Emissions/Safety Inspection

My 2005 Pontiac Aztek was giving me a couple different trouble codes. [p0300/p0302…so I switch that coil pack with the one beside it to see if code followed coil pack…before I could find out, the car over heated and was driven home in 'limp mode.
Also, there’s a p0171 code where the transmission shifts hard sometimes…not all of the time…hardly ever actually.
Took to Pontiac dealership and they said that they checked compression and also checked for gas in coolant, looking for cracked head or blown head gasket. The results were negative for both.
They did say that the top of radiator wasn’t getting hot as it should and said I needed a new engine. They reset the computer and I drove it home. The car ran fine and acted fine.
I took the car to get it inspected for emissions and safety and they said that I needed to put about a hundred miles on it and bring it back. Several things were not ready, or available.
How can I get these thing ready/available so I can pass this inspection? I’m afraid to drive car with plate that’s ran out. Can’t afford to get a ticket.
There has been about 50 miles put on car, and no check engine light as of yet.
Thank you,

Don’t go back there. Find an owner-operated local shop with a good reputation and try it out. They can probably reset everything for you or tell you what the issues are.

These crooks can’t diagnose your problem so they want to change the engine?

If they can’t diagnose the current problem, on what basis do they want to replace the engine? Because the radiator top tank wasn’t getting as hot as they thought it should? How did they determine that? With an IR thermometer or by guessing? How hot do they think it should get? Did they even bother to let the thermostat open? Since they can’t diagnose the current problem, can you imagine the problems you’d have if you let them change out the entire engine?


yeah I know…right?!..I’m 60 yrs old and always thought cooler was better when it came to radiator temp.

Sigh, I wish I were 60 again…

Anyway, that’s not completely accurate. To operate properly, your engine needs to be maintained at full operating temperature. This’ll be reflected in the coolant temperatures, and in the radiator top tank. It’s also true that some cooling systems push the coolant backwards up the radiator (I know not why), and you system could be one of those.

The true function of the thermostat is not to keep the engine cool, but to keep it at operating temp. If its purpose were to cool the engine, you could simply remove it and throw it away. The circulating coolant could do a better job without the T-stat in the way.

My impression is that these guys didn’t care enough to bother. I’ve seen this before at dealerships. Someone brings in a car with a simple problem and they just make up an excuse to say it needs a new engine. I think they hope that’ll scare the customer away so that actual work doesn’t interfere with their coffee breaks.

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yeah they were gonna charge $6000 for engine and car isn’t worth $1500…$500 on trade-in

Meanwhile you have to drive this thing a bunch so that the computer will report everything is ready to be analysed. I can’t help you with your fear of being stopped with expired registration, but there’s really no choice.

Here in the East Bay area of San Francisco lots of cars are running around with expired registration or none at all, which is the same thing, I guess, but with no plates at all.

Couple of things standout here as not making sense. Why did it overheat or more precisely, why do you think it over heated?

A P0171 code is not for the transmission. It is bank 1 too lean. What it is saying is that based on inputs from the front oxygen sensor, the PCM (computer) had to add at least 20% more fuel to get the right air/fuel ratio. The most common causes for this is a dirty MAF sensor or a vacuum leak.

If your engine is running too cold, you will get e check engine light and code for that. Even 2 degrees low will trip it. The top of the radiator is not a good indicator.

You don’t need to drive it 100 miles, but you do need to drive it under all the conditions needed to run each monitor. Usually drive till warmed up, then 10-20 minutes at 45 mph or higher, pretty steady, should do it. Have all your paper work and receipts from the garages that have worked on your vehicle so if you get pulled over, you may get a “by me” on this if the cop is in a good mood and you don’t disrespect him/her.

But you have to address that misfire code. Have you changed plugs recently? Why did you go straight to the coil packs?

Hey, I’m hearing 60 is the new 40 :wink: So no worries about that.

If the check engine light is blinking, suggest to stop driving completely until the p030x misfire problems are resolved. Driving with a CEL blinking can damage the cat or the engine itself. Those misfires could be related to the p0171 btw, since too lean can cause misfires. In other words if you fix the p0171 it might automatically fix the p030x’s. Too lean can also cause overheating, another reason to focus on the p0171 first.

Not sure what they mean by you need a new engine b/c the top of the engine isn’t hot enough. Perhaps a mis-communication there. Ask for clarification or find another well-recommended inde shop to help you going forward.

That means the battery has recently been disconnected or the CEL reset, and the engine computer is in the process of re-testing the car’s emissions components and hasn’t finished that job yet. The emissions testing place makes use of your car’s computer to do the preliminary testing , and it has to wait until your engine computer’s job is done before they can start any of their own testing. They won’t likely test emissions if the CEL is on either, at least for those codes. So your best bet is to focus on getting those two code problems solved. I’d start by looking for vacuum leaks, exhaust leaks. If that’s not the problem, the maf sensor may need to be cleaned. It’s always a good idea prior to emissions testing to make sure the routine engine maintenance is up to date per the manufacturer’s schedule, so replace the fuel filter, air filter, spark plugs as required. Clean engine oil and new filter is helpful for emissions too.

Go to one of the auto parts stores that read codes for free. Tell them you do not want codes cleared, you just want to know if all the systems are ready to read. If you happen to be in NY State , you can pass inspection with one system not ready to read with no check engine light on. The inspection station may not even be aware of this because the states phone setup just tells the station if the car passes or fails emissions and if it fails, why.

The inspection station I used to use put a code reader on my car and told me he didn’t want to inspect my car because it wouldn’t pass because of one code not ready to read. I told hime to go ahead anyway and he was surprised it passed.


I ‘know’ it overheated be cause it was driven "several miles home with no coolant in radiator I had to refill radiator…it all came out the reservoir and cap. How do I know where it came out?..because driver saw it coming out these places.

Pontiac Dealership said a leaking aftermarket radiator cap was the reason for overheating. They put original type cap on.

Yes… I mixed up the p0171 lean code [which I had and turned out to be vacuum hose disconnected ‘per Pontiac Dealership mechanic’] with the p1811 harsh shift code…either way, I’ve had both plus the p0300/p0302 code.

Have not had any code/check engine light for engine temperature.

AND…I went to coil packs because I recently changed plugs and wires. I thought if it was the coil pack for 5/2, and I swapped it with the one beside it, the misfire code would follow coil pack.

I hope this makes a little sense for you.

Yes the additional information clears up all the questions I had from your original post. Now I do have more questions. What is the status of the codes now? Did the misfire code follow the coil change? Did you move the spark plug wires with the coil change or leave the spark plug wires in place?

I don’t know if the Aztec uses the same coils that the Saturn used but there was an issue on the Saturn with a micro crack forming in one of the coil towers. It wasn’t real common but common enough too be notable. I always kept plenty of dielectric grease under the rubber cover and around the wire insulation at the ends.

Ok…I managed to get vehicle inspected today [no check engine light, or codes]. Now I have a check engine light again. Will check it out in the morning.
Not sure about misfire code, but when I drove it to the store a few minutes ago, it started idling rough, so will see what code is showing now. Would be nice if it was the coil, but will have to wait and see.
No, I did not move wires with coil when I swapped it. I left them as was.
Hopefully the CEL code will be where the coil is and a new coil will fix it.

Check engine light went out on it’s own, but not before car overheated again. And -

"I ‘know’ it overheated be cause it was driven "several miles home with no coolant in radiator I had to refill radiator…it all came out the reservoir and cap. How do I know where it came out?..because driver saw it coming out these places."
Coolant was bubbling back into reservoir…again, overflowing reservoir and coming out around the reservoir caps…again.
There is a lot of bubbling sound coming from underneath the dash. I asked dealership to burp it, but I don’t believe they did.

I’ll try burping it but not sure ‘best’ way to do it. I have it parked on a hill right now with front end facing upward hoping air will come to highest location. Hopefully the bleeder valve on engine.
Any suggestions on burping this vehicle? And why/where would air be getting into this?

The air got into the engine when it overheated. If you have a bleeder at the top of the system use it, if you don’t, loosen the top radiator hose clamp and slip a small thin screwdriver between the hose and outlet neck. ( a tip I stole from Tester), when it starts flowing coolant, tighten the clamp.

Most GM vehicles now use a radiator that does not have a cap, the only fill is through the reservoir. On these models, they are self bleeding. But if I recall correctly, the Aztec was made for Pontiac by Kia so that may not apply.

When coolant is forced out the reservoir cap, that usually means a blown head gasket. I think there is a case where the hose or molded line inside the reservoir is either missing or plugged up that can also cause this. Seems that I recall that happening to someone here. Gunk settled into the molded line is a way that acted like a one-way valve. Coolant went into the reservoir as it heated up but could not be drawn back into the radiator on cool down. It is certainly worth checking out.

this engine has [2] bleeder valves, one on left side [driver’s side] by thermostat housing, and the other is on the right side [passenger side]…the one on passenger side sits higher up on engine than the driver’s side bleeder valve…should both valves be opened at the same time?..or lower one first and higher one last?..

plus the sloshing I heard under dash was going on before the over heating and got more apparent before overheating…

with no sign of oil in coolant, or coolant in oil…good compression…and no hydrocarbon gasses in coolant, is it still possible for problem to be blown head gasket?..

this Aztek has a radiator cap…

this vehicle does have [2] bleeder valves on engine…

wondering if the overflow tube from radiator to reservoir needs changing…

and you mention gunk in molded line, not sure if you mean a molded line from radiator to reservoir [which this one is rubber] or a molded fitting on reservoir that the rubber over flow line attaches to…

anyway, the coolant that was bubbling in reservoir has apparently got sucked back into radiator because it isn’t overly full now…maybe if anything a little under the mark where it should be…

Yes…those hydrocarbon gas tests are notoriously unreliable.

In older coolant recovery systems, there was a rubber hose that hung from the cap down into the reservoir. It acted like a straw drawing coolant back in to the radiator after shutdown. Most newer reservoirs have a tube molded into the seam of the tank and the hose from the radiator cap to the reservoir connected to the top of this molded seam.

If your radiator to reservoir hose goes into the top of the cap, then you should have the hose that hangs down. If not, you have the molded tube.

In the early stages of head gasket failure, it can pass the HC test, especially when the engine is warm. The head gasket may be sealing at this point. It would be more likely to fail when the engine is cold. If it is a head gasket, it could also be the cause of your misfire code. When you get the code read, have them look at the freeze frame data and see if the code occurs when the coolant is cold.

It has the rubber hose going into a tube molded into the tank if you’re referring to the reservoir.
I didn’t get a mile up the road yesterday morning and it started overheating. The temp gage went all of the way into the red area and the hot temp coolant light came on [or whatever it is called]. I pulled over and coolant was bubbling in radiator again.

The engine shouldn’t have been all that hot because it hadn’t been running but maybe 10 minutes.