, ANYTHING BUT STOP-LEAK!"

Still have two exhaust manifolds, cross-over pipe and two heads to go. Yay.

 

[hatman]

Andwhile you are at it, you might as well have the radiator scrubbed out (maybe re-cored?) to get all of the crud that may be in there out.

Not really an option to re-core... the money just ain't there. I'll have to settle for a high quality chemical flush... probably one of the ones that you pop in and drive for a week, as opposed to the ones that you run for 5 minutes in your driveway.

In fact, I stopped at the machine shop that rebuilt the engine in my AMC Eagle 10 years ago, and talked to the owner for about 5 minutes about this whole thing. I;m bringing in the heads to be leak tested, and possibly planed... if one of the heads is cracked, I'm scrapping the car, since I'm only doing this work to keep the car going long enough to save up enough money to buy a used car anyway, and spending any more than $500 total just depletes the replacement car fund. If I ended by scrapping it out, we would just give up whatever we need to from the wish-list and buy what we can afford to, rather than holding out for what we are looking for.

YUCK YUCK YUCK!!!