Cracked Head Gasket or something else?

My daughter has a 2003 Pontiac Vibe and we’ve had some trouble with the cooling system. We have replaced the thermostate twice, the water pump, done a pressure check on the system. After the replacing the water pump and the thermostat for the second time we didn’t have any problems for a while, but now it’s started overheating and losing coolant again. I don’t know where the coolant is going as it’s not on the ground?? Although I haven’t checked the oil yet, but no remarks from dealer when the oil was changed. There’s no white smoke from the tailpipe. She said she smelt coolant once, but not anymore. Perhaps she’s immune to it now? (Maybe that’s why she acts so crazy?! TEENAGERS!) The only symptoms it has is running rough (although have bad solenoid), overheating every few days and coolant loss. Can’t really afford to get her a new car right now, or fix the one she has for that matter, but we’ve got to pick one of the two evils! A little history on the car…purchased it from a young couple that stated the engine had been replaced @ 90k. The car had about 146k on it when we bought, but then not sure if they replaced it with a new or used engine, it now has about 182k. (My daughter drives a lot!) I was told the catalytic converter is bad and that keeps the check engine light on. Any and all help would be appreciated…single mom trying to keep her daughter’s car running so she can get back and forth to college and work. Also, any feedback on head gasket sealants? Thank you!!

I’ll try to answer the issues one at a time…but in reverse order.

Additives are last resort efforts to keep beaters alive. Sometimes they work temporarily, but they never really fix the problem. The wrong one can even exascerbate the problem. In your case they might be appropriate, but definitely not until you have a complete diagnosis and know the risks.

Do not make any assumptions about why the CEL is lit. Many parts stores will read the codes for free, and if you post them here we can help interpret their meanings.

Your cat converter may be bad, or it may be a bad oxygen sensor. Either or both could be a symptom of the bigger problem that’s causing the engine to overheat, so you need to address the overheating and coolant loss problem first. If it turn out that the overheating and losing coolant is caused by a headgasket breech, the coolant being burned will contaminate the converter and/or the oxygen sensor.

The rough running could also be caused by a headgasket breech. Not only will it cause inconsistant compression and combustion, it can also affect the oxygen sensor.

Now, to the real heart of the issues…the possibility of a blown headgasket. Yes, this is very likely. You show all the signs and you’ve overheated the engine repeatedly. The smartest thing to so is to run a compression leakdown test. You can have this done or buy a kit at the parts store to do it. It’s easy, inexpensive, and definitive. If you have one cylinder not holding compressed air, than nothing else you do will resolve any of the other problems. There are quick ways to determine a blown headgasket, such as running the engine with the radiator cap off and looking for air bubbles (if you have them, than you have a bown headgasket), but the real definitive way is a leakdown test.

Sorry to be the bearer of the bad news. I think by trying to nurse this problem along the head has probably ended up warped and the cat converter catalyst contaminated. It’s very possible that repair would involve milling or replacement of the head, and it may end up that the cat having to be replaced.

Thank you for your reply! I should have added that I used to work @ VW and had one of the techs there check the codes and he told me the cat was bad. We got the car Labor Day weekend 2yrs ago and no problems until this year, but the check engine light has been on since day one. All of the work and the pressure check was done this year. Although, I do know things can change rapidly.
I have also read the pros and cons of the additives and I’m on the fence about that. I have friend in the car biz that has a 2004 Saturn Ion 3 with 63k that he’ll sell me for $6500, just hate to get strapped into another payment.

Find out where you stand with the Vibe first. The Saturn is a risky bet. I had one and would not buy one again. Apparently I have lots of company, because Saturn folded.

You pressure checked the cooling system but what about pressure testing the cooling system cap? (Radiator cap, coolant bottle cap, whatever)

Maybe the cap is weak and at varying points coolant is being puked out until it’s low enough to cause a problem.
Radiator fans operating, both in the engine temp mode and the A/C compressor running mode?

At this point if you didnt have a bad head gasket…You do now… The multiple overheats are extremely harmful to your engine…and the result is a warped head …and blown head gasket. The only real way to repair it is to remove the cylinder head and have it machined straight again…and then re-assemble…using new parts all along the way.

The last ditch method is to use a $60 bottle of Blue Devil…properly installed it fixes most any head gasket failures believe it or not. Its best to properly repair it…but like I said the last ditch is Blue Devil…bec it works. I’ve seen it fix well over 50 Head Gaskets thus far and all of them are still holding…this is several years after the Deal with the Devil.

Blackbird

Was doing some research on this exact issue prior to working on it which ironically led me here. As I had just purchased this car to replace my aged daily knowing full well the potential task that laid in front of me being a worse case scenario.

On a hunch though I ran some UV dye through the coolant just to make certain something else wasn’t at fault. Wouldn’t leak when cold, wouldn’t leak warm. But as soon as I put a decent load though the engine the fan kicked on and the radiator started blasting coolant everywhere in a cloud of now glowing steam. Pulled it out to see if I could solder it and found a lot of hardened mud and corrosion basically destroyed the bottom-right corner of the radiator.

Ultimately the only fix possible was replacing the radiator at this point, I’ll likely get a new cap as well for it as the rubber in that seems well worn out. Given the fact it was overheated multiple times I was going in with the assumption I’d need to replace the head gasket and have the head decked. Still wary about it, but will only know in due time.

Getting the coolant system to bleed as well was quite a chore, as there was an air pocket trapped in the heater core that took several cycles to clear.

Pulled codes to troubleshoot it:
-Transmission shift solenoid, 1-2 shift seems less than ideal but it’s not awful probably just slow due to possible wear.
-Coolant temp, overheated on the way home likely flagging it in the ECU.
-Likely bad O2 sensor and/or cat. Electrical tape over the CEL light, problem solved.

Well dont do the head gasket work until you are sure…if you found that rad issue…fix that and move forward…if she exhibits HG failure symptoms…then jump on the gasket repair. Fix the rad and let us know what you find. Don’t do the HG repair just cause I thought it might be bad via the internet…If I was there in person i could tell you without question… Take it one step at a time…some engines have a much higher tolerance to overheats than others

Blackbird

Whoops, thought I covered that, I don’t plan on doing it unless it shows symptoms requiring such. As there is no white smoke, leaks, milky oil, or other associated issues so far. This is just reference in case someone has a similar issue of missing coolant on a Vibe/Matrix.

Naturally I’m just wary and keeping an eye on it due to past experience.