Check Engine Light Mystery

[jabel1214]

I recently replaced the air filter, cabin filter, spark plugs and battery in my 04 4Runner SR5. The Check Engine light was on prior to the battery replacement, which consequently was changed before the other items. I changed the rest over the last weekend, and I reset the MAINT light, and it has since turned off, and stayed off. The Check Engine light was reset at AutoZone by a tech there, but the code did not come up for the reason, or at least, so he says.

Nonetheless, I have changed out all 6 spark plugs, and drove around for about a day with the light off. Then Monday morning, I started the truck up and as it started, I heard a surge of water running through somewhere (not sure if that's normal or not), and then the truck began to idle low and vibrate a little bit. I laid on the acc. and it subsided, and the vibration went away. I left work the same day, and it was the same scenario. I cannot figure out what else could be going on, and since I see that a lot of people have great advice on this site, I wondered if anyone could give me some as well. At least to explain what could be happening, or what's wrong. I am on a budget so a dealer's visit would be almost rediculously out of the question. I was able to replace my plugs and do gen. maint on my own, and now, I've got another problem.

Thanks in advance for the help,
- J

 

[jimithing]

Could be a ton of things. Was it running properly before the spark plugs were changed? Could be as simple as a bad tank of gas. Could be as bad as a head gasket.

 

[scottm]

Surge of water? If the coolant temp doesn't rise as expected after start you can get a check engine light. My old Land Cruiser had the software set a little too finicky on that, it was common to get a light and a code for coolant temp. If you have air in your coolant system you could be getting a light for this, and you'd want to get this fixed. Check your coolant level when cold, check the radiator for coolant visible.

 

[kosan]

The Check Engine light was reset at AutoZone by a tech there, but the code did not come up for the reason, or at least, so he says.

Recommend you purchase a diagnostic scan tool (OBDII) so you don't have to run out to AutoZone.

On multiple occasions, I've had the CEL on and used the scan tool with no error codes. Rather it just resets and my CEL is gone. I think there is a thread on here with respect to this.

Reference: Amazon.com: Autel MaxiScan MS300 CAN Diagnostic Scan Tool for OBDII Vehicles: Automotive

Regarding your water surge/ low idle, I wouldn't be surprised if a little moisture got into the spark plug wells.

 

[jabel1214]

I say surge of 'water' because it sounds like that through the defrost vents on the dash when the truck is started *cold*. I can say that the first stall I had was days before the battery was replaced, and I experienced all of the conditions (vibrating, low idle, liquid running) at that time too. Mind you, this seems to have all started as the weather got cooler and progressively worse, when the temps dip below about 25 degrees at night/early morning.

As for it being a case of bad gas (insert chuckle), I fill up at least twice a week and no gas station is the same sometimes. I have to travel almost 40 minutes one way to work each day, and sometimes I have to fill up in between. I just don't want to rule it a bad gas issue.

I have not seen any problems with the truck 'warming up' the temp guage is functioning as needed. Once I hit the highway, which is 1 mile from my house, the heat is great at 80 degrees! I am not experiencing any dips as the truck travels either in the heat/cooling of the guage either.

I'm a little baffled by this, and I just wasn't sure. I didn't think of a head gasket, or even the transmission, but I have no problems with transmission (for now).

 

[scottm]

I would still check the coolant, and all the other fluids just because you should I guess. I have had air trapped in my coolant system on other vehicles, and you can hear the rushing water/air in the lines.

How many miles, how long have you owned it, and have there been any other maintenance issues or mods?

 

[jabel1214]

I have about 111K on it, I am the second owner of the vehicle which was purchased in 05, and then I bought it in June of 11, so I have had it for about 10 months.

As for other maint. on it, the battery, spark plugs, air filter, cabin filter, and I just had an oil change about 2 weeks ago, which I do regularly (every 3 months).

Modifications, I don't think that the previous owner did anything to modify the engine or anything like that, I noticed at the time I changed the spark plugs that the passenger side was the only side changed, and that the battery (when replaced prior to that) was the original Toyota battery from 04 (factory battery).

I wish it wasn't so cold out here, because yesterday when I gave it gas to stop it from vibrating and idling low, I saw a plume of white smoke behind the truck, but I chucked it up to the cold weather against the hot exhaust. I could not tell if there was a 'rainbow' in the smoke, which would indicate me burning oil. But my curiousity is limitless right now.

 

[Sungod]

Liquid is fairly silent as it passes through. Sounds like air that you are hearing. I would doubt that is related to you other issue. Any heating or cooling issues?

What spark plugs did you use? Did you check the gap prior to installing? Did you make sure everything was tight when you put it back together?

 

[PNWSportEd]

HG is my guess

My 85k 06 had exactly the same symptoms, all of them. Bad news is that its a Head Gasket and maybe a head as well.

I would search the forum for Misfires to see what others have ended up with after havning the same symptoms.

Good Luck

 

[scottm]

White smoke can be coolant, or just the normal moisture in cold exhaust. It could just be unburned gas if you have a cylinder not burning properly. If you have a head gasket failure you'll see loss of coolant, brown-milky oil, rough running, bubbles and dark sludge and exhaust smell in coolant tank, and the cylinder that's getting coolant might have a much cleaner sparkplug (although all are new now). I haven't heard of a head gasket problem on these engines, seems unlikely.

You might have bumped a sparkplug and closed the gap, or not tightened it enough, or not gotten the coil pack on right, or maybe one spark plug is defective or cracked. If you still have the old ones you should try swapping them back.

Where are you? Maybe someone here lives near you.