QuestionQUESTION: My girlfriend has a 1995 Honda Civic, 4-dr, Auto. Yesterday when she was driving to work she noticed smoke coming from under the engine. She opened the hood and noticed liquid spilled all over. She said it was mostly clear...maybe a few drops of green.
When she got home I looked at the car...the oil was low, but nothing too low to cause problems. The Anti-freeze level was also normal. I don't think there was a leak.
When I took it for a spin around the block it drives normally, but the temperature shoots above the red to the very top after a few minutes. The car has the biggest problem when it is idling in park. When the car is in drive and you are pressing down on the brakes, it is relatively ok. But when it is just on and in park it seems like its about to die...reving, almost shuts off, reving, almost shuts off, back and forth.
Any clue what the problem could be?
Thanks a lot.
All the best
Denis
ANSWER: Hi Denis,
You seem to have multiple issues there. First of all, operating the engine when it is overheating is a sure NO-NO and will only cause more damage/problems than you already have.
When you describe the liquid on the engine coupled with the almost immediate overheating the only thing I can think of is that either the thermostat is stuck or the radiator or lower radiator hose is blocked and the pressure caused a small rupture in one of the coolant hoses big enough to douse the engine compartment with water when it blew but not large enough to notice a leak when there is no pressure in the system. So, we need to pressurize the system and look.
If the t-stat is stuck closed or the lower hose is blocked and the engine has no coolant in it (yes, the radiator may have coolant to the proper level and still have the engine block empty if there is a blockage somewhere in the system), as the engine heats, air heats much faster than water or coolant and will vaporize within a few minutes making the temperature sensor think the engine is much hotter than it really is.
So, you need to fill the radiator with water until full and replace the cap but don't tighten it. Start the engine and if the radiator is not shooting water out at you from under the cap, which it shouldn't be, remove the cap and add water until it is full, full. Do this as quickly as possible because the purpose of this is to create pressure in the system and the only way that will happen is if the water in the engine does not heat up too much before you tighten down the cap. (I'm assuming you do not have or have access to a cooling system pressure tester which is why I'm giving you these, backyard instructions for pressure testing)
After a few minutes the engine temperature should start to come up and pressure should start to build in the system. Now is the time to start looking for the leak that caused the flood your GF said she saw. It may take about five or ten minutes to show up, but if it leaked once, it will leak again. If you notice the engine starting to overheat, abandon the test and shut it down.
If the leak starts again, you can shut it down and fix the problem before continuing. Once repaired, keep an eye on the temperature of the coolant in the radiator by feeling the back of the radiator near the cooling fan with the engine running. If the engine starts to get pertty hot and the radiator is still cold, there is certainly a blockage or a stuck t-stat.
Shut the engine off and allow to cool for a few minutes and then remove the t-stat housing and remove the t-stat (replace with new if you have it or you can just replace the gooseneck without the t-stat just for the next test procedure).
If the t-stat has been removed, run the engine again and observe the outcome. The radiator 'should' warm up along with the engine this time and cause no overheating issues if that was the problem, which most likely it will be. Replace the t-stat with a new one and move on to the next test. If the engine is still overheating, then a blockage in the system is what you'll be looking for. I don't know if I'll be able to walk you through that process so you'll be best served by letting a professional look for a cooling system blockage if you can't find it.
Problem number two, erratic operation, surging engine. When the engine is idling in Park, there is little-to-no load on the engine so it's idle state is controlled by an IAC (Idle Air Control) valve located near the throttle valve on the intake manifold. This valve opens and closes quickly to adjust the idle speed. When the vehicle is shifted into a forward or rearward gear range, the IAC valve gives most of the idle control to the fuel system. The IAC valve still controls the idle, but the computer takes more control through the injector cycle coupled with the added load of slipping clutch-packs in the transmission and the idle seems to smooth right out.
The issue is most likely a bad or sticking IAC valve but it could also be that the engine is pulling coolant into the intake through a crack or some other internal coolant leak. Only a real pressure test will alert you to that kind of leak or a computer diagnostic because coolant being burned will definitely cause an error in the O2 readings.
Ok, that was best case, worst case would be more likely what you will find and that is a cracked head or block due to extreme overheating or continued overheating or multiple-overheatings. I hope that is not the case in this situation, but I'd put money on it.
If you have additional questions or concerns, feel free to send a follow-up.
Looking for a reputable service technician? My advice on finding a good technician is: Steer clear of the dealership and 'chain' stores like Firestone, Sears, Pep Boys, Monro Muffler/Brake, Midas, etc. as they usually only employ ONE ASE Certified Tech just so they can say they do and chances are, that guy is the asst. manager or manager and is not in the store to diagnose/repair vehicles anyway. Find a service location in the link below or get some names out of the yellow-pages and do a drive-by. Garages that employ ASE Certified Technicians will be marked with the 'Blue-Seal' insignia. If unsure about whether a place employs Certified Techs, just ask to see their credentials. ALL ASE Certified Technicians will be PROUD to show and display their certificate(s).
Thanks for the question, I hope this information was helpful to you.
Fred
Knucklebusters Used Auto & Truck Parts, Inc.
www.knucklebusters.us
570-453-0910
"Re-use is the best form of recycling" Help us recycle by purchasing used parts from us!
Looking for an ASE Certified shop near you? ASE Certified Technicians are the BEST of the BEST!
Click here: http://www.ase.com/bluesealsearch/locator.php
---------- FOLLOW-UP ----------
QUESTION: Hey Fred,
Thanks a lot for such a thorough answer the first time around. My friend and I messed around with the car about and the problem was the thermostat. We did not find a leak, but the car is operating fine now with respect to the overheating.
I also turned the car on and let it sit in park for 20 mins and it seemed normal...nothing like before. Is this normal? What could have been the problem before that now it is fine? Will it probably show up sometime soon again or could it have been something to do with the t-stat?
Thanks again.
Best,
Denis
AnswerHi Denis,
No leak eh? That is strange. Possible that the radiator cap could have blown off the excess pressure right into the engine compartment, but not typical, that's what the recovery tank is for.
It is possible from the dousing of coolant that the engine took that some got into the intake and burnt through the engine. Since coolant is neither alcohol nor petroleum based, the residue produced by burning it could have coated the O2 sensor or something like that giving the ECM false readings and operating the engine erratically. That's just a guess. If the engine WAS running rough or oddly, I'm certain the computer stored a code as to what it thought the most likely cause was. Scan the ETC and you should have your answer.
Good to see you fixed the issue with or without my assistance matters none. Have a nice day.
Thanks for the question, I hope this information was helpful to you.
Fred
Knucklebusters Used Auto & Truck Parts, Inc.
www.knucklebusters.us
570-453-0910
"Re-use is the best form of recycling" Help us recycle by purchasing used parts from us!
Looking for an ASE Certified shop near you? ASE Certified Technicians are the BEST of the BEST!
Click here: http://www.ase.com/bluesealsearch/locator.php
