Hey all! Just had my heater core go out on me. I bypassed the core by looping together the input/output hoses that enter the firewall. Drove it for a while and noticed it was running very hot. Not to the pont of complete shutdown, but very hot anyway. I let it sit for a day or so and now going back to it, I start it up, and it is idling very rough. Not irregular, but definitely fighting itself. It idles at about 1500rpm instead of the usual 550 or so. The rhythm sounds off. I've had this car for about 7 months and so far it has been a very regular and smooth running car. Any ideas?
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"...And so he drove on, the rain clouds dragged down the sky after him, for though he did not know it, Rob McKenna was a Rain God. All he knew that his working days were miserable and he had a succession of lousy holidays. All the clouds knew was that they loved him and wanted to be near him, to cherish him and to water him." -
Never loop the heater hoses. That will allow some of the coolant flow to bypass the radiator and may cause the engine to run hot. If you remove the core, plug the hoses. In this case there were probably other cooling system faults and the looped hoses pushed the system over the edge. A new thermostat and possibly a new fan clutch would be good places to start.
A single "trip into the red" can cause a head gasket failure. I don't know how hot the engine got, but lets hope the rough idle isn't the result of a head gasket failure. The first thing to do would be to have a smoke test run on the intake and fix any/all leaks found. Then clean the ICV.Last edited by jlevie; 06-04-2010, 12:51 PM.The car makes it possible, but the driver makes it happen.
Jim Levie, Huntsville, AL -
Hmm. Well I already put in a new thermostat and up until the heater core went out, there were no real issues with the car running hot. What would be some sure signs of a head gasket failure? Also, I'm pretty new at this, so I'm not sure what a "smoke test run on the intake" means exactly."...And so he drove on, the rain clouds dragged down the sky after him, for though he did not know it, Rob McKenna was a Rain God. All he knew that his working days were miserable and he had a succession of lousy holidays. All the clouds knew was that they loved him and wanted to be near him, to cherish him and to water him."Comment
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What I'd suggest at this point is that you block the heater hoses and check for intake leaks. The best diagnostic for intake leaks is to find a shop that can run a smoke test. But you can get close by visual inspection and spraying carb cleaner on potential leak areas.
If the overheating problem persists after that, other investigations are called for. If it only happens at idle or in stop and go traffic the fan clutch could be the cause. If it happens at speed, the thermostat is a possibility (even though it is relatively new). And in either case a partially plugged radiator is a possibility.The car makes it possible, but the driver makes it happen.
Jim Levie, Huntsville, ALComment
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Gotcha. The engine right now is still idling funny. It seems very rough and shudders the car as if it was running at low RPMs even though the tac reads 1500. Could there be an issue with one of the cylinders not firing?"...And so he drove on, the rain clouds dragged down the sky after him, for though he did not know it, Rob McKenna was a Rain God. All he knew that his working days were miserable and he had a succession of lousy holidays. All the clouds knew was that they loved him and wanted to be near him, to cherish him and to water him."Comment
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That is possible, but what you had to do to loop the heater hoses could have introduced an intake leak.The car makes it possible, but the driver makes it happen.
Jim Levie, Huntsville, ALComment
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Where would an intake leak occur? Are you talking about air leaks?"...And so he drove on, the rain clouds dragged down the sky after him, for though he did not know it, Rob McKenna was a Rain God. All he knew that his working days were miserable and he had a succession of lousy holidays. All the clouds knew was that they loved him and wanted to be near him, to cherish him and to water him."Comment
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An intake leak is where any air enters the intake after the AFM.The car makes it possible, but the driver makes it happen.
Jim Levie, Huntsville, ALComment
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So I un-plugged the spark plugs, removed them, cleaned them, put them back in and plugged the hoses instead of looping them, started it up, and it was back to normal just like that. Thanks for the tips! :-)"...And so he drove on, the rain clouds dragged down the sky after him, for though he did not know it, Rob McKenna was a Rain God. All he knew that his working days were miserable and he had a succession of lousy holidays. All the clouds knew was that they loved him and wanted to be near him, to cherish him and to water him."Comment
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The idle is fixed, running smooth again. Still over heating. Gunna yank out the radiator in the next few days to see if it is to blame. Any tips on how to clean a radiator?"...And so he drove on, the rain clouds dragged down the sky after him, for though he did not know it, Rob McKenna was a Rain God. All he knew that his working days were miserable and he had a succession of lousy holidays. All the clouds knew was that they loved him and wanted to be near him, to cherish him and to water him."Comment
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A pressure washer through a radiator can help but it might be good to spend 100 or so bucks and get a new one. How new is your water pump? You could just have air in your coolant system, there is a bleed screw on your thermostat. Get the car hot, park so the front of your car is elevated, and open the screw and get the bubbles out.Comment
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20'ish year old plastic and rubber parts are an iffy proposition. Replace the radiator, all hoses, expansion tank, and cap.Originally posted by rdbussman View PostThe car makes it possible, but the driver makes it happen.
Jim Levie, Huntsville, ALComment
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I have yet to check the water pump. I got the car used 7 months ago and replaced a lot of the coolant components (thermostat, coolant level sensor, auxiliary fan switch aka the cheap things to replace) and really didn't have an issue with overheating. About a week ago my heater core went out on me and since then I've plugged the hoses going to the heater core and ever since it's been having really bad overheating issues. I've tried to bleed the air out of the system, it's just that when I look for instructions I find about 20 different ways you're supposed to do it."...And so he drove on, the rain clouds dragged down the sky after him, for though he did not know it, Rob McKenna was a Rain God. All he knew that his working days were miserable and he had a succession of lousy holidays. All the clouds knew was that they loved him and wanted to be near him, to cherish him and to water him."Comment
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The hoses have been replaced (by the owner before me, as well as the serpentine belt. From what I can tell, the car was actually very well maintained by the previous owner.) The issue becomes my very small budget. The best I can do for the time being is to remove, examine and clean all the components such as the radiator and water pump. That's why I asked about tips on how to clean my radiator, or what signs to look for if the radiator is bad.Originally posted by jlevie View Post"...And so he drove on, the rain clouds dragged down the sky after him, for though he did not know it, Rob McKenna was a Rain God. All he knew that his working days were miserable and he had a succession of lousy holidays. All the clouds knew was that they loved him and wanted to be near him, to cherish him and to water him."Comment
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The definitive solution (other than a vacuum fill system) is:Originally posted by rdbussman View Post
1) Using ramps or a jack get the front of the car 1' or more higher than
the rear. That will make the radiator and bleed screw the highest point
on the engine and facilitate removal of air.
2) With the bleed screw open, add coolant until no more air comes out of
the bleed.
3) Leave the filler cap off, or at least loose, and set the heat for max
temp and fan speed. Leaving the cap loose will prevent air that's still
in the system from causing a "coolant fountain" once the engine heats
up. Start the engine and allow it to warm up to operating temp. As it
warms up occasionally crack the bleed screw to release any air and top
up the coolant as necessary.
4) Once the engine is at temp bring it up to 2000-2500 for a few seconds
several times. Then crack the bleed until no more air is released. At
this point the heater should be throwing lots of hot air, which
indicates that the heater core is filled with coolant. You may have to
repeat this a few times to get all the air out.
5) Drive the car a bit, allow it to cool back down, and recheck the
bleed for air. Over the next few days you may get very small amounts (a
few bubbles) of air out of the bleed screw.The car makes it possible, but the driver makes it happen.
Jim Levie, Huntsville, ALComment
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