Head gasket failure?? [Archive] - GrandAmGT.com Forum


View Full Version : Head gasket failure??

10-27-2009, 07:31 AM
What would cause a 2005 Gt to have a head gasket issue? This past weekend I just did the long and tedious head gasket replacement on my car. The car has about 70k on it and has had no issues with over heating. I have owned the car since last March when I bought is used from a local Ford dealership. Parts I've changed since buying the car are plugs, wires, air filter, fuel filter, and full synthetic oil.

This is what happened that started me down the road of thinking a head gasket was failing. Firstly, I was getting excess coolant pressures in the system that was causing a rather large amount of coolant to be forced out of the overflow tank. That of course would cause the low coolant light. This issue happened the first time about 4 weeks or so ago. I refilled and bled the air out and didn't have an issue until mid-week last week when it happened again. Only this time it kept doing it after being refilled and bled. So I started looking for any tale tale signs of coolant in the oil or oil in the coolant. Which while after dismantle I found traces of coolant in my oil starting to accumulate under valve covers, I could not see any signs of coolant on the dip stick. Well the next thing that followed was a pretty bad misfire at idle. It wasn't bad enough at first to throw a SES or to cause it to die, but the SES P0301 (cylinder 1 misfire) did show up shortly after the misfire started and then mysteriously turned its self off the next day. Well since I started to wonder about my misfire, I checked my plugs and wires first. My wires were fine, but upon pulling plugs my number 1 cylinder plug was obviously not firing well at all. All 5 other plugs were clean and appeared to be normal. I did not suspect a bad coil or I would have changed that first. To describe what the plug looked like, well it was not oily or anything. But it was black and carbonized a little. You could tell it was firing still just not very well, which I would suspect because of coolant that was entering the cylinder and was drowning the spark.

Well since up to this point I still haven't seen any dead give away signs of a bad gasket, I first changed my plugs which are NGK TR55IX plugs. I bought and replaced with that same kind again. I changed them out and drove around a little to see if the misfire was still there. Which it wasn't at first. But after a little more driving, it started to misfire again and continued to over pressurize my coolant system. So the next thing was to tear it down.

I had no idea what to expect to find, but I felt fairly confident that I was catching this problem pretty quickly and hopefully I would fix it first go around. I will also add that while I did not have any left over parts after the project, I did manage to break my radiator drain plug which I was able to fix by the way. I did not take any pictures of the dismantling, but I did find the leak. I was expecting to find a blown out head gasket somewhere around cylinder 1, but what I found was that it was just leaking. From the looks of it, it appeared as though the head was not torqued down properly or something. I used a brand new aluminum level for my straight edge to check for flatness on the head, which I know is not really the correct way to be sure, but I was confident enough that I did not have warped heads so I cleaned any deposits off with carb cleaner and proceeded. Also along with the gasket set I bought brand new head bolts to be sure they were not an issue. I do have the old gaskets and my intake gaskets that I pulled and I will post the pics of them in another post.

Labor wise changing the head gaskets takes forever. I would have to say the most time consuming part of the whole process was the exhaust heat shielding and the exhaust manifold removal and re-installation. Those mainly because they are out of sight and not a lot of hand room. While it has only been 2 days, the pressuring effect on the coolant system is gone as best as I can tell and my misfire is gone. I'm gonna drive it around a few more days and then pull my plugs to check their wear. I'm also going to keep my eye on my coolant and oil for signs or new mixing which should show up easily since oil and coolant are new and every internal part I took off in the process was thoroughly cleaned of any mixed fluid, which like I said was very minimal IMO. I did an intake gasket swap on an old 3.1 Grand Prix before and the fluid mix on it was very bad.

I know this turned out to not be much of a question, but I would like to know what any of you guys or gals think could have caused such an early failure of a head gasket.

10-27-2009, 09:24 AM
Mine did the exact same thing except it was P0302 (misfire #2) and then a day later blew white smoke. This was at ~95k miles.

Shop time for this repair is I believe ~11 hours. I took probably double that, although I went ahead and pulled both heads and had them redone (cooked, machined, new seals, etc.) while it was all apart.

I know this car had the intake gaskets replaced at ~50k miles but the coolant appeared to have been maintained and it never overheated for me, so I was at a loss as well as to why a head gasket failed so early. It appears they simply deteriorated.

I just turned over 100k miles and am now looking at probable transmission replacement. This is my DD and isn't driven hard so needless to say I'm disappointed. I bought the car less than 2 years ago and have only put about 7k miles on it, and at this point thinking I would have been better off buying an import.

10-27-2009, 12:35 PM
That is very similar to how mine looked to. The gasket was intact and not broken any where, but you could plainly see what looked like rust on the metal ring that is supposed to seal the cylinder. I would say that it looked as though atleast 1/4 of the gasket around my #1 cylinder was leaking coolant into the cylinder and pressurizing the cooling system. All other cylinders were clean and did not show these signs.

By the way those heads look pretty:) I was limited by funds, so I cleaned any deposits or gunk I could find and just reinstalled them. I also replaced both head gaskets too and it took me somewhere around 15-20 hours. I stayed up really lete so I didn't really pay attention to the time cause it had to be finished by the mid day the next day.

10-27-2009, 02:13 PM
That guy is local to me and only charges $100 to do a set of heads. Compared to the $180 for the head set I thought that was a bargain. The Fel Pro set for my 3.4 Firebird was only $55 and I have yet to figure out why the gaskets for the 3400 are more than three times the cost. I did not even opt for the "heavy duty" version which use upgraded head and intake gaskets, that was $70 more.

Coincidentally my radiator drain plug must have been broken previously also, and was epoxied in place, so I had to pull the lower hose. Who knows, maybe the Dexcool was responsible for eating the gaskets. At least I was able to get most of it out of there and replaced with the universal ethylene glycol stuff.

I think the most frustrating things for me were the PS pump 7o'clock bolt, the clamp for the lower rad hose and the bottom #5 exhaust manifold bolt. Oh and figuring out where all those damn vacuum lines went when putting it back together.

10-28-2009, 02:46 AM
Yeah It definitely wasn't an easy job. I would have loved to had the heads cleaned up and everything, but time and money were not on my side. Maybe next time.. I hope not lol.

Getting it all apart took me less time I think than getting it back together. My radiator plug was broken due to not paying attention. I managed to sheer the little pin than that is pressed in it that locks it into place when closed. All I did was drive out the broken pin and cut down a small nail and drove it through where the pin was. It worked like a charm. I had troubles with that bolt too. I ended up supporting the engine and just removing the mount. Something I figured out a bit late into driving myself crazy getting bolts back in where I couldn't see, I took a trip to the bathroom and got a hand mirror. What was taking me hours to do blind, I managed to accomplish in less than 20 minutes after thinking of the mirror.

I do agree with you that dexcool may be the culprit in their demise or maybe it shouldn't be considered to last so long and actually be changed more frequently than they claim.

Here are the pics. You can't really see that well, but if you look at the bottom left cylinder hole it was the culprit. Notice it is completely intact. The only thing I noticed was that although none of the coolant passages were blocked, there were a few that appeared to be restricted which may have helped the condition along.

http://i289.photobucket.com/albums/ll234/grand_am_gt_74/IMG_1534.jpg http://i289.photobucket.com/albums/ll234/grand_am_gt_74/IMG_1535.jpghttp://i289.photobucket.com/albums/ll234/grand_am_gt_74/IMG_1539.jpg