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The code was thrown when i was revving my engine around 5k. (showing off admittedly ) After the code, i couldn't idle steadily. If i held the throttle open little bit my idle would surge very rapidly. Cleared the code and car drives normally again. Flash forward a week or so and the CEL comes on again, this time at a stop light. Cleared the code and it drove normally once again. Hasn't had a CEL since.
The reason I made this thread was to address an issue im having currently. After I rev my engine and the needle is dropping back to idle, the engine surges 200-300 rpm. Sometimes it surges once, sometimes twice. Usually happens after i come to a stop at a light or a stop sign.
I have BlueDriver, so i can offer basic scan tool functions. I recorded the surging as well. Sorry for MASSIVE photos, not too savvy with changing the size.
Re: 96' del Sol SI: Engine surge off load (Scan tool data, pics, video)
I cleaned my IACV recently. Used carb cleaner and sprayed it in both holes of the IACV. Let it air dry for 10 minutes or so and re-installed. Also, just bled my coolant. One thing I noticed with my coolant was small bubbles would appear in the radiator fill neck. And the coolant smelled foul. Its my understanding its supposed to smell sweet?
Thanks
Re: 96' del Sol SI: Engine surge off load (Scan tool data, pics, video)
Old (like, really ******* old) coolant smells sweet. Animals would drink it, so they added a bittering agent. Burning coolant has a bit of a sweet smell to it, but coolant just sitting there shouldn't. Small bubbles in your coolant points towards the possibility of a damaged head gasket. Buy/borrow/rent a block tester, and use it.
When you bled your coolant, exactly how did you do it?
Re: 96' del Sol SI: Engine surge off load (Scan tool data, pics, video)
Ah. Thanks for clarifying.
When i bled my coolant, I opened the radiator when the engine was cold, turned the climate control to heat, turned the fan off, and started the engine. I waited for the fan to turn on and added coolant/water as it sucked it in. Repeated this about 4 times every time the fan turned on. Topped off the coolant overflow and replaced the radiator cap.
Re: 96' del Sol SI: Engine surge off load (Scan tool data, pics, video)
Well, you're close, but not quite there. Do it again, but this time, park your car up an incline. Either secure the front on jack stands, or park up a small hill, or use rolling ramps. You need to elevate the front end of your car, so that the radiator fill neck is the highest point in the system.
Re: 96' del Sol SI: Engine surge off load (Scan tool data, pics, video)
Do a simple diagnostic test. Remove air intake system and use your finger to cover hole inside throttle body leading to IACV. Does the surging stop or continue?
Re: 96' del Sol SI: Engine surge off load (Scan tool data, pics, video)
The plot thickens RonJ. Upon removing the intake tubing, i hear a hissing i've never heard before, but knew instantly what it was. The IACV was open when i turned on my car. When i put my finger over the hole, the engine slows down and runs at about a few hundred rpms it seems. It stays running, but I didn't try to stall it.
Re: 96' del Sol SI: Engine surge off load (Scan tool data, pics, video)
The engine only surges after I rev the engine. After it returns to idle it goes up about 300 rpms. It does this once or maybe twice and occurs most often when I stop at a light or stop sign. And it happens every time I stop, especially so on a cold engine.
Re: 96' del Sol SI: Engine surge off load (Scan tool data, pics, video)
So run it until it starts surging, then pull over. Without turning your car off, remove the intake tubing, cover that hole, and tell us if that stops the surging idle.
Re: 96' del Sol SI: Engine surge off load (Scan tool data, pics, video)
Ah, I get what you're saying.
The slight incline you got there should be good enough for the bleed, well done. It sounds like you're catching the very first signs of intermittent IACV failure. Diagnosing intermittent is hard enough, but when it's first signs, that just makes it harder.
Properly setting your base idle, and making sure your ignition timing is within spec, couldn't hurt though, and might help stave off the symptoms. Unless someone beats me to it, I'll try to find the Del Sol specific FSM procedure for ya when I get home from work. Did those small bubbles continue with the elevated coolant bleed? If they did, you should still do a block test, just for sanity's sake.
Re: 96' del Sol SI: Engine surge off load (Scan tool data, pics, video)
That's the catch though, RonJ. His car isn't doing it permanently, just a few times and then catching itself again. We're trying to diagnose a problem that is not only intermittent, but also only showing first signs.
Re: 96' del Sol SI: Engine surge off load (Scan tool data, pics, video)
Originally Posted by NotARaCist
That's the catch though, RonJ. His car isn't doing it permanently, just a few times and then catching itself again. We're trying to diagnose a problem that is not only intermittent, but also only showing first signs.
He needs to be prepared to do the test quickly when the problem pops up.
Re: 96' del Sol SI: Engine surge off load (Scan tool data, pics, video)
I tried covering the IACV hole during, and after revving the engine. Same behavior as i stated. No matter when I cover the hole, it still just wants to die, unless I open the throttle enough for it to breathe. And in regards to the bubbles, yes they were still present when elevated. When you say block tester, does that mean leak down test? Are they the same?
Re: 96' del Sol SI: Engine surge off load (Scan tool data, pics, video)
no. a block test kit is a vial with a tapered rubber stopped that goes into the radiator fill neck. there is fluid inside of it, and if exhaust gases are present, it will change colors.
Re: 96' del Sol SI: Engine surge off load (Scan tool data, pics, video)
Ah I've seen those before. Im going to try and rent one tomorrow from adanced auto or somewhere. Hopefully I'll have enough fluid in the kit. I'll post tomorrow, thank you all.
Re: 96' del Sol SI: Engine surge off load (Scan tool data, pics, video)
No. A block tester uses litmus (sometimes paper, sometimes liquid), and basically a mechanic's turkey baster. You put coolant on the litmus, and if it turns colors, you have exhaust gasses in your coolant, which means a damaged head gasket. It's the most definitive diagnostic test, and it's cheap. You should do it, because of those air bubbles in your coolant. Those air bubbles might just be a combination of air in the system plus cavitation, or they might be the early warning signs of a head gasket on the brink of failure. Better to know for sure, than to wait until it fails.
Edit: holy **** I sat on this thread for a while before responding. That's what happens when you post from work, I guess
10-18-2015, 09:46 AM
96' del Sol SI: Engine surge off load (Scan tool data, pics, video)
) After the code, i couldn't idle steadily. If i held the throttle open little bit my idle would surge very rapidly. Cleared the code and car drives normally again. Flash forward a week or so and the CEL comes on again, this time at a stop light. Cleared the code and it drove normally once again. Hasn't had a CEL since.
